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Up-regulation of a homeodomain-leucine zipper gene HD-1 contributes to trichome initiation and development in cotton
- NIU, Er-li, CAI, Cai-ping, BAO, Jiang-hao, WU, Shuang, ZHAO, Liang, GUO, Wang-zhen
- Journal of integrative agriculture 2019 v.18 no.2 pp. 361-371
- Gossypium barbadense, Gossypium hirsutum, allotetraploidy, cotton, gene expression regulation, genes, hairs, leaves, loci, phylogeny, retrotransposons, terminal repeat sequences, tissues, trichomes
- Plant trichomes originate from epidermal cells. In this work, we demonstrated that a homeodomain-leucine zipper (HD-Zip) gene, Gh_A06G1283 (GhHD-1A), was related to the leaf trichome trait in allotetraploid cotton and could be a candidate gene for the T1 locus. The ortholog of GhHD-1A in the hairless accession Gossypium barbadense cv. Hai7124 was interrupted by a long terminal repeat (LTR) retrotransposon, while GhHD-1A worked well in the hairy accession Gossypium hirsutum acc. T586. Sequence and phylogenetic analysis showed that GhHD-1A belonged to the HD-Zip IV gene family, which mainly regulated epidermis hair development in plants. Silencing of GhHD-1A and its homoeologs GhHD-1D in allotetraploid T586 and Hai7124 could significantly reduce the density of leaf hairs and affect the expression levels of other genes related to leaf trichome formation. Further analysis found that GhHD-1A mainly regulated trichome initiation on the upper epidermal hairs of leaves in cotton, while the up-regulated expression of GhHD-1A in different organs/tissues also altered epidermal trichome development. This study not only helps to unravel the important roles of GhHD-1A in regulating trichome initiation in cotton, but also provides a reference for exploring the different forms of trichome development in plants.