College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Fruit Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, 350013, China.
BMC Genomics. 2024 Sep 28;25(1):895. doi: 10.1186/s12864-024-10830-0.
DIR (Dirigent) proteins play important roles in the biosynthesis of lignin and lignans and are involved in various processes such as plant growth, development, and stress responses. However, there is less information about VvDIR proteins in grapevine (Vitis vinifera L).
In this study, we used bioinformatics methods to identify members of the DIR gene family in grapevine and identified 18 VvDIR genes in grapevine. These genes were classified into 5 subfamilies based on phylogenetic analysis. In promoter analysis, various plant hormones, stress, and light-responsive cis-elements were detected. Expression profiling of all genes following Colletotrichum gloeosporioides infection and phytohormones (salicylic acid (SA) and jasmonic acid (JA)) application suggested significant upregulation of 17 and 6 VvDIR genes, respectively. Further, we overexpressed the VvDIR4 gene in Arabidopsis thaliana and grapes for functional analysis. Ectopic expression of VvDIR4 in A. thaliana and transient expression in grapes increased resistance against C. gloeosporioides and C. higginsianum, respectively. Phenotypic observations showed small disease lesions in transgenic plants. Further, the expression patterns of genes having presumed roles in SA and JA signaling pathways were also influenced. Lignin contents were measured before and after C. higginsianum infection; the transgenic A. thaliana lines showed higher lignin content than wild-type, and a significant increase was observed after C. higginsianum infection.
Based on the findings, we surmise that VvDIR4 is involved in hormonal and lignin synthesis pathways which regulate resistance against anthracnose. Our study provides novel insights into the function of VvDIR genes and new candidate genes for grapevine disease resistance breeding programs.
DIR（导向）蛋白在木质素和木脂素的生物合成中发挥重要作用，参与植物生长、发育和应激反应等各种过程。然而，关于葡萄（Vitis vinifera L.）中的 VvDIR 蛋白知之甚少。
本研究利用生物信息学方法鉴定了葡萄 DIR 基因家族的成员，在葡萄中鉴定出 18 个 VvDIR 基因。这些基因根据系统发育分析分为 5 个亚家族。在启动子分析中，检测到各种植物激素、应激和光照响应的顺式元件。Colletotrichum gloeosporioides 感染和植物激素（水杨酸（SA）和茉莉酸（JA））处理后所有基因的表达谱分析表明，17 个和 6 个 VvDIR 基因分别显著上调。此外，我们在拟南芥和葡萄中过表达 VvDIR4 基因进行功能分析。VvDIR4 在拟南芥中的异位表达和在葡萄中的瞬时表达分别提高了对 C. gloeosporioides 和 C. higginsianum 的抗性。表型观察表明，转基因植物的病斑较小。此外，假定参与 SA 和 JA 信号通路的基因的表达模式也受到影响。在 C. higginsianum 感染前后测量木质素含量；与野生型相比，转基因拟南芥系的木质素含量更高，感染 C. higginsianum 后显著增加。
基于这些发现，我们推测 VvDIR4 参与了激素和木质素合成途径，调节对炭疽病的抗性。我们的研究为 VvDIR 基因的功能提供了新的见解，并为葡萄抗病性育种计划提供了新的候选基因。
