硫化氢调控酚类化合物代谢缓解番茄盐胁迫的作用机制

Mechanism of hydrogen sulfide regulating metabolism of phenolic compounds to alleviate salt stress in tomato

盐胁迫是限制作物产量形成的重要环境障碍因子之一。本试验以番茄为供试材料,探究了外源不同浓度(50、100、200和500μmol L^(-1))的硫化氢(H_(2)S)供体硫氢化钠(NaHS)对盐胁迫下番茄生长和生理特性的影响,同时对酚类化合物代谢及其与耐盐性的关系进行了探究。结果表明,适宜浓度的H_(2)S处理显著提高盐胁迫下番茄株高、茎粗、地上部鲜重和干重、根鲜重和根长,以及叶绿素和类胡萝卜素含量,有效缓解盐胁迫对番茄生长的抑制。外源H_(2)S显著降低盐胁迫下番茄活性氧(ROS)的积累和丙二醛(MDA)含量,这与其较高的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性以及可溶性蛋白、可溶性糖和脯氨酸等渗透调节物质积累密切相关。此外,外源H_(2)S可显著提高盐胁迫下番茄总酚、类黄酮和花色素苷含量及其抗氧化活性,而外源多酚合成抑制剂AIP处理则显著降低酚类化合物的积累,同时显著降低H_(2)S对盐胁迫下番茄氧化损伤的缓解作用。本研究阐明了H_(2)S提高番茄耐盐胁迫作用机制,证实了H_(2)S诱导酚类化合物积累在番茄耐盐胁迫中的作用机制,为番茄耐盐品种的选育和遗传改良提供了新思路。

Salt stress is one of the important environmental barriers,which limits crop yield formation.The tomato was used as the experimental material,and the effects of different concentrations(50,100,200 and 500μmol·L^(-1))of exogenous hydrogen sulfide(H_(2)S)donor sodium bisulfide(NaHS)on the growth and physiological characteristics of tomato under salt stress were investigated.As well as the metabolism of phenolic compounds and its relationship with salt tolerance were investigated.The results showed that the appropriate concentration of H_(2)S treatment significantly increased the plant height,stem diameter,aboveground fresh and dry weight,root fresh weight and root length,as well as chlorophyll and carotenoid contents of tomato under salt stress,which significantly alleviating the inhibition of tomato growth by salt stress.Exogenous H_(2)S significantly reduced the accumulation of reactive oxygen species(ROS)and malondialdehyde(MDA)content in tomato under salt stress,which was closely related to higher activities of SOD,POD,CAT,APX,and the accumulation of osmoregulatory substances such as soluble protein,soluble sugar and proline.In addition,exogenous H_(2)S significantly increased the content of total phenols,flavonoids,anthocyanidins and antioxidant activities;however,exogenous polyphenol synthesis inhibitor AIP treatment significantly decreased the accumulation of phenolic compounds and significantly reduced the alleviating effect of H_(2)S on oxidative damage in tomato under salt stress.This study elucidated the mechanism of H_(2)S to enhance the effect of salt stress tolerance in tomato and confirmed the role of H_(2)S-induced phenolic compound accumulation of salt stress tolerance in tomato,which provide new ideas for the selection and genetic improvement of salt-tolerant tomato varieties.