Department of Microbial Ecology, Netherlands Institute of Ecology, 6708 PB Wageningen, The Netherlands.
Institute of Biology, Leiden University, 2333 BE Leiden, The Netherlands.
Biomolecules. 2021 Nov 16;11(11):1704. doi: 10.3390/biom11111704.
Genome-wide analysis of plant-growth-promoting strain SS101 (SS101) followed by site-directed mutagenesis previously suggested that sulfur assimilation may play an important role in growth promotion and induced systemic resistance in . Here, we investigated the effects of sulfur metabolism in SS101 on growth, defense, and shoot metabolomes of and the Brassica crop, Broccoli. Root tips of seedlings of and two Broccoli cultivars were treated with SS101 or with a mutant disrupted in the adenylsulfate reductase , a key gene in cysteine and methionine biosynthesis. Phenotyping of plants treated with wild-type SS101 or its mutant revealed that sulfur assimilation in SS101 was associated with enhanced growth of but with a reduction in shoot biomass of two Broccoli cultivars. Untargeted metabolomics revealed that -mediated sulfur assimilation in SS101 had significant effects on shoot chemistry of , in particular on chain elongation of aliphatic glucosinolates (GLSs) and on indole metabolites, including camalexin and the growth hormone indole-3-acetic acid. In Broccoli, SS101 sulfur assimilation significantly upregulated the relative abundance of several shoot metabolites, in particular, indolic GLSs and phenylpropanoids. These metabolome changes in Broccoli plants coincided with SS101-mediated suppression of leaf infections by . Our study showed the metabolic interconnectedness of plants and their root-associated microbiota.
对植物促生菌 SS101（SS101）进行全基因组分析，然后进行定点突变，先前的研究表明，硫同化可能在生长促进和诱导中起重要作用。在这里，我们研究了 SS101 中的硫代谢对生长、防御和拟南芥 shoot 代谢组的影响，以及 Brassica 作物西兰花。用 SS101 或其突变体处理拟南芥和两个西兰花品种的幼苗根尖，突变体破坏了半胱氨酸和蛋氨酸生物合成的关键基因腺苷硫酸还原酶。用野生型 SS101 或其 突变体处理的植物表型显示，SS101 中的硫同化与拟南芥生长的增强有关，但两个西兰花品种的 shoot 生物量减少。非靶向代谢组学表明，SS101 中的硫同化通过介导对拟南芥 shoot 化学物质的影响，特别是对脂肪族硫葡萄糖苷（GLS）和吲哚代谢物的链延伸，包括 camalexin 和生长激素吲哚-3-乙酸的影响。在西兰花中，SS101 硫同化显著上调了几种 shoot 代谢物的相对丰度，特别是吲哚 GLSs 和苯丙烷类化合物。这些西兰花植物的代谢组变化与 SS101 介导的抑制叶片由 引起的感染相一致。我们的研究表明，植物及其与根相关的微生物群之间存在代谢的相互联系。
