Expression pattern of drought-responsive genes in burley tobacco under in vitro water deficit

Abstract

Understanding molecular mechanism in tobacco adaptation to drought stress become indispensable strategy for the development of high-yield tolerant varieties. Profiling the pattern of drought-related gene expression is a promising strategy to preliminary evaluates the plant response to drought stress. This study aims to investigate the expression pattern of drought-responsive genes in burley tobacco under in vitro water deficit. In this study, we used three burley varieties including Marakot, Jepon Mawar and MKY. Drought stress treatment was applied in vitro using MS medium supplemented with several concentration of PEG 6000 (Polyethylen Glycol) (0%, 10%, 20% and 30%). The expression profile of drought-related genes including NtLTP1, NtABA2 and NtERD10B were investigated using quantitative Reverse Transcriptase-PCR (qRT-PCR). The results showed that NtABA2 and NtERD10B genes were parallely overexpressed following an increase concentrations of PEG in var. Jepon Mawar and var. MKY. However, the highest mRNA relative expression of these genes was occured in var. MKY treated with 30% of PEG, which increased 1,7 and 1,64-fold compared to control, respectively. NtLTP1 was down-regulated in var. Jepon Mawar following an increase of PEG concentrations. In contrast, NtLTP1 was up-regulated in var. MKY. Meanwhile, var. Marakot demonstrated similar pattern of all gene expressions, where treatment of 20% PEG induced highest expression compared to the other treatments. The overall result suggests that var. MKY is likely more tolerant to drought stress followed by var. Jepon Mawar and var. Marakot, respectively.