Role of zinc in management of plant diseases: A review

Abstract

Management of disease by using agrochemicals has possessed serious issues and threats to food safety and environment due to excess use. The management of diseases by enhancing resistance or tolerance through plant nutrition contributes to food safety as well as sustainable and integrated disease management. Further, these nutrients optimize yield. Utilization of nutrients in disease management requires the knowledge of their association with plant defence mechanisms. This review describes the association of Zinc (Zn) in developing a plant’s defence mechanism and reducing the severity of diseases. It was found that Zn plays an important role in the functioning of enzymes/proteins like alcohol dehydrogenase, superoxide dismutases, metallothionein and zinc-finger proteins involved in plants’ response to pathogens. Zn supply increases the expression of various antioxidant systems detoxifying the harmful level of free radicals upon infection. Zn enhances the signalling of various defence pathways like salicylic acid-dependent pathways and jasmonic acid/ethylene-dependent pathways as well as improves membrane integrity assisting in defence against pathogens’ attack. A deficiency of Zn makes a plant susceptible to infection due to a deprived condition while an excess level negatively impacts growth and defence due to toxicity. Thus, high and non-toxic levels of Zn supply can be beneficial in enhancing a plant’s defence responses which depend on the nature of the plant and its interaction with pathogens. This study provides a basis for the exploration of the negative relationship between nutrient management and plant diseases.