Plant growth promoting rhizobacteria are known to improve plant performance by developing healthy and productive interactions with the host plants. These associations may be symbiotic or asymbiotic depending upon the genetic potential of the resident microbe and promiscuity of the host. Present study describes the potential of two Serratia spp. strains for promotion of plant growth in homologous as well as non-homologous hosts. The strains KPS-10 and KPS-14; native to potato rhizosphere belong to genus Serratia based on 16S rRNA gene sequences (accession no. LN831934 and LN831937 respectively) and contain multiple plant growth promoting properties along-with the production of quorum sensing acyl homoserine lactone (AHL) molecules. Both Serratia spp. strains showed solubilization of inorganic tri-calcium phosphate while KPS-14 also exhibited phytase activity (1.98 10⁻¹⁰ kcat). KPS-10 showed higher P-solubilization activity (128.5 μg/mL), IAA production (8.84 μg/mL), antifungal activity and also showed the production of two organic acids i.e., gluconic acid and lactic acid. Both strains produced three common AHLs: C6-HSL, 3oxo-C10-HSL, 3oxo-C12-HSL while some strain-specific AHLs (3OH-C5-HSL, 3OH-C6-HSL, C10-HSL specific to KPS-10 and 3OH-C6-HSL, C8-HSL, 3oxo-C9-HSL, 3OH-C9-HSL specific to KPS-14). Strains showed roots and rhizosphere colonization of potato and other non-homologous hosts up to one month. In planta AHLs-detection confirmed a likely role of AHLs during seedling growth and development where both extracted AHLs or bacteria inoculated roots showed extensive root hair. A significant increase in root/shoot lengths, root/ shoot fresh weights, root/shoot dry weights was observed by inoculation in different hosts. PGP-characteristics along with the AHLs-production signify the potential of both strains as candidate for the development of bio-inoculum for potato crop in specific and other crops in general. This inoculum will not only reduce the input of chemical fertilizer to the environment but also improve soil quality and plant growth.

已知促进植物生长的根际细菌通过与宿主植物发展健康和生产性相互作用来改善植物性能。这些结合可以是共生的或非共生的，取决于驻留微生物的遗传潜力和宿主的滥交。本研究描述了两个沙雷氏菌的潜力。菌株用于在同源和非同源宿主中促进植物生长。菌株KPS-10和KPS-14；基于16S rRNA基因序列（分别为登录号LN831934和LN831937），马铃薯根际原生质属于沙雷氏菌属，并具有多种植物生长促进特性，并产生群体感应酰基高丝氨酸内酯（AHL）分子。两种沙雷氏菌spp。菌株显示了无机磷酸三钙的增溶，而KPS-14还显示了植酸酶活性（1.98 10 ^-10 kcat）。KPS-10表现出更高的P增溶活性（​​128.5μg/ mL），IAA产生（8.84μg/ mL），抗真菌活性，并且还表现出两种有机酸的生成，即葡萄糖酸和乳酸。两种菌株均产生三种常见的AHL：C6-HSL，3oxo-C10-HSL，3oxo-C12-HSL，而某些菌株特异性AHLs（3OH-C5-HSL，3OH-C6-HSL，C10-HSL特异于KPS-10和KOH-14专用的3OH-C6-HSL，C8-HSL，3oxo-C9-HSL，3OH-C9-HSL）。菌株显示马铃薯和其他非同源寄主的根和根际定殖长达一个月。在植物中AHL的检测证实了AHL在幼苗生长和发育过程中的可能作用，其中提取的AHL或细菌接种的根均显示出广泛的根毛。通过在不同宿主中接种，观察到根/枝长，根/枝鲜重，根/枝干重的显着增加。PGP的特征以及AHL的产生表明，这两种菌株均具有潜力发展为特定作物和其他作物的马铃薯作物生物菌种。这种接种物不仅可以减少对环境的化学肥料投入，而且可以改善土壤质量和植物生长。