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                                                                 EXHIBIT 10.52

                              CONSULTING AGREEMENT

     This Consulting Agreement ("Agreement") is entered into by and between
William Matthews, Ph.D. ("Matthews") and Deltagen, Inc., a Delaware corporation
("Deltagen") (together the "Parties") as of the Effective Date of the Transition
Agreement and Release by and between Matthews and Deltagen, dated January 17,
2003 (the "Transition Agreement and Release").

                                    RECITALS

     Matthews' employment as Chief Executive Officer ("CEO") of Deltagen has
terminated on the Separation Date pursuant to Section 1(a) of the Transition
Agreement and Release, and Deltagen desires, subject to the terms hereof, to
retain Matthews' services to assist in the transition of his duties as CEO and
to assist in the defense of certain actions now pending and certain actions
which may be brought in the future by any third party against Deltagen and to
provide such other consulting services as may be reasonably requested by the
Deltagen's Board of Directors or its Chief Executive Officer.

     1. Consulting Services.

     Pursuant to this Agreement:

               (a)  Matthews shall assist Deltagen (i) in all matters relating
to the winding up of work pending at the time of his separation from Deltagen
and the orderly transfer of Matthews' prior responsibilities to other person(s)
for a total of up to ninety (90) days (or the equivalent thereof in working
hours) ("Transition Services"), (b) in the vigorous defense of any action
brought by any third party against Deltagen or its affiliates that relates in
any way to Matthews' acts or omissions while he was employed by Deltagen or in
the vigorous defense of any action brought by any third party relating to
litigation or claims pending against Deltagen or its affiliates at the time of
his separation from Deltagen ("Litigation Services") and (c) any other
consulting services reasonably requested during the term of this Agreement by
Deltagen's Board of Directors or its Chief Executive Officer ("Consulting
Services," collectively with Transition Services and Litigation Services, the
"Services"). The Transition Services to be provided shall include, but not be
limited to, meeting with Deltagen's executive staff as needed to discuss pending
work and the on-going responsibilities of the Chief Executive Officer position.
The Litigation Services shall include, but not be limited to: (i) affirmatively
and appropriately assisting Deltagen and its counsel in the defense of any
action brought against Deltagen or its affiliates; (ii) meeting with Deltagen's
counsel as needed to discuss any pending litigation or claims; (iii) being
available for depositions at his and Deltagen's convenience; and (iv) if
necessary, testifying at trial. Matthews agrees to perform the Services with the
standard of care, skill and diligence normally provided by a professional person
in the performance of similar services.

               (b)  Deltagen shall own all rights to any and all work products,
patents, processes, copyrights, studies, flow charts, diagrams, devices,
programs, source codes, inventions, original works of authorship, know-how, and
other tangible or intangible material or data of any nature developed by
Matthews or as a result of any of Matthews' Services. Any

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work product generated by Matthews hereunder shall be deemed a work made for
hire. If any of such work product shall be deemed other than a work for hire,
Matthews hereby assigns to Deltagen all rights, title and interest in and to
such work product, Matthews agrees to execute and deliver such documents and
instruments as Deltagen may deem necessary and appropriate to transfer to
Deltagen any and all rights, title, and interest, including copyrights, Matthews
has in any such work.

               (c)  Matthews agrees that during the term of the Agreement, and
for a period of twelve months immediately following the termination of the
Agreement for any reason, Matthews shall not either directly or indirectly
solicit, induce, recruit or encourage any of Deltagen's or its affiliates'
employees or other consultants to terminate their relationship with Deltagen or
its affiliates, or take away such employees or consultants, or attempt to
solicit, induce, recruit, encourage or take away employees or consultants of
Deltagen or its affiliates, either for himself or for any other person or
entity. Moreover, during the term of this Agreement, and for a period of twelve
months immediately following the termination of this Agreement, Matthews shall
not become an employee or officer or director of (or provide consulting or
advisory services to) any company, entity, venture or business that competes
with Deltagen or its affiliates. For the purposes of this Agreement, a company
shall be deemed to compete with Deltagen if a significant focus or purpose of
its business is to provide mouse transgenics services to a third party in any
form, including without limitation on a fee-for-service or collaborative basis.
Further, for a period of twelve months following termination of this Agreement
for any reason, Matthews shall not solicit any licensor to or customer of
Deltagen or its affiliates or licensee of Deltagen's or its affiliates'
products, in each case, that are known to Matthews, with respect to any
business, products or services that are competitive to the products or services
offered by Deltagen or its affiliates or under development as of the date of
termination of the Agreement.

     2.   Compensation. For Services performed by Matthews under this Agreement,
during the term of this Agreement, Deltagen shall pay Matthews on a monthly
basis (paid in arrears) at an annual rate of $[225,000]. In addition,
Executive's stock options may continue to vest and be exercisable, pursuant to
the option grant terms, while Executive provides consulting services to the
Company pursuant to this Agreement.

     3.   Expenses. Deltagen agrees to reimburse Matthews for all expenses
reasonably incurred in the performance of the Services upon production of
supporting receipts and documentation and where such expenses have been
pre-authorized by Deltagen. Matthews shall invoice Deltagen on a monthly basis
for any expenses reasonably incurred in the performance of the Services.
Deltagen shall pay all invoices within forty-five (45) days after their receipt.

     4.   Term Of Agreement. This Agreement shall become effective upon
Matthews' Separation Date and will remain in effect until the first anniversary
of the Separation Date provided, however, Matthews shall continue to be
available to provide Litigation Services for any litigation against Deltagen or
its affiliates that is (i) pending at the time of Matthews' termination of
employment with Deltagen, or (ii) involves events and circumstances occurring
during Matthews' employment with Deltagen regardless of when the litigation is
initiated ("Consultancy Period"). This Agreement shall also terminate
immediately upon Matthews' death or if Matthews revokes the release of claims
described in Section 6(b) of the Transition

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Agreement and Release and shall be terminable by Deltagen for "Disability"
(which for purposes of this Agreement shall mean Matthews' inability to perform
the Services) or upon Matthews' material breach of either this Agreement
(including, without limitation, Matthews' refusal, or substantial failure, to
perform the services contemplated by this Agreement) or the Transition Agreement
and Release. Upon termination of this Agreement, Matthews shall be entitled to
payment for unpaid amounts for Services completed, and for reimbursement for
expenses incurred, during the Consultancy Period. Thereafter, Deltagen shall owe
Matthews no further amounts or obligations under this Agreement.

