Sajeevan R Sivarajan | University of Agricultural Sciences,GKVK,Bangalore (original) (raw)

Papers by Sajeevan R Sivarajan

Translating Physiological Tools to Augment Crop Breeding, 2023

Translating Physiological Tools to Augment Crop Breeding

BMC Plant Biology, Dec 2, 2022

Background: Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), ha... more Background: Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), has less scientific information but has traditionally been used as a medicinal plant. Moringa species have long been known for their medicinal qualities, which include antioxidant, anti-inflammatory, anticancer, and antihyperglycemic effects. We investigated the antidiabetic potential of MC and MO species in this study by using transcriptome profiling, metabolite analysis, and in vitro assay studies. Results: Our transcriptome analysis revealed the expression of enzymes involved in the biosynthesis of quercetin, chlorogenic acid, and benzylamine, all of which have previously been shown to have antidiabetic activity. We compared the expression patterns of five different tissues from MC and MO and it was found that the key enzymes involved in the biosynthesis of these compounds were highly expressed in leaf tissue. The expression estimated by MC transcriptome data in different tissues was verified using RT-qPCR analysis. The amount of these compounds was further quantified in the crude leaf extract of both species and found that MC had a higher abundance of quercetin and chlorogenic acid than MO. The crude leaf extract from both MC and MO were further tested in vitro, and the results demonstrated strong inhibitory activity for α-glucosidase and DPP-IV enzymes. Our findings suggest that compounds in leaf tissue, such as quercetin, benzylamine, and chlorogenic acid, could play a significant role in this antidiabetic activity. In addition, when comparing MO plants, we found that MC had a slightly higher effect in expression, abundance, and inhibitory activity. Conclusions: This study presents the first report of MC transcriptome data, as well as a comparison of its anti-diabetic activity to MO. Our analysis discussed the significance of leaf tissue in antidiabetic activity compared to other tissues of both species. Overall, this study not only provides transcriptome resources for Moringa species, but also sheds light on antidiabetic potential of both species.

Maintenance of cell membrane stability under heat stress is considered as an important adaptive m... more Maintenance of cell membrane stability under heat stress is considered as an important adaptive mechanism. In this study, an attempt was made to improve membrane stability under high temperature stress through downregulation of fatty acid desaturase (FAD7) gene by post-transcriptional gene silencing (PTGS) approach using virus-induced gene silencing (VIGS) system in order to decrease trienoic fatty acids. Endogenous FAD7 gene fragment from Nicotiana benthamiana was cloned to construct VIGS vector (pTRV2: FAD7). The Agrobacterium strain harboring the pTRV2: FAD7 was infiltrated into 4-leaf stage N. benthamiana. The downregulation of FAD7 gene in VIGS plants were confirmed through semi quantitative RT-PCR. The FAD7 gene downregulated plants were exposed to normal and 35 and 42oC temperature stress. In FAD7 silenced plants, the content of linolenic acid (18:3) decreased significantly, while linoleic acid (18:2) increased under high-temperature stress. FAD7 silenced plants showed higher...

Developmental Biology, 2004

Neurogenesis is one of the most complex events in embryonic development. However, little informat... more Neurogenesis is one of the most complex events in embryonic development. However, little information is available regarding the molecular events that occur during neurogenesis. To identify regulatory genes and underlying mechanisms involved in the differentiation of embryonic stem (ES) cells to neurons, gene expression profiling was performed using cDNA microarrays. In mouse ES cells, we compared the gene expression of each differentiated cell stage using a five-stage lineage selection method. Of 10,368 genes, 1633 (16%) known regulatory genes were differentially expressed at least 2-fold or greater at one or more stages. At stage 3, during which ES cells differentiate into neural stem cells, modulation of nearly 1000 genes was observed. Most of transcription factors (Otx2, Ebf-3, Ptx3, Sox4, 13, 18, engrailed, Irx2, Pax8, and Lim3), signaling molecules (Wnt, TGF, and Shh family members), and extracellular matrix/adhesion molecules (collagens, MAPs, and NCAM) were up-regulated. However, some genes which may play important roles in maintaining the pluripotency of ES cells (Kruppel-like factor 2, 4, 5, 9, myeloblast oncogene like2, ZFP 57, and Esg-1) were down-regulated. The many genes identified with this approach that are modulated during neurogenesis will facilitate studies of the mechanisms underlying ES cell differentiation, neural induction, and neurogenesis.

