Aligarh Muslim University

About: Aligarh Muslim University is a education organization based out in Aligarh, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Adsorption. The organization has 8218 authors who have published 16416 publications receiving 289068 citations. The organization is also known as: AMU.

Fluorescent Pseudomonas -FAP2 and Bacillus licheniformis interact positively in biofilm mode enhancing plant growth and photosynthetic attributes

Abstract: Compatible interaction between commonly used plant growth promoting rhizobacteria (PGPR) in biofilm mode in vitro and in the rhizosphere is expected to provide better understanding for the development of effective consortium. With the above hypothesis, the present study evaluated two characterized PGPR (Pseudomonas fluorescens FAP2 and Bacillus licheniformis B642) for their biofilm-related functions using standard protocols. The interaction between the FAP2 and B642 in planktonic mode was studied by plate spot/overlay method and competitive growth assessment. Biofilm development on a microtitre plate and a glass surface was studied by standard methods. Biofilm formation was characterized by SEM. Rhizosphere and rhizoplane colonization of wheat seedlings by both isolates individually and by co-inoculation was studied by determining CFU/g of soil/root samples. Biofilm development on the root surface was further analyzed by SEM. Both isolates demonstrated multiple plant growth promoting (PGP) traits (production of IAA, siderophore, and ammonia; phosphate solubilization) and biofilm-related functions such as production of EPS, alginate, cell surface hydrophobicity and swarming motility. Both strains formed strong biofilms on a glass cover slip in vitro. Interaction between the two strains under the planktonic mode revealed no antagonism in terms of growth inhibition and competitive growth kinetics. Similarly, FAP2 and B642 strains formed a mixed biofilm on a glass cover slip as well as on seedling roots. Wheat rhizosphere and rhizoplane were colonized by both isolates as evidenced from their viable counts in single and co-inoculation. The effect of single and co inoculation revealed the significant enhancement of vegetative growth and photosynthetic parameters such as chlorophyll content, transpiration rate (E), internal CO2 concentration (Ci), stomatal conductance (gs), and net photosynthetic rate (PN) and leaf water potential (LWP) as compared to uninoculated control. Indigenous Pseudomonas fluorescens FAP2 strain and Bacillus licheniformis B642 are compatible PGPR in both planktonic and biofilm modes of growth and threfore could be developed effective consortium of PGPR. Further indepth investigation is required to understand molecular mechanism of the interaction in biofilm mode of growth under natural condition.

Use of plant growth-promoting rhizobacteria for the biocontrol of root-rot disease complex of chickpea

Abstract: The effects of Pseudomonas putida, Pseudomonas alcaligenes and a Pseudomonas isolate (Ps28) on the hatching and penetration of Meloidogyne incognita in chickpea (Cicer arietinum) roots were studied. Root colonisation, antifungal activity against Macrophomina phaseolina and the production of siderophores, hydrogen cyanide (HCN) and indole acetic acid (IAA) were also estimated for each bacterial isolate. P. putida had the greatest inhibitory effect on hatching and root penetration of M. incognita followed by P. alcaligenes and Ps28, respectively. Similarly, P. putida colonised roots more effectively than P. alcaligenes or Ps28. In addition, P. putida had the greatest inhibitory effect on M. phaseolina and produced the greatest amounts of siderophores, IAA and HCN compared with P. alcaligenes and Ps28. The effects of these bacterial isolates on plant growth and root-rot disease complex of chickpea caused by M. incognita and M. phaseolina were observed. Plant inoculations with these bacterial isolates increased plant growth and the number of seed pods in diseased plants while reducing galling, nematode multiplication and the root-rot disease index. P. putida caused the greatest reduction in galling and nematode multiplication followed by P. alcaligenes and Ps28, respectively. The present study suggests that P. putida has potential for the biocontrol of root-rot disease complex of chickpea.