Analysis of Stress Responsive Genes in Capsicum for Salinity Responses

Aims: This study is an endeavor to gain proper understanding about salt tolerance mechanism in plants; an attempt was made to characterize the differential expression of stress responsive genes, sodium potassium content proline content in three capsicum cultivars having different salt sensitivity level.
Place and Duration of Study: School of Bio Sciences and Technology, VIT University, Vellore of India between June 2013 to May 2014.
Methodology: Capsicum cultivars (salt tolerant, salt moderate sensitive and salt susceptible) were treated with different concentration of NaCl such as 25mM, 50mM, 100mM, 150mM and 200mM. Gene expression studies under different salt treatment were done for the following genes: osmotic adjustment (CaPROX1), osmotin like protein (CaOSM1), aquaporin (CaPIP2), dehydrin responsive gene (CaDREBLP1), ring domain zinc finger protein gene (CaKR1), membrane protein (CaChi2), endoplasmic reticulum ubiquitine ligase (CaRMa1H1) and cell death repressor (CaBI1). Proline content and sodium and potassium ion content also measured.
Results: The result indicated that genes CaDREBLP1, CaRMa1H1, CaKR1, CaOSM1 were up regulated while CaPROX1, CaPIP2 genes were down regulated under salt stress. But no significant difference was noticed in gene expression level of CaBI1 and CaChi 2 gene.
Conclusion: The higher gene expression level of stress responsive genes viz. CaDREBLP1, CaRMa1H1, CaKR1, CaOSM1 may involved in different level of salt tolerance among selected cultivars. Thus differential transcript modulation of these genes in capsicum cultivars indicates their role lending the salt tolerance in salt tolerant cultivar than sensitive.