Browsing by Author "Anuradha Patel"

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Effects of Salt Stress on Osmolyte Metabolism of Crop Plants and Mitigating Strategy by Osmolyte
(wiley, 2021) Abreeq Fatima; Garima Singh; Anuradha Patel; Sanjesh Tiwari; Divya Gupta; Dilip Kumar Prajapati; Anurag Dubey; Sheo Mohan Prasad
Among various abiotic stresses, salinity is a major problem in arid and semiarid regions of the world that negatively reduces the crop productivity. Osmotic stress is the major cause of reduction in growth under salt stress and to minimize the osmotic stress, plants either accumulates or enhances the synthesis of osmoprotectants. The enhanced production of osmolytes is the manifestation of osmoprotectant responsive genes, which improves stress tolerance in plants. Most of the crop plants during abiotic stress conditions such as salinity, drought, and high temperature protect themselves through amino acid metabolism as well. Salinity is one of the most brutal environmental stresses that hamper plant growth and productivity worldwide. The biosynthetic pathways of major osmolyte such as proline, glycine betaine, polyamines, or some synthetic sugar molecules are severely affected under salt stress. Salt-induced toxicity is either alleviated by enhanced antioxidant system or by exogenous supplementation of these major osmolytes. © 2022 John Wiley & Sons Ltd. All rights reserved.
Regulation of temperature stress in plants
(Elsevier, 2020) Sanjesh Tiwari; Anuradha Patel; Madhulika Singh; Sheo Mohan Prasad
Plant, during its entire life cycle, from seedling to reproductive stage, faces changing environment that is sometimes unfavorable for growth and developmental processes; plants develop specific mechanism to overcome these environmental stresses. Adverse environmental factors are categorized majorly in two categories: first biotic factors that include pathogen and herbivore attacks, and second, abiotic factors that include drought, heat, cold, nutrient deficiency, and heavy-metal accumulation in the soil. Among these, salt, drought, and temperature affect the geographical distribution of plant species as well as disrupt the plant metabolism. As a consequence, they limit the quality and quantity of food production in agriculture and reducing the food demand for growing population, and to overcome these adverse effects, tolerance mechanism in plants has been well studied. In general, various environmental factors (biotic and abiotic) induce the plant resistance by activation of stress tolerance genes. The average temperature was found to be increased by 0.2°C/year and it has to be increased by 1.8°C-4°C at the end of year 2100, hence temperature is pondered to be one of the utmost detrimental stress. Climate change due to temperature is a global concern that has altered the physiological and biochemical activities of plant, thereby reducing the productivity of crops. Increased temperature continuously caused heat stress in plants, which depends upon the quality, intensity, and duration of light. Generation of reactive oxygen species is a common phenomenon exhibited by all environmental factors (biotic and abiotic), including heat stress that damaged the macromolecules, such as DNA, proteins, and lipids, and plants are under oxidative stress. Furthermore, heat stress also altered the expression of genes that participate in the formation of and responsible for production of osmoprotectants, detoxifying enzymes, transporters, and regulatory proteins. On contrary to this, heat stress inhibits the protein folding, affects the membrane (lipid bilayer) fluidity and cytoskeleton arrangement, and also affects the vegetative and reproductive tissue. Rise in temperature up to a certain limit is beneficial for plant that regulates the circadian rhythms in plants, regulates plant movements (opening/closing of corolla), and also affects the geographical distribution of plants in nature. Plants susceptibility toward pathogen was also enhanced by high temperature. Infection capacity of tobacco mosaic and tomato-spotted wilt viruses were found to be increased when ambient temperature increased and caused viral diseases in tobacco (Nicotiana tabacum) and pepper (Capsicum annuum), respectively. In wheat genotypes, its sensitivity toward Cochliobolus sativus (caused spot blotch) was associated with increase in nighttime temperature. © 2020 Elsevier Inc. All rights reserved.
