Botany - Research Publications

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Author: search.filters.author.Bhardwaj, Pankaj

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    Transcriptome Analysis Revealed Behavior Complexity of Senescence Responses in Himalayan Tree Species Ulmus wallichiana
    (Springer, 2023-05-17T00:00:00) Singh, Amandeep; Majeed, Aasim; Sharma, Vikas; Gadri, Hari Shankar; Chowdhary, Md. Asif; Bhardwaj, Pankaj
    The Himalayas present a highly contrasting environment for the organisms that inhabit it, with summer and winter being the most disparate seasons. As winter approaches, the temperature drops, and deciduous plants, such as Ulmus wallichiana Planch., undergo senescence. In this study, we used the RNA-seq approach to generate a de novo transcriptome assembly of U. wallichiana, consisting of 300,067 unigenes. We investigated the differential expression pattern of these unigenes under changing climatic conditions, with a focus on the contrast between winter and summer. We observed that 2746 unigenes were differentially expressed, with a fold change of ? 2 and an FDR-adjusted p-value of ? 0.001. Among these unigenes, 37 were found to be related to senescence. We also identified nine DREB unigenes in the U. wallichiana transcriptome, which exhibited more or less contrasting patterns between summer and winter. These DREB unigenes may play an important role in regulating the plant�s tolerance to cold and/or drought stress. Our findings shed light on the complex and dynamic process of transcriptomic reprogramming that enables U. wallichiana to cope with seasonal changes. Furthermore, this study highlights the urgent need for further research on U. wallichiana, as this endangered plant species remains largely unexplored at the genomic level. � 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
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    Transcriptome characterization and generation of marker resource for Himalayan vulnerable species, Ulmus wallichiana
    (Springer Science and Business Media B.V., 2021-01-14T00:00:00) Singh, Amandeep; Majeed, Aasim; Bhardwaj, Pankaj
    Ulmus wallichiana is a traditional medicinal plant listed as a vulnerable in the IUCN red list data. Genomic and transcriptomic resources for this species are lacking, hindering its genetic exploration. Further, no polymorphic marker resource is available for this species, thus limiting the elucidation of its underlying genetic diversity, which is a pre-requisite for its conservation. This study was therefore aimed to generate a functionally annotated transcriptomic resource and screen it for SSR regions. We used paired-end Illumina based RNAseq technology and trinity based de novo assembly approach to generate full length transcripts, which were screened for SSR regions and functionally annotated. Around 6.6 million raw reads were de novo assembled transcripts, which were clustered into 146,083 unigenes. 19,909 transcripts were provided with 3986 unique KEGG ids, 70,519 transcripts with 6621 unique Pfam domains, and 45,125 transcripts with 7302 unique INTERPRO domains. 1456 transcripts were identified as transcriptions factors (TFs). Further, 8868 unique GO terms were obtained for the unigenes. The transcripts mapped to 23,056 known pre-determined orthology clusters in the eggNOG database. A total of 16,570 SSRs were identified from the unigenes. Out of the 90 SSRs selected for characterization on 20 genotypes, 28 were polymorphic. Mean effective alleles (Ne) of 2.53, mean observed heterozygosity (Ho) of 0.77, and average polymorphic information content (PIC) of 0.57 were found. This study may facilitate the genetic exploration of this species. The polymorphic SSRs would prove useful to explore its genetic diversity patterns, required for its conservation. � 2021, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.
