He Yuxi, Guo Wenyu, Peng Jieli, Guo Jinying, Ma Jia, Wang Xu, Zhang Cuimian, Jia Nan, Wang Entao, Hu Dong, Wang Zhanwu
Institute of Agro-Resources and Environment/Hebei Fertilizer Technology Innovation Center, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang, China.
School of Landscape and Ecological Engineering, Hebei University of Engineering, Handan, China.
Front Microbiol. 2022 May 20;13:891245. doi: 10.3389/fmicb.2022.891245. eCollection 2022.
To investigate the mechanism underlying the plant growth-promoting (PGP) effects of strain sp. TOR3209, PGP traits responsible for indoleacetic acid production, siderophore production, and phosphate solubilization were tested by culturing the strain TOR3209 in the corresponding media. The effects of volatile organic compounds (VOCs) produced by the strain TOR3209 on plant growth were observed by co-culturing this strain with tobacco seedlings in I-plates. Meanwhile, the effects of VOCs on tobacco gene expression were estimated by performing a transcriptome analysis, and VOCs were identified by the solid-phase micro-extraction (SPME) method. The results showed positive reactions for the three tested PGP traits in the culture of strain TOR3209, while the tobacco seedlings co-cultured with strain TOR3209 revealed an increase in the fresh weight by up to 100% when compared to that of the control plants, demonstrating that the production VOCs was also a PGP trait. In transcriptome analysis, plants co-cultured with strain TOR3209 presented the highest up-regulated expression of the genes involved in plant growth and development processes, implying that the bacterial VOCs played a role as a regulator of plant gene expression. Among the VOCs produced by the strain TOR3209, two antifungal molecules, 2,4-bis(1,1-dimethylethyl)-phenol and hexanedioic acid dibutyl ester, were found as the main compounds. Conclusively, up-regulation in the expression of growth- and development-related genes via VOCs production is an important PGP mechanism in strain TOR3209. Further efforts to explore the effective VOCs and investigate the effects of the two main VOCs in the future are recommended.
为了探究菌株sp. TOR3209促进植物生长（PGP）效应的潜在机制，通过在相应培养基中培养菌株TOR3209，对负责吲哚乙酸产生、铁载体产生和磷溶解的PGP特性进行了测试。通过将该菌株与烟草幼苗在I型平板中共培养，观察了菌株TOR3209产生的挥发性有机化合物（VOCs）对植物生长的影响。同时，通过进行转录组分析评估了VOCs对烟草基因表达的影响，并通过固相微萃取（SPME）方法鉴定了VOCs。结果表明，菌株TOR3209培养物中三种测试的PGP特性呈阳性反应，而与菌株TOR3209共培养的烟草幼苗与对照植物相比，鲜重增加高达100%，表明VOCs的产生也是一种PGP特性。在转录组分析中，与菌株TOR3209共培养的植物中参与植物生长和发育过程的基因表达上调最为明显，这意味着细菌VOCs起到了植物基因表达调节剂的作用。在菌株TOR3209产生的VOCs中，发现两种抗真菌分子2,4-双（1,1-二甲基乙基）苯酚和己二酸二丁酯为主要化合物。总之，通过VOCs产生上调生长和发育相关基因的表达是菌株TOR3209中一种重要的PGP机制。建议未来进一步努力探索有效的VOCs并研究这两种主要VOCs的作用。
