The Correlation And Mechanism Between Cotton Microbiome And Verticillium Wilt Were Studied

The occurrence of verticillium wilt will seriously affect the yield and quality of cotton.At present,many studies have shown that the rhizosphere,phyllosphere and endosphere of microbiome of cotton is closely related to its own growth and development and disease resistance.Therefore,it is of great significance to clarify the relationship between cotton and cotton microbiome and its mechanism of action with cotton verticillium wilt resistance to further develop new biological control technologies for cotton verticillium wilt resistance.In this study,10 cotton varieties with different resistance to verticillium wilt were selected.Stem tissues,root soil and non-root soil samples were collected.With the under of 16 S r RNA amplification sequencing technology,the species composition,functional potential composition,and species co-occurrence characteristics of the rhizosphere,phyllosphere and endosphere of microbiome of cotton were investigated.Further,the correlation mechanism between cotton microbiome and verticillium wilt resistance was explored.Here are the results of the study.1.Compared with susceptible group,the species composition of cotton stem,root and non-root soil in resistant group are significant differences.Species composition analysis showed that the relative abundance of Proteobacteria in stem of resistant cotton was lower than that of susceptible cotton,while the relative abundance of Actinobacteria and Firmicutes was higher.Compared with susceptible cotton,the relative abundance of Proteobacteria was lower in resistant cotton root,while the relative abundance of Acidobacteria was higher.Besides these two phyla,the root soil of resistant cotton was also an important part,Bacteroidetes,Firmicutes and Acidobacteria.The soil samples mainly composed of Proteobacteria,Actinobacteria,Chloroflexi,Gemmatimonadetes,Acidobacteria,Planctomycetes,Bacteroidetes and Firmicutes.The α diversity index showed that soil microflora was larger than root microflora than stem microflora.The resistant group was greater than the susceptible group.β diversity analysis showed that species composition in stem,root and soil of cotton in resistant and susceptible groups were significantly different,especially roots group.2.There were different species and metabolic pathways in stem,root and soil of cotton in disease-resistant and disease-susceptible groups.LEf Se analysis showed that the resistant cotton enriched Gammaproteobacteria,Alphaproteobacteria,Betaproteobacteria and Actinobacteria in the stems,while the susceptible cotton only enriched Gammaproteobacteria.Disease-resistant cotton is enriched in Aeromonas while disease-susceptible cotton is enriched in pseudomonas in genus level.The resistant cotton enriched Alphaproteobacteria,Deltaproteobacteria in the roots,while the susceptible cotton enriched Gammaproteobacteria.Disease-resistant cotton is enriched in Ilumatobacter while disease-susceptible cotton is enriched in pseudomonas,Aeromonas,Halomonas in genus level.By calculating the abundance of metabolic pathways,it is shown that the main metabolic pathways are biosynthesis of ansamycins bacterial,bacterial chemotaxis,synthesis and degradation of ketone bodies,fatty acid biosynthesis,etc.The relative abundance of biosynthesis of ansamycins bacterial was significantly higher in the root system of resistant cotton than that of susceptible cotton.The abundance of bacterial chemotaxis in the roots and soil of resistant cotton was significantly higher than that of susceptible cotton.According to Venn diagram,about half of the ASV in the stem overlaps with the part in the root system,and a large amount of the ASV in the root system overlaps with the part in the soil,but the ASV in the rhizome has little or no overlap with the part in the soil.Soil bacterial community is a bacterial bank of root bacterial community,and root flora is a bacterial bank of stem bacterial community group.3.Root bacteria cooccurrence network analysis showed that the stability of susceptible cotton root bacteria was higher than that of disease-resistant cotton.Susceptible cotton root bacteria gathered Aeromonas as core species module,and disease-resistant cotton root bacteria gathered Ilumatobacter as core species module.4.Correlation analysis of disease index showed that the bacterial composition(PCo A1)and the relative abundance of Pseudomonas were significantly correlated with the occurrence of Verticillium wilt.Analysis of ASV level further showed that different strains under Pseudomonas had different distribution of cotton roots in the disease-resistant group and the susceptible group,and 17 ASVs in the disease-resistant group and 14 in the susceptible group were significantly up-regulated.