摘要
【目的】分析内生细菌对油茶Camellia oleifera炭疽病的抑制机制。【方法】基于形态学特征与多基因片段系统发育分析对内生细菌B11菌株进行鉴定。通过平板对峙法评估B11菌株对Colletotrichum siamense的抑制作用,通过扫描电镜、化合物合成基因扩增和RT-qPCR等方法探究B11菌株的抑病机制和诱导抗性机制。【结果】内生细菌B11菌株被鉴定为耐盐芽孢杆菌Bacillus halotolerans。该菌株具有较广谱的体外抑菌活性,且对C.siamense具有显著的抑制活性;其发酵液能使菌株CA17分生孢子细胞壁破裂,内含物泄漏,菌丝膨大畸形。此外,拟南芥Arabidopsis thaliana叶片经菌株B11发酵液处理后,水杨酸(Salicylic acid,SA)信号途径中的标记基因PR1和PR5呈上调表达。菌株B11发酵液处理油茶叶片后,抗性相关的防御酶POD和SOD活性显著升高。【结论】本研究为油茶炭疽病的绿色防控技术研发及生物防治制剂的开发应用提供了重要理论支撑。
【Objective】To analyze the disease prevention mechanisms of endophytic bacteria against Colletotrichum siamense causing Camellia oleifera anthracnose.【Method】Identification of endophytic bacterial strain B11 was based on morphological traits and multigene fragment-based phylogenetic analysis.The inhibitory effect of strain B11 on C.siamense was evaluated using the dual-culture method.The diseasesuppressing and induced resistance mechanisms of the endophytic bacteria were investigated through scanning electron microscopy,amplification of compound synthesis genes and RT-qPCR.【Result】The endophytic bacterial strain B11 was identified as Bacillus halotolerans.This strain exhibited broad-spectrum in vitro antimicrobial activity,with significant inhibitory effects on C.siamense.Its fermentation broth caused disruption of the cell wall of C.siamense strain CA17,leakage of intracellular contents and abnormal swelling of hyphae.Additionally,after treatment with the fermentation broth of strain B11,the marker genes PR1 and PR5 in the salicylic acid(SA)signaling pathway were upregulated in Arabidopsis thaliana leaves.Following treatment with the fermentation broth,the activities of defense-related enzymes POD and SOD in Camellia oleifera leaves significantly increased.【Conclusion】This study provides important theoretical support for the research and development of green prevention and control technologies for C.siamense,as well as the development and application of biological control agents.
作者
朱幼娇
陈健鑫
吴峰婧琳
彭睿琦
温名佳
马焕成
伍建榕
ZHU Youjiao;CHEN Jianxin;WU Fengjinglin;PENG Ruiqi;WEN Mingjia;MA Huancheng;WU Jianrong(Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province/College of Forestry,Southwest Forestry University,Kunming 650224,China;Key Laboratory of Biodiversity Conservation in Southwest China National Forestry and Grassland Administration/College of Forestry,Southwest Forestry University,Kunming 650224,China)
出处
《华南农业大学学报》
北大核心
2025年第5期659-668,共10页
Journal of South China Agricultural University
基金
国家自然科学基金(31860208)
国家重点研发计划(2019YFD100200X)
云南省教育厅科学研究基金(2023Y0720,2106150086Y615)。
关键词
油茶
炭疽病
内生细菌
耐盐菌
芽孢杆菌
生物防治
Camellia oleifera
Anthracnose
Endophytic bacteria
Salt tolerant bacterium
Bacillus halotolerans
Biological control