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    Codon usage pattern in Gnetales evolved in close accordance with the Gnetifer hypothesis
    (Oxford University Press, 2021-01-06T00:00:00) Majeed, Aasim; Kaur, Harpreet; Kaur, Amitozdeep; Das, Sreemoyee; Joseph, Josepheena; Bhardwaj, Pankaj
    The evolution of Gnetales is ambiguous, and their phylogenetic position is still debated. The biological and molecular processes may evolve with the evolutionary history of a species or a clade. The molecular/biological processes of phylogenetically similar lineages closely follow their evolutionary pattern. If Gnetales evolved as a sister to Pinaceae, cupressophytes or Coniferales as a whole, then it is expected that the molecular or biological processes may reflect this pattern of evolution. In light of this, we deciphered the codon usage pattern of Gnetales, compared it with angiosperms, Pinaceae, cupressophytes and Coniferales as a whole. We evaluated whether this important molecular process has evolved in agreement with the Anthophyte, Gnepine, Gnecup or Gnetifer hypothesis. We observed that Gnetales prefer A/U-ending codons to G/C-ending codons like other lineages. Natural selection plays a dominant role in governing the codon usage bias (CUB). The CpA/CpT dinucleotides were over-represented, whereas the CpG dinucleotide was suppressed. Hierarchical clustering (HC) and correspondence analysis (CA) on relative synonymous codon usage values of 59 synonymous codons showed Gnetales as a sister clade to Coniferales as a whole and revealed that the codon usage pattern in Gnetales has evolved in close accordance with the Gnetifer hypothesis. � 2021 The Linnean Society of London, Botanical Journal of the Linnean Society.
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    Transcribing molecular and climatic data into conservation management for the Himalayan endangered species, Taxus contorta (Griff.)
    (Springer Science and Business Media B.V., 2020-11-12T00:00:00) Majeed, Aasim; Singh, Amandeep; Bhardwaj, Pankaj
    Owing to the changing climatic scenario globally, and human overexploitation, the risk of extinction of Himalayan endangered species has increased many folds. Taxus contorta, an endangered gymnosperm has reached a decisive state in the Western Himalayas, thus, demands immediate attention to rescue it. This study aims to elucidate population and landscape genetics of T. contorta to plan a successful conservation strategy. We used SSR genotyping to identify genetic diversity hotspots, and ecological niche modeling to reveal climatic hotspots of T. contorta in the Indian Western Himalayas. We observed a substantial genetic diversity, and a negligible level of inbreeding among T. contorta populations. A genetic bottleneck was observed in several populations. We propose that changing climate can cause a failure of an entire conservation management plan if the shift produces a degraded environment in the future, at the sites of conservation. Further, the conservation management is futile if it fails to enhance or conserve the genetic diversity. We propound that use of germplasm from genetic diversity hotspots for propagation in climatic hotspots, and prioritization of these hotspot patches for conservation would ensure greater genetic variability under a safe environment. This integrative approach of translating molecular and climatic data into conservation planning would save our efforts, time, and capital investment, and ensure greater success in managing the revival of T. contorta in the Western Himalayas. � 2020, Springer Nature B.V.
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    Adaptability of Rhododendrons in high altitude habitats
    (Northeast Forestry University, 2020-01-03T00:00:00) Choudhary, Shruti; Thakur, Sapna; Majeed, Aasim; Bhardwaj, Pankaj
    Tree species dominate many ecosystems throughout the world and their response to climate, in light of global warming, is a matter of primary concern. This review describes past and ongoing research in Rhododendron, an ecologically important and well-adapted genus of more than 1000 species, occupying diverse habitats. Research to date indicates survival ability and mechanisms, with an emphasis on cold tolerance. The capability of long-distance gene flow in these species increases their genetic variability which in turn enhances their adaptability to newer niches as well as to environmental gradients (mainly temperature). Attempts to explain the molecular basis of morphological and behavioural changes in Rhododendron against cold-induced damage has been made. Gradual advances in �omics� have led to an enriched genomic resource dissecting the role and interaction of multiple molecular factors participating in cold adaptability. However, fewer genetic studies are available on species with an inherent or a default cold-tolerance ability. Considering this fact, understanding specific features of an adapted species can provide insights on overriding the effects of desiccation and determining phase transitions in other plants as well. We propose to integrate ecological and evolutionary studies with functional genomics to improve predictions of tree responses to their environment. � 2020, Northeast Forestry University.
