The tat pathway of the plant pathogen Pseudomonas syringae is required for optimal virulence
The tat pathway of the plant pathogen Pseudomonas syringae is required for optimal virulence
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DOI：
10.1094/mpmi-19-0200
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发表时间：
2006-02-01
影响因子：
3.5
通讯作者：
Palmer, T
中科院分区：
文献类型：
--
作者：
Caldelari, I;Mann, S;Palmer, T
假单胞菌是一种革兰氏阴性细菌，感染许多农业上重要的植物物种。生物体通过植物细胞壁传递毒力因子的能力是其致病性的关键。两个致病型的双精氨酸易位（达特）途径的缺失突变体。番茄DC 3000和maculicola ES 4326表现出一系列的多效性表型变化，如荧光铁载体产生缺陷，十二烷基硫酸钠和铜抗性降低，以及使用拟南芥或番茄作为植物宿主的适应性的显著损失。该菌的基因组序列。番茄DC 3000编码许多潜在的毒力因子，预测这些毒力因子通过达特途径易位，包括几种参与铁清除的蛋白质（两种铁载体受体PSPTO 3474和PSPTO 3294，以及一种氨基转移酶PSPTO 2155，参与铁载体生物合成）。Tat依赖性致病性决定簇的其他候选物包括细胞壁酰胺酶（PSPTO 5528）、参与周质葡聚糖生物合成的酶（PSPTO 5542）和两种推定的磷脂酶（PSPTO 3648和PSPTOB 0005）的同系物。假定的酰胺酶，氨基转移酶，葡聚糖生物合成酶，和两个磷脂酶，但不是两个铁载体受体的易位，被证明是依赖于达特途径。缺失编码可能的氨基转移酶和酰胺酶的基因的菌株的感染性显著低于野生型。我们的结论是，由于未能正确定位至少两个，可能更多的，达特基板的增量效应引起的衰减健身表型的P.lingae pv。番茄DC3000达特菌株。
Pseudomonas syringae is a gram-negative bacterium that infects a number of agriculturally important plant species. The ability of the organism to deliver virulence factors across the plant cell wall is a key to its pathogenicity. Deletion mutants in the twin arginine translocation (Tat) pathway of two pathovars of P. syringae, pvs. tomato DC3000 and maculicola ES4326, displayed a range of pleiotropic phenotypic changes, such as defects in fluorescent siderophore production, a decrease in sodium dodecyl sulfate and copper resistance, and a significant loss in fitness using Arabidopsis thaliana or tomato as plant hosts. The genome sequence of P syringae pv. tomato DC3000 encodes a number of potential virulence factors that are predicted to be translocated via the Tat pathway, including several proteins involved in iron scavenging (two siderophore receptors, PSPTO3474 and PSPTO3294, and an aminotransferase, PSPTO2155, involved in siderophore biosynthesis). Further candidates for Tat-dependent pathogenicity determinants include the homologs of a cell wall amidase (PSPTO5528), an enzyme involved in periplasmic glucans biosynthesis (PSPTO5542), and two putative phospholipases (PSPTO3648 and PSPTOB0005). Translocation of the putative amidase, aminotransferase, glucans biosynthetic enzyme, and the two phospholipases, but not the two siderophore receptors, is shown to be dependent on the Tat pathway. Strains deleted for the genes encoding the probable aminotransferase and amidase enzymes are significantly less infectious than the wild type. We conclude that the incremental effects due to the failure to correctly localize at least two, and possibly more, Tat substrates gives rise to the attenuated fitness phenotype of the P syringae pv. tomato DC3000 tat strain.