Browsing by Author "Pandey, Mandavi"

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Dissecting chickpea genomic loci associated with the root penetration responsive traits in compacted soil
(Springer Nature Publishing AG, 2024) Donde, Ravindra; Kohli, Pawandeep Singh; Pandey, Mandavi; Sirohi, Ujjwal; Singh, Bhagat; Giri, Jitender
Soil compaction is a major concern for modern agriculture, as it constrains plant root growth, leading to reduced resource acquisition. Phenotypic variation for root system architecture (RSA) traits in compacted soils is present for various crops; however, studies on genetic associations with these traits are lacking. Therefore, we investigated RSA traits in diferent soil compaction levels and identifed signifcant genomic associations in chickpea. We conducted a Genome-Wide Association Study (GWAS) of 210 chickpea accessions for 13 RSA traits under three bulk densities (BD) (1.1BD, 1.6BD, and 1.8BD). Soil compaction decreases root exploration by reducing 12 RSA traits, except average diameter (AD). Further, AD is negatively correlated with lateral root traits, and this correlation increases in 1.8BD, suggesting the negative efect of AD on lateral root traits. Interestingly, we identifed probable candidate genes such as GLP3 and LRX for lateral root traits and CRF1-like for total length (TL) in 1.6BD soil. In heavy soil compaction, DGK2 is associated with lateral root traits. Reduction in laterals during soil compaction is mainly due to delayed seedling establishment, thus making lateral root number a critical trait. Interestingly, we also found a higher contribution of the GxE component of the number of root tips (Tips) to the total variation than the other lateral traits. We also identifed a pectin esterase, PPE8B, associated with Tips in high soil compaction and a signifcantly associated SNP with the relative change in Tips depicting a trade-of between Tips and AD. Identifed genes and loci would help develop soil-compaction-resistant chickpea varieties.
A lipid synthase maintains metabolic flux for jasmonate synthesis to regulate root growth and phosphate homeostasis
(Oxford University Press, 2025) Pandey, Mandavi; Verma, Lokesh; Kohli, Pawandeep Singh; Singh, Bhagat; Kochi, Abhijith; Giri, Jitender
Plants require phosphate (Pi) for proper growth and development but often face scarcity of this vital nutrient in the soil. Pi-starvation triggers membrane lipid remodeling to utilize the membrane phospholipid-bound Pi in plants. In this process, phospholipids are replaced by non-Pi-containing galactolipids (MGDG, DGDG) and sulfolipids. The galactolipids ratio (MGDG:DGDG) is suggested to influence jasmonic acid (JA) biosynthesis. However, how the MGDG:DGDG ratio, JA levels, and root growth are coordinated under Pi deficiency in rice (Oryza sativa) remains unknown. Here, we characterized DGDG synthase 1 (OsDGD1) for its role in regulating root development by maintaining metabolic flux for JA biosynthesis. We showed that OsDGD1 is responsive under low Pi and is under the direct control of Phosphate Starvation Response 2 (OsPHR2), the master regulator of low Pi adaptations. Further, OsDGD1 knockout (KO) lines showed marked phenotypic differences compared to the wild type (WT), including a significant reduction in root length and biomass, leading to reduced Pi uptake. Further, lipidome analyses revealed reduced DGDG levels in the KO line, leading to reduced membrane remodeling, thus affecting P utilization efficiency. We also observed an increase in the MGDG: DGDG ratio in KO lines, which enhanced the endogenous JA levels and signaling. This imbalance of JA in KO plants led to changes in auxin levels, causing drastic root growth inhibition. These findings indicate the critical role of OsDGD1 in maintaining optimum levels of JA during Pi deficiency for conducive root growth. Besides acting as signaling molecules and structural components, our study widens the role of lipids as metabolic flux controllers for phytohormone biosynthesis.
