A number of abnormal environment parameters such as drought, salinity, cold, freezing, high temperature, anoxia, high light intensity and nutrient imbalances etc. are collectively termed as abiotic stresses. Abiotic stresses lead to dehydration or osmotic stress through reduced availability of water for vital cellular functions and maintenance of turgor pressure.

Plants have evolved mechanisms to respond to various abiotic stresses at morphological, anatomical, cellular and molecular levels. Some responses to tolerance or adjustment are highly species-specific, whereas others are fairly common even among plants belonging to different families and orders, microorganisms and animals. In response to dehydration or osmotic stress, a series of compatible osmolytes are accumulated for osmotic adjustment, water retention and free radical scavenging. Attempts have been made to understand the molecular basis of tolerance to certain abiotic stresses. Enzymes responsible for the production of compatible osmolytes have been cloned and characterized and used for genetic transformation of stress susceptible genotypes or mutants to confirm their unequivocal role in stress protection and relief. In the absence of well documented and reliable sources of genetic resistance to abiotic stresses in the germplasm of crop plants and their related wild species for sound breeding programs using conventional approaches, improvement of tolerance to the abiotic stresses through genetic engineering may be the second best available alternative. These developments have also resulted in precise understanding of the genome organization and regulation of gene expression in higher plants. Notable innovation along this line of research is the subject of this session.

Organic Gardeners Composting

Organic Gardeners Composting

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