Judul: Transformasi genetik Nicotiana benthamiana L. dan kedelai dengan Gen MaMt2 penyandi Metallothionein Tipe II dari Melastoma malabathricum L.
Abstrak: Cekaman pH rendah dan kandungan aluminium yang tinggi pada tanah masam, khususnya tanah Ultisol, merupakan faktor-faktor pembatas produksi dan kualitas tanaman pangan. Kemampuan beberapa tanaman pangan penting dalam mengatasi toksisitas logam dapat ditingkatkan dengan cara mengekspresikan gen-gen yang terkait dengan toleransi pH rendah dan aluminium (Al) tinggi. Melastoma malabathricum merupakan salah satu tanaman yang mampu hidup di tanah ber- pH rendah dan kelarutan Al tinggi. Sejumlah gen yang ekspresinya diinduksi oleh cekaman pH rendah dan aluminium tinggi pada M. malabathricum sebagian sudah berhasil diisolasi dan dikarakterisasi. Salah satu gen tersebut adalah gen MaMt2 yang menyandi metallothionein tipe II. Protein ini banyak mengandung sistein yang mampu mengikat berbagai macam logam. Penelitian ini bertujuan untuk mengkonstruksi vektor ekspresi berlebih gen MaMt2 menggunakan plasmid pIG6, mentransformasi tanaman Nicotiana benthamiana dan kedelai dengan gen MaMt2, dan menganalisis tanaman transgenik secara molekular.
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Judul: Transformasi Genetik Padi (Oryza sativa L.) dengan Gen Penyandi Metallothionein Tipe II dari Melastoma malabathricum L. (MaMt2) Menggunakan Perantara Agrobacterium tumefaciens
Abstrak: Rice production can be decrease caused by abiotic stresses. These abiotic stresses, cause oxidative stress in plants overproducting radical oxygen species (ROS). ROS could cause damage and death in plants cells. The tolerant varieties adapted to abiotic stress could be created by introducing and expressing the abiotic stress tolerant genes. Metallothionein (MT) has an important role to detoxity some heavy-metal ions, e.g. cadmium and mercury by binding these metal ions. MaMt2 gene encoding for metallothionein type II had been isolated from Melastoma malabathricum. We suppose that plant overexpressing this gene would be tolerant to metal ions, including Al. This research had an objective to introduce this MaMt2 gene under the control of pUbiquitin promoter and NosT terminator into rice (Oryza sativa L.) genom. Two rice cultivars i.e. Kasalath and Nipponbare were transformed with MaMt2, through Agrobacterium-mediated gene transfer method. Kasalath is indica rice and Nipponbare is japonica rice. Genetic transformation of rice was carried out on Kasalath and Nipponbare cultivars by using calli of seeds as explants. The calli were obtained from seeds cultivated in 2N6 medium containing 2 mg/L 2.4 D. These 3-4 week old calli (235 calli of Kasalath and 165 calli of Nipponbare) were co-cultivated with A. tumefaciens LBA4404 carrying pIG6-SMt2 containing MaMt2 gene under the control of Ubiquitin promoter and Nos terminator. Co-cultivation was carried out 3 days in the 2N6 media containing 100 mg/L acetosiringone. After cocultivation, the calli were selected in two steps in 2NBK and nN6C media containing 20 and 30 mg/L hygromycin respectively. The resistant calli were regenerated in 2N6 medium containing 0.5 mg/L kinetin. Based on hygromycin resistant calli on hygromycin selection medium, the transformation efficiency in Kasalath was 14.04%, while in Nipponbare was 19.39%. Based on resistant calli on selective medium, the efficiency of regeneration of transgenic shoots in Kasalath was 6.06%, while in Nipponbare was 28.1%. Molecular analysis by PCR showed that two of eleven putative rice transgenic were confirmed as transgenic ones containing MaMt2 transgene under the control of Ubiquitin promoter and NosT terminator. This transgenic rice can be used as source of MaMt2 that can be transferred to other cultivars of rice by conventional crossing.
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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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