ORIGINAL ARTICLE

In Silico Characterization of DREB and AP2/ERF Domain-Containing Transcription Factors in the important Crop Plants and Their Role in Drought Tolerance in Plants

Background, the context and purpose of the study: Climate change is having a significant impact on crop plants around the world. As temperatures rise, some crops are becoming more difficult to grow in certain regions and are being replaced by other crops that are more tolerant of heat and drought. Plants have evolved various mechanisms, including physiological adaptations, structural modifications, and biochemical responses to withstand a wide range of environmental stresses, including drought, heat, salinity, and cold. Complex networks of genes play crucial roles in eliciting stress responses in plants. These genes encode a diverse array of proteins that function in various aspects of stress adaptation, from regulating hormone signalling to protecting cellular components from damage.

Transcription factors act as master regulators of gene expression, controlling which genes are turned on or off in response to specific stimuli. Dehydration responsive element binding protein (DREB) and AP2/ERF domain-containing protein are transcription factors in plants that regulate the expression of stress-responsive genes involved in drought tolerance. The purpose of the present study is in silico characterization of DREB and AP2/ERF domain-containing transcription factors, identification of conserved motifs and phylogenetic analysis to understand the evolutionary relationships of these sequences in the important crop plants – Sorghum bicolor (Sorghum), Zea mays (Maize), Oryza sativa subsp. indica (Rice), Hordeum vulgare (Barley), and Triticum aestivum (Wheat).

Results, the main findings: Transcription factors- F8V180 (Sorghum bicolor), C5XNL0 (Sorghum bicolor), A0A1D6FEN0 (Zea mays), A2WL19 (Oryza sativa subsp. indica), Q4ZGK0 (Hordeum vulgare) , and Q4U0C8 (Triticum aestivum) have a conserved AP2/ ERF domain, all show their subcellular localization in the nucleus and are involved in DNA binding and transcription regulation. There is variation in id position of AP2/ERF domain in the selected transcription factors.

Phylogenetic data indicate that the relative amounts of evolutionary change have occurred since the proteins shared a common ancestor. Data also suggests that these proteins have evolved at different rates, indicating varying degrees of divergence among the proteins.

The grand average of hydropathicity and pI values of DREB - AP2/ERF transcription factors F8V180 (Sorghum bicolor), C5XNL0 (Sorghum bicolor) and A0A1D6FEN0 (Zea mays) indicate that these are more stable and have better binding affinity to their target gene, thereby better transcription regulation.

Conclusions, brief summary and potential implications: There is a need to extensively study stress tolerance mechanisms in plants and to increase the adaptability of plants to various abiotic stresses like heat, drought and salinity.

Study reveal that DREB and AP2/ERF domain-containing transcription factors from Sorghum bicolor (Sorghum), Zea mays (Maize) , Oryza sativa subsp. indica (Rice), Hordeum vulgare (Barley) , and Triticum aestivum (Wheat) share a common ancestor. These proteins have evolved at different rates, indicating varying degrees of divergence among the proteins. Physico-chemical properties of DREB and AP2/ERF domain-containing transcription factors reveal that F8V180 (Sorghum bicolor), C5XNL0 (Sorghum bicolor), A0A1D6FEN0 (Zea mays) are the most stable and with better binding affinity to their target genes thereby better transcriptional regulation.

Overexpression of DREB and AP2/ERF transcription factors in transgenic plants can be a promising strategy for enhancing plant tolerance to abiotic stresses (particularly drought and salinity) and improving crop productivity under challenging environmental conditions.