Lipid-mediated responses to nutrient and other stresses: Roles in plant adaptation and signaling
(Oxford University Press, 2026) Pandey, Mandavi; Ganotra, Jahanvi; Singh, Astha; Parchuri, Prasad; Giri, Jitender
Lipids are essential components of biological membranes; however, their roles in plants go far beyond providing structural support. They are actively involved in signaling and metabolic regulation during abiotic and biotic stress. Plants use lipid-based strategies to adapt to nutrient shortages, toxic conditions, and changing environments. Signaling lipids such as phosphatidic acid (PA), phosphoinositides, sphingolipids, and oxylipins serve as molecular messengers that transmit stress signals to regulate ion transport, hormone interactions, and developmental flexibility. During nutrient deprivation, especially of phosphorus (P), nitrogen (N), and potassium (K), plants adjust membrane composition by replacing phospholipids with P-free glycolipids like galactolipids and sulfolipids, conserving critical nutrients while keeping membrane structure intact. Lipid intermediates, including PA, glycerol-3-phosphate, and negatively charged phospholipids, also act as secondary messengers in stress signaling networks. Lipid droplets and lipophagy help maintain carbon and redox balance, while enzymes like phospholipases and glycerophosphodiesterases recycle nutrients and alter lipid profiles. Under K deficiency and toxic metal exposure (e.g., aluminum (Al), cadmium (Cd)), lipid turnover influences membrane stability, reactive oxygen species (ROS) production, and transporter function. Lipid modifications also reduce toxic ion binding and cellular damage, and molecules derived from lipids, such as jasmonates, play roles in secondary metabolism and hormonal defense pathways. Although lipid-based stress responses are conserved throughout plant lineages, the regulatory mechanisms controlling lipid fluxes are not yet fully understood. New tools, like genetically coded lipid biosensors and lipidomics platforms, are uncovering the spatial and temporal dynamics of lipid signaling with unprecedented detail. Improving our understanding of lipid-mediated stress responses may enable the development of crops with better nutrient efficiency and resilience to climatic and edaphic stresses, contributing to sustainable agriculture.
Method for the dissection of genomic loci associated with chickpea root penetration traits in compact soil
(Springer Nature Publishing AG, 2026) Ganotra, Jahanvi; Pandey, Mandavi; Donde, Ravindra; Giri, Jitender
Mechanical impedance in agricultural land is a significant constraint in modern agriculture. It dramatically affects seed germination, plant growth, development, and grain yield. Soil compaction hinders root growth and the ability to access deeper nutrients and water resources, impacting climate resilience, crop productivity, and global food security. Crops display variations in root system architecture (RSA) traits when grown in compacted soils. We can better understand the mechanisms behind soil compaction by examining root-related traits and their associated genes. Our recently published study investigated RSA traits across different soil compaction levels and identified significant genomic associations in chickpeas. We developed reliable methods for creating soils with varying bulk densities (i.e., compaction levels), growing chickpea seedlings, and harvesting the roots. We also conducted high-throughput phenotyping and screening of root-related traits using winRHIZO software. By integrating these phenotypic data with available genotypic data through Genome-Wide Association Studies (GWAS), we could identify genetic loci influencing root penetration in response to increasing soil compaction. These methods will help us identify key architectural traits of roots that can be targeted in crop breeding efforts to enhance resilience and productivity in compacted soils. By improving the root system and understanding the genes involved, we aim to develop plants more responsive to root penetration.
Network-based multiomics and transgenic validation reveal that OsPHR3 modulates phosphate-carbon metabolic trade-offs during rice seed development
(Elsevier B.V., 2026) Pazhamala, Lekha; Pandey, Mandavi; Deveshwar, Priyanka; Ghatak, Arindam; Weckwerth, Wolfram; Chaturvedi, Palak; Giri, Jitender
Phosphate (Pi) allocation during the grain-filling stage is a major determinant of crop yield, supporting macromolecule synthesis, energy metabolism, and nutrient storage. However, its storage as phytic acid (PA) reduces nutritional quality by chelating essential minerals. Despite its importance, a comprehensive understanding of the molecular mechanisms integrating Pi transport, carbohydrate metabolism, and PA biosynthesis during seed development remains incomplete. To address this gap, we investigated stage-specific phosphate regulatory networks in rice by integrating transcriptomic, proteomic, and metabolomic approaches. Temporal expression profiling and gene coexpression network analyses of phosphate regulators and transporter genes revealed their distinct roles during early and mid-grain filling stages. PHOSPHATE STARVATION RESPONSE 3 (OsPHR3) emerged as a central regulatory hub, coordinating the balance of Pi, sugar, starch and phytate, along with other metabolites. Network-based multiomics integration further identified 126 genes involved in nutrient storage and stress tolerance, with myo-inositol-1-phosphate synthase (OsMIPS1) and starch synthase 3 (OsSSIII) as key genes. CRISPR/Cas9-generated osphr3 knockout lines confirmed the critical role of OsPHR3 in regulating these target genes. Mutants exhibited significantly reduced seed starch, PA, and total phosphorus contents, while scanning electron microscopy revealed aberrant starch granule morphology. Loss-of-function of OsPHR3 lowered PA levels by 19.46–22.50 %, with moderate trade-offs in yield-related traits. Although, OsPHR3 is known to contribute to nitrogen and phosphorus homeostasis, our findings establish it as a key regulator orchestrating a stage-specific phosphate-carbon allocation during seed development. These insights provide key targets for refining nutrient partitioning to achieve increased yields, reduced phytic acid, and enhanced phosphorus use efficiency for agricultural sustainability.
