Genome-wide identification and analysis of TIFY family in highbush blueberry and their responses to exogenous jasmonic acid

Abstract

Most plant-specific TIFY proteins, the transduction hubs of jasmonic acid (JA) signals, determine transcriptional activities of JA-responsive genes, and play important regulatory roles in plant development and stress responses. In the present study, 34 TIFY genes from the highbush blueberry genome were identified, and their expression patterns during flower and fruit development and responses to exogenous JA treatment were investigated. The results showed that VcTIFY members had similar gene structures within highly conserved motifs, which were clustered into 5 main clades. Numerous phytohormone-, tissue- and development-related regulatory elements and stresses-responsive elements were widely distributed in the VcTIFY promoter regions. Gene expression analysis showed that VcTIFYs had distinct spatiotemporal expression patterns during flower enlargement and fruit development, while their expression levels were significantly different between the large-size cultivar ‘O'Neal’ and the small-size cultivar ‘Bluerain’. Under exogenous JA treatments, the weight, horizontal diameter and ripening of mature fruit were affected to different degrees, and the expression levels of VcTIFYs varied significantly in ‘O'Neal’ and ‘Bluerain’ mature fruits, indicating that VcTIFYs might be involved in regulating blueberry fruit size and development. These results should enrich our knowledge of TIFY genes and lay the groundwork for future functional research and genetic breeding of highbush blueberry.