Browsing by Author "Ankit"

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Dark-induced hormonal regulation of plant growth and development
(Frontiers Media S.A., 2020) Deepika; Ankit; Sagar, Sushma; Singh, Amarjeet
The sessile nature of plants has made them extremely sensitive and flexible towards the constant flux of the surrounding environment, particularly light and dark. The light is perceived as a signal by specific receptors which further transduce the information through the signaling intermediates and effector proteins to modulate gene expression. Signal transduction induces changes in hormone levels that alters developmental, physiological and morphological processes. Importance of light for plants growth is well recognized, but a holistic understanding of key molecular and physiological changes governing plants development under dark is awaited. Here, we describe how darkness acts as a signal causing alteration in hormone levels and subsequent modulation of the gene regulatory network throughout plant life. The emphasis of this review is on dark mediated changes in plant hormones, regulation of signaling complex COP/DET/FUS and the transcription factors PIFs which affects developmental events such as apical hook development, elongated hypocotyls, photoperiodic flowering, shortened roots, and plastid development. Furthermore, the role of darkness in shade avoidance and senescence is discussed.
Molecular analysis indicates the involvement of Jasmonic acid biosynthesis pathway in low-potassium (K+) stress response and development in chickpea (Cicer arietinum)
(Elsevier B.V., 2022) Deepika, Deepika; Ankit; Jonwal, Sarvesh; Mali, Komal Vitthalrao; Sinha, Alok Krishna; Singh, Amarjeet
K+ is a major macronutrient and its deficiency hampers plant growth and yield. Plants combat low-K+ stress by modifying their root system architecture (RSA). Here, morphophysiological analysis revealed that chickpea plants exhibit sensitivity to low-K+ stress as shown by impaired primary root growth. Phytohormone JA regulates various facets of plant root growth, however, information of JA biosynthesis genes in chickpea is missing. We performed genome-wide identification and molecular characterization of JA biosynthesis pathway genes in chickpea. Total 33 genes belonging to different families i.e., LOXs-18, AOSs-3, AOCs-2, OPRs-6 and JARs-4 were identified in the chickpea genome. In-planta analysis revealed the localization of CaLOX7, − 10, CaAOS1, − 2 and CaAOC1 at subcellular compartments, such as membrane, chloroplast and cytoplasm. Protein expression and in-vitro enzymatic activity analysis showed that CaAOS1 an CaOPR2 are the functional enzymes in chickpea. Promoters of most genes harboured abiotic stress, hormone and development related cis-regulatory elements, suggesting their role in nutrient deficiency, abiotic stress and plant development. qRT-PCR expression profiling showed that about 15 JA biosynthesis genes from different families express differentially whereas, JA catabolism genes were repressed in chickpea root and shoot under low-K+ stress. In addition, JA biosynthesis genes showed differential expression in vegetative and reproductive development, senescence stages, desiccation, salinity and cold stress. These findings indicate the involvement of JA biosynthesis pathway in low-K+ stress response and development in chickpea. Low-K+ stress and development related genes identified in this study could be utilized in genetic engineering of chickpea plants for improved traits.
Potassium (K+) transporters in plants: Regulation and functional role in K+ uptake and homeostasis
(Elsevier B.V., 2022) Ankit; Singh, Amarjeet
Potassium (K+) is an essential macronutrient for plants and plays an important role in various cellular processes in plants. K+ transporters and channels are responsible for K+ uptake, translocation, as well as maintaining its homeostasis in plants. Other than transportation, these K+ transporters and channels are involved in other physiological processes. Several studies have shown differential expression for K+ transporter genes under abiotic stresses, such as salinity and drought. Plants can sense K+ deficiency through different mechanisms. K+ transporters and channels activity have been regulated by transcriptional as well as post–transcriptional modifications. This chapter discusses various K+ transporters and channels, their function, regulation at different levels, and their role in biotic and abiotic stress responses in plants.