     5.   Notices. Any notice or other communication under this Agreement must
be in writing and shall be effective upon delivery by hand, upon facsimile
transmission to either party or three (3) business days after deposit in the
United States mail, postage prepaid, certified or registered, and addressed to
Deltagen or to Matthews at the corresponding address or fax number (if any)
below. Matthews shall be obligated to notify Deltagen in writing of any change
in his address. Notice of change of address shall be effective only when done in
accordance with this Section 5.

Deltagen's Notice Address:

     740 Bay Road
     Redwood City, CA 94063
     Fax Number:  650-569-5280

Matthews' Notice Address:

     William Matthews, Ph.D.
     60 Summit Springs Road
     Woodside, CA 94062
     Fax Number:

     6.   Relationship Of The Parties.

               (a)  Matthews enters into this Agreement as, and shall continue
to be, an independent contractor throughout the Consultancy Period. In no
circumstance shall Matthews look to Deltagen or its affiliates as Matthews'
employer during the term of this Agreement. Except as may be otherwise stated in
the Transition Agreement and Release, Matthews shall not be entitled to any
benefits accorded to Deltagen's or its affiliates' employees, including workers'
compensation, disability insurance, retirement plans, or vacation or sick pay.
Matthews' exclusion from benefit programs maintained by Deltagen or its
affiliates during the Consultancy Period is a material component of the terms of
compensation negotiated by the Parties, and is not premised on Matthews' status
as a non-employee with respect to Deltagen or its affiliates. To the extent that
Matthews may become eligible for any benefit programs maintained by Deltagen or
its affiliates (regardless of the timing of or reason for eligibility) during
the Consultancy Period, Matthews hereby waives Matthews' right to participate in
the programs. Matthews' waiver is not conditioned on any representation or
assumption concerning Matthews' status under the common law test. Matthews also
agrees that, consistent with Matthews' independent

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contractor status, Matthews will not apply for any government-sponsored benefits
that are intended to apply to employees, including, but not limited to,
unemployment benefits.

               (b)  Matthews shall be responsible for providing, at Matthews'
expense and in Matthews' name, to the extent applicable, disability, workers'
compensation, or other insurance as well as licenses and permits usual or
necessary for performing the Services. Matthews shall pay, when and as due, any
and all taxes incurred as a result of Matthews' compensation, including
estimated taxes and payroll taxes, and shall provide Deltagen with proof of
payment as may be requested under Section 6(c) below.

               (c)  Matthews and Deltagen shall provide to each other upon
request any information reasonably necessary to determine their obligations
under this Agreement, to fulfill the purposes of the Services, or to maintain
accurate records.

     7.   Privileged and Confidential Information.

     (a)  Matthews acknowledges and understands that, in assisting Deltagen with
the defense of actions under this Agreement, the Parties intend the attorney
client privilege and/or attorney-work product to apply to the fullest extent
permitted by law ("Privileged Information"). Matthews agrees to hold all
Privileged Information in confidence and shall not disclose any Privileged
Information to any third-party except at the direction of Deltagen's counsel.
Deltagen agrees to provide legal representation, at no cost to Matthews, for any
assistance requested by Deltagen and provided by Matthews under this Agreement.

     (b)  Matthews shall not publish, disclose, or otherwise divulge
Confidential Information to any person, at any time during or after the term of
this Agreement, without Deltagen's prior express written consent. For purposes
of this Agreement, "Confidential Information" shall mean non-public,
confidential or proprietary information belonging to Deltagen or its affiliates.

     The term "Confidential Information" does not include any information which
(i) at the time of disclosure or thereafter is generally available to the public
(other than as a result of a disclosure by Matthews or her representatives in
violation of this Agreement), (ii) was available to Matthews on a
non-confidential basis from a source other than Deltagen, provided that such
source is not bound by a confidentiality agreement that was applicable to the
Confidential Information, or (iii) has been independently acquired or developed
by Matthews without violating any of his obligations under this Agreement.

     In the event that Matthews becomes legally compelled (by deposition,
interrogatory, request for documents, subpoena, civil investigative demand or
other similar legal process) to disclose any of the Confidential Information,
Matthews shall give Deltagen prompt prior written notice of such requirement so
that Deltagen may seek a protective order or other appropriate remedy and/or
waive compliance with the terms of this Agreement. In the event that such
protective order or other remedy is not obtained, or that Deltagen waives
compliance with the terms hereof, Matthews agrees to provide only that limited
portion of the Confidential Information that it is advised by written opinion of
counsel is legally required and to exercise

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reasonable efforts to obtain assurance that confidential treatment will be
accorded such Confidential Information.

     Matthews represents that his performance of all terms of this Agreement as
a consultant of Deltagen has not breached and will not breach any agreement to
keep in confidence proprietary information, knowledge or data acquired by
Matthews in confidence or trust prior or subsequent to the commencement of the
Agreement, and Matthews will not disclose to Deltagen or its affiliates, or
induce Deltagen or its affiliates to use, any inventions, confidential or
proprietary information or material belonging to any previous employer or any
other party.

     The Parties agree that in the event of a breach of this Confidentiality
provision, Deltagen shall be entitled to equitable relief, including injunction
and specific performance, in addition to all other remedies available at law or
equity.

