Innovative solutions to cure abiotic stress in plants by biotechnological interventions

Introduction:

Biotic and abiotic stresses reduce the plant productivity and sometimes depend on the crop. In plant development biotic stress and abiotic stress influence the growth of plant. Abiotic stresses include drought, cold, heavy metals, salt, etc. To survive in biotic stress, plants can initiate a number of changes in cellular and molecular level. Some environmental conditions that cause abiotic stress are water logging, drought, high temperature, low temperature soil salinity, inadequate minerals in soil etc. Sensitivity of plants to abiotic stress depends on the plant species, genotype and also depends on development stage.

Drought: It is environmental condition caused by lack of rain fall. Water deficit is considered as an important abiotic factor limiting plant growth and yield in many areas on earth. During drought, plant suffers from dehydration and lack of water in plant is caused by high temperature. A plant can be drought resistance by its ability to withstand in dehydration and its capability to resist high temperature.

Heat: Heat stress occurs when the environmental temperature is high enough to cause damage in plant function. In minimum temperature there is no growth and development. At optimum temperature maximum plant growth and development occurs. At maximum temperature plant growth stops.

Cold: Cold stress occurs when plants are exposed at low temperature, which disrupts their physiological condition. Plant’s moisture gets freeze and damages the roots, drying them out completely. Cold temperature slows down and stops cell division, cell elongation and growth.

Salinity: Approximately 10% of the land is covered with saline plant. Most importantly, about 25% of irrigated land has suffered from secondary salinization and 50% of irrigation schemes are affected by salt. Many of the salt-affected areas remain unproductive for many years because of plant establishment problems. Despite using salt-tolerant plants and other techniques for plant establishment in these habitats, re-vegetation is very difficult. Re-vegetation of saline lands decreases soil erosion and produces forage for livestock and wildlife and can convert these degraded areas into productive lands. Salt stress occurs when dissolved salt accumulated in soil and inhibit the plant growth.

Heavy-Metal Stress: Contamination of the natural environment by industry causes many adverse changes in ecosystems. Emitted with dusts, large amounts of heavy metals such as lead (Pb), Cadmium (Cd) and zinc (Zn) are accumulated and high concentrations of these metals disturb biological processes in both soil and living organisms. One of the most dangerous elements is cadmium. It has no essential biological function, and even at low concentrations it is highly toxic to all living organisms. Cadmium pollution of the environment has been rapidly increasing in recent decades as a result of rising consumption of Cd by industry. Sources of contamination by Cd are mining and smelting of Pb and Zn, atmospheric pollution from metallurgical industries, the disposal of wastes containing Cd, sewage sludge application to land and the burning of fossil fuels.

Conclusion:

Abiotic stress, responsible for crop losses is as depicted in the figure above. Different techniques are employed for management of stress. Biotechnological techniques are used for improvement in plants against abiotic stress. Conventional techniques like plant breeding are less successful than modern techniques. Glycine betaine is an enzyme that performs an important role in plant. It mediates osmotic adjustment and protects the sub cellular and cellular structure in stressed plants. So the use of genetic engineering can synthesize the glycine betaine in crops and it has a promising strategy to increase stress tolerance of plants.

                                                                                                               -by Bindu R. Goswami
                                                                          Rai University, Ahmedabad