Chromosome regions and stress-related sequences involved in resistance to abiotic stress in Triticeae

Drought, low temperature and salinity are the most important abiotic stress factors limiting crop productivity. A genomic map of major loci and QTLs affecting stress tolerance in Triticeae identified the crucial role of the group 5 chromosomes, where the highest concentration of QTLs and major loci controlling plant's adaptation to the environment (heading date, frost and salt tolerance) has been found. In addition, a conserved region with a major role in drought tolerance has been localized to the group 7 chromosomes. Extensive molecular biological studies have led to the cloning of many stress-related genes and responsive elements. The expression of some stress-related genes was shown to be linked to stress-tolerant QTLs, suggesting that these genes may represent the molecular basis of stress tolerance. The development of suitable genetic tools will allow the role of stress-related sequences and their relationship with stress-tolerant loci to be established in the near future.