外源H_(2)S及JA供体对干旱胁迫下水稻幼苗侧根生长的调节作用

Regulation of Exogenous H_(2)S Donor and JA Donor on the Lateral Root Growth of Rice Seedlings Under Drought Stress

本研究对根长为2 cm的水稻幼苗进行干旱胁迫处理,通过观察不同处理下水稻幼苗的长势、主根根尖的形态及侧根原基的发生,以及检测内源硫化氢(hydrogen sulfide,H_(2)S)含量等,探究干旱胁迫下外源H_(2)S供体和外源茉莉酸(jasmonic acid,JA)供体对水稻幼苗侧根生长的影响。结果表明,一定浓度范围的外源H_(2)S供体或外源JA供体均能促进干旱胁迫下水稻幼苗主根的伸长和侧根原基的发生及增加侧根的数量。可见,外源H_(2)S供体和外源JA供体具有相似的作用效应,且外源H_(2)S供体和外源JA供体的较适作用浓度分别为0.05 mmol/L和0.25μmol/L。此外,外源JA供体可以提高干旱胁迫下水稻幼苗根尖内源H_(2)S的含量。据此推测,外源JA供体可能通过促进内源H_(2)S的产生,从而缓解干旱胁迫对水稻幼苗侧根的抑制作用。

In this study,the rice seedlings with root length of 2 cm were subjected to drought treatment.To explore the regulatory mechanism of exogenous hydrogen sulfide(H_(2)S) donor and jasmonic acid(JA)donor on the growth of lateral roots in rice seedlings under drought stress,the growth vigor of rice seedlings,the tip morphology of primary root and the occurrence of lateral root primordia,the contents of endogenous H_(2)S were observed.The results showed that treatments with exogenous H_(2)S donor or exogenous JA donor within a certain concentration range promoted the elongation of the radicle and the occurrence of lateral root primordia of rice seedlings under drought stress,and increased the number of lateral roots.Obviously,exogenous H_(2)S donor and JA donor had similar effects,and the optimal concentrations of the two kinds of donors were 0.05 mmol/L and 0.25μmol/L,respectively In addition,exogenous JA donor could increase the endogenous H_(2)S content in the root tips of rice seedlings under drought stress.Therefore,exogenous JA donor may alleviate the inhibition of drought stress on the lateral roots of rice seedlings by promoting the production of endogenous H_(2)S.