Identification and expression of the TIP subfamily in apple in response to drought stress

Abstract

Abstract [Objective] This study aims to identify and analyze the members of the tonoplast intrinsic protein (TIP) subfamily in apple, and to investigate the expression patterns under drought stress. It provides information for further research on utilization of drought resistance gene resources in apple. [Methods] The MdTIPs in apple genome was identified by bioinformatics methods. The physicochemical properties, gene structures, conserved motifs, cis-regulatory elements, and phylogenetic trees, etc. of the subfamily members were analyzed. The expression patterns of MdTIPs in different organs under drought stress were analyzed by qRT-PCR. [Results] A total of 13 MdTIP genes were identified in the apple genome, and most members were localized at the plasma membrane. Chromosome localization analysis suggested that all members were distributed on 10 chromosomes, with 1-3 members on each chromosome. Besides, the promoter regions of the genes contained response elements for hormonal and adversity stresses. qRTPCR showed that MdTIP members were up-regulated in roots except MdTIP1;1, of which MdTIP1;3 and MdTIP1;4 were up-regulated 5.27 times and 5.69 times, respectively, compared with the control, suggesting that these two genes might be critical in response to drought stress. [Conclusion] Identification of MdTIP subfamily members is provided in this study. 10 MdTIP members are differentially expressed in roots, stems, and leaves, and 12 members are highly expressed in roots.

Keywords

• apple
• aquaporin
• tips subfamily
• water transport
• bioinformatics