Potential use of plant colonizing Pantoea as generic plant growth promoting bacteria for cereal crops

Abstract

Aim: To investigate Pantoea isolates for multifarious plant growth promoting activities, their phylogenetic positioning and inoculation impact on plant growth of cereal crops to develop as generic PGP biofertilizer for different crops Methodology: Eight Pantoea sp. isolated from wheat and maize growing in different agro-climatic conditions were used for studying cultural characteristics (pH, Salt and Temp tolerance) PGP traits (nutrient solubilization, siderophore, IAA and hydrolytic enzyme production) and 16SrRNA gene phylogenetic analysis. In vivo evaluation of Pantoea inoculants was studied with 3 cereal test crops in pot house studies. Results: Pantoea isolates identified through 16S rRNA gene sequencing viz. Pantoea cyperipedii, Pantoea dispersa, Pantoea sp. (endophytes) from maize and Pantoea agglomerans, Pantoea ananatis (rhizospheric), Pantoea eucalypti, Pantoea sp., and Pantoea dispersa (endophytes) from wheat, possessed major and micronutrient solubilization activities with solubilization Index for P (PSI), K (KSI) and Zn (ZSI) varied from 2.7 to 5.3, 0 to 5.3 and 3.7 to 6.0, respectively. Production of siderophore (SPI) and IAA varied from 3.3 to 5.7 and 9.0 to 131.8 µg mg-1 proteins. Isolates of P dispersa and P agglomerans possessed extracellular activities of hydrolytic enzymes cellulase, amylase, lipase and protease. The inoculation effect of Pantoea isolates in pot house studies indicated positive influence on plant growth of maize, wheat and rice crops. Interpretation: Pantoea isolates, due to their plant growth improving capabilities and wide colonization capabilities, may be used for preparing a new safe biofertilizer.