     8.   Arbitration; Attorney's Fees. To the fullest extent permitted by law,
subject to Section 10(c) of the Transition and Release Agreement, all claims
that Matthews may have against Deltagen, or which Deltagen may have against
Matthews in any way related to the subject matter, interpretation, application,
or alleged breach of this Agreement shall be resolved by arbitration as set
forth in Section 10 of the Transition Agreement and Release. The provisions of
Section 12 of the Transition Agreement and Release shall apply to this Agreement
as set forth in the Transition Agreement and Release.

     9.   Integration. The parties understand and agree that this Agreement
represents the entire Agreement as to the matters discussed in this Agreement,
except as otherwise referenced in the Transition Agreement and Release. There
has been no representation or promise made by Matthews or Deltagen on any
subject discussed in this Agreement, except as expressly set forth in the
Transition Agreement and Release. This Agreement shall supersede all prior or
contemporaneous agreements and understandings among Matthews and Deltagen,
whether written or oral, express or implied, with respect to any subject under
this Agreement, except as has otherwise provided in the Transition Agreement and
Release.

     10.  Amendments; Waivers. This Agreement may not be amended except by an
instrument in writing, signed by each of the Parties. No failure to exercise and
no delay in exercising any right, remedy, or power under this Agreement shall
operate as a waiver thereof, nor shall any single or partial exercise of any
right, remedy, or power under this Agreement preclude any other or further
exercise thereof, or the exercise of any other right, remedy, or power provided
herein or by law or in equity.

     11.  Assignment; Successors and Assigns. Matthews agrees that he will not
assign, sell, transfer, delegate, or otherwise dispose of, whether voluntarily
or involuntarily, or by operation of law, any rights or obligations under this
Agreement. Any such purported assignment, transfer, or delegation prohibited
hereunder shall be null and void. In the event of Matthews' death, payments due
and arising hereunder shall be made to Matthews' estate, designee(s) or legal
heirs and assigns. Matthews represents that he has not previously assigned or
transferred any claims or rights released, or purported to be released, by him
pursuant to this Agreement. Deltagen shall not assign or transfer its rights and
obligations hereunder except to a successor to all or substantially all of the
assets of Deltagen, whether by merger, consolidation, transfer of assets or

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otherwise so long as such successor assumes Deltagen's obligations hereunder.
Subject to the foregoing, this Agreement shall be binding upon and shall inure
to the benefit of the Parties and their respective heirs, successors,
affiliates, attorneys, and permitted assigns. This Agreement shall not benefit
any other person or entity except as specifically enumerated in this Agreement
and their permitted heirs, successors, affiliates and assigns.

     12.  Severability. If any provision of this Agreement, or its application
to any person, place, or circumstance, is held by an arbitrator or a court of
competent jurisdiction to be invalid, unenforceable, or void, such provision
shall be enforced to the greatest extent permitted by law, and the remainder of
this Agreement and such provision as applied to other persons, places, and
circumstances shall remain in full force and effect.

     13.  Governing Law. This Agreement shall be governed by and construed in
accordance with the laws of the State of California.

     14.  Interpretation. This Agreement shall be construed as a whole,
according to its fair meaning, and not in favor of or against any party. By way
of example and not in limitation, this Agreement shall not be construed in favor
of the party receiving a benefit or against the party responsible for any
particular language in this Agreement. Captions are used for reference purposes
only and should be ignored in the interpretation of the Agreement.

     15.  Representation by Counsel. The Parties acknowledge that (i) they have
had the opportunity to consult counsel in regard to this Agreement; (ii) they
have read and understand the Agreement and they are fully aware of its legal
effect; and (iii) they are entering into this Agreement freely and voluntarily,
and based on each party's own judgment and not on any representations or
promises made by the other party, other than those contained in this Agreement
and the Transition Agreement and Release.

     The Parties have duly executed this Agreement as of the date first written
above.

DELTAGEN, INC.                          WILLIAM MATTHEWS, PH.D.

By: _________________________________   ________________________________________

Title:

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                                                                 EXHIBIT 10.53

                        TRANSITION AGREEMENT AND RELEASE

     This Transition Agreement and Release (the "Agreement") is entered into as
of January ___, 2003 (the "Execution Date") by and between Deltagen, Inc., a
Delaware corporation (the "Company"), and William Matthews, Ph.D. ("Executive")
(together "the Parties"). This Agreement is effective only if it has been
executed by the Parties and the revocation period has expired as set forth in
Sections 20(a)(3) and (a)(4) below and Executive does not revoke this Agreement
as set forth in Sections 20(a)(3) and (a)(4) (the "Effective Date").

     WHEREAS, Executive was employed by the Company as Chairman and Chief
Executive Officer pursuant to the terms of an employment agreement dated April
7, 2000 and as amended on June 26, 2002 (the "Employment Agreement");

     WHEREAS, Executive resigned as Chairman of the Board of Directors of the
Company (the "Board") on November 22, 2002;

     WHEREAS, the Company has initiated a search for a new Chief Executive
Officer;

     WHEREAS, the Parties have mutually agreed to hereby terminate the
Employment Agreement upon the Effective Date and further agree that Executive
will continue to serve the Company as its Chief Executive Officer under the
terms of this Agreement; and

     WHEREAS, the Parties have mutually agreed that they will release each other
from any and all claims as of the Effective Date.

     NOW, THEREFORE, in consideration of the mutual promises contained herein,
the Parties agree as follows:

     1.   Term of Employment.

          (a)  Basic Term. The Company agrees to employ Executive, and Executive
agrees to be employed by the Company, under the terms of this Agreement from the
Effective Date until the earlier of (1) the date of Executive's death or (2) the
date when Executive's employment terminates pursuant to Section 1(b), (c), (d)
or (e) below (the "Separation Date").

          (b)  Early Termination; Resignation. The Company may terminate
Executive's employment at any time and for any reason by giving Executive
written notice. The Executive may terminate his employment at any time and for
any reason by giving the Company 10 business days advance written notice. The
foregoing shall be subject to all of the rights and obligations described
herein.

