1. A cotton endoreduplication gene, GaTOP6B, regulates trichome branching development.
- Author
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Song J, Wang A, Zhu W, Yang L, Xie Z, Han X, Wang B, Tian B, Zhang L, Chen W, Wei F, and Shi G
- Subjects
- Brassinosteroids metabolism, Plants, Genetically Modified, Genes, Plant, DNA Topoisomerases, Type II genetics, DNA Topoisomerases, Type II metabolism, Steroids, Heterocyclic, Trichomes genetics, Trichomes growth & development, Trichomes metabolism, Gossypium genetics, Gossypium growth & development, Gossypium metabolism, Cyclopentanes metabolism, Plant Proteins genetics, Plant Proteins metabolism, Gene Expression Regulation, Plant, Oxylipins metabolism, Arabidopsis genetics, Arabidopsis growth & development, Arabidopsis metabolism, Endoreduplication genetics
- Abstract
Trichomes are specialized epidermal structures that protect plants from biotic and abiotic stresses by synthesizing, storing, and secreting defensive compounds. This study investigates the role of the Gossypium arboreum DNA topoisomerase VI subunit B gene (GaTOP6B) in trichome development and branching. Sequence alignment revealed a high similarity between GaTOP6B and AtTOP6B, suggesting a conserved function in trichome regulation. Although AtTOP6B acts as a positive regulator of trichome development, functional analyses showed contrasting effects: Virus-induced gene silencing (VIGS) of GaTOP6B in cotton increased trichome density, while its overexpression in Arabidopsis decreased trichome density but enhanced branching. This demonstrates that GaTOP6B negatively regulates trichome number, indicating species-specific roles in trichome initiation and branching between cotton and Arabidopsis. Overexpression of the GaTOP6B promotes jasmonic acid synthesis, which in turn inhibits the G1/S or G2/M transitions, stalling the cell cycle. On the other hand, it suppresses brassinolide synthesis and signaling while promoting cytokinin degradation, further inhibiting mitosis. These hormonal interactions facilitate the transition of cells from the mitotic cycle to the endoreduplication cycle. As the level of endoreduplication increases, trichomes develop an increased number of branches. These findings highlight GaTOP6B's critical role as a regulator of trichome development, providing new genetic targets for improving cotton varieties in terms of enhanced adaptability and resilience., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)
- Published
- 2024
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