TITLE:
A Comparative Study of ESTs Induced under Drought and Salinity Stress in Hyacinth Bean (Lablab purpureus)
AUTHORS:
S. Kokila, Varadahally R. Devaraj
KEYWORDS:
Hyacinth Bean, Drought, Salinity, DDRT-PCR, ESTs
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.12 No.5,
May
28,
2021
ABSTRACT: Abiotic stressors like
drought and salinity are major causes for loss of agricultural productivity. Comparison
of expressed sesquence tags (ESTs) under different abiotic stresses
provides insight into underlying mechanism of stress response, and candidate
genes to improve tolerance to abiotic and biotic stresses via breading and
transgenic methods. In order to identify and compare stress-specific ESTs from
drought and salinity stressed Hyacinth Bean, ten days old seedlings were
subjected to respective stresses and RNA was extracted from control and
stressed leaves for EST identification. 31 and 12 ESTs, respectively, were
characterized from leaves of drought and salinity stressed seedlings of
Hyacinth Bean, Lablab purpureus by differential display RT-PCR using
identical combinations of 48 primers and validated using quantitative RT-PCR.
Relative fold expression was higher under salt stress than drought stress.
Whereas 19 EST overexpressed under drought, 12 EST were down regulated. Of the
12 EST under salinity, 9 EST were downregulated and 3 EST upregulated. Putative
functions predicted from sequence homology indicated that 11 drought specific
EST corresponded to metabolic functions, and 4 of them corresponded to
transcription regulation. Under salinity, 4 and 2 EST, respectively,
corresponded to metabolic and RNA associated functions. Under both stresses,
there were ESTs associated with unknown functions, whose characterization may
throw light on the regulatory mechanism. Differing number of ESTs
differentially expressed under drought and salt stress, and their predicted
functionalities, suggested distinct set of response genes involved under these
two stresses, despite a good number of physiological players being common. From
the predicted functions of ESTs, the paper attempts to explain the possible
mechanism of response of Hyacinth Bean to these two stresses.