Browsing by Author "Meena, Ram Prasad"

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    Biotechnological strategies for enhancing heavy metal tolerance in neglected and underutilized legume crops: A comprehensive review
    (Academic Press, 2021) Rai, Krishna Kumar; Pandey, Neha; Meena, Ram Prasad; Rai, Shashi Pandey
    Contamination of agricultural land and water by heavy metals due to rapid industrialization and urbanization including various natural processes have become one of the major constraints to crop growth and productivity. Several studies have reported that to counteract heavy metal stress, plants should be able to maneuver various physiological, biochemical and molecular processes to improve their growth and development under heavy metal stress. With the advent of modern biotechnological tools and techniques it is now possible to tailor legume and other plants overexpressing stress-induced genes, transcription factors, proteins, and metabolites that are directly involved in heavy metal stress tolerance. This review provides an in-depth overview of various biotechnological approaches and/or strategies that can be used for enhancing detoxification of the heavy metals by stimulating phytoremediation processes. Synthetic biology tools involved in the engineering of legume and other crop plants against heavy metal stress tolerance are also discussed herewith some pioneering examples where synthetic biology tools that have been used to modify plants for specific traits. Also, CRISPR based genetic engineering of plants, including their role in modulating the expression of several genes/ transcription factors in the improvement of abiotic stress tolerance and phytoremediation ability using knockdown and knockout strategies has also been critically discussed. � 2020 The Authors
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    PLANT CIRCADIAN RHYTHM: A BIOLOGICAL CLOCK AS DEVELOPMENTAL AND METABOLIC REGULATOR
    (Nova Science Publishers, Inc., 2022) Rai, Nidhi; Kumari, Sabitri; Saha, Pajeb; Apoorva; Rai, Sanjay Kumar; Meena, Ram Prasad; Pandey-Rai, Shashi
    Plants have an internal biological system that receives differential environmental fluctuations/stimuli such as temperature and light controlling circadian rhythm for maintenance of growth and developmental processes. These biological rhythms are regulated by the interaction of certain external signals and internal receptors. In plants, it is complex networking within transcription factors that functions in feedback loops. These light-induced phototropic controls are mediated by photoreceptors like phytochromes, cryptochrome, phototropin and master genes/regulators for floral development. These responses are genetic in nature and have master clock genes which further regulates many copies of the master transcription factor that are responsible for regulating/switch-on many important genes of metabolism by binding with the promoter region of target genes. The diurnal behavior in plants has been observed because of the existence of a feedback loop and a phosphorylation-dephosphorylation cycle. The light and temperatures positively regulate the induction of various genes along with a set of polycomb gene. Many long non-coding RNAs, micro-RNA and RNAdependent polymerases are indispensable parts of the diurnal cycle in plants. Environmental signals are involved in activating clock genes, and clock repressor circuits work to alienate and degrade these extrinsic gene activation pathways. Most transcription factors are cyclic and these subclasses can regulate clock parameters. Transcriptional regulators and associated chromatids that control transcriptional regulation are only one step in a multistep regulatory network. Post-translational relaxation, nuclear-cytoplasmic dissociation, RNA splicing and proteolytic functions participate in the stimulation. Homogenization of all these activities leads to the generation and sustainable facilitation of the robust rhythm and response to the diurnal variations of the environment. The purpose of this chapter is to explain the physiological and molecular mechanisms of the circadian clocks of plants, including biochemistry, and to demonstrate the function/role of the circadian clock in metabolic, physiological processes and plant behavior. � 2022 by Nova Science Publishers, Inc.
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    Short term UV-B radiation mediated modulation of physiological traits and withanolides production in Withania coagulans (L.) Dunal under in-vitro condition
    (Springer, 2021) Tripathi, Deepika; Meena, Ram Prasad; Pandey-Rai, Shashi
    Accumulation of secondary metabolites is a key process in the growth and development of plants under different biotic/abiotic constraints. Many studies highlighted the regulatory potential of UV-B treatment towards the�secondary metabolism of plants. In the present study, we examined the impact of UV-B on the�physiology and secondary metabolism of Withania coagulans, which is an important ayurvedic plant with high anti-diabetic potential. Results showed that in-vitro UV-B exposure negatively influenced chlorophyll content and photosynthetic machinery. However, Fv/Fm ratio was found non-significantly altered up to 3�h UV-B exposure. The maximum lipid peroxidation level was recorded with 46.8% higher malondialdehyde content in the plants supplemented with 5�h UV-B radiation, that was indicated the oxidative stress in W. coagulans. Conversely, UV-B treatment significantly increased the plant's stress protective compounds like carotenoids, anthocyanin, phenol and proline, in W. coagulans. Free radical scavenging activity was also significantly increased ~ 18% than the control with 3�h UV-B treatment. The maximum antioxidative enzymes activities were observed with the short-term (up to 3�h) UV-B treatment. Specifically, UV-B radiation exposure significantly increased the content of withaferin A and withanolide A in W. coagulans with maximum 1.38 and 3.42-folds, respectively. Additionally, withanolides biosynthesis related genes transcript levels were found over-expressed under the response of UV-B elicitation. The acquired results suggested that short-term UV-B supplementation triggers secondary metabolism along with combating oxidative stress via improving the antioxidative defense system in W. coagulans. Also, UV-B can be used as an efficient abiotic elicitor to increase pharmaceutical compounds (withanolides) production. � 2021, Prof. H.S. Srivastava Foundation for Science and Society.