Judul: Studi Anatomi dan Histokimia pada Akar Kedelai (Glycine max (L.) Merr) Kandidat Mutan Protein Gα terhadap Cekaman Aluminium
Abstrak: Plant heterotrimeric G-proteins subunit α has been implicated in a number of signaling process such as biotic (pathogen) stress. Recently result showed, the expression of G gene was induced by aluminum stress as much as 1.6 mM AlCl3 and accumulation of Al was decreased on soybean cv. Slamet root as a tolerant cultivar. The aim of this research was to examine the role of G protein  sub unit in aluminum stress by using G mutant candidate of soybean cv. Slamet through anatomy and histochemical analyzes. Involvement of the heterotrimeric G protein  sub unit in the aluminum stress were investigated using plant root from two G mutant candidates (Slm 103 and Slm 338) compared with wild type cv. Slamet which grown in liquid nutrient media pH 6.0, pH 4.0, pH 4.0 + 1.6 mM AlCl3 for 8, 24, 48 h. The plants cultivated in pH 6.0 media were used as a control. Involvement of Gα protein was examined by measuring inhibition of root growth, accumulation of aluminum by using hematoxilin staining, and vertical section of root (1-5 cm) after aluminum treatment. Result indicated that aluminum treatment highly increased root growth inhibition, accumulation of Al on hematoxilin staining, root damage especially on meristimatic area in G mutant candidate compared to wild type soybean cv. Slamet. Result of this study demonstrated that the possibility of heterotrimeric G protein sub unit was involved in the aluminum stress of soybeans.
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Judul: Identifikasi Molekular Kandidat Mutan Protein Heterotrimerik G Subunit α (Gα) dari Kedelai (Glycine max (L.) Merrill) Toleran Aluminium Kultivar Slamet
Abstrak: Heterotrimeric G protein α Subunit (Gα) is predicted to play an important role in soybean tolerance mechanism to aluminum stress and low pH. Aluminum stress inhibits soybean growth and induces root damage. The expression of Gα gene is induced under Al stress condition. The objective of this research was to identify six lines of Gα mutant candidates using molecular technique. Six soybean mutant lines were planted and selected based on representative characters of Gα mutant, which were dwarf phenotypes and stomatal closure during daylight. Identification of Gα gene on mutant candidates was carried out through PCR method by using genomic DNA as a template from mutant and wild type cv. Slamet as the control plant. Three mutant candidates (338/3S1.174/12/1/4, 103/3S3.103/8/5/1/4, and 344/3S1.196/14/1/8) were chosen from all the selected lines to identify Gα gene. Before gene identification, a proper primer choosed by combined a designed primer from cDNA of Gα gene from cv. Slamet and Gα genomic of rice. A numbers of primers were generated from rice Gα genomic and soybean Gα cDNA sequences. Three primers were selected based on the ability of the primer to amplify soybean Gα cDNA cv. Slamet. Only primers that could amplify Gα cDNA used in molecular identification. Among those selected primer, three pairs of primers were successfully amplifying Gα cDNA. Only the primers combination U3-L4 could identify Gα mutant in line number 338/3S1.174/12/1/4 and 103/3S3.103/8/5/1/4, but not in number 344/3S1.196/14/1/8.
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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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