Plant Growth-Prompting Bacteria Influenced Metabolites of Zea mays var. amylacea and Pennisetum americanum p. in a Species-Specific Manner

Abstract

Poor soil is one of the agricultural world’s principal challenges, inciting the use of chemical fertilizer’s to improve overall soil quality. However, the use of chemical fertilizer has significant and cascading environmental consequences. Therefore, the use of beneficial microbes’ inoculation in treating poor soil is a considerably ecofriendly sustainable solution. In the current study, we supplemented nutrient-deprived soil with plant growth promoting bacteria (PGPB), Pseudomonas fluorescens. The bacterial inoculations of Pseudomonas fluorescenswere added to the poor soil following two days post-sowing of Zea mays var. amylacea and Pennisetumamericanum p. seedlings. Metabolite analyses were conducted two months after treatment for both shoots and roots using nuclear magnetic resonance method (NMR). The data indicated significant changes in 19 metabolites relative to control in both plants shoot and roots. Among these metabolites, 7 were upregulated in roots of Zea mays var. amylacea, and 9 metabolites were upregulated in roots of Pennisetum americanum p. The PGPB enhanced sugars (fructose, glucose, sucrose) and amino acids (glutamate, alanine and succinate) in roots, while down regulating in shoots of Pennisetum americanum p. The Pseudomonas fluorescens induced, predominantly,Aminoacyl-tRNA related metabolite, and Alanine, aspartate and glutamate metabolite biosynthesis in Zea mays var. amylacea), whereas PGPB induced metabolites in Pennisetum americanum p., dominated by up regulated carbohydrate related (starch and sucrose) metabolites. The difference in some metabolic response between the two plants indicated that PGPB influence has a species-specific manner.