Chapter 10 - Immune response

Abstract

Maintaining a high immune status in plants is especially important today due to the unfavorable environmental situation that leads to immune deficiency. The change of the genome activity leads to accumulation of new products in the cell, and many of them are toxic for parasites. Some of these accumulated products include phytoalexins and PR-proteins (PR-1–type proteins, PR-2–type proteins, PR-3–type proteins, PR-4 type proteins, and PR-5–type proteins). This chapter discusses inhibitor of viral replication (IVR) (inhibitors from “green islands” and antiviral factors), proteinase inhibitors, and phenylpropanoids and lignin. Phenylpropanoids and lignin are formed as a result of deamination of the amino acid phenylalanine by the enzyme phenyl alanine-ammonia lyase (PAL). Lignin is a complex of the polymers formed from a mix of simple phenylpropanoids. It is covalently bound with cellulose and hemicellulose as well as with the oxyproline-rich proteins. The proteins bound to the primary plant cell wall are usually glycoproteins. Most cell wall glycoproteins are rich in oxyproline. The section on modification of plant gene expression at nematode invasion includes topics such as genetics of plant resistance to nematodes, hypersensitive response, biochemical factors of plant resistance to parasitic nematodes, and proteinase inhibitors. The molecular response of a plant includes the reaction to all factors of stressful action of the nematodes. Systemic acquired resistance (SAR) is a secondary immune response to infection that is generated due to the presence of localized resistance. Research in the area of systemic SAR signals will promote the development of new approaches of plant protection against diseases and stresses.