Chapters authored
Drought Stress: Manifestation and Mechanisms of Alleviation in Plants
Drought can be referred to as a meteorological period without significant rainfall and it is one of such major abiotic stresses that contributes to a huge reduction in crop yield throughout the world. Plant shows a broad range of physiological, morphological, and biochemical changes such as reduced photosynthetic accumulation, altered gene expression, etc. Under the drought stress which ultimately causes reduced growth as well as poor grain yield. Drought stressconditions trigger production of ROS, which disrupts the dynamic balance between ROS production and ROS scavenging systems and its accumulation depends on the intensity as well as duration of water stress, and it varies among species. A plant species that has a better inherited genetic response allowing it to rapidly deploy its antioxidant enzymatic and non-enzymatic defense system, can tolerate drought better than a plant species with a poor antioxidant defense system. Furthermore, enzyme and protein encoding drought specific genes have the ability to enhance drought tolerance. These two enzymatic and genetic engineering strategies are unique and vital tools, which can be used to help alleviate the world’s future problems related to energy, food, and environmental stresses, particularly drought. This chapter attempts to discuss developments in understanding effects of drought stress and underlying mechanisms in plants for its alleviation.
Part of the book: Drought
Secondary Metabolites of Brassica juncea (L.) Czern and Coss: Occurence, Variations and Importance
There are numerous secondary plant metabolites found in the crop B. juncea, especially glucosinolates. Isothiocyanates, the by-products of glycosinolate breakdown, are beneficial to human health. A number of studies have also called attention to phenolic compounds and carotenoids, both well known for their anti-oxidant properties. A notable feature is that the profiles and concentrations of secondary plant metabolites vary greatly between varieties and that genetic factors are thought to be the most significant factors. In addition, environmental and agronomic factors have also been noted to change the concentrations of secondary plant metabolites. Secondary plant metabolites are primarily produced for defense purposes. Consequently, the intrinsic quality of Indian mustard, including color, aroma, taste, and medicinal properties, is profoundly influenced by its secondary metabolite profile. The health benefits of glycosinolates and the cancer prevention properties of their breakdown products make them of specific interest. Plant cells that have been injured undergo enzymatic decomposition of glucosinolate by endogenous enzymes such as myrosinase, which releases degradation products such as nitriles, epithionitriles, or isothiocyanates. The main phenolic compounds found in B. juncea are flavonoids and hydroxycinnamic acid derivatives. A diverse secondary metabolite pool is also essential for plant-environment interactions.
Part of the book: Brassica