natural-products-in-plant-pest-management

Proteinaceous and Polyketide Compounds in Plant Protection 111chemical pesticides in order to be adopted by so-called ‘cottage industry’ orgovernmentally regulated farming.The disease-preventing effect of natural compounds that are used or canbe used for crop protection is a result of a direct or plant-mediated influenceon targeted pathogens. Affecting phytopathogens directly, the compoundsinterrupt pivotal metabolic pathways and/or disrupt vitally important structuresthat have as a consequence the death of the pathogens (biocidal effect).Some natural substances or their analogues do not produce lethal effects toplant pathogens but specifically influence pathways related to pathogenicityor/and toxigenesis, e.g. mycotoxin production (Kumar et al., 2008; Shuklaet al., 2008). Such non-biocidal suppressors can impair the pathogenicity forplants as well as the toxic risk for people and animals. In the case of aplant-mediated mode of action, natural compounds elicit and activatedefence responses in plants that result in induced resistance to diseases (e.g.Shcherbakova et al., 2007; 2008; Odintsova et al., 2009). Lastly, some of biogeniccompounds influencing plants do not induce resistance but enhancetolerance to pathogens (sometimes by improving the physiological state ofplants). The structural and functional diversity of natural compounds as wellas their abundance provide a great potential for bringing plant protectiontechnologies in line with green consumerization.The main goal of this chapter is to analyse properties of a few chemicallyand functionally different natural compounds and demonstrate their prospectiveas promising candidates for new plant protection products with significantpotential in relation to green consumerization. The chapter will focuson the characterization of two proteinaceous compounds of bacterial origin,the elicitor properties of which provide disease resistance, and also on fungalstatins as natural compounds, which inhibit a pathogenicity-related pathwayin melanin-producing fungi and can be used for developing biopesticidesthat reduce the harmful impact of crop diseases without killingpathogenic organisms. In addition, microbial and plant proteinaceous compoundsthat have been previously well documented to be promising forgreen consumerization will be briefly surveyed.5.2 Proteinaceous Compounds of Microbial and Plant Origin inthe Biocontrol of Plant PathogensProteins are abundant and ubiquitous natural compounds strongly associatedwith all living organisms, hence it is possible to believe their involvementin plant protection will not conflict with green consumerizationprinciples. Because proteinaceous compounds are important constituents ofa plant immune system and take part in the natural plant defence againstpathogens, scientists have emphasized their potential for plant protection fora long time. Basically, two general approaches to the practical realization ofthe protective potential of these compounds are the formulation of producers(biocontrol or non-pathogenic microorganisms) or the engineering of transgenicplants. The compounds synthesized by formulated biocontrol agents