School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, China.
Environ Sci Pollut Res Int. 2018 Mar;25(9):8871-8879. doi: 10.1007/s11356-018-1200-6. Epub 2018 Jan 12.
Bacterial seed endophytes can facilitate germination and early plant development. Therefore, the introduction of seed-borne endophytes may improve selected plant characteristics across generations. In this study, regenerated plantlets of common reed (Phragmites australis) were inoculated with activated sludge to obtain a specific functional endophytic bacterium. Denaturing gradient gel electrophoresis demonstrated that abundant endophytic bacteria could be enriched in the roots. A siderophore-producing endophytic bacterium was isolated from the roots and identified as Herbaspirillum frisingense RE3-3 based on 16S rRNA sequences. This endophyte secrets indole-3-acetic acid to promote plant growth and cadmium-binding siderophores. The strain was successfully colonized into synthetic seeds using bacterium-propagule co-cultivation and transmitted to regenerated seedlings. These seedlings exhibited improved growth under cadmium stress. This study identifies Herbaspirillum colonization and transmission as a potentially valuable strategy to improve the phytotoxin resistance of reeds for constructed wetlands.
细菌种子内生菌可以促进种子萌发和早期植物发育。因此，引入种子内生菌可能会改善所选植物在各世代中的特征。在这项研究中，再生的芦苇（Phragmites australis）植物用活性污泥接种，以获得特定的功能内生细菌。变性梯度凝胶电泳表明，丰富的内生细菌可以在根部富集。从根部分离出一种产铁载体的内生细菌，并根据 16S rRNA 序列鉴定为 Herbaspirillum frisingense RE3-3。这种内生菌分泌吲哚-3-乙酸来促进植物生长和结合镉的铁载体。该菌株通过细菌-繁殖体共培养成功定植于合成种子，并传递给再生幼苗。这些幼苗在镉胁迫下表现出更好的生长。本研究确定 Herbaspirillum 的定植和传播是一种潜在的有价值的策略，可以提高芦苇对人工湿地中植物毒素的抗性。