Background Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), has... more Background Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), has less scientific information but has traditionally been used as a medicinal plant. Moringa species have long been known for their medicinal qualities, which include antioxidant, anti-inflammatory, anticancer, and antihyperglycemic effects. We investigated the anti-diabetic potential of MC and MO species in this study by using transcriptome profiling, metabolite analysis, and in vitro assay studies. Results Our transcriptome analysis revealed the expression of enzymes involved in the biosynthesis of quercetin, chlorogenic acid, and benzylamine, all of which have previously been shown to have anti-diabetic activity. We compared the expression patterns of five different tissues from MC and MO and it was found that the key enzymes involved in the biosynthesis if these compounds were highly expressed in leaf tissue. The expression estimated by MC transcriptome data in different tissues was ve...

Scientific Reports

Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fa... more Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fabaceae family. It is a multipurpose crop used as herb, spice, vegetable and forage. It is a traditional medicinal plant in India attributed with several nutritional and medicinal properties including antidiabetic and anticancer. We have performed a combined transcriptome assembly from RNA sequencing data derived from leaf, stem and root tissues. Around 209,831 transcripts were deciphered from the assembly of 92% completeness and an N50 of 1382 bases. Whilst secondary metabolites of medicinal value, such as trigonelline, diosgenin, 4-hydroxyisoleucine and quercetin, are distributed in several tissues, we report transcripts that bear sequence signatures of enzymes involved in the biosynthesis of such metabolites and are highly expressed in leaves, stem and roots. One of the antidiabetic alkaloid, trigonelline and its biosynthesising enzyme, is highly abundant in leaves. These findings are ...

Федеральное государственное бюджетное образовательное учреждение высшего образования «Новосибирский государственный технический университет», 2013

Холокост и его использование в нравственном воспитании личности Holocaust and its use in moral ed... more Холокост и его использование в нравственном воспитании личности Holocaust and its use in moral education of the personality Anna Bolucencova, doctor în istorie, conferențiar universitar, Catedra de ştiinţe ale educaţiei, Facultatea de Științe ale Educației și Informatică, UPS Ion Creangă, Chișinău CZU: 94(=411.16)"1939/1945":37.034 Резюме В современном обществе важно воспитывать в духе уважения и любви ко всем народам мира. Явление Холокоста убедительно доказало необходимость данного направления воспитательной работы. Содержание работы опирается на интеграцию усилий историков, педагогов и всех социальных институтов общества. Необходимо создавать «прививку» всему человеческому сообществу против человеконенавистнической фашистской идеологии.

Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fa... more Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fabaceae family. It is a multipurpose crop used as herb, spice, vegetable and forage. It is a traditional medicinal plant in India attributed with several nutritional and medicinal properties including antidiabetic and anticancer. We have performed a combined transcriptome assembly from RNA sequencing data derived from leaf, stem and root tissues. Around 2,09,831 transcripts were deciphered from the assembly of 92% completeness and an N50 of 1382 bases. Whilst secondary metabolites of medicinal value, such as trigonelline, diosgenin, 4-hydroxyisoleucine and quercetin, are distributed in several tissues, we report transcripts that bear sequence signatures of enzymes involved in the biosynthesis of such metabolites and are highly expressed in leaves, stem and roots. One of the antidiabetic alkaloid, trigonelline and its biosynthesising enzyme, is highly abundant in leaves. These findings are...

