Promoter characterization of a citrus linalool synthase gene mediating interspecific variation in resistance to a bacterial pathogen

• DOI: 10.1186/s12870-023-04413-6
• Publication Date: 2023-08-25T03:24:45Z
• Authors: Qiying Wang; Xiaochun Wang; Linhua Huang; Yujiao Cheng; Li Ren; Huayu Yang; Changyong Zhou; Xuefeng Wang; Jun He
• Keywords: Citrus; QK1-989; Research; Acyclic Monoterpenes; Botany; Arabidopsis; Monoterpenes; Promoter; Canker disease; Nitric Oxide Synthase; Plants, Genetically Modified; Terpene synthase; Linalool

Terpenoids play essential roles in plant defense against biotic stresses. In Citrus species, the monoterpene linalool mediates resistance citrus canker disease caused by gram-negative bacteria Xanthomonas citri subsp. (Xcc). Previous work had associated contents with resistance; here we characterize transcriptional responses of synthase genes.Leaf are highly variable among different species. "Dongfang" tangerine (Citrus reticulata), a species high levels was more resistant to Xcc than "Shatian" pummelo (C. grandis) which accumulates only small amounts linalool. The coding sequences major leaf-expressed gene (STS4) conserved, while transcript differ between two To understand this apparent differential transcription, isolated promoters STS4 from fused them GUS reporter and expressed Arabidopsis. This system revealed that have constitutive activities, mainly trichomes. Interestingly, both insensitive infestation plants, but these transgenic Arabidopsis activated challenge bacterial pathogen Pseudomonas syringae, as well wounding external jasmonic acid treatment.Our study reveals variation may be mediated promoter activities terpene