Phytochemistry The World of a Chemist among Plants

Abstract

Germination, growth and senescence of plants are governed by chemical molecules and processes. Molecules form the fabric of plants and green plants represent the most versatile synthetic agents we know, producing an enormous range of organic compounds from simple mineral nutrient elements in the soil or atmosphere. A range of elements is indispensable for plant growth but some others are accumulated by particular species in amounts far in excess of an normal requirement. Accumulation of certain element, e.g. selenium, may confer toxicity on the plan concerned, probably because this element substitutes for sulphur in compounds vital to cell metabolism. Metabolic antagonism between unique amino acid of plants and structurally similar components of protein may explain the toxicity of some plants: it also may provide the basis for a new biochemical approach to the selection of mutant plant cell able to produce larger amount of nutritionally important amino acids, such aa methionine and lysine.Many compounds considered to have a secondary importance in the life processes of plants are nevertheless extremely useful to man as medicinals or as feedstock for industrial processes. Newer uses are described for plant products a novel sweeteners, potent insecticides or, in the case of sucrose, as an alternative precursor material, replacing petrochemicals in the manufacture of detergents, emulsifiers and plastics, but a great challenge remains for the fuller utilization of the products of plant photosynthesis.