ROLE OF A GENE ENCODING RNA BINDING PROTEIN CLONED FROM INDIAN MULBERRY (Morus alba L.) IN IMPARTING STRESS TOLERANCE

THARUN, E.

ROLE OF A GENE ENCODING RNA BINDING PROTEIN CLONED FROM INDIAN MULBERRY (Morus alba L.) IN IMPARTING STRESS TOLERANCE

Date

2019-09-13

Authors

THARUN, E.

Publisher

UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU

Abstract

RNA binding proteins (RBPs) associate with the RNAs in the cell to form ribonucleoprotein complexes, to mediate post-transcriptional regulation of gene expression. This RBP-RNA interaction operates at different levels of RNA metabolism, to determine the mRNA stability, protein synthesis and turn over, there by regulating plant growth, development and its response to environmental cues. The present study aims at evaluating the functional relevance of a RBP (MaRRM1-like) previously identified and cloned from Indian mulberry, in imparting abiotic stress tolerance in model system tobacco (Nicotiana tabacum). In-silico expression analysis performed using the Arabidopsis homologue of MaRRM1-like, and the in-vivo analysis in mulberry indicated that the gene was responsive to diverse abiotic stresses. Experiments conducted using transgenic tobacco seeds overexpressing (T1 generation) MaRRM1-like showed that the gene has no effect on developmental processes such as seed germination, growth and development under normal conditions. However, under NaCl induced salt stress, over-expression of MaRRM1-like improved seed germination and seedling growth. The transgenic plants exhibited better phenotype with higher relative water content, leaf thickness, lower leaf temperature, reduced cell membrane damage and osmolality under drought. Transgenic plants showed delayed leaf senescence under PEG induced drought stress as evidenced by the leaf disc assay. The transgenic cell lines exhibited sustained cell division in-vitro under salt stress. Higher heat stable fraction of buffer soluble protein in transgenic lines indicated improvement in protein stability. Overall, the study reiterated the role of a RBP identified from mulberry, MaRRM1-like, in imparting abiotic stress tolerance.