Abstract
Phosphorus (P) limits the production of maize, one of the major food crops in China. Phosphate-solubilizing bacteria (PSB) have the capacity to solubilize phosphate complexes into plant absorbable and utilizable forms by the process of acidification, chelation, and exchange reactions. In this study, six bacteria, including one Paenibacillus sp. B1 strain, four Pseudomonas sp. strains (B10, B14, SX1, and SX2) and one Sphingobium sp. SX14 strain, were those isolated from the maize rhizosphere and identified based on their 16S rRNA sequences. All strains could solubilize inorganic P (Ca3(PO4)2, FePO4 and AlPO4), and only B1 and B10 organic P (lecithin). All strains, except of SX1, produced IAA, and SX14 and B1 showed the highest level. B1 incited the highest increase in root length and the second increase in shoot and total dry weight, shoot length, and total P and nitrogen (N), along with increased root length. In addition, by confocal laser scanning microscopy (CLSM), we found that green fluorescent protein (GFP)-labeled B1 mainly colonized root surfaces and in epidermal and cortical tissue. Importantly, B1 can survive through forming spores under adverse conditions and prolong quality guarantee period of bio-fertilizer. Therefore, it can act as a good substitute for bio-fertilizer to promote agricultural sustainability.
Highlights
Maize (Zea mays L.), a major food and energy crop, is the third most important food crop in China after wheat and rice [1]
Six bacteria strains producing obvious transparent zone in Pikovskaya (PVK) medium were purified from rhizosphere soil (Table 1)
Strains SX1, SX2, and SX14, which were obtained from Shanxi Province, China, showed milky white colony with short rods, white colony with short rods and vitelline colony with rods, respectively
Summary
Maize (Zea mays L.), a major food and energy crop, is the third most important food crop in China after wheat and rice [1]. There are large amounts of inorganic and organic forms in soils, only 0.1% total P is available for assimilation by plants [5] This leads to strong demand for the application of P fertilizer. Phosphate solubilizing bacteria (PSB) play a critical role in biogeochemical cycling models of soluble and insoluble P cycling forms in agricultural ecosystems. They can convert insoluble P (inorganic and organic forms) to soluble P (ionic phosphate and low molecular-weight organic phosphate) accessible to plants [17,18,19]. These areas share about a third of total maize planting area of China [39] It was hypothesized the plant rhizosphere of these areas have some potential fine PSB that can greatly promote plant P-nutrition and growth, especially for maize. To the best of our knowledge, this is the first report of Paenibacillus isolated from maize rhizosphere that presents a phosphate solubilization ability
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