          (c)  Termination for Cause. The Company may terminate Executive's
employment at any time for Cause. For all purposes under this Agreement, "Cause"
shall mean (1) failure by Executive to substantially perform Executive's duties
under this Agreement, other than a failure resulting from Executive's complete
or partial incapacity due to physical or mental

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illness, (2) Executive's gross misconduct, (3) breach by Executive of a material
provision of this Agreement, (4) a violation of a federal or state law or
regulation applicable to the business of the Company, (5) Executive refuses or
intentionally fails to act in accordance with any lawful and appropriate
direction or order of the Board, (6) Executive is convicted of a felony crime
involving moral turpitude or (7) breach by Executive of the Company's code of
business conduct, code of ethics or other similar policies applicable to
Executive.

          (d)  Termination for Disability. The Company may terminate Executive's
employment for Disability by giving Executive written notice. For all purposes
under this Agreement, "Disability" shall mean that Executive, at the time the
notice is given, has been unable to perform Executive's duties under this
Agreement for a period of not less than three (3) consecutive months as a result
of Executive's incapacity due to physical or mental illness.

          (e)  Successor Chief Executive Officer. Executive shall voluntarily
resign his employment, offices and directorships effective at such time as the
Company shall have employed another Chief Executive Officer.

From and after the Separation Date, Executive shall voluntarily resign from all
positions as employee, officer and director of the Company and its affiliates
and shall resign from any other positions and offices with the Company and its
affiliates; provided, however, that in the event that Executive's employment
terminates pursuant to Sections 1(b), (d) or (e), subject to Executive's
execution and non-revocation of the release of claims described in Section 6(b),
Executive shall serve the Company as, an independent consultant in accordance
with the consulting agreement attached hereto as Exhibit A (and which is also
part of this Agreement) (the "Consulting Agreement") which shall hereby be
deemed effective by the Company and Executive upon the applicable Separation
Date. From and after the Separation Date, Executive will not accrue any vacation
time and will not be eligible for any further participation in the Company's
401(k) plan, Employee Stock Purchase Plan or any other Company benefit plan or
program. Executive's vested shares of common stock in the Company shall continue
to be subject to the terms of the applicable stock option plan or stock option
agreement or stock agreement.

     2.   Duties and Scope of Employment.

          (a)  Position. During his employment hereunder, Executive shall serve
in the position of Chief Executive Officer of the Company and in such other
capacities as the Board shall determine in its sole discretion. Executive shall
be given such duties, responsibilities and authorities as determined by the
Board in its sole discretion and shall report directly to the Board. In
addition, Executive will serve as a member of the newly established "Office of
the Chairman."

          (b)  Obligations. During his employment hereunder, Executive shall
devote Executive's full business efforts and time to the business and affairs of
the Company as needed to carry out his duties and responsibilities, subject to
the overall supervision of the Board. The foregoing shall not preclude Executive
from engaging in appropriate civic, charitable or religious activities or from
devoting a reasonable amount of time to private investments or, with the prior
consent of the Board, from serving on up to two boards of directors of other
entities, in each

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case, as long as such activities and service do not interfere or conflict with
Executive's duties and responsibilities to the Company and its affiliates.

     3.   Base Compensation. During Executive's employment hereunder, the
Company agrees to pay Executive as compensation for services to the Company and
its affiliates a base salary at the annual rate of $400,000. Such salary shall
be payable in accordance with the standard payroll procedures of the Company.

     4.   Employee Benefits.

          (a)  Vacation. During Executive's employment hereunder, Executive
shall be entitled to three (3) weeks of annual paid vacation.

          (b)  Benefits. During Executive's employment hereunder, the Company
shall also provide Executive with the usual health insurance benefits it
generally provides to its other senior management employees, other than life
insurance (which shall be paid directly by Executive). As Executive becomes
eligible in accordance with criteria adopted by the Company, the Company shall
provide Executive with the right to participate in and to receive benefits from
accident, disability, medical, profit-sharing and savings plans and similar
benefits made available generally to employees of the Company as such plans and
benefits may be adopted by the Company. The amount and extent of benefits to
which Executive is entitled shall be governed by the specific benefit plan as it
may be amended from time to time and the discretion and determinations of any
person, committee or entity administering such plan made in accordance with the
terms and conditions of such plan.

          (c)  Business Expense Reimbursement. During Executive's employment
hereunder, Executive shall be entitled to receive proper reimbursement for all
reasonable and necessary out-of-pocket expenses incurred by him (in accordance
with the policies and procedures established by the Company for its senior
executive officers) in performing services hereunder upon presentation of an
itemized account and appropriate supporting documentation.

     5.   Additional Benefits. In consideration for the release of claims set
forth in Section 20 and other obligations under this Agreement and in full
satisfaction of the Company's obligations to Executive under the terms of the
Employment Agreement, and provided this Agreement is signed by Executive and not
revoked under Section 20 herein, and further provided that Executive remains in
full compliance with all of his obligations under this Agreement and the
Consulting Agreement, the Company agrees to provide to Executive the benefits
specified below in this Section 5. The Company's obligations under this
Agreement and the Consulting Agreement will be subject to cancellation upon
written notice to Executive of a material breach of Executive's obligations or
covenants under either agreement.

          (a)  Stock Options. Except as provided under Section 5(b), Section
6(c) and in the following sentence of this Section 5(a), Executive's outstanding
stock options shall continue to be governed by the applicable stock option plan
and applicable option agreement. Executive's stock options may continue to vest
and be exercisable, pursuant to the option grant terms, while Executive provides
consulting services to the Company pursuant to the Consulting Agreement

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and Executive's unvested stock options having a per-share exercise price that is
greater than the Company's closing share price on the Execution Date shall vest
in full on the Execution Date; provided, that such accelerated vesting shall be
forfeited if Executive revokes this Agreement pursuant to Sections 20(a)(3) and
20(a)(4).

