Abstract

This review provides a comprehensive overview of the effects of drought on the growth of medic plants; then, it explores some drought tolerance traits including the morpho-physiological and biochemical parameters. In addition, medic plants were compared to other legumes and to cereals. At the molecular level, the response of Medicago plants to drought was also highlighted. Results of several independent experiments showed that the reduction of plant biomass production of medic plants ranged between 12 and 73% under water deficit stress. Cereals are more tolerant to drought than legumes. Yield reduction in cereals ranged between 25 and 40% versus 20 and 80% in legumes. For cereal species, wheat exhibited the lowest (25%) yield reduction as compared to barley and maize (34 and 40%), respectively. In legumes, reductions were about 20, 40, and 60% in lentils, chickpea, and common bean. Medic drought tolerance was found to be associated with traits like the ability to maintain the photosynthetic activity, the optimization of root development, the water use efficiency, the osmoregulation capacity via the decrease of osmotic potential, accumulation of mineral (K⁺) or organic solutes (proline), and the modification of carbohydrate metabolism toward the accumulation of soluble sugars. Water deficit stress induces a lipid and protein metabolism adaptation via the accumulation of some amino acids and the decrease in malondialdehyde concentrations. The target traits suggested in medic for breeding and for genetic engineering are related to water relations, such as relative water content, water use efficiency as well as root development.

摘要

本综述全面概述了干旱对药用植物生长的影响；然后，它探索了一些耐旱性状，包括形态生理和生化参数。此外，将药用植物与其他豆类和谷物进行了比较。在分子水平上，紫花苜蓿的反应还强调了植物抗旱。几个独立实验的结果表明，在缺水胁迫下，药用植物的植物生物量产量减少了 12% 到 73%。谷物比豆类更耐旱。谷物减产幅度为 25% 至 40%，而豆类减产幅度为 20% 至 80%。对于谷物品种，与大麦和玉米（34% 和 40%）相比，小麦的减产幅度最低（25%）。在豆类中，小扁豆、鹰嘴豆和普通豆类减少了约 20%、40% 和 60%。发现 Medic 耐旱性与维持光合活性的能力、优化根系发育、水分利用效率、通过降低渗透势的渗透调节能力、矿物质 (K⁺ ) 或有机溶质（脯氨酸），以及碳水化合物代谢向可溶性糖积累的改变。缺水应激通过一些氨基酸的积累和丙二醛浓度的降低诱导脂质和蛋白质代谢适应。医学育种和基因工程建议的目标性状与水分关系有关，例如相对水分含量、水分利用效率以及根系发育。