Comparative analysis of defence responses induced by the endophytic plant growth-promoting rhizobacterium Burkholderia phytofirmans strain PsJN and the non-host bacterium Pseudomonas syringae pv. pisi in grapevine cell suspensions
Comparative analysis of defence responses induced by the endophytic plant growth-promoting rhizobacterium Burkholderia phytofirmans strain PsJN and the non-host bacterium Pseudomonas syringae pv. pisi in grapevine cell suspensions
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DOI：
10.1093/jxb/erq291
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发表时间：
2011-01-01
影响因子：
6.9
通讯作者：
Dorey, Stephan
中科院分区：
文献类型：
--
作者：
Bordiec, Sophie;Paquis, Sandra;Dorey, Stephan
植物根际促生菌（PGPR）是一类在植物根际分布的有益微生物，具有促进植物生长的作用。PGPR也是众所周知的植物对病原体的系统抗性的诱导剂。然而，植物细胞直接感知这些细菌后局部涉及的分子机制仍然在很大程度上未知。植物伯克霍尔德氏菌菌株PsJN是一种内生PGPR，其定殖于葡萄藤并保护植物免受由灰葡萄孢（Botrytis cinerea）引起的灰霉病。本报告主要研究B诱发的局部防御事件。phytofirmans PsJN后感知葡萄藤细胞。结果表明，在加入细胞悬浮培养物后，细菌以类似于葡萄藤非宿主细菌假单胞菌pv. pisi。B。phytofirmans PsJN的感知导致了短暂的和单相的细胞外碱化，但没有检测到活性氧的积累或细胞死亡。与此相反，挑战与P. pisi诱导持续的双相细胞外碱化、双相氧化爆发和HR样反应。感知的PGPR也导致水杨酸（SA）的生产和防御基因的电池的表达，然而，强度较弱的防御基因表达触发的非宿主细菌。部分防御基因在B处理后表达上调。phytofirmans PsJN的挑战是特异性诱导的外源处理SA或茉莉酸，这表明这两个信号转导途径被激活的PGPR在葡萄藤。
Plant growth-promoting rhizobacteria (PGPR) are beneficial microorganisms that colonize the rhizosphere of many plant species and confer beneficial effects, such as an increase in plant growth. PGPR are also well known as inducers of systemic resistance to pathogens in plants. However, the molecular mechanisms involved locally after direct perception of these bacteria by plant cells still remain largely unknown. Burkholderia phytofirmans strain PsJN is an endophytic PGPR that colonizes grapevine and protects the plant against the grey mould disease caused by Botrytis cinerea. This report focuses on local defence events induced by B. phytofirmans PsJN after perception by the grapevine cells. It is demonstrated that, after addition to cell suspension cultures, the bacteria were tightly attaching to plant cells in a way similar to the grapevine non-host bacteria Pseudomonas syringae pv. pisi. B. phytofirmans PsJN perception led to a transient and monophasic extracellular alkalinization but no accumulation of reactive oxygen species or cell death were detected. By contrast, challenge with P. syringae pv. pisi induced a sustained and biphasic extracellular alkalinization, a two phases oxidative burst, and a HR-like response. Perception of the PGPR also led to the production of salicylic acid (SA) and the expression of a battery of defence genes that was, however, weaker in intensity compared with defence gene expression triggered by the non-host bacteria. Some defence genes up-regulated after B. phytofirmans PsJN challenge are specifically induced by exogenous treatment with SA or jasmonic acid, suggesting that both signalling pathways are activated by the PGPR in grapevine.