Journal of Plant Growth Regulation, 2022

In plants, abscisic acid (ABA)-mediated responses during abiotic stress, growth, and development ... more In plants, abscisic acid (ABA)-mediated responses during abiotic stress, growth, and development have been well studied. Many chemicals which modulate ABA responses have been identified. In this study, we report that dithiothreitol (DTT), an inducer of endoplasmic reticulum (ER) stress, can overcome ABA-mediated responses in plants. In rice seedlings, combined treatment of ABA and DTT increased shoot growth compared to ABA alone. The phenotype correlated with the expression pattern of ABA and ER stress-responsive genes. In finger millet, increase in root growth was observed in combined treatment, compared to ABA treatment. Experiments using dimethyl sulfoxide indicated that the phenotype observed was specific to DTT. Priming of germinated rice seeds with DTT followed by salinity stress indicated that DTT can mask the ABA effect. In ABA bioassay using cotton petioles, an increase in intact petioles in combined treatment of ABA and DTT was observed compared to ABA treatment. The expression of OsWRKY48, an ABA-responsive gene, was down-regulated in combined treatment, indicating that the target of DTT-induced ER stress is upstream of OsWRKY48 in the ABA signaling pathway. The study demonstrated that DTT-induced ER stress can be a potential mechanism to regulate ABA-mediated responses in plants.

Frontiers in Plant Science, Mar 11, 2020

The genome of Asian cultivated rice (Oryza sativa L.) shows the presence of six organelle-specifi... more The genome of Asian cultivated rice (Oryza sativa L.) shows the presence of six organelle-specific and one plasma membrane (OsNHX1-7) NHX-type cation proton antiporters. Of these, vacuolar-localized OsNHX1 is extensively characterized. The genus Oryza consists of 27 species and 11 genome-types, with cultivated rice, diploid O. sativa, having an AA-type genome. Oryza NHX1 orthologous regions (gene organization, 5′ upstream cis elements, amino acid residues/motifs) from closely related Oryza AA genomes cluster distinctly from NHX1 regions from more ancestral Oryza BB, FF and KKLL genomes. These sequence-specific distinctions also extend to two separate intron retention (IR) events involving Oryza NHX1 transcripts that occur at the 5′ and 3′ ends of the NHX1 transcripts. We demonstrate that the IR event involving the 5′ UTR is present only in more recently evolved Oryza AA genomes while the IR event governing retention of the 13th intron of Oryza NHX1 (terminal intron) is more ancient in origin, also occurring in halophytic wild rice, Oryza coarctata (KKLL). We also report presence of a retro-copy of the OcNHX1 cDNA in the genome of O. coarctata (rOcNHX1). Preferential species and tissue specific up- or down-regulation of the correctly spliced NHX1 transcript/5′ UTR/13th intron-retaining splice variants under salinity was observed. The implications of IR on NHX1 mRNA stability and ORF diversity in Oryza spp. is discussed.

Current Science, Sep 10, 2016

Regulatory proteins such as protein kinases are known to play a crucial role in plant stress accl... more Regulatory proteins such as protein kinases are known to play a crucial role in plant stress acclimation pathways. In this study, we report the identification and characterization of an abiotic stress responsive protein kinase called CBL Interacting Protein Kinase (EcCIPK31-like) from finger millet, a drought-tolerant crop. PCR-based approach was followed to clone 1350 bp coding region that encodes a 449 amino acid protein with a calculated molecular mass of 50.69 kDa. The conserved domain analysis revealed the presence of CIPK domain with 90% sequence similarity with fox tail millet SiCIPK31-like gene. We also report its upregulation under salinity, desiccation, oxidative and temperature stresses at seedling level in finger millet. Drought stress at wholeplant level significantly induced the expression of EcCIPK31-like, indicating that the gene is linked to drought signalling pathways. The stress-responsive nature of EcCIPK31-like to diverse stresses indicates that the gene could regulate multiple cellular tolerance traits and its further functional validation can highlight the relevance in abiotic stress acclimation in plants.

