Int.J.Curr.Microbiol.App.Sci (2018) 7(8): 3132-3146 3132 Review Article https://doi.org/10.20546/ijcmas.2018.708.335 Invasion and Nutrient Acquisition Strategies of Phytopathogens: Fungi, Bacteria and Viruses Prahlad Masurkar 1 , Raina Bajpai 1* , Vandana Sahu 1 , Munnesh Kumar 2 and Rahul Singh Rajput 1 1 Department of Mycology and Plant Pathology, 2 Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Utter Pradesh-221005, India *Corresponding author ABSTRACT Introduction The major plant phytopathogens are fungi bacteria and viruses in terms of infecting crop plants and losses. Approx 12% annual crop losses are due to diseases other than nematodes (Singh, 2002). The major plant phytopathogen fungi, bacteria are biotrophic, hemibiotrophic and necrotrophic in nature, while the viruses are strictly biotrophic phytopathogen. The fungal phytopathogens have effective mechanism of invasion in to host plant to produce symptoms of disease and later their spores disseminate in to another plant and cause an epidemic. Bacteria also have strategies to enter in to plants. Bacteria International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 08 (2018) Journal homepage: http://www.ijcmas.com Major phytopathogens (fungi, bacteria and viruses) cause heavy damage to crop plants. The comprehensive knowledge of phytopathogens nature i.e. biotrophic, hemibiotrophic and necrotrophic, their intrusion tools by which they get entrainment in plant cell and the machinery of nutrient acquisition so we can make a better understanding about the phytopathogen. This information about phytopathogen helps us to develop novel disease control strategy against them. In this review we have tried to reveals the invasion mechanism by the phytopathogens as fungi physical invasion with help of haustoria, intacellular hyphae and cell wall degrading enzymes, bacteria do passive invasion from stomata and viruses with help of vectors they transmit in to plant cells. This review also deals with the various nutrient acquisition strategies of phytopathogens. Biotrophic fungi usually prefer carbohydrate and in adverse condition shifted towards nitrogen containing compounds whereas necrotrophic fungi get nutrients by altering cell membrane permeability of host. During sporulation of fungi, the role of mannitol is well established. Bacteria use transporters (TBDRs and ABC) and porin proteins for fulfilling their nutrient hunger. During scarcity of nutrients SWEET proteins regulate the acquisition of nutrient in bacteria. Viruses by cellular reprogramming capture the host machinery of replication factories. Protein metabolism also altered during the viral infection by changing target cell for which nutrients are made by host cell so virus can multiply. Keywords Nutrients, Haustoria, Sporulation, Transporters, Metabolism etc. Accepted: 17 July 2018 Available Online: 10 August 2018 Article Info