Genetics and genomics of wheat: Storage proteins, ecological plasticity, and immunity

Abstract

Recent advances in genetics and genetic research methods made it possible to explain the large polymorphism observed among storage proteins of wheat weevil (gliadins and glutenins), to determine their genetic control mechanism, and to develop a system for the identification of wheat genotypes on the basis of multiple allelism. This system has extremely high sensitivity and efficiency, which makes it possible to conduct studies to determine the purity and authenticity of wheat varieties, the dynamics of alleles diversity in time and space, the phylogenetics, etc., through the use of an extensive database on the allelic composition of gliadin loci. An investigation of the molecular structure of genes controlling the synthesis of storage proteins and their organization on chromosomes, as well as an analysis of wheat genome structure, revealed the molecular mechanisms of variability in the wheat genome and its reorganization in response to changes in environmental conditions and cultivation technologies. The multilevel genetic system of protection against pathogens and adverse environmental factors that developed in the course of wheat evolution continues to astound researchers' imagination with new resistance genes and novel types of antimicrobial peptides having been discovered and sequenced in recent years and the diversity of their structures and mechanisms of action in response to pathogens. An analysis of gene sequences involved in wheat domestication, namely, those that define ecological plasticity, i. e. the type of plant development (Vrn genes), and those responsible for spikelet traits (Q genes), which ensured the successful cultivation of wheat by humans, revealed that the basis for these features are specific mutations.