Beneficial and pathogenic plant-microbe interactions: A review

Just like animals and human beings, plants also accommodate a countless number of microorganisms as hosts. Microorganisms enjoy this hospitality by developing an interaction with the plants either in a synergistic way benefiting each other or in an antagonistic manner damaging their hosts. Such types of mutualistic and pathogenic interactions also take place among microbial community. Proteins, metabolites and certain molecular mechanisms determine whether the intruder is a symbiotic or pathogenic microorganism. Various bacteria and fungi interact symbiotically and play significant role in plant growth promotion. Certain species of fungi, oomycetes, bacteria and nematodes are also pathogenic in nature and cause impact on soil and plant. Soil serves as a big substrate for microbial community, which are important in a number of ways owing to their role in mineralization, nutrient availability and are sources of industrial products such as enzymes, hormones, antibiotics, vitamins etc. This review will improve our understanding about relationships between plants and their microbial friends and foes. The mechanisms adopted by soil microbes to contribute in the betterment of soil leading towards enhanced plant growth as well as pathogenicity caused by these microbes have also been discussed. Recent advances to recognize the molecular mechanisms involved in such interactions have also been discussed. Recent advances made in this field and the areas needing further research have also been mentioned.