Publications (26)38.51 Total impact
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Article: Brassica coenospecies: a rich reservoir for genetic resistance to leaf spot caused by Alternaria brassicae
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ABSTRACT: Development of leaf spot resistant mustard cultivars is a relevant objective in view of heavy crop losses caused by this pathogen. Thirty-eight species belonging to 9 genera, including cultivated and wild allies, of the genus Brassica were evaluated under epiphytotic conditions for two years. Inoculations were done on whole plants (in vivo) and on detached leaves (in vitro). Data on incubation period, number of lesions per leaf, lesion size and leaf area covered by lesions were recorded. Species which never produced disease symptoms throughout the growing period in pots and until 72 hours after inoculation in detached leaf assays during both years were treated as resistant, while those that produced symptoms were classified as moderately resistant, susceptible or highly susceptible depending upon incubation period, size of lesions and leaf area covered by disease symptoms. Eight species (Brassica desnottesii, Camelina sativa, Coincya pseuderucastrum, Diplotaxis berthautii, D. catholica, D. cretacea, D. erucoides, and Erucastrum gallicum) were found completely resistant, whereas others were classified as moderately resistant (12), susceptible (11) or highly susceptible (9). Since resistance is unavailable within the cultivated species, these 8 resistant wild species could be used as donor parents for introgressing resistance to leaf spot disease in Indian mustard.Euphytica 04/2012; 125(3):411-417. · 1.55 Impact Factor -
Article: Homeotic-like modification of stamens to petals is associated with aberrant mitochondrial gene expression in cytoplasmic male sterile OguraBrassica juncea
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ABSTRACT: We have previously reported correction of severe leaf chlorosis in the cytoplasmic male sterile Ogura (also called Ogu)Brassica juncea line carrying Ogura cytoplasm by plastid substitution via protoplast fusion. Two cybrids obtained from the fusion experiment, Og1 and Og2, were green and carried the plastid genome ofB. juncea cv. RLM198. While Og1 displayed normal flower morphology comparable to that of its euplasmicB. juncea counterpart except for sterile anthers, Og2 retained homeotic-like floral modification of stamens to petal-like structures and several other floral deformities observed in the chlorotic (Ogu)B. juncea cv. RLM198 (or OgRLM). With respect to the mitochondrial genome, Og1 showed 81% genetic similarity to the fertile cultivar RLM while Og2 showed 93% similarity to OgRLM. In spite of recombination and rearrangements in the mitochondrial genomes in the cybrids, expression patterns of 10 out of 11 mitochondrial genes were similar in all the three CMS lines; the only exception wasatp6, whose expression was altered. While Og1 showed normalatp6 transcript similar to that in RLM, in Og2 and OgRLM weak expression of a longer transcript was detected. These results suggest that the homeotic-like changes in floral patterning leading to petaloid stamens in Og2 and OgRLM may be associated with aberrant mitochondrial gene expression.Journal of Genetics 04/2012; 85(2):133-139. · 1.09 Impact Factor -
Article: Characterization of upstream sequences of the peroxidase gene, Atprx18 of Arabidopsis thaliana.
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ABSTRACT: T-DNA insertional based strategies have been successfully employed to identify genes and promoters in plants. A promoter trap mutant line anth85, carrying TDNA insertion in the 5′-UTR region of the Atprx18 (At2G24800) gene was found to exhibit GUS gene expression characteristically in anthers and cotyledons of Arabidopsis. The homozygous mutant, anth85 lacking Atprx18 transcript did not exhibit any discernable phenotypic aberration. Transcript analysis in wild type Arabidopsis reveals abundance of the Atprx18 transcript in the inflorescence. 5′ RACE analysis of the transcript reveals ‘C’ nucleotide lying 58 bp upstream from ATG as the Transcription Start Site (TSS). Deletion analysis of the upstream sequences of the Atprx18 gene led to identification of a 507 bp (−507/−1) promoter sequence sufficient to drive the reporter gene expression preferentially in anthers.Journal of Plant Biochemistry and Biotechnology 01/2012; 21(1):121-127. · 0.52 Impact Factor -
Article: Upstream sequence of fatty acyl-CoA reductase (FAR6) of Arabidopsis thaliana drives wound-inducible and stem-specific expression.
