The yield potential and quality of main cereals crop plants including maize,
wheat, rice and barley have improved through breeding and introduction of
transgenic crop plants from last three decades. There has been intensive
research for the improvement of resistance against biotic and abiotic
environmental conditions to safe the potential of cereal crop plants. Among
abiotic stresses drought and heat are two most important abiotic factors
which caused major loss in yield and quality of crop plants. The heat stress
leads towards drought due to loss of water from soil and plant surfaces,
therefore drought and heat caused combined adverse effects on plant
morphological, physiological and yield traits which leads to reduce crop
plant potential. There has been always an interaction among the
environmental conditions and crop plants to produce grain and restore
productivity. The drought and heat stress caused changes at cellular level,
molecular changes and gene expression changes in cereals at various
vegetative and reproductive stages/phases of crop growth and development. A
large number of genes have indentified in cereals which switch up-regulated
and down-regulated during drought and heat stress conditions. However, there
is a need to improve resistance in cereals at gene level to maintain
potential of yield and quality under abiotic stress conditions like drought,
heat, salinity, and cold.