Chapter 42 - Systemic resistance inducers from plants—an ecofriendly approach for the management of viral diseases of crops

Abstract

Plant viruses are obligatory intracellular parasites that are dependent on the host machinery to multiply. They cannot penetrate hosts themselves but could penetrate into plant cells through wounds or through the action of vectors during feeding on the plants. Viruses are responsible for considerable losses in crop productivity and quality of agricultural produce. Several conventional strategies are used to prevent the infection of viruses. These conventional methods are not successfully effective for the control of virus infection. At present, several types of induced resistance, such as localized acquired resistance, induced systemic resistance (ISR), and systemic acquired resistance, are used to prevent the infection of viruses. The phenomenon of ISR in host plants against virus infections is discussed in this chapter. Resistance against virus infection can be induced in plants by a wide range of biotic and abiotic agents. A large number of chemicals, biochemicals, and biological activators have been reported in several studies against many viruses causing diseases in plants. These include plant extracts, phytochemicals, microorganism, such as bacteria, fungi and microorganism derivatives whereas, abiotic inducers include protein, polysaccharides, and other chemicals. Large numbers of chemical and physiological changes have been observed to be associated with ISR in plants by the application of plant extracts, phytochemicals, and microorganism. These chemical and physiological changes include cell death and the oxidative burst, deposition of callose and lignin, the synthesis of phytoalexins, and novel proteins.