P5CS and HSP 81-2 Gene Expression Profile of Banana (Musa acuminata) in vitro Culture Under Salt Stress Condition

Banana (Musa acuminata spp.) is a fruit as a source of staple food of Asia. Musa acuminata cv Barangan is
a type of banana that live in low-lying areas and most widely consumed by an Indonesian people. Bananas are thought to have resistance to salinity stress by knowing the defense mechanisms against stress is expected banana can be used as an alternative crop for marginal land. Banana (Musa spp.) is mesophytic plant that intolerant to high salinity. The presence of proline and Heat Shock Protein (HSP) compounds are an indicator that the plant is under stress conditions. The purpose of this study was to evaluate the banana plant defense mechanisms against the state of high salinity. Methodology: In this study will be observed accumulation of proline produced by the activity of banana planlets after being treated in the form of salinity stress condition. In this study was observed as well, Heat ShockProtein 81-2 (HSP 81-2) and delta-1-pyrroline-5-carboxylate synthase (P5CS1) gene expression profiles of plantlets were treated by salinity stress condition. To achieve the study objectives, Musa acuminata Barangan cultivar culturing in vitro carried out. Banana shoots were cultured in MS medium with BAP with additional 25, 50, 75 and 100 mM NaCl. Proline analyzed with ninhydrin methods. The RNA was isolated from control (K) and treated plantlets. The cDNA made from isolated RNA to be used for qRT-PCR analysis. Transcript levels determination was validated and confirmed using quantitative real-time PCR (qRT-PCR). Results: The results of this study are as follows, proline accumulated by plantlets treated with NaCl, HSP 81-2 and P5CS1 genes expressed by all plantlets with different levels. The HSP 81-2 highest expressed by shoots and roots of plants with 75 mM NaCl treatment. Likewise, the highest proline accumulation occurred in this treatment. On the whole of the roots and shoots treated by NaCl, HSP 81-2 gene expression is higher than the P5CS1 gene expression. Results from this study may answer the purpose of the study itself. Conclusion: Musa acuminata cv Barangan plant has
defense mechanisms against the state of high salinity. The expected contribution of this study is that Musa acuminata cv Barangan can be used as plant resistant to soil with high salt content conditions to resolve the problem of exploitation of critical marginal land.