ABI3 mediates dehydration stress recovery response in Arabidopsis thaliana by regulating expression of downstream genes

Transcription factor ABI3 auto‐activates its own expression during dehydration stress response

“…For this, ChIP‐qPCR was performed using anti‐ABI3 antibody. As we have shown previously, ABI3 recruitment to the TGTCTC element was observed during conditions of dehydration stress and recovery ; however, relative to the TGTCTC site, ABI3 occupancy at the upstream region bearing CATGCA element was found to be several folds higher during dehydration stress as well as stress recovery. Interestingly, no significant ABI3 occupancy was detected at the CATGCA element situated downstream to TSS (Fig.…”

“…Regulated exposure of the cis ‐elements at ABI3 promoter region was further complemented by the fact that ABI3 occupies its own upstream regulatory sequences during transcription activation. Interestingly, the pattern of ABI3 occupancy observed at either CATGCA or TGTCTC element was found to be similar to the expression pattern of ABI3 during dehydration stress and recovery observed earlier . Significantly higher ABI3 occupancy observed at the CATGCA element compared to TGTCTC was striking, especially during stress recovery (Fig.…”

“…The positive correlation between H3 K4me3 modification and levels of transcripts has been established in systems ranging from yeast to Arabidopsis and human cells . We too observed such correlation and found that similar to the pattern of ABI3 expression , H3 K4me3 modifications at the promoter and TSS regions of ABI3 locus increased during stress and further during stress recovery. This correlation thus clearly establishes the fact that ABI3 promoter activation involves H3 K4me3 modifications.…”

“…We observed that H3 K9ac marks at the ABI3 locus were found to be distinctly enriched at the TSS and towards the 5′ coding regions, under conditions of active transcription. Additionally, H3 K9 acetylation level could be correlated with ABI3 gene expression level which increases during dehydration stress and further during stress recovery . It is thus evident that H3 K9ac is a histone modification mark which is essentially associated with ABI3 gene expression.…”

“…A. thaliana plants were stress treated as described earlier in Bedi et al . . Three‐ to four‐week‐old plants were transferred to empty Petri plates from MS agar plates and dehydrated for 2 h at room temperature (~22 to 25°C).…”