Entry of Xanthomonas campestris pv. campestris into hydathodes of Arabidopsis thaliana leaves:: A system for studying early infection events in bacterial pathogenesis
Entry of Xanthomonas campestris pv. campestris into hydathodes of Arabidopsis thaliana leaves:: A system for studying early infection events in bacterial pathogenesis
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DOI：
10.1094/mpmi.1998.11.6.537
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发表时间：
1998-06-01
影响因子：
3.5
通讯作者：
Daniels, MJ
中科院分区：
文献类型：
--
作者：
Hugouvieux, V;Barber, CE;Daniels, MJ
野油菜黄单胞菌野油菜致病变种（Xanthomonascampestrispv，campestris，Xcc）是十字花科植物的一种维管病原菌，通常通过根管进入植物体内。通过对表面灭菌的抗性评估，可以在1小时后检测到细菌进入叶片。对叶片进行解剖并对细菌产生的β-葡萄糖醛酸酶进行组织化学染色，表明它们位于包虫中。与此相反，类似的实验与叶斑病原体X。campestrispv，armoraciae在叶片上有分布的染色，表明是通过气孔进入的。根据在标准条件下进入的Xcc的总数和对水囊菌定殖的偏好，拟南芥种质显示它们分为三类。测试先前分离的致病性受影响的Xcc突变体的包虫定植：HIP突变体的行为与野生型相比是不可替代的，rpf调节突变体的定殖减少了10倍，而对于具有改变的脂多糖的rfaX突变体，几乎没有活细菌可从包虫中回收。这一事实，连同位于包虫中的细菌中超氧化物歧化酶的快速诱导，表明水阴极中存在早期防御反应。
Xanthomonas campestris pv, campestris (Xcc) is a vascular pathogen of cruciferous plants that normally gains entry to plants via hydathodes, In order to study the basis of the preference for this portal of entry we have developed an Arabidopsis thaliana model with attached or detached leaves partially immersed in a bacterial suspension. Entry of bacteria into leaves, assessed by resistance to surface sterilization, could be detected after 1 h, Dissection of leaves and histochemical staining for beta-glucuronidase produced by the bacteria indicated that they were located in hydathodes. In contrast, similar experiments with the leaf-spotting pathogen X. campestris pv, armoraciae gave patterns of localized staining dispersed over the leaf area, indicative of entry through stomata, A survey of 41 A. thaliana accessions showed that they fell into three classes distinguishable by total numbers of Xcc that entered under standard conditions and by preference for hydathode colonization. Previously isolated Xcc mutants affected in pathogenicity were tested for hydathode colonization: an hip mutant behaved indistinguishably from the wild type, and rpf regulatory mutants gave 10-fold reduced colonization, whereas with rfaX mutants with altered lipopolysaccharide, few if any viable bacteria were recoverable from hydathodes, This fact, together with the rapid induction of superoxide dismutase in the bacteria located in hydathodes, suggests that an early defense reaction is mounted in the hydathode.