Rhizosphere competent Pantoea agglomerans enhances maize (Zea mays) and chickpea (Cicer arietinum L.) growth, without altering the rhizosphere functional diversity

Abstract

Plant growth promoting Pantoea agglomerans NBRISRM (NBRISRM) was able to produce 60.4 μg/ml indole acetic acid and solubilize 77.5 μg/ml tri-calcium phosphate under in vitro conditions. Addition of 2% NaCl (w/v) in the media induced the IAA production and phosphate solubilization by 11% and 7%, respectively. For evaluating the plant growth promotory effect of NBRISRM inoculation a micro plot trial was conducted using maize and chickpea as host plants. The results revealed significant increase in all growth parameters tested in NBRISRM inoculated maize and chickpea plants, which were further confirmed by higher macronutrients (N, P and K) accumulation as compared to un-inoculated controls. Throughout the growing season of maize and chickpea, rhizosphere population of NBRISRM were in the range 10(7)-10(8) CFU/g soil and competing with 10(7)-10(9) CFU/g soil with heterogeneous bacterial population. Functional richness, diversity, and evenness were found significantly higher in maize rhizosphere as compared to chickpea, whereas NBRISRM inoculation were not able to change it, in both crops as compared to their un-inoculated control. To the best of our knowledge this is first report where we demonstrated the effect of P. agglomerans strain for improving maize and chickpea growth without altering the functional diversity.

Novel plant growth promoting rhizobacteria—Prospects and potential

“…Pantoea agglomerans Enhancement of yield and growth of tomato and cucumber (Dursun et al, 2010) Pantoea agglomerans Growth promotion in maize and chickpea (Mishra et al, 2011) …”

Role of plant growth promoting rhizobacteria in sustainable production of vegetables: Current perspective

“…(Fatemeh et al, 2014), Pseudomonas, Azotobacter(Gaytan et al, 2012), Bacillus (Ashwini and Srividya, 2014), Enterobacter(Collavino et al, 2010), Burkholederia(Minaxi et al, 2013), Serratia(Dastager et al, 2011), Pantoea(Mishra et al, 2011), Rhizobium(Hungria et al, 2013), Mesorhizobium…”

The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification

“…This may correlate with the role as plant-growth promoter which has been identified for some Pantoea spp. [4,5]. …”

“…Most frequently they are found associated with a broad range of plant hosts, as non-pathogenic endophytes or epiphytes, colonizing the leaves, stems and roots [2,3]. In this context, some Pantoea strains can be beneficial to the plant host by contributing to growth promotion through processes such as the production of the plant-growth hormone indole-acetic acid (IAA), phosphate solubilization or nitrogen fixation [4,5]. Some Pantoea strains also provide effective protection to plants against various bacterioses as well as fungal diseases and postharvest fruit rots [6-8].…”