Transcriptomic and proteomic analyses provide new insights into the regulation mechanism of low-temperature-induced leafy head formation in Chinese cabbage.

Unlabelled: In Chinese cabbage, leafy head-related traits are directly related to the cabbage yield and marketability, which are often primarily concerned target for breeders. Although intensive studies has been on head formation in Chinese cabbage in the past decade, very scanty information is available on mechanism involved in the head formation under the influence of low temperature at transcriptome and proteome perspective. In this study, quantitative expression profiling based on RNA-Seq transcriptome and iTRAQ proteome were combined to investigate this trait for a global picture of the molecular dynamics. Total of 2931 transcripts and 365 proteins were identified with significantly changed level in abundance from heading and non-heading Chinese cabbage. Related analyses including function annotations, hierarchical categories, as well as the correlation from transcript-to-proteins were performed. The results indicated that the leafy head formation of Chinese cabbage has involved a complex regulatory pattern. The correlated genes that were mapped to the pathway of plant hormone signal transduction suggested that the head formation might be an integrated result of various plant hormones. Our combined analysis will provide a comprehensive approach to understanding the regulation mechanism of leafy head formation in Chinese cabbage.

Biological Significance: This study revealed the direct relation of leafy-heading traits with the yield of the plant. A comprehensive investigation was done by integrating quantitative expression profiling analysis of transcriptome and proteomic to provide crucial information for further research on the molecular mechanism involved in head formation in Chinese cabbage. The correlation of transcript-to-protein in abundance may afford some necessary information of involvement of post-transcriptional factors influencing leafy head formation in Chinese cabbage.