Characterization and Metabolism Effect of Seed Endophytic Bacteria Associated With Peanut Grown in South China
Characterization and Metabolism Effect of Seed Endophytic Bacteria Associated With Peanut Grown in South China
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DOI：
10.3389/fmicb.2019.02659
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发表时间：
2019-11-13
影响因子：
5.2
通讯作者：
Li, Xiaoyun
中科院分区：
文献类型：
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作者：
Li, Limei;Zhang, Zhi;Li, Xiaoyun
植物内生菌被认为是优良的生物防治剂和生物肥料，并与植物生长促进和健康有关。特别是种子内生细菌通过垂直传递有益于宿主植物的后代，并且可以在植物生长和防御中发挥作用。然而，种子相关的内生细菌尚未得到充分研究，例如，对它们如何与花生（Arachis hypogaea）相互作用知之甚少。从无菌培养和土壤培养的花生幼苗根尖中分离到10个属的内生细菌。从土壤中生长的花生幼苗中获得42个细菌菌落，大多数来自芽孢杆菌属。从无菌苗根尖获得8个菌落，包括芽孢杆菌属，类芽孢杆菌属，和分散泛菌（Pantoea dispersa）。4株花生芽孢杆菌GL 1-GL 4（B.p.GL1-GL 4）均能产生生物膜，而B.p.GL2和类芽孢杆菌YMR 3（P. g. YMR 3）具有较强的淀粉分解能力，能提高花生生物量和根瘤数。相反，分散疫霉YMR 1（P.d.YMR1）引起花生植株枯萎。P.g.YMR3主要分布在液泡周围或液泡内部，并通过雌蕊柄和胚珠传递给下一代。P.g.YMR3处理后，花生根尖中己酸、琥珀酸和茉莉酸（JA）含量增加，亚麻酸含量显著降低。这表明菌株P. g. YMR 3提高了花生JA含量（14.93倍变化）并调节了花生的代谢以促进根瘤的形成和生长。这些发现为花生植物-种子内生细菌的相互作用提供了新的见解。
Endophytes are considered to be excellent biocontrol agents and biofertilizers, and are associated with plant growth promotion and health. In particular, seed-endophytic bacteria benefit the host plant's progeny via vertical transmission, and can play a role in plant growth and defense. However, seed-associated endophytic bacteria have not been fully explored, with very little known about how they interact with peanut (Arachis hypogaea), for example. Here, 10 genera of endophytic bacteria were isolated from the root tips of peanut seedlings grown either aseptically or in soil. Forty-two bacterial colonies were obtained from peanut seedlings grown in soil, mostly from the genus Bacillus. Eight colonies were obtained from aseptic seedling root tips, including Bacillus sp., Paenibacillus sp., and Pantoea dispersa. Four Bacillus peanut strains GL1-GL4 (B.p.GL1-GL4) produced bio-films, while B.p.GL2 and Paenibacillus glycanilyticus YMR3 (P.g.YMR3) showed strong amylolytic capability, enhanced peanut biomass, and increased numbers of root nodules. Conversely, P. dispersa YMR1 (P.d.YMR1) caused peanut plants to wilt. P.g.YMR3 was distributed mainly around or inside vacuoles and was transmitted to the next generation through gynophores and ovules. Hexanoate, succinate, and jasmonic acid (JA) accumulated in peanut root tips after incubation with P.g.YMR3, but linolenate content decreased dramatically. This suggests that strain P.g.YMR3 increases JA content (14.93-fold change) and modulates the metabolism of peanut to facilitate nodule formation and growth. These findings provide new insight into plant-seed endophytic bacterial interactions in peanut.