槟榔黄化病叶际微生物群落结构与多样性

Phyllosphere microbial community structure and diversity of Areca catechu with yellow leaf disease

摘要:

目的 明确叶际微生物对槟榔黄化病APV1病毒入侵的响应，为槟榔叶际微生态的研究、优异生防资源的挖掘及槟榔黄化病的绿色防控提供理论依据和技术支持。方法 分别采集健康、轻度发病及重度发病槟榔叶片，通过高通量测序技术和生物信息学方法比较叶际微生物的群落结构与多样性并分析功能差异。结果 槟榔叶际优势细菌门为放线菌门(Actinobacteriota)、变形菌门(Proteobacteria)、酸杆菌门(Acidobacteriota)、厚壁菌门(Firmicutes)和黏球菌门(Myxococcota)，优势真菌门为子囊菌门(Ascomycota)和担子菌门(Basidiomycota)。随着发病程度的增加，槟榔叶际细菌丰富度先升后降，真菌丰富度先降后升；细菌和真菌多样性均呈先升后降的趋势。厚壁菌门(Firmicutes)和担子菌门(Basidiomycota)作为轻度发病槟榔的标志物种，其相对丰度与α多样性变化趋势一致。健康与不同发病程度槟榔叶际微生物功能均发生了不同程度的变化，其中重度发病槟榔的环境信息处理功能显著高于健康槟榔；共生营养型(symbiotroph)的相对丰度极显著高于健康槟榔。结论 槟榔黄化病显著改变了叶际微生物群落结构与多样性，且在发病初期变化较大，说明槟榔可能通过招募有益微生物、调控细胞代谢、生化反应、进行自身免疫等方式来抵御APV1病毒侵染。

Abstract:

Objective To clarify phyllosphere microbial responses to the invasion of areca palm velarivirus 1 (APV1), a virus causing yellow leaf disease of areca (Areca catechu), and provide a theoretical basis and technical support for the study of phyllosphere micro-ecology, exploration of excellent biocontrol resources, and green prevention and control of yellow leaf disease of areca.Methods We collected healthy leaves, mildly diseased leaves, and severely diseased leaves of areca. The phyllosphere microbial community structure and diversity were compared by high-throughput sequencing and bioinformatics methods. Furthermore, functional differences of phyllosphere microbial communities were analyzed.Results The dominant bacterial phyla in the phyllosphere of areca included Actinobacteriota, Proteobacteria, Acidobacteriota, Firmicutes, and Myxococcota, while the dominant fungal phyla were Ascomycota and Basidiomycota. As the disease became increasingly severe, bacterial richness initially increased then decreased while fungal richness initially decreased then increased. However, both bacterial diversity and fungal diversity showed a trend of first increasing and then decreasing. Firmicutes and Basidiomycota served as indicators of mildly diseased areca, with the relative abundance showing consistent trends with alpha diversity. The healthy plants and the diseased plants showed different phyllosphere microbial functions. Specifically, the environmental information processing function was significantly higher in severely diseased areca plants than in healthy ones. Additionally, the relative abundance of symbiotroph fungi in the phyllosphere were significantly higher in severely diseased areca plants than in healthy ones.Conclusion The yellow leaf disease significantly alters the phyllosphere microbial community structure and diversity of areca, with greater changes during the early disease stage. This suggests that areca may defend against APV1 infection by recruiting beneficial microorganisms, regulating cellular metabolism and biochemical reactions, and activating autoimmunity.