NAC VS: ABIOTIC STRESSES, CURRENT UNDERSTANDING AND PERSPECTIVE, WITH SPECIAL REFERENCE TO THE CROPS OF POACEAE FAMILY

Abiotic stresses are one of the major challenges for crop growth and productivity, and climate change has the potential to further worsen the scenario. The identification and characterization of unique genes, and the understanding their molecular mechanisms, are critical for the development of abiotic-stress-resistant crops with improved yield. NAC is one of the largest families of transcription factors (TFs) unique to plants and is a key player in the defense against harsh environmental conditions. NAC TFs also play a crucial role in the physiological processes of plants, including the formation of secondary walls and roots, leaf senescence, phytohormone homeostasis, the formation of embryos, and flowers. The Poaceae family encompasses many primary sources of food, including rice, wheat, maize, and barley. Being a model plant several NAC TFs characterized from rice, however, a large number remain unidentified or functionally analyzed yet. Far fewer NAC TFs have been identified in other crops than in rice. The exploration and in-depth analyses on NAC TFs from crops will help to identify novel NAC members, which can be used to induce tolerance in crops. In this review, we have summarized the functionally analyzed NAC TFs specific to rice, wheat, maize, and barley. Through this review, we demonstrate that NAC TFs have a crucial role in abiotic stress tolerance mechanisms. We believe further investigation and in-depth studies on NAC TFs are necessary to engineer stress tolerance in crops and provide food security to a growing population.