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ABSTRACT: An Arabidopsis mutant line T90, exhibiting a stem-specific and wound-responsive GUS expression was identified from a population of Arabidopsis thaliana tagged with a promoterless β-glucuronidase (GUS) in the T-DNA. Sequence flanking the insertion from the right border was amplified by TAIL PCR and cloned. The insertion was located in the third chromosome, 57 bp upstream of the ATG start codon in 5' untranslated region (UTR) of the fatty acyl-CoA reductase 6 (FAR6) gene. RT-PCR analysis of the FAR6 gene revealed that the gene is expressed predominantly in stem tissue. Semi-quantitative RT-PCR showed that the expression is also induced by wounding in the epidermal layer of mature stem internodes. The transcription initiation site (TSS) was identified by 5' RACE PCR. Different 5' deletion fragments of the promoter sequences were developed and linked to the GUS reporter gene as transcriptional fusions and the expression patterns of GUS were histochemically analyzed in transgenic Arabidopsis plants. Sequences from -510 bp upstream to the transcriptional start site were sufficient to exhibit wound-inducible GUS expression in the stems. The addition of further upstream sequences (-510 to -958, -1,400 or -1,456) enhanced and extended the wound-inducible GUS expression throughout the mature stem.Plant Cell Reports 12/2011; 31(5):839-50. · 2.27 Impact Factor -
Chapter: History, Evolution, and Domestication of Brassica Crops
10/2011: pages 19 - 84; , ISBN: 9781118100509 -
Chapter: Brassica and Its Close Allies: Cytogenetics and Evolution
11/2009: pages 21 - 187; , ISBN: 9780470593783 -
Article: Resynthesized Brassica juncea lines with novel organellar genome constitution obtained through protoplast fusion.
Journal of Genetics 05/2009; 88(1):109-12. · 1.09 Impact Factor -
Article: A unique introgression from Moricandia arvensis confers male fertility upon two different cytoplasmic male‐sterile lines of Brassica juncea
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ABSTRACT: A Brassica juncea line carrying an introgression from Moricandia arvensis restored male fertility to two cytoplasmic male-sterile (CMS) B. juncea lines carrying either M. arvensis or Diplotaxis catholica cytoplasm. Genetics of fertility restoration was studied in the F1, F2, F3 and backcross generations of the cross between CMS and fertility-restorer lines. No male-sterile plants were found in F1-F3 generations of the cross between CMS [M. arvensis] B. juncea and the restorer. However, a 1: 1 segregation for male sterility and fertility was observed when the F1 was pollinated with non-restorer pollen from a euplasmic line. These results clearly show that restoration is mono-genic and gametophytic. In CMS lines carrying D. catholica cytoplasm, the restorer conferred male fertility to the F1 and showed 3: 1 and 1: 1 segregations for male fertility and sterility in F2 and BC1 generations, respectively, indicating a monogenic, sporophytic mode of fertility restoration. The results were also supported by pollen stainability in the F1 which was about 65% in M. arvensis-based CMS and >90% in D. catholica-based CMS. The above results are discussed in the light of previous molecular studies which showed association between CMS and atpA in both systems.Plant Breeding 06/2008; 124(2):117 - 120. · 1.60 Impact Factor -
Article: A duplicated coxI gene is associated with cytoplasmic male sterility in an alloplasmic Brassica juncea line derived from somatic hybridization with Diplotaxis catholica.
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ABSTRACT: A cytoplasmic male sterile (CMS) line of Brassica juncea was derived by repeated backcrossing of the somatic hybrid (Diplotaxis catholica + B. juncea) to B. juncea. The new CMS line is comparable to euplasmic lines for almost all characters, except for flowers which bear slender, needle-like anthers with aborted pollen. Detailed Southern analysis revealed two copies of coxI gene in the CMS line. One copy, coxI-1 is similar to the coxI gene of B. juncea, whereas the second copy, coxI-2 is present in a novel rearranged region. Northern analysis with eight mitochondrial gene probes showed altered transcript pattern only for the coxI gene. Two transcripts of 2.0 and 2.4 kb, respectively, were detected in the CMS line. The novel 2.4 kb transcript was present in floral bud tissue but absent in the leaf tissue. In plants where male sterility broke down under high temperature during the later part of the growing season, the 2.4 kb coxI transcript was absent, which suggested its association with the CMS. The two coxI genes from the CMS line showed two amino acid changes in the coding region. The novel coxI gene showed unique repeats in the 5' region suggesting recombination of mitochondrial genomes of the two species. The possible role of the duplicated coxI gene in causing male sterility is discussed.Journal of Genetics 09/2007; 86(2):93-101. · 1.09 Impact Factor -
Article: Identification of AFLP markers linked to the male fertility restorer gene of CMS (Moricandia arvensis) Brassica juncea and conversion to SCAR marker.
