Department of Botany, Yogi Vemana University, Kadapa, Andhra Pradesh, 516005, India.
Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore, Karnataka, 560005, India.
Planta. 2024 Jun 16;260(1):29. doi: 10.1007/s00425-024-04427-w.
The review discusses growth and drought-response mechanisms in minor millets under three themes: drought escape, drought avoidance and drought tolerance. Drought is one of the most prominent abiotic stresses impacting plant growth, performance, and productivity. In the context of climate change, the prevalence and severity of drought is expected to increase in many agricultural regions worldwide. Millets (coarse grains) are a group of small-seeded grasses cultivated in arid and semi-arid regions throughout the world and are an important source of food and feed for humans and livestock. Although minor millets, i.e., foxtail millet, finger millet, proso millet, barnyard millet, kodo millet and little millet are generally hardier and more drought-resistant than cereals and major millets (sorghum and pearl millet), understanding their responses, processes and strategies in response to drought is more limited. Here, we review drought resistance strategies in minor millets under three themes: drought escape (e.g., short crop cycle, short vegetative period, developmental plasticity and remobilization of assimilates), drought avoidance (e.g., root traits for better water absorption and leaf traits to control water loss), and drought tolerance (e.g., osmotic adjustment, maintenance of photosynthetic ability and antioxidant potential). Data from 'omics' studies are summarized to provide an overview of the molecular mechanisms important in drought tolerance. In addition, the final section highlights knowledge gaps and challenges to improving minor millets. This review is intended to enhance major cereals and millet per se in light of climate-related increases in aridity.
干旱逃避、干旱避免和干旱耐受。干旱是影响植物生长、性能和生产力的最主要非生物胁迫因素之一。在气候变化的背景下，预计世界上许多农业地区的干旱发生频率和严重程度将会增加。小米（粗粮）是一类在世界各地干旱和半干旱地区种植的小种子禾本科植物，是人类和牲畜的重要食物和饲料来源。虽然小粒谷物，如谷子、高粱、黍、御谷、薏苡和画眉草，通常比谷物和主要谷物（高粱和珍珠粟）更耐寒和耐旱，但对其响应、过程和策略的了解更为有限。在这里，我们综述了小粒谷物在三个主题下的抗旱策略：干旱逃避（例如，短生育期、短营养生长期、发育可塑性和同化产物的再利用）、干旱避免（例如，更好吸水的根系特性和控制水分损失的叶片特性）和干旱耐受（例如，渗透调节、维持光合作用能力和抗氧化潜力）。本文总结了‘组学’研究的数据，提供了干旱耐受相关的重要分子机制的概述。此外，最后一节还强调了提高小粒谷物的知识空白和挑战。本综述旨在增强主要谷物和小米本身在干旱相关增加方面的适应能力。
