Identification of C2H2 subfamily ZAT genes in Gossypium species reveals GhZAT34 and GhZAT79 enhanced salt tolerance in Arabidopsis and cotton.

Soil salinization is a vital factor that restricts the efficient and sustainable development of global agriculture. Studies enlightened that the C2H2 zinc finger proteins (C2H2-ZFP) were involved in regulating the stress response in plants. However, knowledge of the C2H2-ZFP subfamily C1 (ZAT; Zinc finger of Arabidopsis thaliana) in cotton is still a mystery. In this study, 47, 45, 94, and 88 ZAT genes were obtained from diploid A2, D5 and tetraploid AD1, AD2 cotton genomes, respectively. The function of hybridization and allopolyploidy in the evolutionary linkage of allotetraploid cotton was explained by the family of ZAT gene in 4 species. Duplication of gene activities indicates that the family of ZAT gene of cotton evolution was under strong purifying selection. The integration of previous transcriptome data related to NaCl stress, strongly suggests the GhZAT34 and GhZAT79 may interact with salt resistance in upland cotton. The expression level of certain ZAT genes, higher seed germination rate of transgenic Arabidopsis and gene- silenced cotton revealed that both genes were involved in the salt tolerance of upland cotton. This study may pave the substantial understandings into the role of ZATs genes in plants as well as suggest appropriate candidate genes for breeding of cotton varieties against salinity tolerance.