Drought, as an abiotic stress, is multidimensional in nature, and it affects plants at various
levels of their organization. In fact, under prolonged drought, many plants will dehydrate
and die. Water stress in plants reduces the plant-cell’s water potential and turgor, which
elevate the solutes’ concentrations in the cytosol and extracellular matrices. As a result, cell
enlargement decreases leading to growth inhibition and reproductive failure. This is
followed by accumulation of abscisic acid (ABA) and compatible osmolytes like proline,
which cause wilting. At this stage, overproduction of reactive oxygen species (ROS) and
formation of radical scavenging compounds such as ascorbate and glutathione further
aggravate the adverse influence. Drought not only affects plant water relations through the
reduction of water content, turgor and total water, it also affects stomatal closure, limits
gaseous exchange, reduces transpiration and arrests carbon assimilation (photosynthesis)
rates. Negative effects on mineral nutrition (uptake and transport of nutrients) and
metabolism leads to a decrease in the leaf area and alteration in assimilate partitioning
among the organs. Alteration in plant cell wall elasticity and disruption of homeostasis and
ion distribution in the cell has also been reported. Synthesis of new protein and mRNAs
associated with the drought response is another outcome of water stress on plants. Under
the water stress cell expansion slows down or ceases, and plant growth is retarded.
However, water stress influences cell enlargement more than cell division. Plant growth
under drought is influenced by altered photosynthesis, respiration, translocation, ion
uptake, carbohydrates, nutrient metabolism, and hormones.
Drought, as an abiotic stress, is multidimensional in nature, and it affects plants at variouslevels of their organization. In fact, under prolonged drought, many plants will dehydrateand die. Water stress in plants reduces the plant-cell’s water potential and turgor, whichelevate the solutes’ concentrations in the cytosol and extracellular matrices. As a result, cellenlargement decreases leading to growth inhibition and reproductive failure. This isfollowed by accumulation of abscisic acid (ABA) and compatible osmolytes like proline,which cause wilting. At this stage, overproduction of reactive oxygen species (ROS) andformation of radical scavenging compounds such as ascorbate and glutathione furtheraggravate the adverse influence. Drought not only affects plant water relations through thereduction of water content, turgor and total water, it also affects stomatal closure, limitsgaseous exchange, reduces transpiration and arrests carbon assimilation (photosynthesis)rates. Negative effects on mineral nutrition (uptake and transport of nutrients) andmetabolism leads to a decrease in the leaf area and alteration in assimilate partitioningamong the organs. Alteration in plant cell wall elasticity and disruption of homeostasis andion distribution in the cell has also been reported. Synthesis of new protein and mRNAsassociated with the drought response is another outcome of water stress on plants. Underthe water stress cell expansion slows down or ceases, and plant growth is retarded.However, water stress influences cell enlargement more than cell division. Plant growthunder drought is influenced by altered photosynthesis, respiration, translocation, ionuptake, carbohydrates, nutrient metabolism, and hormones.
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