The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, PR China.
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, PR China.
Microbiol Res. 2024 Sep;286:127823. doi: 10.1016/j.micres.2024.127823. Epub 2024 Jun 30.
Plant-associated streptomycetes play important roles in plant growth and development. However, knowledge of volatile-mediated crosstalk between Streptomyces spp. and plants remains limited. In this study, we investigated the impact of volatiles from nine endophytic Streptomyces strains on the growth and development of plants. One versatile strain, Streptomyces setonii WY228, was found to significantly promote the growth of Arabidopsis thaliana and tomato seedlings, confer salt tolerance, and induce early flowering and increased fruit yield following volatile treatment. Analysis of plant growth-promoting traits revealed that S. setonii WY228 could produce indole-3-acetic acid, siderophores, ACC deaminase, fix nitrogen, and solubilize inorganic phosphate. These capabilities were further confirmed through genome sequencing and analysis. Volatilome analysis indicated that the volatile organic compounds emitted from ISP-2 medium predominantly comprised sesquiterpenes and 2-ethyl-5-methylpyrazine. Further investigations showed that 2-ethyl-5-methylpyrazine and sesquiterpenoid volatiles were the primary regulators promoting growth, as confirmed by experiments using the terpene synthesis inhibitor phosphomycin, pure compounds, and comparisons of volatile components. Transcriptome analysis, combined with mutant and inhibitor studies, demonstrated that WY228 volatiles promoted root growth by activating Arabidopsis auxin signaling and polar transport, and enhanced root hair development through ethylene signaling activation. Additionally, it was confirmed that volatiles can stimulate plant abscisic acid signaling and activate the MYB75 transcription factor, thereby promoting anthocyanin synthesis and enhancing plant salt stress tolerance. Our findings suggest that aerial signaling-mediated plant growth promotion and abiotic stress tolerance represent potentially overlooked mechanisms of Streptomyces-plant interactions. This study also provides an exciting strategy for the regulation of plant growth and the improvement of horticultural crop yields within sustainable agricultural practices.
植物相关链霉菌在植物生长和发育中起着重要作用。然而，链霉菌属与植物之间挥发性介导的串扰的知识仍然有限。在这项研究中，我们研究了来自 9 种内生链霉菌菌株的挥发物对植物生长和发育的影响。一种多功能菌株，链霉菌属 setonii WY228，被发现显著促进拟南芥和番茄幼苗的生长，赋予耐盐性，并在挥发性处理后诱导早花和增加果实产量。植物促生特性分析表明，链霉菌属 setonii WY228 可以产生吲哚-3-乙酸、铁载体、ACC 脱氨酶、固定氮和溶解无机磷。这些能力通过基因组测序和分析得到了进一步证实。挥发物组分析表明，ISP-2 培养基中释放的挥发性有机化合物主要由倍半萜和 2-乙基-5-甲基吡嗪组成。进一步的研究表明，2-乙基-5-甲基吡嗪和倍半萜类挥发物是促进生长的主要调节剂，这通过使用萜烯合成抑制剂磷霉素、纯化合物以及挥发性成分比较的实验得到了证实。转录组分析，结合突变体和抑制剂研究，表明 WY228 挥发物通过激活拟南芥生长素信号和极性运输促进根生长，并通过乙烯信号激活增强根毛发育。此外，还证实了挥发物可以刺激植物脱落酸信号并激活 MYB75 转录因子，从而促进花青素合成并增强植物耐盐性。我们的研究结果表明，空中信号介导的植物生长促进和非生物胁迫耐受性代表了链霉菌与植物相互作用中可能被忽视的机制。本研究还为植物生长的调控和园艺作物产量的提高提供了一种令人兴奋的策略，这符合可持续农业实践的要求。
