南方农业学报2024，Vol.55Issue(2)：397-410,14.DOI:10.3969/j.issn.2095-1191.2024.02.010
外源茉莉酸对脂氧合酶基因LOX3敲除的粳稻防御响应的影响
Effects of exogenous jasmonic acid on defense response of lipoxygenase gene LOX3 knockout japonica rice
摘要
Abstract
[Objective]The purpose of the study was to reveal the effects of exogenous jasmonic acid(JA)on defense response of lipoxygenase gene LOX3 knockout rice plants,and to provide basic data for the use of exogenous JA and other exciters to improve the reduced defense response of rice caused by the loss of resistance related genes in crops.[Method]The susceptible japonica rice Lijiang Xintuan Heigu(LTH)and its LOX3 knockout rice lines(Δlox3#1,Δlox3#10 and Δlox3#20)were used as materials.Phenotypic analysis including plant height,tiller number and 100-grain weight,detection of the antimicrobial compound activity(content)of peroxidase(POD),reactive oxygen species(ROS)and lig-nin,as well as analysis of the expression of defense-related genes were carried out.Further,the tested rice was inoculated with Magnaporthe oryzae,the rice blast symptoms of the tested rice were investigated,the activity(content)of antimi-crobial compounds and expression of defense-related genes in M.oryzae inoculated rice plants were examined,and the in-oculation process of M.oryzae in rice was observed.On this basis,exogenous JA was applied to M.oryzae inocu-lated Δlox3 knockout rice lines and LTH at 36 and 48 hpi.The effects of JA on rice blast symptom,activity(content)of antimicrobial compounds and expression of defense-related genes in M.oryzae inoculated rice were analyzed,and the ef-fects of JA on the inoculation process of M.oryzae were also observed.[Result]The seeds of Δlox3 knockout rice plants exhibited faster germination speed than that of the wild type,but the plant height,tiller number and 100-grain weight were similar to those of the wild type.The more serious blast symptom appeared on M.oryzae inoculated Δlox3 knockout rice plants than that on M.oryzae inoculated wild type rice.M.oryzae inoculated Δlox3 knockout rice plants exhibited lower number of callose,POD activity and lignin content,and higher ROS content and number of dead cells,and the magnitude of the down-regulation of OsWRKY45,OsPR1a,and OsPOX1 genes and the amount of M.oryzae hyphae colonization were greatly higher than that of M.oryzae inoculated wild type rice.Exogenous JA effectively alleviated rice blast symptom in Δlox3 knockout rice plants inoculated with M.oryzae for 36 and 48 hpi.Moreover,JA enhanced the number of callose,POD activity,lignin content and expression levels of defense-related genes OsWRKY45,OsPR1a and OsPOX1 in Δlox3 knockout rice plants inoculated with M.oryzae for 36 and 48 hpi,decreased expression of OsRbohB,ROS content and number of dead cells,and inhibited expansion of M.oryzae hyphae.The effects of JA on the alleviation of rice blast symptoms in Δlox3 knockout rice plants inoculated with M.oryzae for 48 hpi were better than those of JA on Δlox3 knockout rice plants inoculated with M.oryzae for 36 hpi.It was mainly reflected in the fact that JA induced a better increase in antimicrobial compounds,expression levels of defense-related genes,number of cell deaths,and inhibition of M.oryzae hyphae expansion in the Δlox3 knockout rice plants inoculated with M.oryzae for 48 hpi than in the Δlox3 knockout rice plants inoculated with M.oryzae for 36 hpi under JA treatment.[Conclusion]LOX3 gene knockout en-hances rice seed germination speed and decreases rice blast resistance,while exogenous JA alleviates the decrease of rice defense response caused by LOX3 knockout and enhances rice blast resistance.JA has a potential application prospect in mitigating reduction or loss of crop resistance resulted from short durability of resistance genes.关键词
水稻/稻瘟菌/脂氧合酶基因/茉莉酸/防御响应Key words
rice/Magnaporthe oryzae/lipoxygenase gene/jasmonic acid/defense response分类
农业科技引用本文复制引用
杨婧,苏顺雨,赵添琦,李永杰,唐萍,左如斌,刘崇兰,杨静..外源茉莉酸对脂氧合酶基因LOX3敲除的粳稻防御响应的影响[J].南方农业学报,2024,55(2):397-410,14.基金项目
国家自然科学基金项目(32160643) （32160643）
云南省基础研究计划重点项目(202101AS070038) （202101AS070038）
云南省中青年学术和技术带头人后备人才项目(202305AC160006) National Natural Science Foundation of China(32160643) （202305AC160006）
Yunnan Fundamental Research Pro-gram Key Project(202101AS070038) （202101AS070038）
Reserve Talents Project for Young and Middle-aged Academic and Technical Leaders of Yunnan(202305AC160006) （202305AC160006）
