Publications of NIPGR Scientists

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Now showing 1 - 7 of 7
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    Plant responses to concurrent abiotic and biotic stress: unravelling physiological and morphological mechanisms
    (Springer Nature Publishing AG, 2024) Dixit, Shikha; Sivalingam, Palaiyur Nanjappan; Baskaran, R. K. Murali; Senthil-Kumar, Muthappa; Ghosh, Probir Kumar
    With the increasing impact of climate change and global warming, not only abiotic stress factors have gained prominence, but their infuence on plant–biotic interaction has also increased. Plants respond diferently to abiotic factors compared to pests and pathogens, which thrive under intense climatic conditions, leading to higher disease susceptibility and potential epidemic outbreaks. Therefore, a comprehensive understanding of the efects of concurrent biotic and abiotic stress on plants is essential. Despite its signifcance, there have been limited studies on the physiological and morphological responses of plants to combined stress, and the underlying molecular mechanisms remain elusive. While model crops like rice and maize have been explored under the context to some extent there is a scarcity of research on other crops. Furthermore, the impact of environmental factors on physiological changes in plants remains largely unknown. This review aims to consolidate existing literature on this topic, with a focus on interaction between abiotic stresses (drought, heat, and salinity) and biotic stresses (pathogens and pests). Additionally, it highlights agriculturally important morpho-physiological traits that can be utilized to identify genotypes with combined stress tolerance. Moreover, the review will outline the potential role of recent techniques and genomic tools in unravelling combined stress tolerance in plants. The fndings of this review will help physiologists and molecular biologists to design agronomically relevant strategies for developing broad-spectrum stress-tolerant crops.
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    The tomato receptor CuRe1 senses a cell wall protein to identify Cuscuta as a pathogen
    (Springer Nature Publishing AG, 2020) Hegenauer, Volker; Slaby, Peter; Körner, Max; Bruckmüller, Julien-Alexander; Burggraf, Ronja; Albert, Isabell; Kaiser, Bettina; Löffelhardt, Birgit; Droste-Borel, Irina; Sklenar, Jan; Menke, Frank L. H.; Maček, Boris; Ranjan, Aashish; Sinha, Neelima; Nürnberger, Thorsten; Felix, Georg; Krause, Kirsten; Stahl, Mark; Albert, Markus
    Parasitic plants of the genus Cuscuta penetrate shoots of host plants with haustoria and build a connection to the host vasculature to exhaust water, solutes and carbohydrates. Such infections usually stay unrecognized by the host and lead to harmful host plant damage. Here, we show a molecular mechanism of how plants can sense parasitic Cuscuta. We isolated an 11 kDa protein of the parasite cell wall and identified it as a glycine-rich protein (GRP). This GRP, as well as its minimal peptide epitope Crip21, serve as a pathogen-associated molecular pattern and specifically bind and activate a membrane-bound immune receptor of tomato, the Cuscuta Receptor 1 (CuRe1), leading to defense responses in resistant hosts. These findings provide the initial steps to understand the resistance mechanisms against parasitic plants and further offer great potential for protecting crops by engineering resistance against parasitic plants.
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    Blast resistance gene Pi54 over-expressed in rice to understand its cellular and sub-cellular localization and response to different pathogens
    (Springer Nature Limited, 2020) Singh, Jyoti; Gupta, Santosh Kumar; Devanna, B. N.; Singh, Sunil; Upadhyay, Avinash; Sharma, Tilak R.
    Rice blast resistance gene, Pi54 provides broad-spectrum resistance against diferent strains of Magnaporthe oryzae. Understanding the cellular localization of Pi54 protein is an essential step towards deciphering its place of interaction with the cognate Avr-gene. In this study, we investigated the subcellular localization of Pi54 with Green Fluorescent Protein (GFP) as a molecular tag through transient and stable expression in onion epidermal cells (Allium cepa) and susceptible japonica cultivar rice Taipei 309 (TP309), respectively. Confocal microscopy based observations of the onion epidermal cells revealed nucleus and cytoplasm specifc GFP signals. In the stable transformed rice plants, GFP signal was recorded in the stomata, upper epidermal cells, mesophyll cells, vascular bundle, and walls of bundle sheath and bulliform cells of leaf tissues. These observations were further confrmed by Immunocytochemical studies. Using GFP specifc antibodies, it was found that there was sufcient aggregation of GFP::Pi54protein in the cytoplasm of the leaf mesophyll cells and periphery of the epidermal cells. Interestingly, the transgenic lines developed in this study could show a moderate level of resistance to Xanthomonas oryzae and Rhizoctonia solani, the causal agents of the rice bacterial blight and sheath blight diseases, respectively. This study is a frst detailed report, which emphasizes the cellular and subcellular distribution of the broad spectrum blast resistance gene Pi54 in rice and the impact of its constitutive expression towards resistance against other fungal and bacterial pathogens of rice.
