Gene pyramiding: An innovative approach towards the generation of stress tolerant plants for the future

Abstract

Man has been always in all circumstances, tried to adapt to his environment and in course of evolution, has always been looking for an alternative to feed himself. Early hominids were known to be hunter gatherers, but as food declined, man sifted to agriculture as well as exploited resources and technical means to survive. But with the growing population of world and adverse climatic changes, the scenario becomes increasingly complex as the demand for food will continuously increase. Furthermore, the world population is expected to increase from 7 to 9–10 billion people by 2050 thus global food production will need to increase by 60 to 110 percent. Land resources being limited and climate change constantly affecting the plants due to changing environmental conditions will no doubt take a toll on agriculture and productivity. Abiotic stress is one of the most serious issues confronting agriculture today and causes significant crop production losses worldwide and reduces planted acreage. Abiotic factors thus threaten not only crop productivity in agricultural ecosystems but also the economies of many countries. As far as the plants are concerned, it interferes with vital physiological and biochemical functions of plants such as nutrient uptake, osmosis, translocation and ionic toxicity, ultimately resulting in cellular disruptions by the generation of reactive oxygen species (ROS) such as singlet oxygen (O2−), hydrogen peroxide (H2O2), and hydroxyl radicals (OH). Hence, to improve tolerance against abiotic stress and maintain the development and well-being of plants, a plant biologist must understand how plants perceive environmental signals, Physiology and behaviour of plants, signalling events and responses of plants to various stresses and finally the mechanisms, pathways and molecules plant utilise to combat these environmental stress conditions. Abiotic stress tolerance by plants is a multigenic trait and is governed by more than one genes or pathway or molecules. Thus, the roadmap to develop a stress-tolerant plant will require activation of several genes, articulating more than one pathway and numerous molecules.