Phosphate deficiency inducible OsGDPD5 affects root growth by regulating sugar-auxin crosstalk
(John Wiley & Sons, 2025) Verma, Lokesh; Pandey, Mandavi; Bhatia, Chitra; Mehra, Poonam; Singh, Bhagat; Giri, Jitender
Glycerophosphodiester phosphodiesterases (GDPDs) enzymes are known to be involved in phospholipids degradation pathways, where glycerophosphodiesters are hydrolyzed to glycerol-3-phosphate (G3P) and corresponding alcohol. In plants, GDPDs are involved in phosphate deficiency adaptive responses and have been shown to impact root length, but the precise mechanism remains unclear. This study focuses on the rice GDPD5 gene and its role in regulating primary root growth. Our research demonstrates that OsGDPD5 encodes a functional GDPD enzyme and could hydrolyze glycerophosphocholine and glycerophosphorylethanolamine. At transcriptional levels, OsGDPD5 is preferentially expressed in the root tip and regulated by transcription factor OsPHR2. We have used CRISPR/Cas9 to generate OsGDPD5 knock-out lines, allowing us to explore its role in root growth. Our findings show that osgdpd5 mutants had a shorter primary root, which could be restored to a normal level by the exogenous application of sugar or G3P. Further, knocking out OsGDPD5 alters endogenous levels of G3P and sugars, affecting auxin biosynthesis in the root and, ultimately, primary root growth. In this manner, OsGDPD5 has a crucial role in regulating physiological processes, specifically sugar and auxin signaling, which are known to be involved in root growth regulation in rice. Our research thus unraveled a link between rice phosphate deficiency-responsive lipid remodeling and root growth via sugar-hormone signaling.
Unearthing root response mechanisms to soil compaction in legumes
(John Wiley & Sons, 2026) Ganotra, Jahanvi; Pandey, Mandavi; Pandey, Bipin K.; Giri, Jitender
Roots are essential for the survival and functioning of plants, serving as anchors in the soil and drawing in vital nutrients and water. Roots also engage in diverse microbial interactions, including pathogenic interactions that cause plant disease and non-pathogenic interactions, such as symbiotic and commensal relationships. Mechanical resistance in compacted soil is one of the biggest challenges for root exploration. Soil compaction hampers plant growth by restricting root elongation, reducing root proliferation, and limiting access to water, nutrients, and oxygen. These restrictions interfere with root-microbe interactions and also impair aboveground growth, leading to decreased shoot biomass, stunted development, and lower overall productivity. Legume roots form symbiotic relationships with soil-dwelling Rhizobium, resulting in root nodules that convert atmospheric nitrogen (N) into ammonia, thereby promoting plant growth. However, the impact of soil compaction on legume roots remains poorly studied. In this review, we examine key adaptive strategies used by legume roots to counteract soil compaction, focusing on the underlying molecular pathways. A complex signalling network regulates molecular processes that control root development and nodulation in legumes. We also explore the genetic and environmental factors that influence morphological, anatomical, and biochemical traits under mechanical stress, providing insights for improving stress resilience in legumes.