摘要
【目的】分析外源喷施茉莉酸(JA)对甘蔗白条病发生的影响,揭示JA在甘蔗抵抗白条病中的作用及其提升甘蔗白条病抗性的机制,为甘蔗抗白条病的分子育种提供重要基因资源,并为甘蔗白条病防治提供参考。【方法】对健康的甘蔗苗接种白条病菌Xa-FJ1菌液(简称Xa),通过对接种Xa 72 h的甘蔗苗喷施纯净水(CK)或不同浓度的JA和茉莉酸抑制剂(IBU)后,观察甘蔗发病情况并统计病情指数,筛选出最适的JA和IBU浓度;将最适浓度的JA和IBU分别喷雾处理接种Xa 72 h的甘蔗,于接种后不同时间测定甘蔗体内防御相关生理指标和相关基因的表达情况。【结果】喷施JA可减缓甘蔗白条病的发生,喷施浓度为200μmol/L时对白条病的抑制效果显著(P<0.05,下同);喷施IBU在一定程度上促进甘蔗白条病的发生,喷施浓度为200μmol/L时对白条病的抵抗效果最差。分别选取200μmol/L的JA和IBU进行后续试验。在接种Xa 72 h时,CK与JA处理的甘蔗叶片JA含量呈极显著差异(P<0.01,下同);在接种Xa96和120 h时,CK与IBU处理的甘蔗叶片JA含量呈极显著差异;在接种Xa 72、96和120 h时,IBU处理与JA处理的甘蔗叶片JA含量呈极显著差异。在接种Xa 72 h,JA处理和IBU处理的甘蔗叶片丙二醛(MDA)含量均明显上升,CK与JA处理、IBU处理的MDA含量均呈极显著差异,JA处理与IBU处理亦呈极显著差异。在接种Xa 24 h时,CK、JA处理和IBU处理的甘蔗叶片过氧化物酶(POD)和超氧化物歧化酶(SOD)活性均达最大值,随后下降;在接种Xa 72 h时,CK与JA处理的POD活性呈显著差异。在接种Xa 72 h时喷施JA和IBI,CK和IBU处理的甘蔗叶片JA通路各基因的相对表达量总体呈下降趋势,而JA处理呈上升趋势。【结论】外源喷施JA引起甘蔗植株JA通路相关基因的表达升高,进而提高体内JA含量和相关防御酶活性,最终增强甘蔗对白条病的抗性。
【Objective】The purpose of the study was to analyze the effects of exogenous spraying of jasmonic acid(JA)on the occurrence of sugarcane leaf scald,to reveal the role of JA in sugarcane resistance to leaf scald and its mechanism to enhance the resistance of sugarcane leaf scald,to provide important gene resources for molecular breeding of sugarcane resistance to leaf scald and to provide a reference for the prevention and control of sugarcane leaf scald.【Method】Healthy sugarcane seedlings were inoculated with Xa-FJ1 bacterial solution(Xa solution).After spraying purified water(CK)or different concentrations of JA and jasmonic acid inhibitor(IBU)on sugarcane seedlings inoculated with Xa for 72 h,the incidence of sugarcane was observed and the disease index was counted,and the optimum concentrations of JA and IBU were selected.The sugarcane inoculated with Xa for 72 h was sprayed with the optimum concentrations of JA and IBU,respectively.The physiological indexes and related gene expression of defense in sugarcane were measured at different times after inoculation.【Result】Spraying JA could slow down the occurrence of sugarcane leaf scald,and the inhibition effect on the incidence of leafscald was significant when the spraying concentration was 200 μmol/L(P<0.05,the same below).Spraying IBU promoted the occurrence of sugarcane leaf scald to a certain extent,and the resistance to leaf scald was the worst when the spraying concentration was 200 μmol/L.JA and IBU at 200 μmol/L were selected for subsequent experiments,respectively.At 72 h after inoculation with Xa,the JA content of sugarcane leaves treated with CK and JA was extremely significantly different(P<0.01,the same below).At 96 and 120 h after inoculation with Xa,the JA content of sugarcane leaves treated with CK and IBU was extremely significantly different.At 72,96 and 120 h after inoculation with Xa,the JA content of sugarcane leaves of JA and IBU treatment was extremely significantly different.At 72 h after inoculation with Xa,the MDA content of sugarcane leaves treated with JA and IBU increased obviously.The malonaldehyde(MDA)content of CK was extremely significantly different from that of JA and IBU treatments,and JA treatment was extremely significantly different from IBU treatment.At 24 h after inoculation with Xa,the activities of peroxidase(POD)and superoxide dismutase(SOD)in sugarcane leaves treated with CK,JA,and IBU reached the maximum,and then decreased.At 72 h after inoculation with Xa,the POD activity of CK and JA treatment was significantly different.Spraying JA and IBU at 72 h after inoculation with Xa,the relative expression levels of JA pathway genes in sugarcane leaves treated with CK and IBU generally showed a downward trend,while JA treatment showed an upward trend.【Conclusion】After exogenous spraying of JA,the expression of JA pathway related genes in sugarcane plants increases,and the jasmonic acid content and the activity of related defense enzymes increase,and finally the resistance of sugarcane to Xa is enhanced.
作者
许珲镁
张天杰
史梦婷
洪鼎剀
高三基
王锦达
XU Hui-mei;ZHANG Tian-jie;SHI Meng-ting;HONG Ding-kai;GAO San-ji;WANG Jin-da(National Engineering Research Center of Sugarcane,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2023年第7期2039-2049,共11页
Journal of Southern Agriculture
基金
国家现代农业产业技术体系建设专项(CARS-170302)
福建农林大学科技创新基金项目(CXZX2020146C)。
关键词
甘蔗
白条病
茉莉酸
基因表达
sugarcane
leaf scald
jasmonic acid
gene expression