Frontiers in Plant Science

Translating Physiological Tools to Augment Crop Breeding, 2023

Translating Physiological Tools to Augment Crop Breeding

BMC Plant Biology, Dec 2, 2022

Background: Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), ha... more Background: Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), has less scientific information but has traditionally been used as a medicinal plant. Moringa species have long been known for their medicinal qualities, which include antioxidant, anti-inflammatory, anticancer, and antihyperglycemic effects. We investigated the antidiabetic potential of MC and MO species in this study by using transcriptome profiling, metabolite analysis, and in vitro assay studies. Results: Our transcriptome analysis revealed the expression of enzymes involved in the biosynthesis of quercetin, chlorogenic acid, and benzylamine, all of which have previously been shown to have antidiabetic activity. We compared the expression patterns of five different tissues from MC and MO and it was found that the key enzymes involved in the biosynthesis of these compounds were highly expressed in leaf tissue. The expression estimated by MC transcriptome data in different tissues was verified using RT-qPCR analysis. The amount of these compounds was further quantified in the crude leaf extract of both species and found that MC had a higher abundance of quercetin and chlorogenic acid than MO. The crude leaf extract from both MC and MO were further tested in vitro, and the results demonstrated strong inhibitory activity for α-glucosidase and DPP-IV enzymes. Our findings suggest that compounds in leaf tissue, such as quercetin, benzylamine, and chlorogenic acid, could play a significant role in this antidiabetic activity. In addition, when comparing MO plants, we found that MC had a slightly higher effect in expression, abundance, and inhibitory activity. Conclusions: This study presents the first report of MC transcriptome data, as well as a comparison of its anti-diabetic activity to MO. Our analysis discussed the significance of leaf tissue in antidiabetic activity compared to other tissues of both species. Overall, this study not only provides transcriptome resources for Moringa species, but also sheds light on antidiabetic potential of both species.

Maintenance of cell membrane stability under heat stress is considered as an important adaptive m... more Maintenance of cell membrane stability under heat stress is considered as an important adaptive mechanism. In this study, an attempt was made to improve membrane stability under high temperature stress through downregulation of fatty acid desaturase (FAD7) gene by post-transcriptional gene silencing (PTGS) approach using virus-induced gene silencing (VIGS) system in order to decrease trienoic fatty acids. Endogenous FAD7 gene fragment from Nicotiana benthamiana was cloned to construct VIGS vector (pTRV2: FAD7). The Agrobacterium strain harboring the pTRV2: FAD7 was infiltrated into 4-leaf stage N. benthamiana. The downregulation of FAD7 gene in VIGS plants were confirmed through semi quantitative RT-PCR. The FAD7 gene downregulated plants were exposed to normal and 35 and 42oC temperature stress. In FAD7 silenced plants, the content of linolenic acid (18:3) decreased significantly, while linoleic acid (18:2) increased under high-temperature stress. FAD7 silenced plants showed higher...

Developmental Biology, 2004

Neurogenesis is one of the most complex events in embryonic development. However, little informat... more Neurogenesis is one of the most complex events in embryonic development. However, little information is available regarding the molecular events that occur during neurogenesis. To identify regulatory genes and underlying mechanisms involved in the differentiation of embryonic stem (ES) cells to neurons, gene expression profiling was performed using cDNA microarrays. In mouse ES cells, we compared the gene expression of each differentiated cell stage using a five-stage lineage selection method. Of 10,368 genes, 1633 (16%) known regulatory genes were differentially expressed at least 2-fold or greater at one or more stages. At stage 3, during which ES cells differentiate into neural stem cells, modulation of nearly 1000 genes was observed. Most of transcription factors (Otx2, Ebf-3, Ptx3, Sox4, 13, 18, engrailed, Irx2, Pax8, and Lim3), signaling molecules (Wnt, TGF, and Shh family members), and extracellular matrix/adhesion molecules (collagens, MAPs, and NCAM) were up-regulated. However, some genes which may play important roles in maintaining the pluripotency of ES cells (Kruppel-like factor 2, 4, 5, 9, myeloblast oncogene like2, ZFP 57, and Esg-1) were down-regulated. The many genes identified with this approach that are modulated during neurogenesis will facilitate studies of the mechanisms underlying ES cell differentiation, neural induction, and neurogenesis.

