State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Zhenjiang College, Zhenjiang 212028, China.
J Appl Microbiol. 2024 Jun 3;135(6). doi: 10.1093/jambio/lxae131.
Understanding the inhibitory effects of natural organic substances on soil-borne pathogenic fungi and the relevant molecular mechanisms are highly important for future development of green prevention and control technology against soil-borne diseases. Our study elucidates the inhibitory effect of the combined application of humic acids (HAs) and chitosan on Alternariasolani and the light on the corresponding mechanism.
The effect on A. solani growth by HAs incorporated with chitosan was investigated by plate culture and the corresponding mechanism was revealed using transcriptomics. The colony growth of A. solani was suppressed with the highest inhibition rate 33.33% when swine manure HAs was compounded with chitosan at a ratio of 1:4. Chitosan changed the colony morphology from round to irregularly. RNA-seq in the HAs and chitosan (HC) treatment revealed 239 differentially expressed genes compared with the control. The unigenes associated with enzymes activities related to growth and biological processes closely related to mycelial growth and metabolism were downregulated. RNA-seq also revealed that chitosan altered the expression of genes related to secondary metabolism, fungal cell wall formation and polysaccharide synthesis, and metabolism. Meanwhile, weighted gene co-expression network analysis showed that, genes expression in the module positively correlated with mycelial growth was significantly reduced in the HC treatment; and the results were verified by real-time quantitative polymerase chain reaction.
The co-inhibition effect of HAs and chitosan on A. solani is associated with downregulated genes expression correlated with mycelial growth.
了解天然有机物质对土传病原真菌的抑制作用及其相关分子机制，对于未来土传病害绿色防控技术的发展具有重要意义。本研究阐明了腐植酸（HA）与壳聚糖联合应用对茄病镰刀菌和光照的抑制作用及其相关机制。
通过平板培养研究了 HA 与壳聚糖复合对 A. solani 生长的影响，并通过转录组学揭示了相应的机制。当猪粪 HA 与壳聚糖以 1:4 的比例复合时，A. solani 的菌落生长受到抑制，抑制率最高可达 33.33%。壳聚糖使菌落形态从圆形变为不规则形。与对照相比，HA 和壳聚糖（HC）处理的 RNA-seq 显示有 239 个差异表达基因。与生长相关的酶活性和与菌丝生长和代谢密切相关的生物过程相关的同工基因下调。RNA-seq 还表明，壳聚糖改变了与次级代谢、真菌细胞壁形成和多糖合成及代谢相关的基因表达。同时，加权基因共表达网络分析表明，HC 处理中与菌丝生长呈正相关的基因表达显著降低；实时定量聚合酶链反应验证了这一结果。
HA 和壳聚糖对 A. solani 的协同抑制作用与与菌丝生长相关的下调基因表达有关。
