Zhang Ya-Lin, Li Zhi-Fang, Feng Zi-Li, Feng Hong-Jie, Zhao Li-Hong, Shi Yong-Qiang, Hu Xiao-Ping, Zhu He-Qin
State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Curr Genet. 2015 Nov;61(4):555-66. doi: 10.1007/s00294-015-0476-z. Epub 2015 Feb 5.
The fungal plant pathogen Verticillium dahliae is the causal agent of vascular wilt, a disease that can seriously diminish cotton fiber yield. The pathogenicity mechanism and the identity of the genes that interact with cotton during the infection process still remain unclear. In this study, we investigated the low-pathogenic, non-microsclerotium-producing mutant vdpr3 obtained in a previous study from the screening of a T-DNA insertional library of the highly virulent isolate Vd080; the pathogenicity-related gene (VdPR3) in wild-type strain Vd080 was cloned. Knockout mutants (ΔVdPR3) showed lower mycelium growth and obvious reduction in sporulation ability without microsclerotium formation. An evaluation of carbon utilization in mutants and wild-type isolate Vd080 demonstrated that mutants-lacking VdPR3 exhibited decreased cellulase and amylase activities, which was restored in the complementary mutants (ΔVdPR3-C) to levels similar to those of Vd080. ΔVdPR3 postponed infectious events in cotton and showed a significant reduction in pathogenicity. Reintroduction of a functional VdPR3 copy into ΔVdPR3-C restored the ability to infect cotton plants. These results suggest that VdPR3 is a multifunctional gene involved in growth development, extracellular enzyme activity, and virulence of V. dahliae on cotton.
真菌植物病原菌大丽轮枝菌是维管束萎蔫病的致病因子，这种病害会严重降低棉花纤维产量。在感染过程中，其致病机制以及与棉花相互作用的基因身份仍不明确。在本研究中，我们对先前从高毒力菌株Vd080的T-DNA插入文库筛选中获得的低致病性、不产生微菌核的突变体vdpr3进行了研究；克隆了野生型菌株Vd080中与致病性相关的基因（VdPR3）。基因敲除突变体（ΔVdPR3）的菌丝生长较慢，产孢能力明显下降，且不形成微菌核。对突变体和野生型菌株Vd080的碳利用情况进行评估表明，缺失VdPR3的突变体纤维素酶和淀粉酶活性降低，而在互补突变体（ΔVdPR3-C）中恢复到与Vd080相似的水平。ΔVdPR3延缓了棉花中的感染进程，致病性显著降低。将功能性VdPR3拷贝重新导入ΔVdPR3-C中恢复了其感染棉花植株的能力。这些结果表明，VdPR3是一个多功能基因，参与大丽轮枝菌在棉花上的生长发育、胞外酶活性和毒力。
