Browsing by Author "Singh, Nidhi"

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CaLAP1 and CaLAP2 orchestrate anthocyanin biosynthesis in the seed coat of Cicer arietinum
(Springer Nature Publishing AG, 2024) Singh, Samar; Pal, Lalita; Rajput, Ruchika; Chhatwal, Himani; Singh, Nidhi; Chattopadhyay, Debasis; Pandey, Ashutosh
The seed coat color is a major economic trait in leguminous crop chickpea (Cicer arietinum). Anthocyanins and proanthocyanidins (PAs) are two classes of flavonoids that mainly contribute to the flower, seed coat and color of Desi chickpea cultivars. Throughout the land plant lineage, the accumulation of anthocyanins and PAs is regulated by MYB and bHLH transcription factors (TFs), which form an MBW (MYB, bHLH, and WD40) complex. Here, we report two R2R3-MYB TFs in chickpea belonging to the anthocyanin-specific subgroup-6, CaLAP1 (Legume Anthocyanin Production 1), and CaLAP2 (Legume Anthocyanin Production 2), which are mainly expressed in the flowers and developmental stages of the seeds. CaLAP1 and CaLAP2 interact with TT8-like CabHLH1 and WD40, forming the MBW complex, and bind to the promoter sequences of anthocyanin- and PA biosynthetic genes CaCHS6, CaDFR2, CaANS, and CaANR, leading to anthocyanins and PA accumulation in the seed coat of chickpea. Moreover, these CaLAPs partially complement the anthocyanin-deficient phenotype in the Arabidopsis thaliana sextuple mutant seedlings. Overexpression of CaLAPs in chickpea resulted in significantly higher expression of anthocyanin and PA biosynthetic genes leading to a darker seed coat color with higher accumulation of anthocyanin and PA. Our findings show that CaLAPs positively modulate anthocyanin and PA content in seed coats, which might influence plant development and resistance to various biotic and abiotic stresses.
Lighting the path: how light signaling regulates stomatal movement and plant immunity
(Oxford University Press, 2025) Singh, Nidhi; Giri, Mrunmay Kumar; Chattopadhyay, Debasis
Stomata, the small pores on the surfaces of leaves and stems, are crucial for gas exchange in plants and also play a role in defense against pathogens. The stomatal movement is not only influenced by surrounding light conditions but also by the presence of foliar pathogens. To put it more crisply, certain light wavelengths such as blue or strong red light, cause stomatal opening, which tragically makes it easier for bacteria to enter through opened stomata and causes disease progression in plants. Illumination of blue or intense red light autophosphorylates phototropin, a blue light photoreceptor protein kinases that in turn activates signaling cascade to open stomata. Undoubtedly stomatal defense is a fascinating aspect of plant immunology, especially in plant-foliar pathogen interaction. During these interactions, stomata fundamentally serve as entry points for intrusive pathogens and initiate plant defense signaling cascade. The present review highlights how the light-activated photoreceptors like cryptochromes (CRYs), phytochromes (phys), and UV-receptors (UVRs) influence the stomatal movement and defense signaling after foliar pathogen intrusion. It also explores the link between stomatal defense, light signaling, and plant immunity, which is vital for safeguarding crops against pathogens.
Unearthing the secrets of drought-driven root system architecture: Nutrient acquisition and rhizosphere microbe interplay
(Elsevier B.V., 2026) Nayak, Jagatjeet; Chattopadhyay, Debasis; Giri, Mrunmay Kumar; Singh, Nidhi
Drought, a climatic occurrence that cyclically affects all climatic regions, is more prevalent in tropical and subtropical areas. This phenomenon inflicts physiological harm upon plants within ecosystems and agroecosystems. Apart from the direct scarcity of water, which severely impairs plant development and productivity, there can be consequential issues related to mineral nutrition. These secondary effects can arise and further impact plant development. Amidst drought conditions, roots play a critical role in shaping the growth and development of plants. During these circumstances, our understanding of the molecular mechanisms governing critical responses and interactions between plant roots and their surrounding rhizosphere is less comprehensive in comparison to other studies with well-characterized model species like Arabidopsis. This article examines the molecular mechanisms governing the adaptability of root system architecture (RSA) to drought stress in plants. It also explores how soil nutrients and microorganisms are regulated in response to these adaptive processes. We first give a general description of how plant hormones control RSA under water-scarce conditions. Additionally, we explore how nutrients, particularly phosphorus and nitrogen, affect the developmental responses of RSA to low water status. Additionally, this article delves into the existing understanding of the interactions between RSA and soil microbial niches under drought. Based on these understandings, our conclusion emphasizes that to achieve a more comprehensive grasp of the mechanisms underlying drought adaptation in plant roots, future research should adopt a holistic network perspective.
Updating the impact of drought on root exudation: A strigolactones perspective
(Springer Nature Publishing AG, 2023) Singh, Nidhi; Chattopadhyay, Debasis; Gupta, Santosh Kumar
With the changing global climate, drought is considered one of the most devastating abiotic factors. Drought not only limits plant productivity by changing growth and development but also alters the microbiome in the rhizosphere. In addition to influencing the root microbes, drought modifies the root exudate's composition and profile in the rhizosphere. Plant health, root exudation, and abundance of soil microbes in the rhizosphere are inter-connected. The composition of root exudate is altered in terms of the abundance of primary metabolites such as sugar, amino acids, and organic acids and secondary metabolites like flavonoids, strigolactones, and terpenoids. Here, we discuss how a plethora of soil microbes may be involved in a feedback mechanism by utilizing root exudate constituents to promote drought tolerance in plants. Furthermore, plant drought tolerance is positively associated with strigolactones (SLs) exudation via coordination with ABA hormone signaling. Lastly, while the collection, sampling, and analysis of root exudates are all promising, we attempted to present advanced methodology and the development of novel processes in the review, which benefited greatly.