Protein-Protein Interactions of Transcription Factors from the Drought QTL-Hotspot Linked to Stress Tolerance in Chickpea

Drought is the most prominent abiotic stress that affects the productivity of chickpea.  The signalling networks in response to drought comprise several major components that include transcription factors (TFs). Drought related QTL analysis identified a genomic region (QTL-hotspot) in the chickpea biparental population (ICC4958 × ICC 1882) that comprise several genes. Gene enrichment and expression analyses identified 13 genes which constitute 3 TF as follows: a dehydration responsive element binding protein (DREB7), ethylene responsive factor like (ERF 110-like) and a transcription initiation factor like (TFID like).  qRT-PCR data showed 2 to 6 fold differences between the contrasting drought responsive chickpea genotypes for these TFs.  To further understand their roles and the ability to interact with other components in the stress signalling pathways, predictive protein-protein interaction analysis was performed with STRING 9.1 using A. thaliana as a reference model.  Using query sequences with similarity to these TFs, several potential interactors were identified and the ones with the highest confident scores were selected.  DREB7 possibly interacts with Ice 1 (Inducer of CBF Expression1) and ABF2 (Abscisic acid responsive elements-binding factor 2).   TFID like showed predictive interaction with other transcription factors such as TAFs (TBP-Associated factors) and EER4 (Enhanced ethylene response) while ERF 110-like showed predictive interactions with an LTP (Lipid transfer protein) and an amino acid transporter protein. Yeast two hybrid screening has been initiated to validate protein interactions of these TFs.  This study will enhance the understanding of drought tolerance mechanism in chickpea.