Browsing by Author "Singh, Archana"

Now showing 1 - 3 of 3

A comprehensive investigation of lipid-transfer proteins from Cicer arietinum disentangles their role in plant defense against Helicoverpa armigera-infestation
(Frontiers Media S.A., 2023) Saxena, Harshita; Negi, Harshita; Keshan, Radhika; Chitkara, Pragya; Kumar, Shailesh; Chakraborty, Amrita; Roy, Amit; Singh, Indrakant K.; Singh, Archana
Lipid Transfer Proteins (LTPs) play a crucial role in synthesizing lipid barrier polymers and are involved in defense signaling during pest and pathogen attacks. Although LTPs are conserved with multifaceted roles in plants, these are not yet identified and characterized in Cicer arietinum. In this study, a genome-wide analysis of LTPs was executed and their physiochemical properties, biochemical function, gene structure analysis, chromosomal localization, promoter analysis, gene duplication, and evolutionary analysis were performed using in silico tools. Furthermore, tissue-specific expression analysis and gene expression analysis during pest attack was also conducted for the LTPs. A total of 48 LTPs were identified and named as CaLTPs. They were predicted to be small unstable proteins with "Glycolipid transfer protein" and "Alpha-Amylase Inhibitors, Lipid Transfer and Seed Storage" domains, that are translocated to the extracellular region. CaLTPs were predicted to possess 3-4 introns and were located on all the eight chromosomes of chickpea with half of the CaLTPs being localized on chromosomes 4, 5, and 6, and found to be closely related to LTPs of Arabidopsis thaliana and Medicago trancatula. Gene duplication and synteny analysis revealed that most of the CaLTPs have evolved due to tandem or segmental gene duplication and were subjected to purifying selection during evolution. The promoters of CaLTPs had development-related, phytohormone-responsive, and abiotic and biotic stress-related cis-acting elements. A few CaLTP transcripts exhibited differential expression in diverse tissue types, while others showed no/very low expression. Out of 20 jasmonate-regulated CaLTPs, 14 exhibited differential expression patterns during Helicoverpa armigera-infestation, indicating their role in plant defense response. This study identified and characterized CaLTPs from an important legume, C. arietinum, and indicated their involvement in plant defense against H. armigera-infestation, which can be further utilized to explore lipid signaling during plant-pest interaction and pest management.
Differential transcript accumulation in chickpea during early phases of compatible interaction with a necrotrophic fungus Ascochyta rabiei
(Springer Science, 2012) Jaiswal, Purnima; Cheruku, Jyothi Reddy; Kumar, Kamal; Yadav, Saurabh; Singh, Archana; Kumari, Pragati; Dube, Sunil Chandra; Upadhyaya, Kailash C.; Verma, Praveen K.
The initial phases of the disease establishment are very crucial for the compatible interactions. Pathogens must overcome the responses generated by the host for the onset of disease invasion. The compatible interaction is inadequately represented in plant-pathogen interaction studies. To gain broader insight into the early responses elicited by chickpea blight fungus Ascochyta rabiei during compatible interaction; we isolated early responsive genes of chickpea using PCR based suppression subtractive hybridization (SSH) strategy. We obtained ~250 unique genes after homology search and redundancy elimination. Based on their potential cellular functions, these genes were broadly classified into eleven different categories viz. stress, signaling, gene regulation, cellular metabolism and genes of unknown functions. Present study revealed few unexpected genes which have a possible role in induced immunity and disease progression. We employed macroarray, northern blot, real-time PCR and cluster analysis to develop transcript profiles. Most of the genes analyzed were early induced and were transcriptionally upregulated upon 24 h post inoculation. Our approach has rendered the isolation of early responsive genes involved in signaling and regulation of metabolic changes upon fungal infection. The information obtained will help to dissect the molecular mechanisms during compatible chickpea-Ascochyta interactions.
Differential transcript accumulation in Cicer arietinum L. in response to a chewing Insect Helicoverpa armigera and defense regulators correlate with reduced insect performance
(Oxford University Press, 2008) Singh, Archana; Singh, Indrakant Kumar; Verma, Praveen K.
Monitoring transcriptional reorganization triggered in response to a particular stress is an essential first step for the functional analysis of genes involved in the process. To characterize Cicer arietinum L. defence responses against Helicoverpa armigera feeding, transcript patterns elicited by both herbivore and mechanical wounding were profiled and compared, and the application of defence regulators was assessed. A combination of approaches was employed to develop transcript profiles, including suppression subtractive hybridization (SSH), macroarray, northern blot, and cluster analysis. Of the 63 unique genes isolated, 29 genes expressed differentially when Helicoverpa feeding and wounding responses were compared. Comparative macroarray analyses revealed that most of the Helicoverpa-induced transcripts were methyl jasmonate (MeJA) and ethylene (ET) regulated. The effects of mild insect infestation and the exogenous application of signalling compounds on larval feeding behaviour were also monitored. Bioassays were performed to measure dispersal percentage and growth of larvae on elicited plants. Larvae released on elicited plants had decreased larval performance, demonstrating the central role of induced plant defence against herbivory. Similarly, wounding and exogenous application of MeJA and ET also affected larval growth and feeding behaviour. Our results demonstrated that Helicoverpa attack up-regulated large transcriptional changes and induced chickpea defence responses. Therefore, the results of this study advance the understanding of non-model plant–insect interactions on a broader scale.