Abstract:

Proteinase inhibitors in plants are mainly involved in conferring resistance against herbivores and pathogens. However, their role in abiotic stress resistance has also been reported. Therefore, transgenic tobacco plants were generated constitutively expressing the tomato proteinase inhibitor-II (PI-II) under control of the rice root germin-like protein 2 (OsRGLP2) promoter using Agrobacterium tumefaciens. T1 transgenic seedlings were subjected to stress treatments with different concentrations of sodium chloride (NaCl) (100 mM, 200 mM, 300 mM). Quantitative real-time PCR revealed considerable levels of expression and upregulation of PI-II in transgenic lines under salt stress. Considering the phenotypic effects, the transgenic seedlings showed better growth, higher chlorophyll content, higher proline contents, and higher average fresh weight when compared to the wild type. This comparative analysis of transgenic and wild-type seedlings allows us to suggest that PI-II gene activity can be upregulated via the OsRGLP2 promoter under osmotic stress conditions.

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