          (b)  Promissory Note. The Executive's promissory note, dated March 16,
2000, to pay the Company $536,700 plus interest (the "Promissory Note") is
eligible for prepayment, in whole or in part, at Executive's election without
penalty, fee or acceleration pursuant to the terms of the Promissory Note. Both
Parties desire that Executive fully repay his loan obligations under the
Promissory Note on the Execution Date. Subject to a right of rescission in favor
of the Company if Executive revokes this Agreement pursuant to Sections 20(a)(3)
and 20(a)(4), the following shall occur on the Execution Date in full
satisfaction of Executive's accumulated debt of $635,888.00, which represents
the amount of such debt as of the Execution Date:

               (i)    The Company shall repurchase all 107,146 unvested shares
pledged to the Promissory Note at their original cost of $1.5662 per share. The
aggregate repurchase amount of $167,812 shall be applied by the Company to repay
accrued unpaid interest and principal on the Promissory Note;

               (ii)   All 235,710 vested shares pledged to the Promissory Note
shall be repurchased by the Company using the Company's closing share price on
the Execution Date, and the proceeds of such repurchase shall be applied by the
Company and Executive to repay accrued unpaid interest and principal on the
Promissory Note;

               (iii)  All 876,114 of Executive's outstanding vested stock
options (including those vested by reason of Section 5(a)) having a per-share
exercise price that is greater than the Company's closing share price on the
Execution Date shall be surrendered to the Company on the Execution Date in
exchange for 613,280 shares of Company common stock pursuant to the Company's
option exchange program, provided that 275,976 of such shares shall be withheld
for tax purposes. Executive shall transfer the number of Company common shares
to the Company needed (up to a maximum of 337,304 shares) to fully off pay any
remaining accrued interest and principal on the Promissory Note. Such
transferred shares shall be valued using the Company's closing share price on
the Execution Date. If there is any outstanding balance on the Promissory Note
after such transfer of shares, then such portion of the Company's $400,000
obligation under Section 6(a) equal to the Offset Amount (as defined below)
shall become payable to Executive and shall be applied, on an after-tax basis,
in satisfaction of such outstanding balance thereby reducing the Company's
obligation under Section 6(a) by the Offset Amount; provided, however, that if
the Offset Amount shall exceed $400,000, the Company may, on a similar basis,
reduce its obligation to provide any other monies or benefits owed to Executive
whether under this Agreement, the Consulting Agreement or otherwise in order to
satisfy the remaining outstanding balance. For purposes of this Section
5(b)(iii), "Offset Amount" means such pre-tax amount that is equal, on an
after-tax basis, to the outstanding balance described in the preceding sentence.

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               (iv)  Any tax obligations of Executive (and tax liability
therefor) relating to any of the above transactions in this Section 5(b),
including any penalties and interest based upon such tax obligations are
entirely the responsibility and liability of Executive and all tax withholding
requirements must be timely satisfied by Executive.

          6.   Termination Payments. In the event that Executive's employment
hereunder terminates for any reason, then Executive shall be entitled to the
Accrued Benefits. For purposes of this Section 6, "Accrued Benefits" shall mean,
subject to any applicable plan terms (including, without limitation, any vesting
requirements), the compensation, benefits and reimbursements described in
Sections 3 and 4 of this Agreement for the period through the Executive's date
of the termination including payment in lieu of any accrued and unused vacation
and any Disability or death benefits to which Executive (or his estate or
beneficiary(s)) may be entitled as a result of termination of his employment on
account of Disability or death. In the event that Executive's employment
hereunder is terminated by the Company (other than by reason of Cause or death)
or Executive resigns pursuant to Section 1(b) or (e), then, after, and subject
to, Executive's execution and non-revocation of the release of claims described
in Section 6(b) and subject to full compliance by the Executive with all of his
obligations under this Agreement (including, but not limited to, loan repayment)
and the Consulting Agreement, Executive shall be entitled to receive the
payments described in Section 6(a). Executive shall not be entitled to receive
the payments described in Section 6(a) if he resigns for any reason other than
as set forth in Section 1(b) or (e).

          (a) Severance Payments. The Company shall pay to Executive salary
continuation payments after taking into account applicable income and employment
state and federal withholding taxes in the aggregate gross amount of $400,000
("Severance Payments"). Subject to Executive's continuing compliance with this
Agreement and the Consulting Agreement, the Severance Payments (less applicable
withholding) will be paid to Executive in substantially equal payments over a
twelve month period pursuant to the Company's standard payroll practices
commencing with the first such payroll period following the effective date of
the release described in Section 6(b) and, subject to Section 5(b)(iii).

          (b)  Release of Claims. Upon termination of the Executive's employment
hereunder and as a condition to the receipt of the payments described in Section
6(a), Executive and Company shall execute a mutual release of all claims in the
form of the release set forth in Section 20 but covering claims through the
effective date of such release and having such other terms necessary to make it
valid and encompassing under applicable law. Said release of claims will not
release the Executive's rights to enforce the release agreement and Executive
will not release his rights to any rights he has in any employee benefit plan(s)
including but not limited to his rights in any stock or stock option agreements
and plans.

          (c)  Conditions to Receipt of Payments and Benefits. The obligation to
provide to the Executive the payments described in this Section 6 shall cease,
and, notwithstanding anything to the contrary in the applicable plan(s) (or
agreement(s) thereunder), all unexercised stock options and any unvested
equity-based awards shall terminate in the event of, and at such time as, any
material breach of any of the provisions of this Agreement (including, but not
limited to, loan repayment) by Executive.

                                       5

<PAGE>

     7.   Confidential Information. In addition to applicable law, from and
after the Execution Date, including after the Separation Date, Executive agrees
to continue to be bound by and comply with the Proprietary Information and
Inventions Agreement that was executed by and between Executive and the Company
and these obligations shall survive the termination of this Agreement.

     8.   Conflicting Obligations. Executive certifies that Executive has no
outstanding agreement or obligation that is in conflict with any of the
provisions of this Agreement or the Consulting Agreement, or that would preclude
Executive from complying with the provisions thereof, and further certifies that
Executive will not enter into any such conflicting agreement.

