Mei Chuansheng, Chretien Robert L, Amaradasa B Sajeewa, He Yimeng, Turner Amy, Lowman Scott
The Plant Endophyte Research Center, The Institute for Advanced Learning and Research, Danville, VA 24540, USA.
Microorganisms. 2021 Sep 11;9(9):1935. doi: 10.3390/microorganisms9091935.
Phosphate is one of the most important nutrients for plant growth and development, and only 0.1% of the phosphate in soils is available to plants. Currently, the use of excess phosphate fertilizer has caused surface and ground water pollution and water eutrophication, resulting in algal blooms in lakes and oceans. Therefore, it is imperative to explore alternative ways to solve these problems for sustainable agricultural production and improvement of soil fertility, while protecting the environment. Microorganisms from the rhizosphere and within plants are able to solubilize insoluble soil phosphate, making it available to plants. Five high phosphate solubilizing bacteria from our bacterial endophyte library were chosen for this study and identified as IALR611, IALR632, IALR1033, IALR1035 and IALR1325. All five bacteria significantly promoted tall fescue growth in vitro. Greenhouse experiments showed that IALR1325 significantly promoted pepper and tomato growth, and IALR632 was the best in promoting tomato growth. In addition, all these bacteria had extracellular acid phosphatase and phytase activities. One of the mechanisms for phosphate solubilization by bacteria is pH reduction caused by gluconic acid production. Our results indicate that IALR1325 is a promising bacterium for future applications.
磷是植物生长发育最重要的养分之一，而土壤中仅有0.1%的磷能被植物利用。目前，过量使用磷肥已导致地表水和地下水污染以及水体富营养化，致使湖泊和海洋中藻类大量繁殖。因此，为了实现可持续农业生产、提高土壤肥力并保护环境，探索解决这些问题的替代方法势在必行。根际和植物体内的微生物能够溶解土壤中不溶性的磷，使其可供植物利用。本研究从我们的细菌内生菌库中选取了5株高效解磷细菌，分别鉴定为IALR611、IALR632、IALR1033、IALR1035和IALR1325。这5株细菌在体外均显著促进了高羊茅的生长。温室试验表明，IALR1325显著促进了辣椒和番茄的生长，IALR632在促进番茄生长方面表现最佳。此外，所有这些细菌都具有胞外酸性磷酸酶和植酸酶活性。细菌解磷的机制之一是产生葡萄糖酸导致pH值降低。我们的结果表明，IALR1325是一种具有应用前景的细菌。
