Understanding the natural variation in heat stress response in Pigeonpea
and crop wild relatives through time-series transcriptome analysis
As the temperatures are projected to increase across the world due to
global warming, heat stress (HS) is a major concern for all crop plants.
We report here, a time-series transcriptome analysis of one Pigeonpea
cultivar (Cajanus cajan) and two Crop Wild Relatives (CWRs),
Cajanus acutifolius and Cajanus scarabaeoides under heat
stress (HS) at 42±2ºC. A total of 9521, 12447, 5282 transcripts were
identified to be differentially expressed in C. cajan, C.
acutifolius and C. scarabaeoides respectively. In this study, we
also examined alternative splicing (AS) during HS and revealed that a
significant number of DEGs undergo AS in a species-specific pattern.
Both transcriptome and qRT-PCR analysis showed that the HS caused the
down-regulation of photosynthetically important genes such as Curvature
Thylakoid protein, RuBisCO small chain, and NDH complex subunit; fatty
acid modulating genes and up-regulation of defense mechanisms such as
expression of HSPs and anti-oxidant enzymes in all Cajanus species. The
results of histochemical assay showed higher lipid peroxidation in
C. acutifolius inferring the presence of high quantity of PUFA in
the plasma membrane which might have led to severe damage of
membrane-bound organelles like chloroplast during HS, coupled by high
electrolyte leakage during HS.