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ABSTRACT: We have developed a cytoplasmic male sterile (CMS) line of Brassica juncea through somatic hybridization with Moricandia arvensis and introgressed the fertility restorer gene into B. juncea. This fertility restorer locus is unique in that it is capable of restoring male fertility to two other alloplasmic CMS systems of B. juncea. As a first step toward cloning of this restorer gene we attempted molecular tagging of the Rf locus using the amplified fragment length polymorphism (AFLP) technique. A BC(1)F(1) population segregating for male sterility/fertility was used for tagging using the bulk segregant analysis method. Out of 64 primer combinations tested in the bulks, 5 combinations gave polymorphic amplification patterns. Further testing of these primers in individual plants showed four amplicons associated with the male fertility trait. Polymorphic amplicons were cloned and used for designing SCAR primers. One of the SCAR primers generated amplicons mostly in the fertile plants. Linkage analysis using MAPMAKER showed two AFLP and one SCAR markers linked to the male fertility gene with a map distance ranging from 0.6 to 2.9 cM. All the markers are located on one side of the Rf locus.Theoretical and Applied Genetics 02/2007; 114(2):385-92. · 3.30 Impact Factor -
Article: Organization and expression of the mitochondrial genome in CMS (Moricandia) Brassica juncea: nuclear‐mitochondrial incompatibility results in differential expression of the mitochondrial atpα gene
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ABSTRACT: The mitochondrial genome of CMS (Moricandia) Brassica juncea has been characterized. Southern analysis using nine different mt-specific gene probes revealed differences between B. juncea and M. arvensis and the CMS line. A northern profile of flower bud and leaf mt RNA blots was found conserved for six genes tested. However, tissue-specific expression was observed for atpα. A longer transcript was present in the bud tissue of the CMS line, which reverted to normal in the presence of the fertility restorer gene, while its expression was normal in the leaf tissues. The atpα gene was cloned from B. juncea, M. arvensis and the CMS line. Restriction mapping shows a high degree of restriction site conservation between the CMS and B. juncea lines with minor alterations at the 5′ and the 3′ ends, indicating the presence of an almost intact M. arvensisatpα gene in the CMS line harbouring a B. juncea nucleus. The results are discussed with respect to the potential role of atpα in generating male sterility in CMS (Mori) B. juncea.Plant Breeding 11/2006; 125(6):623 - 628. · 1.60 Impact Factor -
Article: Homeotic-like modification of stamens to petals is associated with aberrant mitochondrial gene expression in cytoplasmic male sterile Ogura Brassica juncea.
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ABSTRACT: We have previously reported correction of severe leaf chlorosis in the cytoplasmic male sterile Ogura (also called Ogu) Brassica juncea line carrying Ogura cytoplasm by plastid substitution via protoplast fusion. Two cybrids obtained from the fusion experiment, Og1 and Og2, were green and carried the plastid genome of B. juncea cv. RLM198. While Og1 displayed normal flower morphology comparable to that of its euplasmic B. juncea counterpart except for sterile anthers, Og2 retained homeotic-like floral modification of stamens to petal-like structures and several other floral deformities observed in the chlorotic (Ogu) B. juncea cv. RLM198 (or OgRLM). With respect to the mitochondrial genome, Og1 showed 81% genetic similarity to the fertile cultivar RLM while Og2 showed 93% similarity to OgRLM. In spite of recombination and rearrangements in the mitochondrial genomes in the cybrids, expression patterns of 10 out of 11 mitochondrial genes were similar in all the three CMS lines; the only exception was atp6, whose expression was altered. While Og1 showed normal atp6 transcript similar to that in RLM, in Og2 and OgRLM weak expression of a longer transcript was detected. These results suggest that the homeotic-like changes in floral patterning leading to petaloid stamens in Og2 and OgRLM may be associated with aberrant mitochondrial gene expression.Journal of Genetics 09/2006; 85(2):133-9. · 1.09 Impact Factor -
Article: Introgression of a gene restoring fertility to CMS (Trachystoma) Brassica juncea and the genetics of restoration
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ABSTRACT: A dominant gene restoring fertility to a cytoplasmic male sterile (CMS) line of Brassica juncea was derived from the somatic hybrid Trachystoma ballii+B. juncea. Its introgression resulted from forced pairing between chromosomes of the cultivar ‘Pusa Bold’ and chromosomes of the fusion hybrid. Segregation ratios of this fertility restorer gene followed a monogenic pattern. The introgression of the fertility restorer gene did not cause any abnormalities, such as reduced fertility; pollen and seed fertilities of the restored plants were over 90%. Restored fertile and CMS plants exhibited similar Southern hybridization patterns when probed with the mitochondrial probe atp6.Plant Breeding 04/2006; 116(3):259 - 262. · 1.60 Impact Factor -
