Mechanism Of Cytokinin And Signal Transduction Related Genes Regulating Swelling Of Zizania Latifolia

Zizania latifolia is a kind of characteristic aquatic vegetable in China,which is rich in nutrition and delicious in taste.The thickening of Zizania latifolia shoots,referred to as gall formation,depends on infection with the fungal endophyte Ustilago esculenta.At present,the yield and quality of Zizania latifolia in agricultural production mainly depend on natural conditions,and there is no way to control it artificially.A key role for cytokinin action in this process was postulated.Here,trans-Zeatin stimulated swelling in fungi-infected Zizania latifolia.A two-component system(TCS)linked cytokinin binding to receptors with transcriptional regulation in the nucleus and played important roles in diverse biological processes.Therefore,this study aims to analyze the effects of exogenous cytokinins on the enlargement of Zizania latifolia through morphological and physiological observation,and identify and analyze the genes of the dual signaling system family in combination with bioinformatics,and finally reveal the roles of related genes in the enlargement process of Zizania latifolia by molecular biology methods.The main results are as follows:In this study,field experiments were carried out to determine the growth and development cycle of Zizania latifolia,and the growth and development curve was drawn.To investigate the morphological changes of Zizania Latifolia in response to cytokinin,a 150 mg/L trans-Zeatin optimal solution in 2% Et OH was sprayed onto the leaves of fungi-infected plants two weeks before their shoot swelling began.Two percent Et OH was used as mock treatment.It was found that exogenous cytokinin spraying could promote the swelling of Zizania latifolia,and improve The frequency of swelling and yield.We characterized 69 TCS genes encoding for 25 histidine kinase/ histidine-kinase-like(HK(L))(21 HKs and 4 HKLs),8 histidine phosphotransfer proteins(HP)(5 authentic and 3 pseudo),and 36 response regulators(RR;14 type A,14 type B,2 type C,and 6 pseudo)in the genome of Zizania Latifolia.These TCS genes have a close phylogenetic relationship with their rice counterparts.Nineteen duplicated TCS gene pairs were found and the ratio of nonsynonymous to synonymous mutations indicated that a strong purifying selection acted on these duplicated genes,leading to few mutations during evolution.Finally,molecular biological techniques were used to further analyze the mechanism of cytokinin action on Zizania latifolia.The transcriptome data and fluorescence quantitative analysis showed that Zl CHK1,Zl RRA5,ZIRRA9,Zl RRA10,Zl PRR1,and Zl PHYA expression was associated with gall formation.Among them,Zl RR5,Zl RR9,and Zl PHYA are quickly induced by trans-Zeatin,suggesting a role for cytokinin signaling in shoot swelling of Zizania latifolia.