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    Integrative network analyses of wilt transcriptome in chickpea reveal genotype dependent regulatory hubs in immunity and susceptibility
    (Springer Nature, 2018) Ashraf, Nasheeman; Basu, Swaraj; Narula, Kanika; Ghosh, Sudip; Tayal, Rajul; Gangisetty, Nagaraju; Biswas, Sushmita; Aggarwal, Pooja R.; Chakraborty, Niranjan; Chakraborty, Subhra
    Host specific resistance and non-host resistance are two plant immune responses to counter pathogen invasion. Gene network organizing principles leading to quantitative differences in resistant and susceptible host during host specific resistance are poorly understood. Vascular wilt caused by root pathogen Fusarium species is complex and governed by host specific resistance in crop plants, including chickpea. Here, we temporally profiled two contrasting chickpea genotypes in disease and immune state to better understand gene expression switches in host specific resistance. Integrative gene-regulatory network elucidated tangible insight into interaction coordinators leading to pathway determination governing distinct (disease or immune) phenotypes. Global network analysis identified five major hubs with 389 co-regulated genes. Functional enrichment revealed immunome containing three subnetworks involving CTI, PTI and ETI and wilt diseasome encompassing four subnetworks highlighting pathogen perception, penetration, colonization and disease establishment. These subnetworks likely represent key components that coordinate various biological processes favouring defence or disease. Furthermore, we identified core 76 disease/immunity related genes through subcellular analysis. Our regularized network with robust statistical assessment captured known and unexpected gene interaction, candidate novel regulators as future biomarkers and first time showed system-wide quantitative architecture corresponding to genotypic characteristics in wilt landscape.
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    Alterations in rice chloroplast integrity, photosynthesis and metabolome associated with pathogenesis of Rhizoctonia solani
    (Nature Publishing Group, 2017) Ghosh, S; Kanwar, P; Jha, Gopaljee
    Sheath blight disease is caused by a necrotrophic fungal pathogen Rhizoctonia solani and it continues to be a challenge for sustainable rice cultivation. In this study, we adopted a multi-pronged approach to understand the intricacies of rice undergoing susceptible interactions with R. solani. Extensive anatomical alteration, chloroplast localized ROS, deformed chloroplast ultrastructure along with decreased photosynthetic efficiency were observed in infected tissue. GC-MS based metabolite profiling revealed accumulation of glycolysis and TCA cycle intermediates, suggesting enhanced respiration. Several aromatic and aliphatic amino acids along with phenylpropanoid intermediates were also accumulated, suggesting induction of secondary metabolism during pathogenesis. Furthermore, alterations in carbon metabolism along with perturbation of hormonal signalling were highlighted in this study. The gene expression analysis including RNAseq profiling reinforced observed metabolic alterations in the infected tissues. In conclusion, the present study unravels key events associated during susceptible rice-R. solani interactions and identifies metabolites and transcripts that are accumulated in infected tissues.
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    Functional involvement of a mitogen activated protein kinase module, OsMKK3-OsMPK7-OsWRK30 in mediating resistance against Xanthomonas oryzae in rice
    (Nature Publishing Group, 2016) Jalmi, Siddhi Kashinath; Sinha, Alok Krishna
    Mitogen-activated protein kinases (MAPKs) are highly conserved signaling modules in eukaryotes, transmitting signals from upstream receptor to downstream target by phosphorelay mechanism. Here we report involvement of a poorly characterized group C MAPK of rice namely, OsMPK7 along with its upstream MAPK kinase, OsMKK3 and downstream target, OsWRKY30 during Xanthomonas oryzae infection, a causal agent of leaf blight disease in rice. X. oryzae infection resulted in induction of OsMPK7 and OsMKK3. OsMKK3 was found to physically interact and phosphorylate OsMPK7. Overexpression of OsMPK7 and OsMKK3, individually and in combinations resulted in inhibition of disease symptoms caused by X. oryzae, however silencing of OsMPK7 resulted in disease susceptibility. Furthermore, OsWRKY30 was identified as downstream target of OsMPK7 through protein-protein interaction techniques and was found to be a positive regulator of defence response against X. oryzae pathogen. The overexpression of OsMKK3-OsMPK7 upregulated genes involved in pathogenesis, cell wall structure maintenance and cell metabolism indicating possible mechanism of disease resistance. These leaves also showed restricted movement of the pathogen from the point of infection to uninfected area. Taken together, this work suggests a positive involvement of OsMKK3-OsMPK7-OsWRKY30 module in imparting disease resistance against X. oryzae infection in rice.
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    Tomato 26S Proteasome subunit RPT4a regulates ToLCNDV transcription and activates hypersensitive response in tomato
    (Nature Publishing Group, 2016) Sahu, Pranav Pankaj; Sharma, Namisha; Puranik, Swati; Chakraborty, Supriya; Prasad, Manoj
    Involvement of 26S proteasomal subunits in plant pathogen-interactions, and the roles of each subunit in independently modulating the activity of many intra- and inter-cellular regulators controlling physiological and defense responses of a plant were well reported. In this regard, we aimed to functionally characterize a Solanum lycopersicum 26S proteasomal subunit RPT4a (SlRPT4) gene, which was differentially expressed after Tomato leaf curl New Delhi virus (ToLCNDV) infection in tolerant cultivar H-88-78-1. Molecular analysis revealed that SlRPT4 protein has an active ATPase activity. SlRPT4 could specifically bind to the stem-loop structure of intergenic region (IR), present in both DNA-A and DNA-B molecule of the bipartite viral genome. Lack of secondary structure in replication-associated gene fragment prevented formation of DNA-protein complex suggesting that binding of SlRPT4 with DNA is secondary structure specific. Interestingly, binding of SlRPT4 to IR inhibited the function of RNA Pol-II and subsequently reduced the bi-directional transcription of ToLCNDV genome. Virus-induced gene silencing of SlRPT4 gene incited conversion of tolerant attributes of cultivar H-88-78-1 into susceptibility. Furthermore, transient overexpression of SlRPT4 resulted in activation of programmed cell death and antioxidant enzymes system. Overall, present study highlights non-proteolytic function of SlRPT4 and their participation in defense pathway against virus infection in tomato.