VdSNF1, the Sucrose Nonfermenting Protein Kinase Gene of Verticillium dahliae, Is Required for Virulence and Expression of Genes Involved in Cell-Wall Degradation
VdSNF1, the Sucrose Nonfermenting Protein Kinase Gene of Verticillium dahliae, Is Required for Virulence and Expression of Genes Involved in Cell-Wall Degradation
复制标题
DOI：
10.1094/mpmi-09-09-0217
复制
发表时间：
2011-01-01
影响因子：
3.5
通讯作者：
Kang, Seogchan
中科院分区：
文献类型：
--
作者：
Tzima, Aliki K.;Paplomatas, Epaminondas J.;Kang, Seogchan
大丽轮枝菌（Verticillium dahliae）是一种土传真菌，可引起多种植物的枯萎病。它的毒力已被归因于，除其他因素外，水解细胞壁降解酶（CWDE）的活性。蔗糖nonfermenting 1基因（VdSNF 1），调节分解代谢抑制，在大丽花V番茄种族1被破坏。在诱导培养基和模拟木质部流体培养基中，CWDE在所产生的突变体中的表达不被诱导。当以果胶或半乳糖为碳源生长时，突变体的生长显著减少，而以葡萄糖、蔗糖和木糖生长时，它们与野生型和异位转化体生长相似。突变体在番茄和茄子上的毒力严重受损（最终疾病严重程度平均降低87%）。显微镜下观察绿色荧光蛋白标记的VdSNF 1突变体（70 Delta SF-gfp 1）的侵染行为表明，该突变体在根的初始定殖中存在缺陷。番茄茎在子叶水平的横截面显示，70 Δ SF-gfp 1定殖木质部导管大大低于野生型菌株。野生型菌株大量定殖于木质部导管和邻近的薄壁细胞。植物组织中真菌生物量的定量进一步证实了相对于野生型菌株，70 Δ SF-gfp 1减少了根、茎和子叶的定殖。
Verticillium dahliae is a soilborne fungus causing vascular wilt in a diverse array of plant species. Its virulence has been attributed, among other factors, to the activity of hydrolytic cell wall degrading enzymes (CWDE). The sucrose nonfermenting 1 gene (VdSNF1), which regulates catabolic repression, was disrupted in V dahliae tomato race 1. Expression of CWDE in the resulting mutants was not induced in inductive medium and in simulated xylem fluid medium. Growth of the mutants was significantly reduced when grown with pectin or galactose as a carbon source whereas, with glucose, sucrose, and xylose, they grew similarly to wild-type and ectopic transformants. The mutants were severely impaired in virulence on tomato and eggplant (final disease severity reduced by an average of 87%). Microscopic observation of the infection behavior of a green fluorescent protein (gfp)-labeled VdSNF1 mutant (70 Delta SF-gfp1) showed that it was defective in initial colonization of roots. Cross sections of tomato stem at the cotyledonary level showed that 70 Delta SF-gfp1 colonized xylem vessels considerably less than the wild-type strain. The wildtype strain heavily colonized xylem vessels and adjacent parenchyma cells. Quantification of fungal biomass in plant tissues further confirmed reduced colonization of roots, stems, and cotyledons by 70 Delta SF-gfp1 relative to that by the wild-type strain.