Tianjin Agricultural University, College of Horticulture and Landscape Architecture, Tianjin, 300394, China.
Tianjin Agricultural University, College of Engineering and Technology Architecture, Tianjin, 300394, China.
Plant Physiol Biochem. 2024 Oct;215:108869. doi: 10.1016/j.plaphy.2024.108869. Epub 2024 Jun 20.
Crown gall caused by Agrobacterium vitis (A. vitis) is one of the crucial issues restricting the to grape industry. In this study, Agrobacterium tumefaciens (Ag-8) was separated from the soil that could prevent the occurrence of grape crown gall. By the mutagenesis of Ag-8 transposon, the siaD gene deletion strain (ΔsiaD) showed significantly lower efficacy in grape and tomato plants for controlling grape crown gall, but the relevant mechanism was not clear. The biofilm formation and motility of ΔsiaD were significantly decreased, and the colonization ability of ΔsiaD in tomato roots was significantly reduced. RNA-seq analysis showed that the expression of nemR significantly reduced in the ΔsiaD and that the expression of nemR showed a high correlation with biofilm and motility. Further studies showed that the nemR gene deletion strain of Ag-8 (ΔnemR) showed significantly reduced motility, biofilm formation and control of grape crown gall compared to Ag-8, and the nemR gene complementary strain of Ag-8 (ΔnemR-comp) recovered to Ag-8 wild-type levels. The inoculation experiments of preventive, curative or simultaneous treatment further showed that the preferential inoculation with Ag-8 reduced the incidence of grape crown gall on tomato plants, and studies showed that the mutation of siaD affected the site competition between Ag-8 and A. vitis, and that the mutation of nemR was consistent with the previous results. This study provides a new strategy for the prevention and control of grape crown gall, which is of great significance to the grape industry to increase production and income.
由根癌农杆菌（Agrobacterium vitis）引起的冠瘿病是制约葡萄产业发展的关键问题之一。本研究从能够预防葡萄冠瘿病发生的土壤中分离出根癌农杆菌（Agrobacterium tumefaciens）（Ag-8）。通过 Ag-8 转座子的诱变，siaD 基因缺失菌株（ΔsiaD）在葡萄和番茄植株上控制葡萄冠瘿病的效果明显降低，但相关机制尚不清楚。ΔsiaD 的生物膜形成和运动能力显著降低，在番茄根系中的定殖能力显著降低。RNA-seq 分析表明，ΔsiaD 中 nemR 的表达显著降低，且 nemR 的表达与生物膜和运动性呈高度相关。进一步研究表明，与 Ag-8 相比，Ag-8 的 nemR 基因缺失菌株（ΔnemR）的运动性、生物膜形成和控制葡萄冠瘿病的能力显著降低，而 Ag-8 的 nemR 基因互补菌株（ΔnemR-comp）则恢复到 Ag-8 野生型水平。预防性、治疗性或同时处理的接种实验进一步表明，优先接种 Ag-8 可降低番茄植株上葡萄冠瘿病的发病率，研究表明 siaD 的突变影响了 Ag-8 和 A. vitis 之间的位点竞争，而 nemR 的突变与之前的结果一致。本研究为葡萄冠瘿病的防治提供了新策略，对葡萄产业增产增收具有重要意义。