Background Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), has... more Background Moringa concanensis Nimmo (MC), a plant that resembles Moringa oleifera Lam. (MO), has less scientific information but has traditionally been used as a medicinal plant. Moringa species have long been known for their medicinal qualities, which include antioxidant, anti-inflammatory, anticancer, and antihyperglycemic effects. We investigated the anti-diabetic potential of MC and MO species in this study by using transcriptome profiling, metabolite analysis, and in vitro assay studies. Results Our transcriptome analysis revealed the expression of enzymes involved in the biosynthesis of quercetin, chlorogenic acid, and benzylamine, all of which have previously been shown to have anti-diabetic activity. We compared the expression patterns of five different tissues from MC and MO and it was found that the key enzymes involved in the biosynthesis if these compounds were highly expressed in leaf tissue. The expression estimated by MC transcriptome data in different tissues was ve...

Scientific Reports

Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fa... more Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fabaceae family. It is a multipurpose crop used as herb, spice, vegetable and forage. It is a traditional medicinal plant in India attributed with several nutritional and medicinal properties including antidiabetic and anticancer. We have performed a combined transcriptome assembly from RNA sequencing data derived from leaf, stem and root tissues. Around 209,831 transcripts were deciphered from the assembly of 92% completeness and an N50 of 1382 bases. Whilst secondary metabolites of medicinal value, such as trigonelline, diosgenin, 4-hydroxyisoleucine and quercetin, are distributed in several tissues, we report transcripts that bear sequence signatures of enzymes involved in the biosynthesis of such metabolites and are highly expressed in leaves, stem and roots. One of the antidiabetic alkaloid, trigonelline and its biosynthesising enzyme, is highly abundant in leaves. These findings are ...

Федеральное государственное бюджетное образовательное учреждение высшего образования «Новосибирский государственный технический университет», 2013

Холокост и его использование в нравственном воспитании личности Holocaust and its use in moral ed... more Холокост и его использование в нравственном воспитании личности Holocaust and its use in moral education of the personality Anna Bolucencova, doctor în istorie, conferențiar universitar, Catedra de ştiinţe ale educaţiei, Facultatea de Științe ale Educației și Informatică, UPS Ion Creangă, Chișinău CZU: 94(=411.16)"1939/1945":37.034 Резюме В современном обществе важно воспитывать в духе уважения и любви ко всем народам мира. Явление Холокоста убедительно доказало необходимость данного направления воспитательной работы. Содержание работы опирается на интеграцию усилий историков, педагогов и всех социальных институтов общества. Необходимо создавать «прививку» всему человеческому сообществу против человеконенавистнической фашистской идеологии.

Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fa... more Fenugreek (Trigonella foenum-graecum L.) is a self-pollinated leguminous crop belonging to the Fabaceae family. It is a multipurpose crop used as herb, spice, vegetable and forage. It is a traditional medicinal plant in India attributed with several nutritional and medicinal properties including antidiabetic and anticancer. We have performed a combined transcriptome assembly from RNA sequencing data derived from leaf, stem and root tissues. Around 2,09,831 transcripts were deciphered from the assembly of 92% completeness and an N50 of 1382 bases. Whilst secondary metabolites of medicinal value, such as trigonelline, diosgenin, 4-hydroxyisoleucine and quercetin, are distributed in several tissues, we report transcripts that bear sequence signatures of enzymes involved in the biosynthesis of such metabolites and are highly expressed in leaves, stem and roots. One of the antidiabetic alkaloid, trigonelline and its biosynthesising enzyme, is highly abundant in leaves. These findings are...

