摘要
为探究枣树感染枣疯病植原体后的发病规律和内在机制,以‘木枣’健康与感病植株为材料,连续测定现蕾后10~60 d叶片中玉米素、生长素、脱落酸、赤霉素、水杨酸等内源激素的含量以及过氧化物酶、超氧化物歧化酶、过氧化氢酶等抗氧化保护酶的活性;通过转录组测序,筛选感病诱发的差异表达基因,并利用qRT-PCR技术对相关基因的表达模式进行验证。结果表明:感病植株中玉米素含量在现蕾后30 d时开始显著升高,水杨酸含量在现蕾后50 d时开始显著升高,过氧化氢酶活性呈降低趋势但在现蕾后60 d时显著升高。以现蕾后20~30 d的叶片进行转录组测序分析,共筛选到1 669个差异表达基因,其中1 114个基因在感病植株中上调表达,555个下调表达。差异表达基因的GO功能富集主要包括生物进程、代谢进程及催化活性,KEGG代谢通路主要为次级生物代谢。在差异表达基因中发现了15个与激素和保护酶代谢相关的基因,经qRT-PCR验证,ZjNCED、ZjGA20、ZjPAL、ZjPOD2和ZjPOD5在转录水平上的表达与对应的激素含量和保护酶活性变化趋势一致,表明这些基因的表达调控对感病后植株的内源激素含量和抗氧化保护酶活性的动态变化具有重要作用。枣疯病植原体感染枣树引起基因表达改变、激素和保护酶的代谢紊乱可能是导致枣树发育畸形的原因。
This research used healthy and infected Ziziphusjujuba Mill. ＇Muzao＇ to investigate the pathogenicity and mechanism of Jujube witches＇ broom disease. Five endogenous hormones （IAA, Zeatin, SA, ABA, and GA3 ）content and three antioxidant enzymes （POD, SOD, CAT ）activities were determined at 10- 60 days after flower bud stage. The differentially expressed genes （DGEs） were screened by transcriptome sequencing. Genes associated with hormones and protective enzymes metabolic pathways were identified using qRT-PCR. The results showed that the Zeatin and SA contents of infected plants began to increase significantly at 30 d and 50 d, respectively, after flower bud stage; the CAT activity tended to decrease first, and increased significantly at 60 d after flower bud stage. Based on transcriptome analysis, 1 669 DGEs were identified unique in the diseased plants, among which 1 114 DGEs were up-regulated genes and 555 were down-regulated ones. GO analysis indicated significant enrichment m biological process, metabolic process and catalytic activity; and KEGG pathway analysis showed significant enrichment in biosythesis of secondary metabolites. Among the differentially expressed genes, 15 key genes were screened to be related to the metabolism of hormones and protective enzymes. The results indicated that the expression of ZjNCED, ZjGA20, ZjPAL, ZjPOD2 and ZjPOD5 was consistent with the change of the hormone content and the protective enzyme activity shown by qRT-PCR, which suggested that they may play important roles in the dynamic changes of endogenous hormones content and protective enzyme activity in infected plants. The changes in gene expression and disorder of hormones and protective enzymes caused by phytoplasma infection may be the cause of deformity in jujube.
作者
张舒怡
张钟
张春梅
李欢
李新岗
ZHANG Shuyi ZHANG Zhong ZHANG Chunmei LI Huan and LI Xingang(College of Forestry, Northwest A ＆ F University, Key Comprehensive Laboratory of Forestry, Shanxi Province, Yangling, Shaanxi 712100, China)
出处
《园艺学报》
CAS
CSCD
北大核心
2017年第7期1287-1298,共12页
Acta Horticulturae Sinica
基金
国家‘十二五’科技支撑课题(2013BAD14B03)
陕西省科技统筹课题(2013KTZB02-03)
关键词
枣
枣疯病
转录组
内源激素
保护酶
发病机理
Chinese jujube
Ziziphus jujuba
Jujube witches＇ broom disease
transcriptomic analysis
plant hormone
protective enzyme
pathogenesis
