Climate change and future agriculture: gene discovery for engineering heat stress tolerance in plants
Student name: Ms Pratyasha Barooah
Guide: Dr Anandita Singh
Year of completion: 2018
Host Organisation: Plant Molecular Biology Department, Delhi University
Supervisor (Host Organisation): Prof. Anil Grover
Abstract: Crop productivity being one of the victims of global climate change, needs immediate attention,
to provide security to the world at large. Plants are constantly exposed to various combinations
of stresses. This subjects the members of a species in diverse geographical locations, to different
selection pressures, which lead to inter-specific diversity in order to adapt to such stresses.
Analysis of natural variation confers a remarkable platform to comprehend the correlation
between gene expression and inter-specific phenotypic diversity. However much still needs to be
explored on the role of stress associated genes (sag) in this aspect. Herein, we explored the
importance of a sag in developing thermo tolerance in both natural as well as transgenic lines of
Arabidopsis. Thermo tolerance of 10 accessions of Arabidopsis, isolated from diverse
geographical locations, in various heat stress regimes were analyzed. Phenotypic and molecular
analysis revealed accession F to be highly sensitive, indicating the significance of the sag.
Quantitative complementation of sag (isolated from a rice variety (Pusabasamati)) into its
mutant in Arabidopsis, downstream a 35S CaMV promoter, showed no drastic changes in the
susceptibility of transgenic lines to heat stress. However, western blot analysis showed a band
shift in two of these lines. This can be attributed to the complemented gene being co-suppressed
or the protein formed being truncated. Exposing the accessions to salt and drought stress
depicted them to be sensitive to these abiotic stresses as well. Moreover, observation of two
bands in PCR analysis of differently stressed tissues of Columbia-0 accession built the
probability of the existence of sag splice variants, the confirmation of which is still under
process. Further analysis on it can aid to unfold the role of splice variants in developing thermo
tolerance in plants.
Keywords: Heat stress, food security, susceptibility, tolerance, Arabidopsis accessions, overexpression,
splice variants.