Journal of Plant Growth Regulation, 2022

In plants, abscisic acid (ABA)-mediated responses during abiotic stress, growth, and development ... more In plants, abscisic acid (ABA)-mediated responses during abiotic stress, growth, and development have been well studied. Many chemicals which modulate ABA responses have been identified. In this study, we report that dithiothreitol (DTT), an inducer of endoplasmic reticulum (ER) stress, can overcome ABA-mediated responses in plants. In rice seedlings, combined treatment of ABA and DTT increased shoot growth compared to ABA alone. The phenotype correlated with the expression pattern of ABA and ER stress-responsive genes. In finger millet, increase in root growth was observed in combined treatment, compared to ABA treatment. Experiments using dimethyl sulfoxide indicated that the phenotype observed was specific to DTT. Priming of germinated rice seeds with DTT followed by salinity stress indicated that DTT can mask the ABA effect. In ABA bioassay using cotton petioles, an increase in intact petioles in combined treatment of ABA and DTT was observed compared to ABA treatment. The expression of OsWRKY48, an ABA-responsive gene, was down-regulated in combined treatment, indicating that the target of DTT-induced ER stress is upstream of OsWRKY48 in the ABA signaling pathway. The study demonstrated that DTT-induced ER stress can be a potential mechanism to regulate ABA-mediated responses in plants.

Frontiers in Plant Science, Mar 11, 2020

The genome of Asian cultivated rice (Oryza sativa L.) shows the presence of six organelle-specifi... more The genome of Asian cultivated rice (Oryza sativa L.) shows the presence of six organelle-specific and one plasma membrane (OsNHX1-7) NHX-type cation proton antiporters. Of these, vacuolar-localized OsNHX1 is extensively characterized. The genus Oryza consists of 27 species and 11 genome-types, with cultivated rice, diploid O. sativa, having an AA-type genome. Oryza NHX1 orthologous regions (gene organization, 5′ upstream cis elements, amino acid residues/motifs) from closely related Oryza AA genomes cluster distinctly from NHX1 regions from more ancestral Oryza BB, FF and KKLL genomes. These sequence-specific distinctions also extend to two separate intron retention (IR) events involving Oryza NHX1 transcripts that occur at the 5′ and 3′ ends of the NHX1 transcripts. We demonstrate that the IR event involving the 5′ UTR is present only in more recently evolved Oryza AA genomes while the IR event governing retention of the 13th intron of Oryza NHX1 (terminal intron) is more ancient in origin, also occurring in halophytic wild rice, Oryza coarctata (KKLL). We also report presence of a retro-copy of the OcNHX1 cDNA in the genome of O. coarctata (rOcNHX1). Preferential species and tissue specific up- or down-regulation of the correctly spliced NHX1 transcript/5′ UTR/13th intron-retaining splice variants under salinity was observed. The implications of IR on NHX1 mRNA stability and ORF diversity in Oryza spp. is discussed.

Current Science, Sep 10, 2016

Regulatory proteins such as protein kinases are known to play a crucial role in plant stress accl... more Regulatory proteins such as protein kinases are known to play a crucial role in plant stress acclimation pathways. In this study, we report the identification and characterization of an abiotic stress responsive protein kinase called CBL Interacting Protein Kinase (EcCIPK31-like) from finger millet, a drought-tolerant crop. PCR-based approach was followed to clone 1350 bp coding region that encodes a 449 amino acid protein with a calculated molecular mass of 50.69 kDa. The conserved domain analysis revealed the presence of CIPK domain with 90% sequence similarity with fox tail millet SiCIPK31-like gene. We also report its upregulation under salinity, desiccation, oxidative and temperature stresses at seedling level in finger millet. Drought stress at wholeplant level significantly induced the expression of EcCIPK31-like, indicating that the gene is linked to drought signalling pathways. The stress-responsive nature of EcCIPK31-like to diverse stresses indicates that the gene could regulate multiple cellular tolerance traits and its further functional validation can highlight the relevance in abiotic stress acclimation in plants.

Frontiers in Plant Science