褪黑素对水稻幼芽镍胁迫的缓解作用  

Alleviation Effects of Exogenous Melatonin on Ni Toxicity in Rice Seedings

作　　者：刘仕翔[1,2] 黄益宗[1] 罗泽娇[2] 黄永春[1] 蒋航[1] 

机构地区：[1]农业部环境保护科研监测所,天津300191 [2]中国地质大学(武汉)环境学院,武汉430074

出　　处：《环境科学》2017年第4期1675-1682,共8页Environmental Science

基　　金：国家科技支撑计划项目(2015BAD05B02)

摘　　要：研究添加外源褪黑素对水稻幼芽Ni胁迫的缓解作用.结果表明,较低浓度Ni(10μmol·L^(-1)、50μmol·L^(-1))胁迫对水稻幼芽根系生长影响不大,而较高浓度Ni(100~1 000μmol·L^(-1))胁迫显著地抑制水稻根系的生长.与CK处理相比,100~1 000μmol·L^(-1)Ni胁迫导致水稻总根长降低63.3%~98.0%,根表面积降低56.9%~96.3%.褪黑素的添加能明显地促进Ni胁迫下水稻幼芽的生长,尤其是对幼芽的根系生长促进作用更明显.当Ni胁迫浓度为100μmol·L^(-1)时,两个水稻品种总根长相较于无Ni胁迫的对照组降低了58.4%~83.8%,在添加10μmol·L^(-1)褪黑素处理后,水稻总根长相较于无Ni胁迫的对照组仅降低了8.7%~29.1%.添加外源褪黑素导致Ni胁迫下水稻幼芽的O_2^(-·)产生速率和相对电导率显著降低,CAT活性和可溶性蛋白含量显著提高.与100μmol·L^(-1)Ni胁迫处理相比,添加10μmol·L^(-1)褪黑素能显著地降低两种水稻品种O_2^(-·)产生速率43.2%~50.2%、相对电导率25.7%~31.6%,提高CAT活性21.9%~33.7%、可溶性蛋白含量82.6%~84.6%.褪黑素可以有效地缓解Ni胁迫对水稻幼芽的毒害作用.The alleviation effect of exogenous melatonin（MT） on Ni toxicity in rice seedings was investigated.The results showed that low concentration of Ni stress（10,50 μmol·L^-1） had little effect on the growth of root of rice seedings,while higher concentration of Ni stress（100^-1 000 μmol·L^-1） significantly inhibited the growth of rice root.Compared with the control treatment,the addition of100 and 1 000 μmol·L^-1Ni would decrease the total length and surface area of root by 63.3%-98.0% and 56.9%-96.3%,respectively.The results showed that addition of exogenous melatonin had a positive effect on the growth of rice seedings under Ni stress.This kind of positive effect was even more obvious in the root of rice seedings.The total length of rice root decreased by 58.4%-83.8% at Ni concentration of 100 μmol·L^-1,whereas it decreased by only 8.7%-29.1% when 100 μmol·L^-1Ni and 10 μmol·L^-1MT were added,compared with the control treatment.The addition of exogenous melatonin had significant alleviation effects on oxidative stress in rice seedings caused by Ni.Compared with the 100 μmol·L^-1Ni treatment,addition of 10 μmol·L^-1exogenous MT could significantly decrease the production rate of O_2^（-·） by 43.2%-50.2% and the relative electrolytic leakage by 25.7%-31.6%,whereas increase the activities of CAT by 21.9%-33.7% and the soluble protein content by 82.6%-84.6%.The results suggested that application of exogenous melatonin could effectively alleviate the toxic effects of Ni on rice seedings.

关 键 词：水稻 镍 褪黑素 抗氧化系统 毒害 

分 类 号：X171[环境科学与工程—环境科学]