     9.   Non-Disparagement. From and after the Execution Date, including after
the Separation Date, the Parties agree not to make any unfavorable or
disparaging written or oral remarks about the other or its past or present
officers, affiliates, employees or directors to third parties. However,
Executive acknowledges and agrees that the Company's non-disparagement
obligation pursuant to this Agreement shall extend solely to the actions of the
Company's current or future directors and officers. For purposes of this
Agreement, "officers" are those persons meeting the definition provided under
Rule 16a-1(f) of the Securities Exchange Act of 1934, as amended. Executive
agrees not to do or say anything that damages or impairs in any way the business
organization, goodwill, or reputation of Company or any of its affiliates or
related entities.

     10.  Arbitration and Equitable Relief.

          (a)  Disputes. Except as provided in Section 10(c) below, the Company
and Executive agree that any dispute or controversy arising under or in
conjunction with this Agreement will be settled exclusively by arbitration in
San Francisco, California. The Company and Executive will share equally the
expense of the arbitration (other than as set forth in Section 12 with respect
to attorney's fees). Any claim for arbitration shall be filed in writing with
the arbitrator selected by both Parties within three business days after either
party has notified the other in writing that it desires a dispute between them
to be settled by arbitration. In the event the Parties cannot agree on a single
arbitrator within such three-day period, each party will select an arbitrator
and inform the other party in writing of such arbitrator's name and address
within two business days after the end of such three-day period and the two
arbitrators so selected will as soon thereafter as possible select a third
arbitrator who shall serve as the sole arbitrator in deciding the dispute;
provided, however, that in the event of a failure by either party to select an
arbitrator and notify the other party of such selection within the time period
provided above, the arbitrator selected by the other party will be the sole
arbitrator of the dispute. The arbitration hearing will be held within seven
business days (or as soon thereafter as possible) after the selection of the
arbitrator. Hearing procedures, which will expedite the hearing, may be ordered
at the arbitrator's discretion and the arbitrator may close the hearing in his
or her discretion after determining that he/she has heard sufficient evidence.
The decision of the arbitrator will be issued in writing as expeditiously as
possible and in no event later than five business days after the hearing and the
decision will be binding upon the Parties and judgment in accordance with that
decision may be entered in any court having jurisdiction therefore. The
arbitrator may award attorneys' fees and costs of the arbitration to the
prevailing party.

                                       6

<PAGE>

          (b)  Consent to Personal Jurisdiction. The arbitrator(s) will apply
California law to the merits of any dispute or claim, without deference to
conflicts of law rules. Executive and the Company hereby consent to the personal
jurisdiction of the state and federal courts located in California for any
action or proceeding arising from or relating to this Agreement or relating to
any arbitration in which the parties are participants.

          (c)  Equitable Relief. The parties may apply to any court of competent
jurisdiction for a temporary restraining order, preliminary injunction, or other
interim or conservatory relief as necessary, without breach of this arbitration
agreement and without abridgment of the powers of the arbitrator.

          (d)  Acknowledgment. EXECUTIVE HAS READ AND UNDERSTANDS THIS
AGREEMENT, WHICH DISCUSSES ARBITRATION. EXECUTIVE UNDERSTANDS THAT BY SIGNING
THIS AGREEMENT, EXECUTIVE AGREES TO SUBMIT ANY CLAIMS ARISING OUT OF, RELATING
TO, OR IN CONNECTION WITH THIS AGREEMENT, OR THE INTERPRETATION, VALIDITY,
CONSTRUCTION, PERFORMANCE, BREACH OR TERMINATION THEREOF, TO BINDING
ARBITRATION, EXCEPT AS PROVIDED IN SECTION 10(C), AND THAT THIS ARBITRATION
CLAUSE CONSTITUTES A WAIVER OF EXECUTIVE'S RIGHT TO A JURY TRIAL AND RELATES TO
THE RESOLUTION OF ALL DISPUTES RELATING TO ALL ASPECTS OF THE EMPLOYMENT
RELATIONSHIP BETWEEN THE PARTIES.

     11.  Governing Law. This Agreement shall be governed by and construed in
accordance with the laws of the State of California, without regard to the
conflicts of law principles thereof.

     12.  Attorney's Fees. The Company shall pay for Executive's reasonable
legal fees incurred with respect to the review of this Agreement and the
Consulting Agreement. Such fees shall not exceed $10,000 and shall be supported
by invoices to the Company that provide sufficient documentation of the work
performed. In any action brought by one of the parties to enforce or interpret
the provisions of this Agreement or the Consulting Agreement, the prevailing
party will be entitled to reasonable attorney's fees, in addition to any other
relief to which that party may be entitled under this Agreement or the
Consulting Agreement.

     13.  Assignment. This Agreement and all rights under this Agreement will be
binding upon and inure to the benefit of and be enforceable by the Parties
hereto and their respective owners, agents, officers, stockholders, employees,
directors, attorneys, subsidiaries, parents, affiliates, successors, personal or
legal representatives, executors, administrators, heirs, distributes, devisees,
legatees, and assigns. This Agreement is personal in nature, and neither of the
Parties to this Agreement will, without the written consent of the other, assign
or transfer this Agreement or any right or obligation under this Agreement to
any other person or entity; except that the rights and obligations of the
Company under this Agreement may be assigned (without the consent of the
Executive) to an entity which becomes the successor to the Company as the result
of a merger or other corporate reorganization or sale of substantially all the
assets to a

                                       7

<PAGE>

successor which continues the business of the Company or any other subsidiary of
the Company, provided, that such assignment will not relieve the Company of its
obligations hereunder.

     14.  Notices. For purposes of this Agreement, notices and other
communications provided for in this Agreement will be in writing and will be
delivered personally or sent by United States certified mail, return receipt
requested, postage prepaid, addressed as follows:

     If to the Executive:          William Matthews, Ph.D.
                                   60 Summit Springs Rd.
                                   Woodside, CA 94062

     If to the Company:            Deltagen, Inc.
                                   740 Bay Road
                                   Redwood City, CA 94063
                                   Attn: Board of Directors

or to such other address or the attention of such other person as the recipient
party has previously furnished to the other party in writing in accordance with
this Section 14. Such notices or other communications will be effective upon
delivery or, if earlier, three days after they have been mailed as provided
above.

