Biotechnology for drought and salinity tolerance of crops

Drought and salinity are major constraints on crop production and food security and have adverse impact especially on socioeconomic aspect in many developing countries. Water-deficit stress caused by drought and soil salinisation adversely affects plant growth and crop productivity. Increasing salt tolerance of crop plants either by genetic breeding or use of transgenic approach for gene transfer becomes a challenge today. Biotechnological approaches have enhanced our understanding of the processes underlying plant responses to drought and salinity at the molecular and whole plant levels. Biotechnological tools, including plant transformation, random and targeted mutagenesis, transposon/T-DNA tagging and RNA interference, permit the linking of genes to their biological function, thereby elucidating their contribution to traits, in ways not previously possible (closing the genotype to phenotype gap). With this information, biotechnology has the potential to deliver higher and more stable yields for saline and water-limited environments. Here, we review the biotechnological methodologies that are available and the prospects for their successful application for improving drought and salinity tolerance in cereals.