Genomic identification of bZIP family genes involved in drought and heat stresses in strawberry (Fragaria vesca)

Authors: WANG, XIAO-LONG - Nanjing Agricultural University; CHEN, XINLU - Nanjing Agricultural University; Yang, Tianbao; CHENG, ZONG-MING - University Of Tennessee; CHENG, QUANKANG - University Of Tennessee

Submitted to: International Journal of Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2017
Publication Date: 4/11/2017
Citation: Wang, X., Chen, X., Yang, T., Cheng, Z., Cheng, Q. 2017. Genomic identification of bZIP family genes involved in drought and heat stresses in strawberry (Fragaria vesca). International Journal of Genomics. Available: https://doi.org/10.1155/2017/3981031.

Interpretive Summary: Strawberry is an important rosaceous crop. However, the fruit quality and shelf-life are negatively affected by external stresses. Genes known as basic leucine zipper (bZIP) genes play dominant roles in plant development, and plant responses to abiotic or biotic stress stimuli. In this study, 50 bZIP genes from the woodland strawberry genome were identified and analyzed. They can be divided into 10 groups (clades) according to their relatedness. The clade A members showed different tissue-specific expression patterns and the duplicated genes in this clade were differentially regulated in response to plant development and stress. The expression of the bZIP genes mrna11837 and mrna30280 in leaves was very weak under normal growth conditions, but higher following drought and heat treatment, respectively, which suggests that these two bZIPs are involved in stress response in strawberry. These results will benefit researchers working to improve strawberry quality and shelf-life.

Technical Abstract: Basic leucine zipper (bZIP) genes are known to play dominant roles in plant response to development signals, as well as abiotic or biotic stress stimuli. Fifty bZIP genes across the woodland strawberry (Fragaria vesca) genome were identified and analyzed. They can be divided into 10 clades according to the phylogenetic relationship of the strawberry bZIP proteins with those in Arabidopsis and rice. The chromosomal distribution and the sequence analyses reveal that bZIP gene family has expansion with segmental and tandem duplication in the strawberry genome. Five kinds of intron patterns (a-e) are observed within the basic and hinge regions of their bZIP domains. The additional conserved motifs have been identified by detailed sequence analysis and present the group specificity. Further, the DNA-binding specificity as well as the dimerization properties were predicted based on the characteristic features in the basic and hinge regions and the leucine zipper, respectively, which supports the phylogenetic clade classification. Across the different developmental stages of 15 organs and two types of fruits, the clade A members showed different tissue-specific expression patterns and the duplicated genes were differentially regulated, indicating a functional diversification coupled with the expansion of this gene family in strawberry. It's worth noting that the expression of mrna11837 and mrna30280 in leaves was very weak under normal growth conditions, but higher following drought and heat treatment, respectively, which may be caused by the separate response pathway between drought and heat treatments.