Rodriguez María V, Tano Josefina, Ansaldi Nazarena, Carrau Analía, Srebot María S, Ferreira Virginia, Martínez María L, Cortadi Adriana A, Siri María I, Orellano Elena G
Área Biología Vegetal (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Universidad Nacional de Rosario, Rosario, Argentina.
Front Plant Sci. 2019 Dec 23;10:1618. doi: 10.3389/fpls.2019.01618. eCollection 2019.
Nowadays, fertilization and pest control are carried out using chemical compounds that contaminate soil and deteriorate human health. Plant growth promoting bacteria endophytes (PGPBEs), are a well-studied group of bacteria that offers benefits to the host plant, such as phytostimulation, biofertilization, and protection against other microorganisms. The study of -which belongs to PGPBEs-aids the development of alternative strategies of an integrated approach for crop management practices. is responsible for bacterial wilt disease. This phytopathogen is of great interest worldwide due to the enormous economic losses it causes. In this study the action of as a growth promoting bacterium in seedlings is analyzed, evaluating the antagonistic mechanisms of this beneficial endophytic bacterium during biotic stress produced by . Effective colonization of was determined through bacterial counting assays, evaluation of anatomical and growth parameters, and pigments quantification. Biocontrol assays were carried out with GMI1000 model strain and A21 a recently isolated strain. Inoculation of (Col 0) with Pal 5 triggers a set of biochemical and structural changes in roots, stems, and leaves of seedlings. Discrete callose deposits as papillae were observed at specific sites of root hairs, trichomes, and leaf tissue. Upon GMI1000 infection, endophyte-treated plants demonstrated being induced for defense through an augmented callose deposition at root hairs and leaves compared with the non-endophyte-treated controls. The endophytic bacterium appears to be able to prime callose response. Roots and stems cross sections showed that integrity of all tissues was preserved in endophyte-treated plants infected with A21. The mechanisms of resistance elicited by the plant after inoculation with the endophyte would be greater lignification and sclerosis in tissues and reinforcement of the cell wall through the deposition of callose. As a consequence of this priming in plant defense response, viable phytopathogenic bacteria counting were considerably fewer in endophyte-inoculated plants than in not-inoculated controls. Our results indicate that colonizes plants performing a protective role against the phytopathogenic bacterium promoting the activation of plant defense system.
如今，施肥和病虫害防治使用的化学化合物会污染土壤并损害人类健康。植物内生促生细菌（PGPBEs）是一类经过充分研究的细菌，能为宿主植物带来诸多益处，如植物刺激、生物施肥以及抵御其他微生物。对属于PGPBEs的[具体细菌名称未给出]的研究有助于开发用于作物管理实践的综合方法的替代策略。[具体细菌名称未给出]会引发青枯病。这种植物病原体因其造成的巨大经济损失而在全球备受关注。在本研究中，分析了[具体细菌名称未给出]作为促生细菌在[植物名称未给出]幼苗中的作用，评估了这种有益内生细菌在由[具体细菌名称未给出]产生的生物胁迫期间的拮抗机制。通过细菌计数分析、解剖学和生长参数评估以及色素定量来确定[具体细菌名称未给出]的有效定殖。使用GMI1000模式菌株和最近分离的A21菌株进行了生物防治试验。用Pal 5接种[植物名称未给出]（Col 0）会在幼苗的根、茎和叶中引发一系列生化和结构变化。在根毛、毛状体和叶组织的特定部位观察到作为乳头状的离散胼胝质沉积。在感染GMI1000后，与未用内生细菌处理的对照相比，经内生细菌处理的植物通过在根毛和叶片处增加胼胝质沉积而表现出防御诱导。内生细菌似乎能够引发胼胝质反应。根和茎的横切面显示，在用A21感染的经内生细菌处理的植物中，所有组织的完整性得以保留。接种内生细菌后植物引发的抗性机制将是组织中更大程度的木质化和硬化以及通过胼胝质沉积增强细胞壁。由于这种植物防御反应的引发，与未接种的对照相比，接种内生细菌的植物中存活的植物病原细菌数量要少得多。我们的结果表明，[具体细菌名称未给出]定殖于[植物名称未给出]植物，对植物病原细菌[具体细菌名称未给出]起到保护作用，促进植物防御系统的激活。
