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: Identifikasi Secara Molekular Kandidat Mutan Gα dari Kedelai Kultivar Slamet Berdasarkan mRNA
Abstrak: Heterotrimeric G proteins composed of α, β, and γ subunits, are bound to the inside surface of the cell membrane. Gα proteins will be activated by extracellular stimuli (biotic or abiotic stress). It is presumably Gα proteins playing an important role in aluminum (Al)-stress tolerance. Soybean cv. Slamet was considered as a tolerant plant to Al and has a single copy of Gα gene. Gamma irradiation to soybean cv. Slamet seeds caused a random chromosomal mutation of second generation plants (designated as M2). The Gα mutant candidates were selected based on stomatal closure in the daylight and dwarf. Gα mutant candidates M4, number 338 and 103 have severe root cell tissues damage compared to non mutant ones. Plant number 338/3S1.174/12/14 (M4) and 103/3S3.103/8/5/1/4 (M5) have a Gα gene mutation at the U3-L4 sequences (exon 5 – exon 11). Whereas, plant number 344/3S1.196/14/1/8 (M4) is assumed as Gα gene mutant. All of those plants were replanted until sixth generation. The candidates of Gα mutant selected have more than fifty percent of closed stomata and dwarf. Four number of M5 plants and three number of M6 plants were selected for Gα mutant identification based on mRNA analysis. The fifth generation plant number 344/3S1.196/14/1/8/7 were decreased its Gα gene expression at L5-L4 sequences (exon 7 – exon 11). The M6 generation plant number 344/3S1.196/14/1/8/7/5 have mutation in Gα gene at L1-L3 sequences (exon 2 – exon 6). A major contributing factor to decreased expression levels of Gα gene may be due to mutation of Gα gene promotor. Three other of M5 plants were assumed as Gα mutant. M6 plant number 103/3S3.103/8/5/1/4/8 has mutation at L3-L2 sequences (exon 6 – exon 15) and number 103/3S3.103/8/5/1/4/9 has mutation at U3-L4 sequences (exon 5 – exon 11). The decreasing of gene expression caused by mutation in those plants was indicated by the less pronounced DNA bands on agarose gel than that of non mutant plants.
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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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