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    Transcriptome Analysis Revealed Behavior Complexity of Senescence Responses in Himalayan Tree Species Ulmus wallichiana
    (Springer, 2023-05-17T00:00:00) Singh, Amandeep; Majeed, Aasim; Sharma, Vikas; Gadri, Hari Shankar; Chowdhary, Md. Asif; Bhardwaj, Pankaj
    The Himalayas present a highly contrasting environment for the organisms that inhabit it, with summer and winter being the most disparate seasons. As winter approaches, the temperature drops, and deciduous plants, such as Ulmus wallichiana Planch., undergo senescence. In this study, we used the RNA-seq approach to generate a de novo transcriptome assembly of U. wallichiana, consisting of 300,067 unigenes. We investigated the differential expression pattern of these unigenes under changing climatic conditions, with a focus on the contrast between winter and summer. We observed that 2746 unigenes were differentially expressed, with a fold change of ? 2 and an FDR-adjusted p-value of ? 0.001. Among these unigenes, 37 were found to be related to senescence. We also identified nine DREB unigenes in the U. wallichiana transcriptome, which exhibited more or less contrasting patterns between summer and winter. These DREB unigenes may play an important role in regulating the plant�s tolerance to cold and/or drought stress. Our findings shed light on the complex and dynamic process of transcriptomic reprogramming that enables U. wallichiana to cope with seasonal changes. Furthermore, this study highlights the urgent need for further research on U. wallichiana, as this endangered plant species remains largely unexplored at the genomic level. � 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
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    Transcriptome characterization and generation of marker resource for Himalayan vulnerable species, Ulmus wallichiana
    (Springer Science and Business Media B.V., 2021-01-14T00:00:00) Singh, Amandeep; Majeed, Aasim; Bhardwaj, Pankaj
    Ulmus wallichiana is a traditional medicinal plant listed as a vulnerable in the IUCN red list data. Genomic and transcriptomic resources for this species are lacking, hindering its genetic exploration. Further, no polymorphic marker resource is available for this species, thus limiting the elucidation of its underlying genetic diversity, which is a pre-requisite for its conservation. This study was therefore aimed to generate a functionally annotated transcriptomic resource and screen it for SSR regions. We used paired-end Illumina based RNAseq technology and trinity based de novo assembly approach to generate full length transcripts, which were screened for SSR regions and functionally annotated. Around 6.6 million raw reads were de novo assembled transcripts, which were clustered into 146,083 unigenes. 19,909 transcripts were provided with 3986 unique KEGG ids, 70,519 transcripts with 6621 unique Pfam domains, and 45,125 transcripts with 7302 unique INTERPRO domains. 1456 transcripts were identified as transcriptions factors (TFs). Further, 8868 unique GO terms were obtained for the unigenes. The transcripts mapped to 23,056 known pre-determined orthology clusters in the eggNOG database. A total of 16,570 SSRs were identified from the unigenes. Out of the 90 SSRs selected for characterization on 20 genotypes, 28 were polymorphic. Mean effective alleles (Ne) of 2.53, mean observed heterozygosity (Ho) of 0.77, and average polymorphic information content (PIC) of 0.57 were found. This study may facilitate the genetic exploration of this species. The polymorphic SSRs would prove useful to explore its genetic diversity patterns, required for its conservation. � 2021, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.