Role of sRNAs in abiotic stress tolerance
(Elsevier, 2020) Anuradha Patel; Sanjesh Tiwari; Madhulika Singh; Sheo Mohan Prasad
Any external factors either biotic or abiotic that significantly reduced the plants’ ability to convert light energy into biomass are studied under a broad category termed stresses that negatively influence the metabolic activities of plants. Along with biotic and abiotic stresses, overgrowing population also caused a lot of pressure on agricultural fields to fulfill the food demand, but the crops productivity was not increased in such manner as population increased. In natural environment, primary producers, that is, plants face a number of adverse environmental conditions such as high salinity, drought, cold, and heat that limits the biomass production and yield of staple food crops; hence, it is a global concern to fulfill the food demand. Various anthropogenic activities contribute to the abiotic stress that changes the climate of environment that causes threat to food security. These adverse environmental changes hamper the various physiological and metabolic factors that results in death of plants. A physiological alteration under abiotic stresses includes growth inhibition associated with photosynthetic pigment loss, decreased whole-cell oxygen evolution (photosynthesis), and significant increase in oxygen consumption. Plants stimulate various adoptive changes in response to abiotic stresses at physiological, cellular, and molecular level or through genetic regulation or reprogramming the expression of gene. Physiological adaptation includes change in protein modification at transcriptional level as well as at posttranslational level that leads the change in particular phenotype that significantly avoids the stressful conditions. One such approach is through the modification in gene expression and also through the activity of sRNAs, which switches on protective mechanisms, that is, the genes that involve in defense systems are upregulated and gens that involve in toxicity are downregulated. Role of proteomics as stress-tolerance mechanism is well known, whereas the role of sRNA as stress regulators is an emerging molecular tool. Further, due to the development of modern molecular techniques, molecular mechanisms in plants give much more attention to identify the stress-responsive proteins and their regulatory gene networks under posttranslational level. In this line, small noncoding RNAs (sRNAs) are considered posttranscriptional regulatory factor in gene regulation under adverse environmental factors and involved in plant development. In molecular world, RNAs are basically categorized into two into transfer RNA and ribosomal RNA, and the only difference in sRNAs from other forms of RNAs is relatively small size of genome (20-30nt) as well as having capacity to make complex with argonaute (AGO) family proteins considered key components of RISC (RNA-induced silencing complex). Among various types of sRNA, two are major, that is, microRNAs and small interfering RNAs that actively mediate the gene regulation, splicing, DNA methylation, chromatin, protein, and nucleotide modification and sRNA-mediated gene silencing termed RNA interference (RNAi). RNAi significantly inhibits the process of transcription or translation by sequence-specific gene regulation initiated by dsRNA and frequently presents in plants as well as in animals, fungi, and ciliates. The present time is totally dependent on crop improvement techniques under adverse environmental conditions by the use of various molecular approaches and among them RNAi is considered an important tool of genetic engineering and functional genomics. In this chapter, we briefly describe the biogenesis of sRNA and their pivotal role against abiotic stress tolerance. © 2020 Elsevier Inc. All rights reserved.
Salt Stress Toxicity Amelioration by Phytohormones, Synthetic Product, and Nutrient Amendment Practices
(wiley, 2021) Divya Gupta; Garima Singh; Sanjesh Tiwari; Anuradha Patel; Abreeq Fatima; Anurag Dubey; Neha Naaz; Jitendra Pandey; Sheo Mohan Prasad
This chapter discusses the various ameliorating approaches to cope up the loss of crop yield under saline environment. Phytohormones are essential growth regulators and are best known for their prominent impact on metabolism and stimulation of defense responses. The exogenous supplementation of plant growth hormones alleviates the salt toxicity and showing vital role in minimizing the stress by improving several metabolic processes like improving seed metabolism, maintaining the homeostasis redox reaction, and other physiological mechanisms. The exogenous supplementation or endogenous accumulation of proline which is an amino acid and a well-known product enhances behavior of salt-stressed plants. Nutrient management significantly improved the growth, physiological, and biochemical modifications as well as quality characteristics of the salt-stressed plants. Salt toxicity induced alterations in growth and development by inducing the ion toxicity, osmotic stress, essential nutrients deficiency, inhibition of electron transport chain associated with oxidative stress that limits the activation of anti-oxidative machinery, and water uptake from soil. © 2022 John Wiley & Sons Ltd. All rights reserved.