Judul: Cloning Trehalose Synthase Gene And Its Expression In Arabidopsis thaliana
Abstrak: Trehalose is a well known as biological stabilizer functioning as stress protecting agent. It is ubiquitously found in bacteria, fungi, invertebrates, and certain desert-adapted resurrection plants such as Selaginella. In most flowering plants, trehalose is synthesized in amounts nearing the detection limit. Gene(s) encoding trehalose-metabolizing enzymes from E.coli, trehalose synthase and trehalose phosphate phosphatase (OtsA and or OtsB) and the same gene from yeast (TPS1 and or TPP) have been introduced to plants and increased stresses resistance, yet resulted in phenotypic defect, due to accumulation of its intermediate product, trehalose-6-phosphate (T6P). T6P increases along with the increase of trehalose level. This research was aimed to find out if introducing trehalose synthase gene (TreS) which does not produce T6P which prevent phenotypic defect resulted from trehalose accumulation, and whether the presence of TreS in plant improves plant resistance to stresses. The use of TreS as an alternative among non toxic selectable markers was also assessed. For this reason, genes encoding trehalose synthase originated from Thermobifida fusca (TfTreS) and originated from Mycobacterium tuberculosis (MtTreS) had been cloned into plant expression vector (pBIN1935S). TfTreS was isolated from T. fusca using PCR and was inserted to pGemT for sequencing. DNA sequent analysis of the 2 clones, TfTreS within pGemT were identical to the published data yet several silent point mutations occured. TfTreS from these clones were inserted into pBIN19 with CaMV35S promoter. It has been successfully transferred to Arabidopsis thaliana via Agrobacterium mediated transformation. MtTreS readily available in pBlunt TOPO II, was exiced from the plasmid and was inserted to pBin1935S, and transferred to Arabidopsis in the same manner, but it has not been successfully transferred to the plant.
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Judul: Transformasi Genetik Tembakau dengan Gen BtCspB Penyandi Cold Shock Protein Melalui Perantara Agrobacterium tumefaciens
Abstrak: Cold shock protein (Csp) is essential for organisms to survive in the abiotic stress condition. It protects RNA from misfolding caused by various abiotic stresses. BtCsp gene had been isolated from Bacillus thuringiensis, fused to promoter of ubiquitin in the T-DNA of pCambia 1300int, and introduced into Agrobacterium tumefaciens LBA4404. We suppose that plant overexpressing this gene would be tolerant to abiotic stress including cold heat and drought stress. This research had an objective to transform genetically Nicotiana tabacum cv Samsun by BtCsp gene under the control of pUbiquitin promoter and NosT terminator mediated by A. tumefaciens. Leaf disks were inoculated by the method of co-cultivation with A. tumefaciens LBA4404 harboring pCambia1300int-BtCspB. We compared the effect of shoaking time between 20 and 30 minutes on the transformation efficiency. The transformation calli were selected on the medium containing 20 mg/l and 50 mg/l hygromcin and regenerated on MS medium containing 1 mg/l BAP and 0,1 mg/L IAA. Based on resistant calli to 50 mg/l hygromicin, the efficiency of transformation between 20 and 30 minutes was selatively equal i.e 65% and 57.5% respectively. PCR analaysis showed that BtCspB gene under the control of Ubquitin promoter is integrated into N. tabacum genome of To generation. Genetic analysis showed that hpt gene was inherited to the progeny T1 generation following Mendalian law. Based on chi-square analysis, the ratio of resistant and sensitive plant To hygromycin in T1 generation was 3:1, indicating that only one copy of hpt gene was integrated into the genome of transgenic plant in To generation.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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