Evolutionary analysis of TCP gene family and its response to hormonal and abiotic stress in rye (Secale cereale L.)

Background: Teosinte branched1/cycloidea/proliferating cell factor (TCP) proteins are plant-specific transcription factors involved in diverse biological processes, including growth and development, abiotic stress resistance, leaf senescence, lateral branch formation, and pollen development. However, the evolution of the TCP family in the rye is poorly understood. Results: A total of 26 TCP genes were identified on seven rye chromosomes. The genes were divided into three subfamilies based on the homology analysis of Arabidopsis thaliana , T. aestivum , H. vulgare , O. sativa , Z. mays , and A. tauschii (not identified) were selected as the related species of rye to evaluate the developmental mechanism of ScTCP gene family during the evolutionary process via motif and collinearity analyses. The results showed that fragment replication events modulated ScTCP gene family expansion. In addition, interactions among ScTCP proteins and the identification of promoters containing many hormonal and stress-responsive cis-acting elements suggested that the regulation of ScTCP expression is complex. The expression patterns of 12 genes were analyzed under different tissues, fruit development stages, three hormones, and six abiotic stresses. Conclusions: The results demonstrated that ScTCP genes, especially ScTCP6 , play a critical role in rye development and its response to various hormones and abiotic stresses. This study provides new insights into the evolution of TCP genes in rye and thus may promote molecular breeding.