Article: Diplotaxis erucoides‐induced cytoplasmic male sterility in Brassica juncea is rescued by the Moricandia arvensis restorer: genetic and molecular analyses
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ABSTRACT: An alloplasmic cytoplasmic male sterile (CMS) line of Brassica juncea was developed by repeated backcrossing of the sexual hybrid (Diplotaxis erucoides × Brassica rapa) with B. juncea cv. ‘Pusa Bold’. The CMS line is comparable to the B. juncea nuclear donor line for all morphological traits except male fertility. Southern and cleaved amplified polymorphic sequence (CAPS) analyses showed that the CMS line carries organellar genomes from the wild species that differ from the organellar genomes of B. juncea. Northern analysis with three mitochondrial gene probes revealed altered atpα transcription pattern associated with male sterility. The restorer of CMS (Moricandia arvensis) B. juncea was found to restore male fertility to the new CMS system. The mode of fertility restoration was found to be monogenic and gametophytic. The study identified CAPS markers for the psbB gene that could be useful in quick identification of the erucoides CMS line. Broad similarities and important differences observed at the molecular level between M. arvensis and D. erucoides CMS systems of B. juncea are discussed.Plant Breeding 03/2006; 125(2):150 - 155. · 1.60 Impact Factor -
Article: T-DNA tagging and characterization of a cryptic root-specific promoter in Arabidopsis.
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ABSTRACT: From a T-DNA tagged Arabidopsis population, a line, M-57 showing GUS (beta-glucuronidase) expression in the vascular regions of young roots was identified. Southern analysis revealed presence of a single T-DNA insert. Using inverse PCR, the plant sequence flanking the T-DNA insertion was cloned. The insertion was identified to be in the intergenic area between loci At4G13940 and At4G13930, coding for SAHH (S-Adenosyl-l-Homocysteine Hydrolase) and SHMT (Serine Hydroxy Methyl Transferase) genes, respectively. A 452-bp fragment immediately upstream of the T-DNA insertion when cloned and mobilized as a GUS fusion was capable of driving a similar root-specific expression of reporter gene in transgenic Arabidopsis plants and their progenies. This cryptic promoter element does not show the presence of any known root-specific promoter element.Biochimica et Biophysica Acta 01/2006; 1731(3):202-8. · 4.66 Impact Factor -
Article: Cloning and characterization of a pentatricopeptide protein encoding gene (LOJ) that is specifically expressed in lateral organ junctions in Arabidopsis thaliana.
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ABSTRACT: A line exhibiting expression of beta-glucuronidase (GUS) in the lateral organ junctions and shoot apical meristem (SAM) was identified from a population of T-DNA tagged lines carrying a promoter-less GUS gene. Southern hybridization confirmed the presence of a single T-DNA insertion in this line. The plant sequences flanking the T-DNA were cloned by TAIL PCR and sequenced. The insertion of T-DNA was found to be in the upstream region of a hypothetical gene (At2g39230). This gene, which we term as LOJ to indicate its specific expression in all lateral organ junctions encodes a predicted protein containing pentatricopeptide (PPR) motifs. This gene appears to belong to a group of TATA-less promoters and codes for a long ORF without any intron. The gene apparently codes for a protein of 97.65 kD with a mitochondrial target sequence at the N-terminal. Transcript analysis revealed that the expression of the gene is specifically restricted to the lateral organ junctions throughout the life of the plants. 5' RACE analysis revealed a 95 nucleotide long UTR region for this hypothetical gene. In silico analysis of the upstream region failed to identify a TATA box within -146 nucleotides. GUS expression analysis of the line 149 and the transgenic plants generated with constructs carrying the upstream sequences of this gene fused to uidA identified that the specificity of the expression of this gene resides within -569 to -152 bp region. The specific expression of LOJ at the base of lateral organ and shoot apical meristem (SAM) suggests an important role of LOJ in lateral organ development and boundary demarcation.Gene 07/2005; 353(1):67-79. · 2.34 Impact Factor -
Article: T-DNA Tagging and Characterization of a cryptic root-specific promoter in Arabidopsis
Biochimica Biophysica Acta. 01/2005; 1731:202-208. -
Article: Cytoplasmic male sterility in alloplasmic Brassica juncea carrying Diplotaxis catholica cytoplasm: molecular characterization and genetics of fertility restoration.
