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Title: Over‐expression of OsASR confers drought tolerance in rice

Dipali Srivastava

CSIR- National Botanical Research Institute, India

Biography

Dipali Srivastava is a Senior research fellow in Genetics and Molecular Biology Division, working under the supervision of Dr. Debasis Chakrabarty (Sr. Scientist) at CSIR-National Botanical Research Institute, India. She had her M.Sc. degree (Biotechnology) from Department of Biotechnology, CSJM University of Kanpur, India. She also qualified CSIR NET-Lectureship in the year 2015. She possesses excellent knowledge and technical experience in the area of Plant molecular biology. With her sound knowledge of scientific writing she earned two international publications. Presently her work is to improve the adaptability of the crop to drought conditions, by developing transgenic rice, which shall be able to cope with drought conditions before grain filling in rice.

Abstract

Rice (Oryza sativa L.), a staple food for more than half of the global population; being as a paddy crop is particularly susceptible to water stress which reduces its yield drastically. Thus, developing strategies which would help in developing rice variety that can grow even in water deficit condition can be beneficial for increasing crop yield as well as increasing probability of agriculture in drought-prone areas. Abscisic acid stress-ripening proteins (ASR) are a family of plant-specific small hydrophilic proteins encoded by an abiotic stress-regulated gene. The expression of OsASR is strongly induced under the application of drought, salt and abscisic acid (ABA). To provide evidence on the biological role of OsASR proteins against drought, we generated transgenic lines of rice overexpressing OsASR. The extent of tolerance to drought stress of these plants correlated well with the level of OsASR expression. Various biochemical and physiological analyses like malondialdehyde content, proline, ROS scavenging enzymes, electrolyte leakage and histochemical analyses for H2O2  and O22- radical showed differential activities during drought tolerance in T3 generation of transgenic lines as compared to wild-type (Wt) plants. In addition, transcriptome analysis revealed that OsASR regulates the expression of a wide spectrum of stress-related genes in response to abiotic stresses through an ABA-dependent regulation pathway. In addition, few genes that are possible OsASR specific target genes were identified based on the comparison of the expression profiles in the transgenic line and the Wt plant and validated through qRT-PCR analysis. These results demonstrate, OsASR to be a positive regulator commonly involved in the tolerance to drought stress in rice and its simple manipulation has great potential with regard to plant improvement.