Burkholderia sp. Strain AU4i Promotes Arabidopsis Growth and Increases Plant Defence Response to Necrotrophic Pathogens
Burkholderia sp. Strain AU4i Promotes Arabidopsis Growth and Increases Plant Defence Response to Necrotrophic Pathogens
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DOI：
10.1007/s00344-020-10238-6
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发表时间：
2020-10-19
影响因子：
4.8
通讯作者：
Marina, Maria
中科院分区：
文献类型：
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作者：
Colavolpe, Maria Belen;Villarreal, Natalia Marina;Marina, Maria
Burkholderia sp.AU4i是一株以前从豌豆中分离出来的菌株，可以作为植物生长促进根际细菌(PGPR)。在这里，我们证明了AU4i能够促进拟南芥的生长，增加侧根的数量以及地上部和根部的干重。用AU4i接种拟南芥叶片，可显著减少由坏死性病原菌灰霉病菌和菌核病引起的病斑面积。细菌接种诱导茉莉酸反应标记基因AtPDF1.2的表达，但不诱导水杨酸标记基因AtPR-1的表达。尽管如此，与COL-0相比，拟南芥突变体coi1和sid2-2(茉莉酸感知缺陷和水杨酸合成缺陷)的AU4I保护作用相似。因此，AU4i的保护作用和植物防御信号通路是独立的。AU4i接种能够诱导花色苷和酚类化合物的积累，以及苯丙氨酸解氨酶的活性。此外，还评价了接种AU4i对植物细胞壁代谢的影响。结果表明，在含有拟南芥叶片细胞壁多糖的培养液中，灰霉菌和核盘菌的菌丝生长受到抑制。此外，被AU4i侵染的叶片表现出与半纤维素和果胶降解相关的基因(分别为AtExp8和AtAra1)的下调和AtPME3的上调，AtPME3基因编码参与果胶主链脱酯的果胶甲基酯酶。综上所述，我们的结果表明伯克霍尔德氏菌。AU4i不仅是潜在的生防剂，而且也是更好地了解PGPR保护植物免受真菌攻击的机制的一个很好的候选者。
Burkholderia sp. AU4i is a strain previously isolated from pea, which can act as plant growth-promoting rhizobacteria (PGPR). Here, we demonstrate that AU4i is able to promote Arabidopsis growth and increase the number of lateral roots as well as shoot and root dry weight. The inoculation of Arabidopsis leaves with AU4i significantly reduced the lesion's areas provoked by the necrotrophic pathogens Botrytis cinerea and Sclerotinia sclerotiorum. Bacterial inoculation induced the expression of the jasmonate responsive marker gene AtPDF1.2, but not the expression of salicylic acid marker gene AtPR-1. Notwithstanding, similar AU4i protective effect was observed in Arabidopsis mutants coi1 and sid2-2 (defective in jasmonate perception and salicylic acid synthesis, respectively) compared with Col-0 plants. Thus, the independence of the AU4i protective effect and plant defence signalling pathways is suggested. AU4i inoculation was able to induced anthocyanins and phenolic compounds accumulation, as well as phenylalanine ammonia-lyase activity. Moreover, the effect of AU4i inoculation on the metabolism of plant cell wall was evaluated. As a result, B. cinerea and S. sclerotiorum mycelial growth was reduced in culture media containing cell wall polysaccharides from inoculated Arabidopsis leaves. Additionally, leaves colonized by AU4i showed the downregulation of genes involved in hemicelluloses and pectins degradation (AtExp8 and AtAra1, respectively) and the upregulation of AtPME3, a gene encoding a putative pectin methylesterase involved in pectin main chain de-esterification. Taken together, our results suggest Burkholderia sp. AU4i not only as potential biocontrol agent, but also as a good candidate for better understanding the mechanisms used by PGPRs to protect plants from fungal attacks.