  • No Thumbnail Available
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    Adaptability of Rhododendrons in high altitude habitats
    (Northeast Forestry University, 2020-01-03T00:00:00) Choudhary, Shruti; Thakur, Sapna; Majeed, Aasim; Bhardwaj, Pankaj
    Tree species dominate many ecosystems throughout the world and their response to climate, in light of global warming, is a matter of primary concern. This review describes past and ongoing research in Rhododendron, an ecologically important and well-adapted genus of more than 1000 species, occupying diverse habitats. Research to date indicates survival ability and mechanisms, with an emphasis on cold tolerance. The capability of long-distance gene flow in these species increases their genetic variability which in turn enhances their adaptability to newer niches as well as to environmental gradients (mainly temperature). Attempts to explain the molecular basis of morphological and behavioural changes in Rhododendron against cold-induced damage has been made. Gradual advances in �omics� have led to an enriched genomic resource dissecting the role and interaction of multiple molecular factors participating in cold adaptability. However, fewer genetic studies are available on species with an inherent or a default cold-tolerance ability. Considering this fact, understanding specific features of an adapted species can provide insights on overriding the effects of desiccation and determining phase transitions in other plants as well. We propose to integrate ecological and evolutionary studies with functional genomics to improve predictions of tree responses to their environment. � 2020, Northeast Forestry University.
  • No Thumbnail Available
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    Transcribing molecular and climatic data into conservation management for the Himalayan endangered species, Taxus contorta (Griff.)
    (Springer Science and Business Media B.V., 2020-11-12T00:00:00) Majeed, Aasim; Singh, Amandeep; Bhardwaj, Pankaj
    Owing to the changing climatic scenario globally, and human overexploitation, the risk of extinction of Himalayan endangered species has increased many folds. Taxus contorta, an endangered gymnosperm has reached a decisive state in the Western Himalayas, thus, demands immediate attention to rescue it. This study aims to elucidate population and landscape genetics of T. contorta to plan a successful conservation strategy. We used SSR genotyping to identify genetic diversity hotspots, and ecological niche modeling to reveal climatic hotspots of T. contorta in the Indian Western Himalayas. We observed a substantial genetic diversity, and a negligible level of inbreeding among T. contorta populations. A genetic bottleneck was observed in several populations. We propose that changing climate can cause a failure of an entire conservation management plan if the shift produces a degraded environment in the future, at the sites of conservation. Further, the conservation management is futile if it fails to enhance or conserve the genetic diversity. We propound that use of germplasm from genetic diversity hotspots for propagation in climatic hotspots, and prioritization of these hotspot patches for conservation would ensure greater genetic variability under a safe environment. This integrative approach of translating molecular and climatic data into conservation planning would save our efforts, time, and capital investment, and ensure greater success in managing the revival of T. contorta in the Western Himalayas. � 2020, Springer Nature B.V.
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    Item
    Codon usage pattern in Gnetales evolved in close accordance with the Gnetifer hypothesis
    (Oxford University Press, 2021-01-06T00:00:00) Majeed, Aasim; Kaur, Harpreet; Kaur, Amitozdeep; Das, Sreemoyee; Joseph, Josepheena; Bhardwaj, Pankaj
    The evolution of Gnetales is ambiguous, and their phylogenetic position is still debated. The biological and molecular processes may evolve with the evolutionary history of a species or a clade. The molecular/biological processes of phylogenetically similar lineages closely follow their evolutionary pattern. If Gnetales evolved as a sister to Pinaceae, cupressophytes or Coniferales as a whole, then it is expected that the molecular or biological processes may reflect this pattern of evolution. In light of this, we deciphered the codon usage pattern of Gnetales, compared it with angiosperms, Pinaceae, cupressophytes and Coniferales as a whole. We evaluated whether this important molecular process has evolved in agreement with the Anthophyte, Gnepine, Gnecup or Gnetifer hypothesis. We observed that Gnetales prefer A/U-ending codons to G/C-ending codons like other lineages. Natural selection plays a dominant role in governing the codon usage bias (CUB). The CpA/CpT dinucleotides were over-represented, whereas the CpG dinucleotide was suppressed. Hierarchical clustering (HC) and correspondence analysis (CA) on relative synonymous codon usage values of 59 synonymous codons showed Gnetales as a sister clade to Coniferales as a whole and revealed that the codon usage pattern in Gnetales has evolved in close accordance with the Gnetifer hypothesis. � 2021 The Linnean Society of London, Botanical Journal of the Linnean Society.