CmNF-YB8 affects drought resistance in chrysanthemum by altering stomatal status and leaf cuticle thickness

• 作者: Tianle Wang Qian Wei Zhiling Wang Wenwen Liu Xin Zhao Chao Ma Junping Gao Yanjie Xu Bo Hong
• 来源期刊: 植物学报（英文版）
• 年，卷（期）: 2022,（3）
• 所属期刊栏目: Plant-abiotic Interactions
• 页码范围: 741-755
• 页数: 15页
• 语种: 英文

摘要

Drought is a major abiotic stress that limits plant growth and development. Adaptive mechanisms have evolved to mitigate drought stress, in-cluding the capacity to adjust water loss rate and to modify the morphology and structure of the epidermis. Here, we show that the expression of CmNF-YB8, encoding a nuclear factor Y (NF-Y) B-type subunit, is lower under drought conditions in chrysanthemum (Chrysanthemum morifolium). Transgenic chrysanthemum lines in which transcript levels of CmNF-YB8 were reduced by RNA interference (CmNF-YB8-RNAi) exhibited enhanced drought resistance relative to control lines, whereas lines overexpressing CmNF-YB8 (CmNF-YB8-OX) were less tolerant to drought. Compared to wild type (WT), CmNF-YB8-RNAi plants showed reduced stomatal opening and a thicker epidermal cuticle that correlated with their water loss rate. We also identified genes involved in stomatal adjustment (CBL-interacting protein kinase 6, CmCIPK6) and cuticle biosynthesis (CmSHN3) that are more highly expressed in CmNF-YB8-RNAi lines than in WT, CmCIPK6 being a direct downstream target of CmNF-YB8. Virus-induced gene si-lencing of CmCIPK6 or CmSHN3 in the CmNF-YB8-RNAi background abolished the effects of CmNF-YB8-RNAi on stomatal closure and cu-ticle deposition, respectively. CmNF-YB8 thus regulates CmCIPK6 and CmSHN3 expression to alter stomatal movement and cuticle thickness in the leaf epidermis, thereby affecting drought resistance.