摘要
【目的】研究外源褪黑素对干旱胁迫下辣椒(Capsicum annuum L.)幼苗生长及生理机制,为外源褪黑素在辣椒生产栽培中的应用提供理论依据。【方法】以辣椒幼苗‘CT29’为试验材料,利用不同浓度(0、50、100、150、200和250μmol/L)褪黑素进行7 d的浇灌预处理,研究干旱胁迫后幼苗生长、色素含量、渗透调节物质含量和抗氧化酶活性的变化。【结果】长期干旱胁迫(干旱6 d)会显著抑制辣椒幼苗的生长,然而不同浓度褪黑素处理却降低了辣椒叶片中丙二醛的含量,提高了类胡萝卜素、相对含水量、可溶性蛋白质、可溶性糖、脯氨酸的含量,相比对照组,增长幅度分别为11.62%~59.11%、2.44%~6.28%、5.34%~21.75%、7.61%~46.44%和42.88%~62.26%。此外,100~250μmol/L褪黑素增强了干旱胁迫下辣椒叶片中过氧化氢酶和过氧化物酶的活性,增长幅度分别为7.08%~26.81%和23.65%~39.23%。生理指标的隶属函数分析结果显示150μmol/L和200μmol/L褪黑素处理后的辣椒幼苗总隶属函数值较大,且幼苗具有较好的生长势,150μmol/L和200μmol/L可确定为缓解干旱胁迫的较优褪黑素浓度。干旱胁迫早期150μmol/L和200μmol/L褪黑素对辣椒幼苗生长的影响较小,干旱4 d后外源褪黑素可显著降低叶片中丙二醛含量,提高2种抗氧化酶(过氧化氢酶和过氧化物酶)活性及3种渗透调节物质(可溶性蛋白质、可溶性糖、脯氨酸)含量。【结论】外源褪黑素可诱导植株体内抗氧化酶活性增强及渗透调节物质积累,有效清除丙二醛,从而缓解干旱对辣椒幼苗的生长抑制,增强其抗旱性。这有助于解析褪黑素缓解辣椒干旱胁迫的生理机制,为外源褪黑素在辣椒生产栽培中的应用提供了理论依据。
【Objective】The effects of exogenous melatonin on the growth and physiological characteristics of pepper(Capsicum annuum L.)seedlings under drought stress were studied to provide a theoretical basis for the application of exogenous melatonin in pepper production and cultivation.【Method】Pepper seedling‘CT29’was identified as experimental materials,and was treated with different concentrations(0,50,100,150,200 and 250μmol/L)of melatonin for 7 days.The changes of seedling growth,pigment content,osmoregulation substance content and antioxidant enzyme activity under drought stress were analyzed.【Result】The results showed that long-term drought stress(drought for 6 days)could significantly inhibit the growth of pepper seedlings.However,different concentrations of melatonin treatments reduced the content of malondialdehyde,and the content of carotenoid,relative water content,soluble protein,soluble sugar and proline were increased by 11.62%~59.11%,2.44%~6.28%,5.34%~21.75%,7.61%~46.44%and 42.88%~62.26%,respectively,compared with the control group.In addition,100~250μmol/L melatonin enhanced the activities of catalase and peroxidase in pepper leaves under drought stress,with an increase of 7.08%~26.81%and 23.65%~39.23%,respectively.The results of membership function analysis of physiological indexes showed that the total membership function values of pepper seedlings treated with 150μmol/L and 200μmol/L melatonin were larger,and the seedlings had better growth potential.150μmol/L and 200μmol/L could be determined as the optimal melatonin concentration to alleviate drought stress.Further dynamic analysis showed that 150μmol/L and 200μmol/L melatonin had little effect on the growth of pepper seedlings at the early stage of drought stress.After 4 days of drought,exogenous melatonin could significantly reduce the content of malondialdehyde in leaves,increase the activity of two antioxidant enzymes(catalase and peroxidase)and the content of three osmotic regulators(soluble protein,soluble sugar and proline).【Conclusion】Exogenous melatonin can induce the increase of antioxidant enzyme activity and the accumulation of osmoregulation substances in plants,and effectively remove malondialdehyde,thereby alleviating the growth inhibition of drought on pepper seedlings and enhancing their drought resistance.These are not only beneficial to analyze the physiological mechanism of melatonin in alleviating drought stress in pepper,but also provide a theoretical basis for the application of exogenous melatonin in pepper production and cultivation.
作者
刘微
陈峰清扬
陈晖
刘琰
廖奕
赵慧婷
刘宇华
LIU Wei;CHEN Fengqingyang;CHEN Hui;LIU Yan;LIAO Yi;ZHAO Huiting;LIU Yuhua(College of Medical Technology,Hunan Polytechnic of Environment and Biology,Hengyang 421005,China;College of Life Sciences,Hengyang Normal University,Hengyang 421008,China;Hunan Key Laboratory for Conservation and Utilization of Biological Resources in the Nanyue Mountainous Region,Hengyang Normal University,Hengyang 421008,China)
出处
《湖南生态科学学报》
CAS
2024年第4期1-12,共12页
Journal of Hunan Ecological Science
基金
国家自然科学基金项目(32302528)
湖南省自然科学基金项目(2022JJ40011)
湖南环境生物职业技术学院院长基金项目(QN2023-14)
衡阳师范学院南岳学院大学生创新创业训练计划项目(NYD202315)
衡阳师范学院大学生创新创业训练计划项目(cxcy2022053)。
