Wolfgang Adrian, Zachow Christin, Müller Henry, Grand Alfred, Temme Nora, Tilcher Ralf, Berg Gabriele
Austrian Centre of Industrial Biotechnology (ACIB GmbH), Graz, Austria.
Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria.
Front Plant Sci. 2020 Sep 30;11:560869. doi: 10.3389/fpls.2020.560869. eCollection 2020.
The rhizosphere microbiome is crucial for plant health, especially for preventing roots from being infected by soil-borne pathogens. Microbiota-mediated pathogen response in the soil-root interface may hold the key for microbiome-based control strategies of phytopathogens. We studied the pathosystem sugar beet-late sugar beet root rot caused by in an integrative design of combining and (greenhouse and field) trials. We used five different cultivars originating from two propagation sites (France, Italy) with different degrees of susceptibility towards (two susceptible, one moderately tolerant and two cultivars with partial resistance). Analyzing bacterial communities in seeds and roots grown under different conditions by 16S rRNA amplicon sequencing, we found site-, cultivar-, and microhabitat-specific amplicon sequences variants (ASV) as well as a seed core microbiome shared between all sugar beet cultivars (121 ASVs representing 80%-91% relative abundance). In general, cultivar-specific differences in the bacterial communities were more pronounced in seeds than in roots. Seeds of -tolerant cultivars contain a higher relative abundance of the genera , , and , while , and were enhanced in responsive rhizospheres. These results indicate a correlation between bacterial seed endophytes and -tolerant cultivars. Root communities are mainly substrate-derived but also comprise taxa exclusively derived from seeds. Interestingly, the signature of Re*1-1-14, a well-studied sugar-beet specific biocontrol agent, was frequently found and in higher relative abundances in -tolerant than in susceptible cultivars. For microbiome management, we introduced microbial inoculants (consortia) and microbiome transplants (vermicompost) in greenhouse and field trials; both can modulate the rhizosphere and mediate tolerance towards late sugar beet root rot. Both, seeds and soil, provide specific beneficial bacteria for rhizosphere assembly and microbiota-mediated pathogen tolerance. This can be translated into microbiome management strategies for plant and ecosystem health.
根际微生物群对植物健康至关重要，尤其是在防止根系被土传病原体感染方面。土壤-根系界面中微生物群介导的病原体反应可能是基于微生物群的植物病原体控制策略的关键。我们在结合温室和田间试验的综合设计中，研究了由引起的甜菜-晚熟甜菜根腐病病理系统。我们使用了来自两个繁殖地点（法国、意大利）的五个不同品种，它们对具有不同程度的易感性（两个易感品种、一个中度耐受品种和两个部分抗性品种）。通过16S rRNA扩增子测序分析在不同条件下生长的种子和根中的细菌群落，我们发现了位点、品种和微生境特异性的扩增子序列变体（ASV），以及所有甜菜品种之间共有的种子核心微生物群（121个ASV，代表相对丰度的80%-91%）。一般来说，细菌群落中品种特异性差异在种子中比在根中更明显。耐品种的种子中属、和的相对丰度较高，而在反应性根际中、和有所增加。这些结果表明细菌种子内生菌与耐品种之间存在相关性。根际群落主要来源于底物，但也包括仅来源于种子的分类群。有趣的是，经常发现一种经过充分研究的甜菜特异性生物防治剂Re*1-1-1-14的特征，并且在耐品种中的相对丰度高于易感品种。为了进行微生物群管理，我们在温室和田间试验中引入了微生物接种剂（菌群）和微生物群移植（蚯蚓堆肥）；两者都可以调节根际并介导对晚熟甜菜根腐病的耐受性。种子和土壤都为根际组装和微生物群介导的病原体耐受性提供了特定的有益细菌。这可以转化为促进植物和生态系统健康的微生物群管理策略。
