2,4-表油菜素内酯对低温胁迫下辣椒幼苗根系生长及抗氧化酶系统的影响

Effects of 2,4- epibrassinolide on Growth and Antioxidant Enzymes System in Pepper Roots Under Chilling Stress

为探讨外源2,4-表油菜素内酯(2,4-epibrassinolide,EBR)对低温胁迫下辣椒(Capsicum annuum L.)幼苗根系的生长和根系抗氧化系统的影响,本试验采用叶面喷施外源EBR(0、10.0、1.0、0.1、0.01、0.001μmol·L-1)的方法,比较分析了低温胁迫下幼苗根系形态、根系抗氧化酶活性、过氧化物质含量等生理指标。结果表明,低温抑制了辣椒幼苗根系的生长,低温胁迫下喷施EBR,辣椒幼苗根系的生长受抑制程度减轻,其根系总长、根表面积、分根数较单纯低温处理显著增加;低温胁迫下喷施0.1μmol·L-1EBR辣椒幼苗根系SOD、POD、CAT活性显著提高,MDA含量降低。外源EBR处理可调节辣椒根系形态和提高根系抗氧化酶活性,增强植株抗低温胁迫的能力,并且EBR的浓度以0.1μmol·L-1最佳。说明在低温胁迫下适宜浓度的EBR可缓解辣椒幼苗的根系生长,这对阐明EBR缓解辣椒幼苗低温胁迫的作用机制提供了理论依据。

The present study was carried out to investigate the growth, roots morphology and activities of antioxidant enzymes effects of exogenously 2,4 - epibrassinolide （EBR） on in pepper （Capsicum annuum L. ） seedling roots under chilling stress. Different levels of EBR （0, 10, 1, 0. 1,0. 01 and 0. 001 μmol·L^-1） were applied to the seedlings by stress inhibited the root growth of pepper seedlings, whereas EBR could alleviate the inhibitory effect of chilling stress via regulating the total root length, root surface area and number of root forts in seedling roots. Compared with alone chilling stress, foliar sprayed 0. 1 p, μmol·L^-1 EBR significantly increased SOD, POD and CAT activities, and decreased MDA content of pepper roots under chilling stress. Likewise, oxidative damage on seedling roots by chilling stress can be significantly alleviated and the tolerance of plants can be elevated when applied EBR by foliar spray. Our results suggest that the 0. 1 μmol·L^-1 EBR is considered the optimum concentration, and a protective role of EBR against chilling stress by enhancing plant tolerance. It provides theoretical basis to clarify the effects of EBR regulating growth on pepper seedlings.