Transcriptome Analysis Reveals the Symbiotic Mechanism of Ustilago esculenta induced Gall formation of Zizania latifolia

Abstract Background: Zizania latifolia is a perennial aquatic vegetable due to the establishment of symbiosis between Z. latifolia and U. esculenta results in the swelling gall formation. However, the mechanism of symbiosis for the gall formation in U. esculenta infected Z. latifolia is still unclear. To understand the mechanism of symbiosis for the gall formation in U. esculenta infected Z. latifolia, we analyzed Z. latifolia and U. esculenta symbiotic circumstances using Triadimefon (TDF) treatment and RNA-seq technique. Results: In this present study, 4 different samples were induced under gall before and after formation of CK and TDF treatment in Z. latifolia. Whole growth cycles were recorded and microstructure observation showed that the presence of U. esculenta could be clearly observed after the gall formation, after TDF treatment were not found U. esculenta. A total of 17541 differentially expressed genes (DEGs) were identified based on transcriptome. Meanwhile, GO term and KEGG pathway analyses, plant hormone metabolism, signal transduction and cell wall loosening factors were significantly enriched due to U. esculenta infected Z. latifolia, and relative expression levels of hormone-related genes were identified, among which IAA-relative DEGs up-regulation was the most obvious in JB_B by qRT-PCR. As revealed by UHPLC analysis, the IAA, GA, Z and ZR content were increase while U. esculenta infected and ratio of these hormones to ABA also increased. Conclusion: In this study, we come up with the hormone-cell wall loosening model to study symbiotic mechanism of gall formation after U. esculenta infected Z. latifolia. Meanwhile, our study provides a new perspective for studying the physiological and molecular mechanisms of U. esculenta infection Z. latifolia that causes swelling gall formation and theoretical basis for further increasing the future yield of Z. latifolia.