Bao Limei, Liu Yuyan, Ding Yafang, Shang Junjie, Wei Yunlin, Tan Yong, Zi Futing
Faculty of Science, Kunming University of Science and Technology, Kunming, China.
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China.
Front Microbiol. 2022 Feb 24;13:791603. doi: 10.3389/fmicb.2022.791603. eCollection 2022.
Large-scale intensive cultivation has made continuous cropping soil sickness more serious for in Yunnan. Autotoxic substances can promote the occurrence of continuous cropping soil sickness. Phenolic acids exert a strong autotoxic effect on . Based on UPLC-MS/MS, the levels of six phenolic acids with the strongest autotoxicity of rhizospheric soil were tested. Based on Illumina MiSeq high-throughput sequencing technology, the variation in the microbial diversity in the rhizospheric soil was used as an index to explore the interactions between phenolic acids and the soil microorganisms of the rhizosphere. (1) Continuous cropping significantly changed the microbial community structure. Continuous cropping increased bacterial Chao1 index and Shannon index and decreased fungal Shannon index. After disease, bacterial Shannon index reduced and fungal Chao1 index decreased. (2) Phenolic acid significantly changed the bacterial community structure. VA significantly reduced the bacterial Shannon index. Exogenous -HA, FA, SA, and VA significantly increased the fungal Chao1 index and -HA showed the most significant effect. Para-HA affected bacterial specificity, and VA affected fungal specificity. (3) VA was positively correlated with most fungi and bacteria. Para-HA was positively correlated with and . Para-HA was also positively correlated with plant pathogens ( and ). Para-HA and VA were able to promote the growth of primary pathogenic bacteria. Thus, -HA and VA are the main phenolic acid-autotoxin substances in under continuous cropping. (4) A correlation analysis of soil environmental factors associated with fungal and bacterial communities showed that AK, TN, OM, and HN were most strongly correlated with soil microorganisms. (5) The microorganisms in the rhizosphere of 3-year-old soil planted with exhibited obvious effects on the degradation of the four phenolic acids. The effect of soil microorganisms on phenolic acids was first-order kinetic degradation with a high degradation rate and a half-life of less than 4.5 h. The results showed that phenolic acids could promote the growth of pathogenic bacteria. And the interaction between rhizospheric soil microorganisms and phenolic acids was the main cause of the disturbance of rhizosphere microflora.
大规模集约化种植使云南三七连作土壤病害愈发严重。自毒物质会促使连作土壤病害的发生。酚酸对三七具有较强的自毒作用。基于超高效液相色谱-串联质谱法（UPLC-MS/MS），检测了三七根际土壤中六种自毒作用最强的酚酸含量。基于Illumina MiSeq高通量测序技术，以根际土壤微生物多样性变化为指标，探究酚酸与三七根际土壤微生物之间的相互作用。（1）三七连作显著改变了微生物群落结构。连作使细菌Chao1指数和香农指数升高，真菌香农指数降低。三七发病后，细菌香农指数降低，真菌Chao1指数下降。（2）酚酸显著改变了细菌群落结构。香草酸（VA）显著降低了细菌香农指数。外源对羟基苯甲酸（-HA）、阿魏酸（FA）、水杨酸（SA）和香草酸显著提高了真菌Chao1指数，其中 -HA作用最为显著。对羟基苯甲酸影响细菌特异性，香草酸影响真菌特异性。（3）香草酸与多数真菌和细菌呈正相关。对羟基苯甲酸与三七和放线菌呈正相关。对羟基苯甲酸还与植物病原菌（尖孢镰刀菌和立枯丝核菌）呈正相关。对羟基苯甲酸和香草酸能够促进主要病原菌的生长。因此，-HA和VA是三七连作条件下主要的酚酸自毒物质。（4）与真菌和细菌群落相关的土壤环境因子相关性分析表明，有效钾（AK）、全氮（TN）、有机质（OM）和水解氮（HN）与土壤微生物相关性最强。（5）种植三七三年的土壤根际微生物对四种酚酸的降解表现出明显效果。土壤微生物对酚酸的作用为一级动力学降解，降解速率高，半衰期小于4.5小时。结果表明，酚酸能够促进病原菌生长。根际土壤微生物与酚酸之间的相互作用是三七根际微生态紊乱的主要原因。
