| DNA methylation plays an important role in fruit ripening.Many studies have shown that DNA methylation is related to fruit development.In this study,different concentrations of methyltransferase inhibitor 5-azaC were sprayed on‘Kyoho'grape berry to investigate the physiological effects of 5-azaC on berry ripening,the changes of DNA methylation level,and the relationship between DNA methylation and the ROS metabolism during berry development.High-throughput sequencing technology was used to study the transcriptome of‘Kyoho'grape berry development process,revealing the overall expression characteristics of the transcriptome of grape berry development,and screening out some genes in response to 5-azaC treatment,which laid a foundation for further research on regulation of grape berry development.The main results were as follows:1.10,50 and 100?M 5-azaC all promoted the early ripening of‘Kyoho'grape.Among them,100?M 5-azaC had the best effect,which could promote the ripening of‘Kyoho'grape 20 days earlier than the control.2.MSAP molecular markers were used to analyze the methylation levels of grape berry genes at different developmental stages after 100?M 5-azaC treatment.The results showed that methylation rate after treatment was lower than that of control at the detected developmental stages.3.5-azaC treatment affected ROS metabolism and related physiological indexes in berries.The sucrose and soluble solid content of 5-azaC-treated berries were significantly higher than control at 75 days post anthesis.The change trend of H2O2content of the control was similar with the 100?M 5-azaC treatment.All treatments enhanced rates of O2-·production.SOD activity in treated berries were higher than the control and had significant difference with the control at 35 days after anthesis.4.The transcriptome analysis of grape berry samples treated with 100?M 5-azaC was carried out.A total of 1.33 billion high-quality reads were generated by sequencing,with an average reads of 45.76 million per sample.The number of differentially expressed genes at the same developmental stages was compared between the treatment and the control,ranging from 9?A3C3?-690?A5C5?.Functional annotation of these differentially expressed genes revealed that there were some genes related to fruit softening,photosynthesis,protein phosphorylation and heat stress.WGCNA was performed for genes?19387?with FPKM?0.5,eight modules showed high correlation with different developmental stages and some hub genes such as POD4,OMT1 and CLFSWN were screened.In conclusion,5-azaC treatment can promote the early ripening of‘Kyoho'grape berry.There is a certain relationship between ROS metabolism and DNA methylation during grape berry development.Further more,5-azaC treatment changes the expression pattern of some genes related to berry development and ripening. |
PDF Full Text Request