     15.  Integration. This Agreement, this Agreement's Exhibit A (the
Consulting Agreement), the Executive's stock option and common stock purchase
agreements and plans with the Company, the Indemnification Agreement and the
Proprietary Information and Inventions Agreement represent the entire agreement
and understanding between the Parties as to the subject matter hereof and
supersede all prior agreements (including but not limited to the Employment
Agreement and the Promissory Note) whether written or oral.

     16.  Modification. This Agreement may only be amended in a writing signed
by Executive and the Chairman of the Board. No waiver, alteration, or
modification of any of the provisions of this Agreement will be binding unless
in writing and signed by the party against whom enforcement of the change or
modification is sought. Failure or delay on the part of either party hereto to
enforce any right, power, or privilege hereunder will not be deemed to
constitute a waiver thereof. Additionally, a waiver by either party or a breach
of any promise hereof by the other party will not operate as or be construed to
constitute a waiver of any subsequent waiver by such other party.

     17.  Right to Advice of Counsel. Executive acknowledges that he has had the
opportunity to fully review this Agreement and, if he so chooses, to consult
with counsel, and is fully aware of his rights and obligations under this
Agreement.

     18.  Civil Code Section 1542. Executive represents that he is not aware of
any claim other than the claims that are released by this Agreement. Executive
also represents that he does not presently intend to bring any claims on his own
behalf or on behalf of any other person or entity against any other person or
entity referred to herein. The Parties acknowledge that they

                                       8

<PAGE>

are familiar with the provisions of California Civil Code Section 1542, which
provides as follows:

          A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES
          NOT KNOW OR SUSPECT TO EXIST IN HIS FAVOR AT THE TIME OF EXECUTING THE
          RELEASE, WHICH IF KNOWN BY HIM MUST HAVE MATERIALLY AFFECTED HIS
          SETTLEMENT WITH THE DEBTOR.

The Parties, being aware of said Code section, agree to expressly waive any
rights they may have thereunder, as well as under any other statute or common
law principles of similar effect.

     19.  Executive's Covenants.

          (a)  General. The Executive agrees that for all periods described in
this Agreement, he shall conduct himself reasonably with respect to the Company
and its employees, directors, stockholders, consultants, customers, affiliates
and agents.

          (b)  Confidentiality of this Agreement. Executive agrees to use his
reasonable efforts to maintain in confidence the existence of this Agreement and
the Consulting Agreement, the contents and terms of this Agreement and the
Consulting Agreement, and the consideration for this Agreement and the
Consulting Agreement (hereinafter collectively referred to as "Agreement
Information"). Executive hereto agrees to take every reasonable precaution to
prevent disclosure of any Agreement Information to third parties, except for
disclosures required by law or necessary to effectuate the terms of this
Agreement or the Consulting Agreement including as necessary disclosures to
Executive's attorney and members of his immediate family.

          (c)  Cooperation. Executive shall fully cooperate in the defense of
any action brought by any third party against the Company or its affiliates that
relates in any way to Executive's acts or omissions while employed by the
Company or in the defense of any action brought by any third party relating to
litigation pending against the Company or its affiliates as of the Separation
Date. Executive shall continue to be indemnified by the Company pursuant to the
Company by-laws, Indemnification Agreement, insurance policies and to the
fullest extent permitted under California law.

          (d)  Company Resources. As of the Separation Date, Executive will no
longer represent that he is an officer, employee or director of the Company or
any of its affiliates. No later than the Separation Date, Executive will return
all property belonging to the Company and its affiliates to the Company
including but not limited to Confidential Information, credit cards, telephone
calling cards, keys, computers, cell phones, pagers, monitors, business cards,
devices, records, data, notes, reports, proposals, lists, correspondence,
specifications, drawings, blueprints, sketches, laboratory notebooks, flow
charts, materials, equipment, other documents or property, or copies or
reproductions of any aforementioned items belonging to the Company or its
affiliates. Executive will also no longer utilize any Company or affiliate
property.

                                       9

<PAGE>

          (e)  Non-Solicitation. Executive agrees that for the period of one
year after the Separation Date he shall not either directly or indirectly
solicit, induce, recruit or encourage any of the Company's or its affiliates'
employees or consultants to terminate their relationship with the Company or its
affiliates, or attempt to solicit, induce, recruit, encourage any of the
Company's or its affiliates' employees or consultants to terminate their
relationship with the Company or its affiliates, or attempt to solicit, induce,
recruit, encourage or take away employees or consultants of the Company or its
affiliates, either for himself or for any other person or entity. Further, for
the same time period, Executive shall not attempt to negatively influence any of
the Company's or its affiliates' clients or customers from purchasing Company or
affiliate products or services or to solicit or influence or attempt to
influence any client, customer or other person either directly or indirectly, to
direct his or its purchase of products and/or services to any person, firm,
corporation, institution or other entity in competition with the business of the
Company or its affiliates.

          (f)  No Further Employment. Executive understands and agrees that
after the Separation Date he is not entitled to any further or future employment
with the Company or its affiliates or further or future compensation and/or
payments of any kind from the Company or its affiliates other than those
specifically provided for under this Agreement and the Consulting Agreement.
Executive warrants and represents that he shall not institute or participate in
any claim, action, lawsuit or proceeding against the Company or its affiliates
for any failure to employ or re-employ him after the effective date of the
release described in Section 6(b).

          (g)  Breach of Agreement. Executive acknowledges that upon material
breach of any provision of this Agreement or the Consulting Agreement, the
Company would sustain irreparable harm from such breach, and, therefore,
Executive agrees that in addition to any other remedies which the Company may
have for any material breach of this Agreement or the Consulting Agreement or
otherwise, the Company shall be entitled to obtain equitable relief including
specific performance and injunctions restraining the Executive from committing
or continuing any such violation of this Agreement or the Consulting Agreement.

