小麦赤霉病胁迫下植物微生物群落特征及其与病害发生的关系

Changes of microbiome in wheat under head blight stress and its correlation with disease occurrence

摘要:

目的 研究小麦赤霉病胁迫下植物微生物变化特征以及差异微生物与病原菌丰度的关系，明确植物微生物与病害发生的关系。方法 本研究通过田间采集健康与患病样本，结合高通量测序分析植物相关微生物组变化特征，并通过实时荧光定量技术测定病原菌丰度，揭示植物微生物群落变化对小麦赤霉病的响应。结果 小麦赤霉病胁迫下穗部细菌和根际真菌α多样性显著增加，更多的潜在有益菌群在患病小麦穗部富集。与患病植株相比，健康植株具有更强的微生物群落稳定性和网络稳定性。植物微生物多样性可以预测病原菌丰度的变化，其中穗部微生物多样性以及群落稳定性对病原菌丰度变化的解释率最高，达76.95%。较高的真菌多样性和群落稳定性不利于病原菌的定殖。结论 健康植株和患病植株的微生物组存在显著差异，健康植株穗部稳定的微生物群落和网络互作模式有利于抵抗病原菌的侵染。此外，小麦穗部出现了植物对有益菌群的招募现象，即“呼救”策略，这扩展了植物“呼救”策略的适用范围。最后，本研究通过解析植物微生物组与病害发生的关系，为靶向调控植物微生物组以防治植物病害提供了重要的数据支撑和理论依据。

Abstract:

Objective To investigate the plant microbiome changes in response to wheat head blight and the correlation between the abundance of differential microorganisms and the pathogen Fusarium graminearum, and elucidate the intricate interplay between plant microbiome and disease occurrence.Methods We collected samples from both healthy and diseased plants in the field, combined with high-throughput sequencing to analyze the characteristics of plant microbiome changes, and the abundance of pathogen was determined by RT-qPCR to reveal the response of plant microbial community changes to wheat head blight.Results The alpha diversity of bacteria in wheat spikes and fungi in the rhizosphere significant increased under the disease stress, with enrichment of potentially beneficial bacteria in spikes of diseased wheat plants. Healthy plants displayed higher stability of microbial community and network than diseased plants. Plant microbial diversity can predict alterations in pathogen abundance. Notably, the microbial diversity and community stability explained the most (76.95%) variations in pathogen abundance. High fungal diversity and community stability were associated with reduced pathogen colonization.Conclusion Significant discrepancies of the plant microbiome were identified between healthy and diseased plants. The stable microbial community and network interactions in the spikes of healthy plants facilitate the resistance against F. graminearum infection. Additionally, the “call for help” phenomenon was observed as wheat plants recruited beneficial microflora in spikes, expanding the applicability of the “call for help” strategy. By examining the connection between plant microbiome and disease occurrence, this study presents crucial data and a theoretical framework for the targeted manipulation of plant microbiome to enhance disease prevention and control.