Phenolic Compounds in Wheat Kernels: Genetic and Genomic Studies of Biosynthesis and Regulations

Whole wheat grains are an important source of bioactive components, particularly of phenolic acids and flavonoids. Due to the health-promoting effects of these phenolics, nowadays, the increase of their content in mature kernels is of great interest and a potential target for wheat breeding programs. The biogenesis of phenolics occurs through the general phenylpropanoid pathway, which is ubiquitous in plant cell walls and leads to the synthesis of secondary metabolites that are involved in plant defence and structural support. This chapter reviews the current knowledge in phenylpropanoid chemistry, and the genetic and molecular basis for the biosynthesis of phenolic acids and anthocyanins in wheat grains. Also, advances in assessing genetic variation in the content and composition of these components in wheat germplasm are reviewed, including the effects of different environmental conditions on their accumulation in mature kernels. The recent, ongoing genomic studies are reviewed providing updates on quantitative trait loci and genes involved in the synthesis and accumulation of phenolics in wheat kernels. Finally, the promise and limitations of breeding programs to potentially develop wheat cultivars rich in phenolic components are discussed

Genomics of quality traits

The quality attributes of cereal grains are valued in the context of a complex food chain that integrates outputs achievable by breeding, production, and processing. New processing technologies, environmental change, and changes in consumer preferences demand that quality attributes of wheat and barley need to be continually modified. The advances in the genomics of quality described in this chapter provide the basis for ensuring that the genetic approaches encompassing the complexities of the gene networks underpinning quality attributes can meet the challenges presented by the rapid changes occurring within the food chain