Response of sugarcane rhizosphere soil fungal communities on a temporal gradient to changes in critical growth periods

Abstract

Understanding the normal variation of the sugarcane rhizosphere fungal microbiota throughout its life cycle is essential for the development of agricultural practices for fungal diseases (e.g., sugarcane tip rot, sugarcane red rot, and sugarcane smut) and ecological health associated with the microbiota. Therefore, we performed high-throughput sequencing of 18S rDNA of soil samples using the Illumina sequencing platform for correlation analysis of sugarcane rhizosphere microbiota time series, covering information from 84 samples in four growth periods. The results revealed that the sugarcane rhizosphere fungi possessed the maximum fungal richness in July (Tillering). Rhizosphere fungi are closely associated with sugarcane growth, including Ascomycota, Basidiomycota, and Ochrophyta showed high abundance in a stage-specific manner. Through the Manhattan plots, 11 fungal genera were found to show a decreasing trend throughout the sugarcane growth period, and two fungal genera were significantly enriched at three stages of sugarcane growth (p < 0.05) including Pseudallescheria and Nectriaceae. In addition, soil pH, soil temperature (Tem), total nitrogen (TN) and total potassium (TP) were important drivers of fungal community structure at different stages of sugarcane growth. Using structural equation modeling (SEM) found that sugarcane disease status showed a significant and strong negative effect with selected soil properties, suggesting that poor soil may increase the likelihood of sugarcane disease. In addition changes in sugarcane rhizosphere community structure over time were mainly influenced by stochastic factors, but the contribution decreased to the lowest value after the sugarcane root adaptation system was stabilized (Maturity). IMPORTANCERhizosphere microbes are closely related to plant growth, and more studies have shown that the rhizosphere fungal microbial community has an important influence on plant health and growth status. However, little is known about the response of the rhizosphere fungal community to plant growth during the critical plant reproductive period. In this study, we analyzed the important response of the rhizosphere fungal community of sugarcane through the pattern of abundance changes in its critical growth nodes by various methods to investigate the subtle changes in the assembly of the rhizosphere fungal community with the growth of sugarcane. Our work provides innovative ideas for the prevention of soil-borne diseases in plants and also provides a solid basis for the development of microbial models of crops rhizosphere soil.