Chapter 18 - Characterization of drought tolerance in maize: omics approaches

Abstract

Agricultural production globally faces serious threats as the climatic changes progresses toward frequent extreme weather conditions. Amongst various environmental stresses impacting the crop production, most pivotal limiting factor globally is water. Water accessibility governs the abundance, distribution and response of a plant species, which in turn is a function of the adaptive mechanisms embraced by that crop plant to ensure its survival and productivity in an environmental niche. Grain production across the world has been reduced by 5% or more in few years owing to water scarcity in key countries. In the tropic regions, it has been estimated that drought stress results in an average annual yield loss of 17%, but losses can be much more severe. Maize (Zea mays L.), also known as “Queen of Cereals,” accommodates approximately 72% starch, 10% protein and 4% fat, with its each vegetative part having an industrial importance. Early flowering time and a shorter vegetative period can be very significant for maize production in conditions of terminal drought since this can minimize exposure to dehydration during the sensitive flowering and postanthesis grain filling periods. Tremendous emphasis has been laid on by breeding stress tolerant plant varieties to alleviate the negative footprint of drought stress on grain productivity but it is limited by the accessibility of genes. Recently, significant progress has been made integrating omics studies with conventional breeding approaches by narrowing down genomic regions and identification of candidate genes that improve the plant performance under water stress conditions. Further, the exploration of complex metabolic pathways and efficient utilization of biological information and its translation into field studies is still lacking.