Judul: Analysis of MmCu/Zn-SOD Gene Expression and Resistance of Transgenic Potato Cultivars IPB CP3 to Parakuat Herbicide
Abstrak: Penggunaan herbisida paraquat untuk mengendalikan pertumbuhan gulma telah menjadi metode yang paling umum. Namun penggunaan herbisida ini juga dapat menyebabkan kerusakan sel pada tanaman kentang yang sedang dibudidayakan karena herbisida paraquat dapat menginduksi terbentuknya senyawa Reactive Oxygen Species (ROS) yang dapat merusak sel tanaman. Ekspresi berlebih dari gen MmCu/Zn-SOD diharapkan dapat memberikan ketahanan terhadap cekaman herbisida paraquat. Penelitian ini bertujuan untuk menganalisis ekspresi gen MmCu/Zn-SOD pada kentang transgenik IPB CP3 kultivar dan ketahanannya terhadap cekaman herbisida paraquat. Perlakuan herbisida paraquat dengan konsentrasi 75 µM pada tanaman transgenik (P3SOD6, P3SOD9, P3SOD17) dan nontransgenik (NT) secara in vitro menunjukkan bahwa semua tanaman transgenik lebih tahan terhadap cekaman paraquat dibandingkan tanaman non-transgenik. Klon P3SOD9 paling tahan terhadap herbisida paraquat, dengan perbandingan 10 tanaman hidup dari 12 tanaman yang diuji. Ekspresi MmCu/Zn-SOD pada galur transgenik lebih tinggi dibandingkan galur non-transgenik. Ekspresi relatif gen MmCu/Zn-SOD pada P3SOD9 lebih tinggi 233,22 kali dibandingkan NT, P3SOD6 127,62 kali, dan P3SOD17 3,18 kali. Semakin tinggi ekspresi MmCu/ZnSOD berkorelasi dengan semakin tinggi ketahanan terhadap cekaman herbisida paraquat., The use of paraquat herbicides to control weed growth has become the most common method. However, using this herbicide can also cause cell damage in potato plants that are being cultivated because paraquat herbicide can form Reactive Oxygen Species (ROS) compounds that can damage cells from plants. Overexpression of the MmCu/Zn-SOD gene is expected to provide resistance to paraquat herbicide stress. This study aimed to analyze the expression of the MmCu/Zn-SOD gene in transgenic potato cultivar IPB CP3 and its resistance to paraquat herbicide stress. Paraquat herbicide treatment with a concentration of 75 µM on transgenic (P3SOD6, P3SOD9, P3SOD17) and non-transgenic (NT) plants in vitro showed that all transgenic plants were more resistant to paraquat stress than that of nontransgenic plants. The P3SOD9 clone was the most resistant to paraquat herbicide, with a ratio of 10 survive plants of the 12 plants tested. The expression of MmCu/Zn-SOD in transgenic lines was higher than in non-transgenic lines. The relative expression of MmCu/Zn-SOD gene in P3SOD9, P3SOD6, and P3SOD17 was 233.22, 127.62, and 3.18 times higher than that of NT, respectively. The expression level of MmCu/ZnSOD correlated with the level of resistance to paraquat herbicide stress.
Keyword: ekspresi gen, herbisida parakuat, MmCu/Zn-SOD

Judul: Introduction of MmCu/ZnSOD Gene into Potato (Solanum tuberosum L.) Genome Cultivar IPB CP3 Mediated Agrobacterium tumefaciens
Abstrak: Cekaman abiotik merupakan salah satu faktor penyebab penurunan kualitas dan hasil produksi pertanian. Pada kondisi tercekam, tanaman akan memproduksi reactive oxygen species (ROS) berlebih seperti superosida (O2*-) dan hydroxyl radical (OH*) yang dapat mendegradasi biomolekul penting seperti protein, lipid, karbohidrat dan DNA sehingga menyebabkan kerusakan dan kematian sel. Tujuan dari penelitian ini adalah mengintroduksi gen MmCu/ZnSOD dibawah kendali promotor 35S CaMV ke dalam genom tanaman kentang IPB CP3 untuk meningkatkan toleransinya terhadap cekaman kekeringan dan salinitas melalui detoksifikasi ROS. Transformasi genetik dengan perantara Agrobacterium tumefaciens pada 300 eksplan ruas batang tanpa mata tunas menghasilkan tanaman transgenik putatif dengan efisiensi transformasi dan regenerasi sebesar 47,33% dan 31,09%, secara berurutan. Analisis integrasi menunjukkan bahwa 18 klon transgenik terbukti membawa gen MmCu/ZnSOD di bawah kendali promotor 35S CaMV yang menandakan bahwa klon tersebut transgenik. Uji cekaman kekeringan dan salinitas secara in vitro menunjukkan bahwa keenam klon transgenik memiliki toleransi lebih tinggi dibandingkan non-transgenik berdasarkan jumlah dan panjang akar total.
Keyword: superoksida dismutase, kekeringan, salinitas, kentang, reactive oxygen species

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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