Endophytic colonization of Vitis vinifera L. by plant growth promoting bacterium Burkholderia sp strain PsJN
Endophytic colonization of Vitis vinifera L. by plant growth promoting bacterium Burkholderia sp strain PsJN
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DOI：
10.1128/aem.71.4.1685-1693.2005
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发表时间：
2005-04-01
影响因子：
4.4
通讯作者：
Barka, EA
中科院分区：
文献类型：
--
作者：
Compant, S;Reiter, B;Barka, EA
欧亚种葡萄的定殖型。植物生长促进菌伯克霍尔德氏菌(Burkholderia sp.菌株PsJN，在诺生菌条件下对其进行了研究。野生型PsJN菌株及其GFP(PsJN：：gfp2x)或GUSA(PsJN：：gusA11)基因工程衍生菌被用来计数和可视化组织定植。用细菌悬浮液接种具有5片发达叶片的4~5周龄试管苗的根际。然后通过稀释平板试验和器官切片的显微镜观察来监测附生和内生定植模式。细菌首先在根表面检测，然后在根内部组织中检测到细菌，最后在第五节间和第五叶组织中检测到细菌。对PsJN定殖型的分析表明，该菌株在葡萄根表面、细胞壁和某些根皮细胞的整个表面都有定殖。侧根出苗部位和根尖细胞丰富。此外，PsJN分泌的降解细胞壁的内切葡聚糖酶和内切多聚半乳糖醛酸酶解释了细菌如何进入根内部组织。在外胚层和几个皮层细胞层中观察到宿主防御反应。在茎和叶表面未发现细菌，但在植株的第五节间和第五叶的木质部导管中发现细菌。此外，细菌在第5叶中的含量高于第5节间，并且在气孔下室中可见。因此，伯克霍尔德氏菌(Burkholderia sp.)菌株PsJN能诱导局部寄主防御反应，并通过蒸腾作用系统地传播到地上部分。
Patterns of colonization of Vitis vinifera L. cv. Chardormay plantlets by a plant growth-promoting bacterium, Burkholderia sp. strain PsJN, were studied under gnotobiotic conditions. Wild-type strain PsJN and genetically engineered derivatives of this strain tagged with gfp (PsJN::gfp2x) or gusA (PsJN::gusA11) genes were used to enumerate and visualize tissue colonization. The rhizospheres of 4- to 5-week-old plantlets with five developed leaves were inoculated with bacterial suspensions. Epiphytic and endophytic colonization patterns were then monitored by dilution plating assays and microscopic observation of organ sections. Bacteria were chronologically detected first on root surfaces, then in root internal tissues, and finally in the fifth internode and the tissues of the fifth leaf. Analysis of the PsJN colonization patterns showed that this strain colonizes grapevine root surfaces, as well as cell walls and the whole surface of some rhizodermal cells. Cells were also abundant at lateral root emergence sites and root tips. Furthermore, cell wall-degrading endoglucanase and endopolygalacturonase secreted by PsJN explained how the bacterium gains entry into root internal tissues. Host defense reactions were observed in the exodermis and in several cortical cell layers. Bacteria were not observed on stem and leaf surfaces but were found in xylem vessels of the fifth internode and the fifth leaf of plantlets. Moreover, bacteria were more abundant in the fifth leaf than in the fifth internode and were found in substomatal chambers. Thus, it seems that Burkholderia sp. strain PsJN induces a local host defense reaction and systemically spreads to aerial parts through the transpiration stream.