     20.  Executive and Company's Mutual Release of Claims.

     (a)  In exchange for the Company's promises set forth herein, all of which
are good and valuable consideration, Executive (and his immediate family) agrees
not to sue and releases and forever discharges the Company, its affiliates,
agents, employees, shareholders, directors, officers and successors of and from
any and all rights, claims, actions, demands, causes of action, obligations,
attorneys' fees, costs, damages, and liabilities of whatever kind or nature, in
law or in equity, that Executive has, has had or may hereafter claim to have or
have had (whether known or not known) arising from any matter, act, omission,
cause or event whatsoever on or prior to the Effective Date (except for his
rights under this Agreement and claims to indemnification to the extent
permitted under the Company's bylaws or pre-existing indemnification agreements
or as permitted by California law or as may be available to Executive under the
Company's directors' and officers' liability insurance coverage and his rights
under any employee benefits plan(s), including, but not limited to stock and
stock option agreements and plans), including but not limited to legal claims
based on and/or arising under Title VII of the Civil Rights Act of 1964, as
amended, The Americans with Disabilities Act, The

                                       10

<PAGE>

Family Medical Leave Act, The Equal Pay Act, The Employee Retirement Income
Security Act, The Fair Labor Standards Act, and/or the California Fair
Employment and Housing Act; The California Constitution, The California
Government Code, The California Labor Code, The Industrial Welfare Commission's
Orders, The Securities Act of 1933, The Securities Exchange Act of 1934 and any
and all other legal claims under any other federal, state or local Constitution,
Statute, Ordinance and/or Regulation; and all other legal claims arising under
common law including but not limited to tort, express and/or implied contract
and/or quasi-contract, arising out of or, in any way, related to Executive's
previous relationship with the Company as an employee or director up to the
Effective Date (collectively, "Claims"). Furthermore, Executive acknowledges
that he is waiving and releasing any rights he may have under the Age
Discrimination in Employment Act of 1967 ("ADEA"), as amended, and that this
waiver and release is knowing and voluntary. Executive acknowledges that the
consideration given for this waiver and release is in addition to anything of
value to which Executive was already entitled. The Executive does not waive his
rights under this Agreement or the Consulting Agreement or his right to enforce
both agreements. Executive further acknowledges that he has been advised by this
writing that:

          (1)  he should consult with an attorney prior to executing this
Agreement;

          (2)  he has at least twenty-one (21) days within which to consider
this Agreement;

          (3)  he has up to seven (7) days following the execution of this
Agreement by the parties to revoke the Agreement; and

          (4)  this Agreement shall not be effective until the revocation period
in Section 20(a)(3) has expired and the Executive has not revoked this Agreement
pursuant to Section 20(a)(3).

     (b)  The Company, in further consideration for Executive's signing this
Agreement, releases and forever discharges Executive and his immediate family
from all actions, causes of action, liabilities, disputes, judgments, damages,
and claims in any manner related to Executive's employment with Company. The
Company reserves its right to enforce this Agreement.

     (c)  The Company and Executive agree that the release set forth in this
Section 20 shall be and remain in effect in all respects as a complete mutual
release as to the matters released up to the Effective Date.

     21.  Severability. Whenever possible, each provision of this Agreement will
be interpreted in such a manner as to be effective and valid under applicable
law, but if any provision of this Agreement is held to be invalid, illegal or
unenforceable in any respect under any applicable law or rule in any
jurisdiction, such invalidity, illegality or unenforceability will not affect
any other provision or any other jurisdiction, but this Agreement will be
reformed, construed and enforced in such jurisdiction as if such invalid,
illegal or unenforceable provision had never been contained herein.

                                       11

<PAGE>

     22.  Counterparts. This Agreement may be executed in counterparts, each of
which will be deemed an original, and which together will be a single
instrument.

     23.  No Representations. Each Party represents that it has had the
opportunity to consult with an attorney, and has carefully read and understands
the scope and effect of the provisions of this Agreement. Neither Party has
relied upon any representations or statements made by the other party hereto
which are not specifically set forth in this Agreement.

     24.  Authority. The Company represents and warrants that the undersigned
has the authority to act on behalf of the Company and to bind the Company and
all who may claim through it to the terms and conditions of this Agreement.
Executive represents and warrants that he has the capacity to act on his own
behalf and on behalf of all who might claim through him to bind them to the
terms and conditions of this Agreement. Each Party warrants and represents that
there are no liens or claims of lien or assignments in law or equity or
otherwise of or against any of the claims or causes of action released herein.

     25.  Voluntary Execution of Agreement. This Agreement is executed
voluntarily and without any duress or undue influence on the part or behalf of
the Parties hereto, with the full intent of releasing all claims. The Parties
acknowledge that:

          (a)  They have read this Agreement;

          (b)  They have been represented in the preparation, negotiation, and
execution of this Agreement by legal counsel of their own choice or that they
have voluntarily declined to seek such counsel;

          (c)  They understand the terms and consequences of this Agreement and
of the releases it contains;

          (d)  They are fully aware of the legal and binding effect of this
Agreement.

     26.  Employment At Will; Limitation of Remedies. The Company and Executive
acknowledge that the Executive's employment is at will, as defined under
applicable law. If the Executive's employment terminates for any reason, the
Executive shall not be entitled to any payments, benefits, damages, awards or
compensation other than as provided by this Agreement (or the Consulting
Agreement).

     27.  Employment Taxes. All payments made pursuant to this Agreement shall
be subject to withholding of applicable taxes.

     IN WITNESS WHEREOF, the Parties hereto have executed this Agreement as of
the day and year first above written.

                                       12

<PAGE>

WILLIAM MATTHEWS, PH.D., EXECUTIVE      DELTAGEN, INC.

By: ______________________________      By: _________________________________

                                        Name: _______________________________

                                        Title: ______________________________

                                       13

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