Division of Microbial Technology, CSIR-National Botanical Research Institute, Lucknow, India.
Academy of Scientific and Innovative Research, AcSIR, Ghaziabad, India.
Microbiol Spectr. 2022 Feb 23;10(1):e0034521. doi: 10.1128/spectrum.00345-21.
Polyphosphate (polyP) accumulation is an important trait of microorganisms. Implication of polyP accumulating bacteria (PAB) in enhanced biological phosphate removal, heavy metal sequestration, and dissolution of dental enamel is well studied. Phosphorous (P) accumulated within microbial biomass also regulates labile P in soil; however, abundance and diversity of the PAB in soil is still unexplored. Present study investigated the genetic and functional diversity of PAB in rhizosphere soil. Here, we report the abundance of Pseudomonas spp. as high PAB in soil, suggesting their contribution to global P cycling. Additional subset analysis of functional genes i.e., polyphosphate kinase () and exopolyphosphatase () in all PAB, indicates their significance in bacterial growth and metabolism. Distribution of functional genes in phylogenetic tree represent a more biologically realistic discrimination for the two genes. Distribution of gene disclosed its phylogenetic conservation at species level, however, clustering of gene of similar species in different clades illustrated its environmental condition mediated modifications. Selected PAB showed tolerance to abiotic stress and strong correlation with plant growth promotary (PGP) traits phosphate solubilization, auxin and siderophore production. Interaction of PAB with enhanced the growth and phosphate status of the plant under salinity stress, suggestive of their importance in P cycling and stress alleviation. Study discovered the abundance of Pseudomonas genera as a high phosphate accumulator in soil. The presence of functional genes (polyphosphate kinase [] and exopolyphosphatase []) in all PAB depicts their importance in polyphosphate metabolism in bacteria. Genetic and functional diversity reveals conservation of the gene at species level. Furthermore, we found a positive correlation between PAB and plant growth promotary traits, stress tolerance, and salinity stress alleviation in .
聚磷酸盐（polyP）的积累是微生物的一个重要特征。聚磷酸盐积累菌（PAB）在增强生物除磷、重金属固定和牙釉质溶解方面的作用已经得到了充分的研究。微生物生物量中积累的磷也调节土壤中可利用磷；然而，土壤中 PAB 的丰度和多样性仍未被探索。本研究调查了根际土壤中 PAB 的遗传和功能多样性。在这里，我们报告了假单胞菌属（Pseudomonas spp.）作为土壤中高 PAB 的丰度，表明它们对全球磷循环的贡献。对所有 PAB 中的功能基因，即聚磷酸盐激酶（）和外多磷酸盐酶（）的附加子集分析，表明它们在细菌生长和代谢中的重要性。功能基因在系统发育树中的分布代表了对这两个基因更具生物学现实意义的区分。基因的分布揭示了其在物种水平上的系统发育保守性，然而，相似物种的基因聚类在不同的进化枝中说明了其受环境条件介导的修饰。所选 PAB 表现出对非生物胁迫的耐受性，并与植物生长促进（PGP）特性呈强相关性，如磷酸盐溶解、生长素和铁载体的产生。PAB 与增强了植物在盐胁迫下的生长和磷酸盐状态，表明它们在磷循环和缓解压力方面的重要性。本研究发现假单胞菌属作为土壤中高磷酸盐积累菌的丰度。所有 PAB 中存在功能基因（聚磷酸盐激酶[]和外多磷酸盐酶[]）表明它们在细菌中多磷酸盐代谢中的重要性。遗传和功能多样性揭示了基因在物种水平上的保守性。此外，我们发现 PAB 与植物生长促进特性、胁迫耐受性和盐胁迫缓解之间存在正相关关系。
