CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
School of Health and Nursing, Wuchang University of Technology, Wuhan, China.
BMC Biol. 2024 Feb 27;22(1):45. doi: 10.1186/s12915-024-01836-x.
Most disease resistance (R) genes in plants encode proteins that contain leucine-rich-repeat (LRR) and nucleotide-binding site (NBS) domains, which belong to the NBS-LRR family. The sequenced genomes of Fusarium wilt-susceptible Vernicia fordii and its resistant counterpart, Vernicia montana, offer significant resources for the functional characterization and discovery of novel NBS-LRR genes in tung tree.
Here, we identified 239 NBS-LRR genes across two tung tree genomes: 90 in V. fordii and 149 in V. montana. Five VmNBS-LRR paralogous were predicted in V. montana, and 43 orthologous were detected between V. fordii and V. montana. The orthologous gene pair Vf11G0978-Vm019719 exhibited distinct expression patterns in V. fordii and V. montana: Vf11G0978 showed downregulated expression in V. fordii, while its orthologous gene Vm019719 demonstrated upregulated expression in V. montana, indicating that this pair may be responsible for the resistance to Fusarium wilt in V. montana. Vm019719 from V. montana, activated by VmWRKY64, was shown to confer resistance to Fusarium wilt in V. montana by a virus-induced gene silencing (VIGS) experiment. However, in the susceptible V. fordii, its allelic counterpart, Vf11G0978, exhibited an ineffective defense response, attributed to a deletion in the promoter's W-box element.
This study provides the first systematic analysis of NBS-LRR genes in the tung tree and identifies a candidate gene that can be utilized for marker-assisted breeding to control Fusarium wilt in V. fordii.
植物中的大多数抗病（R）基因编码含有富含亮氨酸重复（LRR）和核苷酸结合位点（NBS）结构域的蛋白质，这些结构域属于 NBS-LRR 家族。易感品种油桐（Vernicia fordii）和其抗性品种山桐子（Vernicia montana）的测序基因组为油桐功能特征和新型 NBS-LRR 基因的发现提供了重要资源。
本研究在两个油桐基因组中共鉴定出 239 个 NBS-LRR 基因：90 个在 V. fordii 中，149 个在 V. montana 中。在 V. montana 中预测到 5 个 VmNBS-LRR 基因的旁系同源物，在 V. fordii 和 V. montana 之间检测到 43 个直系同源物。直系同源基因对 Vf11G0978-Vm019719 在 V. fordii 和 V. montana 中表现出不同的表达模式：Vf11G0978 在 V. fordii 中表达下调，而其直系同源基因 Vm019719 在 V. montana 中表达上调，表明这一对基因可能与 V. montana 对枯萎病的抗性有关。Vm019719 来自 V. montana，被 VmWRKY64 激活，通过病毒诱导的基因沉默（VIGS）实验显示其在 V. montana 中赋予对枯萎病的抗性。然而，在易感品种 V. fordii 中，其等位基因 Vf11G0978 表现出无效的防御反应，这归因于启动子 W 框元件的缺失。
本研究首次对油桐中的 NBS-LRR 基因进行了系统分析，并鉴定出一个候选基因，可用于标记辅助育种以控制 V. fordii 的枯萎病。
