Plant Tissue Cult. & Biotech. 33(2): 115-133, 2023 (December)

General

Transformation of SNAC1 under Stress Inducible Promoter rd29A Confers High Yield and Stress Tolerance in Rice

Rumana S. Tammi¹, Sudip Biswas, Sabrina M. Elias2 and Zeba I. Seraj^*

Plant Biotechnology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka-1000, Bangladesh

Key words: High yielding rice variety, in planta transformation, Transcription factor SNAC1, stress inducible promoter rd29A.

Abastract

Abiotic stress tolerance in plants is often induced by activation of transcription factors. An increased stress tolerance was observed in indica rice cultivar BRRI dhan55 after transforming with the transcription factor SNAC1 (stress responsive NAC1) under stress inducible promoter rd29A that minimized unexpected phenotype and metabolic burden in transgenic lines. The lines were produced by tissue culture independent Agrobacterium-mediated in planta transformation. Molecular analyses confirmed the successful integration of the SNAC1 gene and significantly higher gene expression level in the transgenic lines. The transgenic lines showed 3:1 segregation ratio at T2 generation following the Mendelian law of inheritance. Assays for leaf disk senescence and chlorophyll content at 100 mM and 200 mM salt and survival rates at 200 mM salt and drought conditions at 12 days of water withdrawal and recovery showed significantly increased stress tolerance in the transgenic lines at seedling stage compared to the wild type. Enhanced yield, spikelet fertility, and 1000-grain weight were observed at the reproductive stage compared to wild type under both salinity and drought stress conditions. Thus, SNAC1 expression in plants under inducible promoter is a beĴer choice to enhance stress tolerance and yield under salinity and drought conditions.

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