Functional genomics approach to understand heat stress response in Arabidopsis thaliana
Student name: Ms Sanchi Bhimrajka
Guide: Dr Anandita Singh
Year of completion: 2017
Host Organisation: Delhi University, New Delhi
Supervisor (Host Organisation): Prof. Anil Grover
Abstract: Due to the inevitable problem of global warming, heat stress is among the chief
challenges that constricts crop productivity worldwide. Heat stress can interrupt
cellular homeostasis through aggregation of native cellular proteins which
further head towards lethality. Heat shock proteins (Hsps) constitute a group of
molecular chaperones that are necessary for survival under such high
temperature conditions. They can maintain the required equilibrium for
homeostasis by facilitating protein refolding, preventing protein aggregation and
degradation of aggregated proteins. There are six families of Hsps (i.e. Hsp100,
Hsp90, Hsp70, Hsp60 and sHsps) defined on the basis of their molecular weight;
each of which has a distinct structure and function. Several Hsps have been
already proven to play significant roles in acquired thermotolerance. Acquisition
of thermotolerance is an important aspect that needs extensive research to
understand its molecular biology which would ultimately help to make heat
tolerant plants. Few members of Hsps are also known to be constitutively
expressed and are developmentally regulated. Such members may or may not
perform protective functions under heat stress conditions. In this study,
importance of two specific Hsps (called SAP and SIP) for survival under various
heat stress conditions was established at different developmental stages. Once, it
was ascertained that SAP is up-regulated during heat stress and is necessary for
acquisition of thermotolerance; phenotype of SAP knockout mutant was studied
under few other abiotic stress conditions. SIP was found to be an Hsp which is
constitutively expressed without any up-regulation under heat stress. To
ascertain the functions of SIP, sub-cellular localisation of SIP through
agrobacterium-mediated infilteration in Nicotiana leaves was performed.
Key words: Heat stress, Arabidopsis, heat shock proteins, basal
thermotolerance, acquired thermotolerance, molecular chaperones, sub-cellular
localisation, phenotypic analysis
