外源茉莉酸甲酯对PEG等干旱胁迫下四季豆幼苗的生理影响

Effect of Exogenous Methyl Jasmine on Physiology of Kidney Bean Seedlings under Drought Stress

摘要: 干旱是最常见的影响农作物产量的重要因素之一，在干旱胁迫下，茉莉酸甲酯参与了植物的生长调控和免疫应答过程。本研究旨在探讨干旱胁迫下茉莉酸甲酯对四季豆(Phaseolus vulgaris L.)幼苗生理的影响。研究结果表明，在受到干旱胁迫时，随着胁迫程度的增加，四季豆幼苗叶片叶绿素含量逐渐下降，细胞内电解质外渗增加，膜质过氧化严重，丙二醛含量逐渐增加，同时植物体内脯氨酸、可溶性蛋白和可溶性糖等渗透调节物质的含量以及抗氧化酶类如超氧化歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性增加。在一定干旱胁迫浓度下，经外源茉莉酸甲酯处理的四季豆幼苗的叶绿素含量增加，同时如脯氨酸、可溶性蛋白和可溶性糖渗透调节物质的含量也会增加，而且抗氧化物酶系统包括SOD、POD和CAT活性呈先增后降的趋势。以上结果说明外源茉莉酸甲酯可以通过增加叶绿素含量、渗透调节物质及增加抗氧化物酶体系活性来缓解干旱胁迫对四季豆幼苗的伤害，从而提高四季豆幼苗抗干旱的能力。

Abstract: Drought stress is one of the most important factors that affect crop yield. Under drought stress, methyl jasmine (MeJA) is involved in the process of plant growth regulation and immune response. In this study, the physiological effects of methyl jasmine on kidney bean (Phaseolus vulgaris L.) seedlings under drought stress were investigated. The results showed that with the increase of PEG stress degree, the chlorophyll content in leaves of kidney bean seedlings gradually decreased; the electrolyte leakage went up and membrane peroxidation were very serious as well as the malondialdehyde content gradually increased . At the same time, the content of osmotic regulatory substances such as proline, soluble protein, and soluble sugar in plants and the activity of antioxidant enzymes (such as SOD, POD, and CAT) increased. But at the same PEG stress concentration, The chlorophyll content of kidney bean seedlings affected by exogenous MeJA increased, while the content of proline, soluble protein and soluble sugar osmotic regulators also increased, and the activity of antioxidant enzyme systems including SOD, POD and CAT showed a trend of increasing first and decreasing later. The results above indicated that exogenous MeJA can enhance the osmotic regulator content and antioxidant enzymes activity in leaves of kidney bean seedlings to alleviate the injury of drought stress on the seedlings of kidney bean, and so it can improve the resistant ability of kidney bean seedlings against drought stress.