Secondary Metabolites and Plant Defense285
13.1Unraveling the Function of Secondary Metabolites
Phytoalexins. Perhaps the best-studied response of plants to bacterial or fungal invasion is the synthesis of phytoalexins. Phytoalexins are a chemically diverse group of secondary metabolites with strong antimicrobial activity that accumulate around the site of infection.
Combinatorial biosynthesis of medicinal plant secondary metabolites.
Plants produce a large, diverse array of organic compounds that appear to have no direct function in growth and development. These substances are known as secondary metabolites, secondary products, or natural products. Secondary metabolites have no generally recognized, direct roles in the processes of photosynthesis, respiration, solute transport, translocation, protein synthesis, nutrient assimilation, differentiation, or the formation of carbohydrates, proteins, and lipids discussed elsewhere in this book.
Lecture 15 - Secondary metabolites and plant defense | …
As long as these compounds were not unduly toxic to the plants themselves and the metabolic cost of producing them was not excessive, they gave the plants that possessed them greater reproductive fitness than undefended plants had. Thus the defended plants left more descendants than undefended plants, and they passed their defensive traits on to the next generation.
Plant Physiol. Chapter13-Secondary Metabolites and …
Plant secondary metabolites can be divided into three chemically distinct groups: terpenes, phenolics, and nitrogen-containing compounds. Figure 13.4shows in simpli-
Secondary Metabolites Defend Plants ..
Rgene products are distributed in more than one place in the cell. Some appear to be situated on the outside of the plasma membrane, where they could rapidly detect elicitors; others are cytoplasmic to detect either pathogen molecules that are injected into the cell or other metabolic changes indicating pathogen infection. Rgenes constitute one of the largest gene families in plants and are often clustered together in the genome. The structures of Rgene clusters may help generate Rgene diversity by promoting exchange between chromosomes.