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ABSTRACT: The present study was aimed at characterizing cytoplasmic male sterility (CMS) and identifying the fertility restorer gene for CMS (Diplotaxis catholica) Brassica juncea derived through sexual hybridization. The fertility restorer gene was identified by crossing the CMS line with progeny plants derived from somatic hybrids of B. juncea and D. cathoilca. The CMS line is comparable to the nuclear donor B. juncea in all respects except for flower and silique characteristics. In CMS plants, the flowers have smaller nectaries, and anthers are converted into petals or tubular structures. Gynoecium exhibits a crooked style and trilocular ovary. Seed fertility was reduced in the CMS line. Genetic segregation data indicated that a single, dominant, nuclear gene governs fertility restoration. Restored plants showed a high female fertility and lacked gynoecium abnormalities. In fertility-restored plants, petal development was found to be variable; some flowers had the normal number of four petals, while others had zero to three petals. Interestingly, the trilocular character of the ovary was found to co-segregate with CMS and became bilocular upon male-fertility restoration. Thus, this trait appears to be affected by the interaction of nuclear and mitochondrial (mt) genomes. Restriction fragment length polymorphism analysis indicated that mt-genome of D. catholica is highly divergent from that of B. juncea. However, in Northern analysis, out of eight mt genes studied, an altered transcript pattern was recorded for only atpA. In fertility-restored plants, the atpA transcript became shorter, thereby showing its association with CMS.Theoretical and Applied Genetics 09/2003; 107(3):455-61. · 3.30 Impact Factor -
Article: Agrobacterium-mediated transformation of cauliflower: optimization of protocol and development of Bt-transgenic cauliflower.
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ABSTRACT: A number of factors that are known to influence genetic transformation were evaluated to optimize Agrobacterium-mediated transformation of hypocotyl explants of cauliflower variety Pusa Snowball K-1. The binary vector p35SGUSINT mobilized into Agrobacterium strain GV2260 was used for transformation and transient GUS expression was used as the basis for identifying the most appropriate conditions for transformation. Explant age, preculture period, bacterial strain and density were found to be critical determinants of transformation efficiency. Using the optimized protocol, the synthetic cryIA(b) gene was mobilized into cauliflower. Molecular analyses of transgenics established the integration and expression of the transgene. Insect bioassays indicated the effectiveness of the transgene against infestation by diamondback moth (Plutella xylostella) larvaeJournal of Biosciences 10/2002; 27(5):495-502. · 1.65 Impact Factor -
Article: Expression of male sterility in alloplasmic Brassica juncea with Erucastrum canariense cytoplasm and the development of a fertility restoration system
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ABSTRACT: An alloplasmic mustard, Brassica juncea, has been synthesized by placing its nucleus into the cytoplasm of the related wild species Erucastrum canariense to express cytoplasmic male sterility. To achieve this, the sexual hybrid E. canariense (2n=18, EcEc) ×Brassica campestris (2n= 20, AA) was repeatedly backcrossed to B. juncea (2n= 36, AABB). Cytoplasmic male-sterile (CMS) plants were recovered in the BC4 generation. These plants are a normal green and the flowers have slender, non-dehiscing anthers that contain sterile pollen. Nectaries are well developed and female fertility is > 90%. The fertility restoration gene was introgressed to CMS B. juncea from the cytoplasmic donor E. canariense through pairing between chromosomes belonging to B. juncea with those of the E. canariense genome. The restorer plants have normal flowers, with well-developed anthers containing fertile pollen. Meiosis proceeds normally. Pollen and seed fertility averaged 90% and 82%, respectively. F1 hybrids between CMS and the restorer are fully pollen fertile and show normal seed set. Preliminary results indicate that restoration is achieved by a single dominant gene. The constitution of the organelle genomes of the CMS, restorer and fertility restored plants is identical, as revealed by Southern analysis using mitochondrial and chloroplast probes atp A and psb D, respectively.Plant Breeding 11/2001; 120(6):479 - 482. · 1.60 Impact Factor
Top co-authors
Top Journals
Institutions
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1998–2012
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National Research Centre on Plant Biotechnology
Delhi, NCT, India
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2009–2011
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Purdue University
West Lafayette, IN, USA
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1998–2009
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Indian Agricultural Research Institute
- National Research Centre on Plant Biotechnology (NRCPB)
New Delhi, NCT, India
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