外源Ca^(2+)对模拟酸雨胁迫下不同抗性水稻根系氮吸收的影响  

Exogenous Ca^(2+) application regulates nitrogen uptake in roots of different resistant rice varieties under simulated acid rain stress

作　　者：张元棋 梁婵娟[1,2] ZHANG Yuanqi;LIANG Chanjuan(Jiangsu Province Key Laboratory of Anaerobic Biological Technology,School of Environmental and Civil Engineering,Jiangnan University,Wuxi 214122,China;Jiangsu Water Treatment Technology and Materials Collaborative Innovation Center,Suzhou University of Science and Technology,Suzhou 215009,China)

机构地区：[1]江苏省厌氧生物技术重点实验室,江南大学环境与土木工程学院,江苏无锡214122 [2]江苏水处理技术与材料协同创新中心,苏州科技大学,江苏苏州215009

出　　处：《农业环境科学学报》2022年第11期2468-2477,共10页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(31971407,31370517);江苏省自然科学基金项目(BK20161131);江苏省研究生研究与实践创新项目(KYCX20_1952)。

摘　　要：为减轻酸雨对植物生长的不利影响,探究Ca^(2+)对植物耐酸性的调控机制,本文以五优308(抗性种)和南粳9108(敏感种)两个品种水稻为研究对象,研究外源Ca^(2+)对低强度酸雨(pH 4.5,SAR1)和高强度酸雨(pH 3.0,SAR2)胁迫下水稻幼苗根系生长、氮(NO_(3)^(-)和NH_(4)^(+))含量及吸收速率、ATP含量、质膜H_(+)-ATPase活性及其磷酸化水平的影响。结果表明:SAR1处理下两个品种水稻的H_(+)-ATPase磷酸化水平和活性增加(P<0.05),促进ATP分解,增加供能,使NH_(4)^(+)吸收增加(P<0.05),但NH_(4)^(+)仅在南粳9108根中过量积累(P<0.05),引起铵毒,造成根系生长抑制,五优308中NO_(3)^(-)和NH_(4)^(+)含量及其生长均未受影响(P>0.05)。SAR2处理下,两个品种水稻质膜H_(+)-ATPase活性和NO_(3)^(-)、NH_(4)^(+)吸收速率及含量均降低,根系生长受到抑制(P<0.05),其中南粳9108降幅大于五优308。Ca^(2+)+SAR1处理组两个品种水稻根系质膜H_(+)-ATPase磷酸化水平和活性、NO_(3)^(-)和NH_(4)^(+)吸收和积累以及根系生长均与对照(叶喷去离子水处理)差异不显著(P>0.05)。Ca^(2+)+SAR2处理下H_(+)-ATPase活性、NO_(3)^(-)和NH_(4)^(+)吸收和积累以及根系生长低于对照(P<0.05),但显著高于单一SAR2处理(P<0.05)。研究表明,外源Ca^(2+)可有效保障模拟酸雨(pH 4.5、3.0)下质膜H_(+)-ATPase磷酸化水平,促进H_(+)-ATPase活性升高,缓解酸雨对NO_(3)^(-)和NH_(4)^(+)吸收的抑制,维持根系生长。其中,外源Ca^(2+)对相同强度模拟酸雨胁迫下五优308的调控效果优于南粳9108,说明外源Ca^(2+)对酸雨胁迫下植物氮吸收的影响不仅受酸雨强度限制,而且也会受品种影响。本实验中,外源Ca^(2+)对不同强度酸雨胁迫下不同抗性水稻氮吸收均有调控效果,合理利用外源Ca^(2+)将有助于调节酸雨区农作物的营养吸收,缓解酸雨对农业生产的危害。To alleviate the adverse effect of acid rain on plant growth,the regulation mechanism of Ca^(2+)on tolerance of plants to acid was explored.In this study,two rice cultivars,Wuyou 308(resistant cultivar)and Nanjing 9108(sensitive cultivar),were selected as research objects.The effect of exogenous Ca^(2+)on root growth,nitrogen(NO_(3)^(-)and NH_(4)^(+))content and uptake rates,ATP content,and plasma membrane H_(+)-ATPase activity and phosphorylation levels in rice seedlings under low-intensity(pH 4.5,SAR1)and high-intensity(pH 3.0,SAR2)simulated acid rain were studied.The results showed that under SAR1 treatment,H_(+)-ATPase phosphorylation levels and activity increased in the two rice cultivars,which promoted the decomposition of ATP and increased energy supply,thereby inducing an increase in NH+4 uptake.However,the accumulation of NH+4 was excessive only in Nanjing 9108,causing ammonium toxicity and inhibiting root growth.Under the same treatment,NO_(3)^(-)and NH_(4)^(+)levels and growth did not change in Wuyou 308.Under SAR2 treatment,H_(+)-ATPase activity and NO_(3)^(-)and NH_(4)^(+)uptake rates and levels as well as root growth decreased in the two rice cultivars.Among them,the degree of decrease in Nanjing 9108 was greater than that in Wuyou 308.Under Ca^(2+)+SAR1 treatment,H_(+)-ATPase phosphorylation levels and activity in the root plasma membrane,uptake and accumulation of NO_(3)^(-)and NH_(4)^(+),as well as root growth of the two rice cultivars were not significantly different from those in the control(the treatment which leaves sprayed deionized water).The H_(+)-ATPase activity,uptake and accumulation of NO_(3)^(-)and NH_(4)^(+),and root growth of the two rice cultivars under Ca^(2+)+SAR2 treatment were lower than those in the control,but significantly higher than those under SAR2 treatment alone.The results showed that exogenous Ca^(2+)effectively guaranteed the phosphorylation levels of H_(+)-ATPase and promoted H_(+)-ATPase activity,and then relieved the inhibition of NO_(3)^(-)and NH_(4)^(+)uptake an

关 键 词：外源Ca^(2+) 模拟酸雨 水稻 耐酸性差异 氮吸收 质膜H^(+)-ATPase磷酸化水平 

分 类 号：S511[农业科学—作物学] X517[环境科学与工程—环境工程]