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Publications (8)13.14 Total impact

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    ABSTRACT: Due to depleting reserves of fossil fuels, political uncertainties, increase in demand of energy needs and growing concerns of environmental effects, bioenergy as an alternative source of energy needs had taken centre stage globally. In this report, we review the progress made in lignocellulose, cellulose and fermentation based biofuels in addition to tree borne oil seeds. Algae as a source of feedstock for the biofuel has also been reviewed. Recent efforts in genome sequencing of biofuel crops, molecular breeding approaches have increased our understanding towards crop improvement of major feedstocks. Besides, patenting trends in bioenergy sector were assessed by patent landscape analysis. The results showed an increasing trend in published patents during the last decade which is maximum during 2011. A conceptual framework of �transgenesis in biofuels to industrial application� was developed based on the patent analytics viz., International Patent Classification (IPC) analysis and Theme Maps. A detailed claim analysis based on the conceptual framework assessed the patenting trends that provided an exhaustive dimension of the technology. The study emphasizes the current thrust in bioenergy sector by various public and private institutions to expedite the process of biofuel production.
    07/2012; 7(1). DOI:10.2174/1872215611307010003
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    ABSTRACT: Improving salinity and drought tolerance of crop plants has been an important aim of modern agricultural development, which depends on understanding the functions of genes expressed during the process of stress adaptation. EST resources are an efficient and cost-effective solution to gene discovery. Jatropha curcas is emerging as the most promising tree oil seed as a source of biodiesel. To identify genes that respond to abiotic stress, in the present study, we report 1240 ESTs generated from root cDNA libraries of J. curcas. ESTs were clustered and assembled into a collection of 865 unigenes, with 107 contigs and 758 singleton sequences. The putative functions of several ESTs could be assigned by similarity to plant gene sequence comparisons. It was found that 23 full-length CDS (34%) and the majority of transcription factors had sequence similarity to genes known to be involved in abiotic and biotic stress tolerance. The expression pattern of nine selected genes revealed that these genes are differentially expressed in various tissues during adaptation to stress. The data could serve as a critical resource to enable plant improvement programmes towards enhancing the adaptability of J. curcas to growth on marginal lands.
    Plant Biology 02/2012; 14(3):428-37. DOI:10.1111/j.1438-8677.2011.00529.x · 2.63 Impact Factor
  • Alok Varshney · Rajendran Sangapillai · Manoj S. Patil · T. Sudhakar Johnson ·
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    ABSTRACT: Jatropha curcas, a non-domesticated energy plant, has emerged as a source of biodiesel as it does not compete with the edible oil supplies. Realizing its importance, in vitro regeneration methods have been established to meet the demand of large scale supply of superior clones. However, no precise histological analysis has been conducted to document the in vitro morphogenesis in J. curcas. Here, we present a detailed histological description of the initiation of growth and morphogenesis from callus induced from immature cotyledon and embryonal axis of J. curcas. Microscopic observations revealed that the cells of sub-epidermis in immature cotyledon became meristematic and divided extensively to result in the formation of meristemoids within 3–4weeks of culture. The meristemoid cells are compact, small, and exhibited densely stained cytoplasm compared to the loosely packed large non-meristematic cells. Presence of meristemoids in different developmental stages above the cambial zone, and the absence of vascular connection to the cotyledon explant led us to conclude that the origin of the meristemoids was adventitious in nature and regeneration is through organogenesis of morphogenic callus. On the other hand, callus derived from immature embryonal axis followed two types of regeneration—one type of shoot regeneration was via organogenesis while the second type was through multiplication of the pre-existing meristems. It was noticed that under similar experimental conditions, the process of organogenesis varied from explant to explant. The present study contributes to adequate knowledge and understanding the process of in vitro shoot morphogenesis in J. curcas. KeywordsCotyledon–Histology–Immature embryo–Meristemoid–Organogenesis–Tissue culture
    Trees 08/2011; 25(4):689-694. DOI:10.1007/s00468-011-0546-x · 1.65 Impact Factor
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    Priyanka Mukherjee · Alok Varshney · T. Sudhakar Johnson · Timir Baran Jha ·
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    ABSTRACT: Plant tissue culture and molecular biology techniques are powerful tools of biotechnology that can complement conventional breeding, expedite crop improvement and meet the demand for availability of uniform clones in large numbers. Jatropha curcas Linn., a non-edible, eco-friendly, non-toxic, biodegradable fuel-producing plant has attracted worldwide attention as an alternate sustainable energy source for the future. This review presents a consolidated account of biotechnological interventions made in J. curcas over the decades and focuses on contemporary information and trends of future research. KeywordsCrop improvement–In vitro plant regeneration– Jatropha curcas –Molecular markers–Organogenesis–Somatic embryogenesis
    Plant Biotechnology Reports 07/2011; 5(3):197-215. DOI:10.1007/s11816-011-0175-2 · 1.19 Impact Factor
  • T Sudhakar Johnson · Nalini Eswaran · M Sujatha ·
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    ABSTRACT: With the increase in crude oil prices, climate change concerns and limited reserves of fossil fuel, attention has been diverted to alternate renewable energy sources such as biofuel and biomass. Among the potential biofuel crops, Jatropha curcas L, a non-domesticated shrub, has been gaining importance as the most promising oilseed, as it does not compete with the edible oil supplies. Economic relevance of J. curcas for biodiesel production has promoted world-wide prospecting of its germplasm for crop improvement and breeding. However, lack of adequate genetic variation and non-availability of improved varieties limited its prospects of being a successful energy crop. In this review, we present the progress made in molecular breeding approaches with particular reference to tissue culture and genetic transformation, genetic diversity assessment using molecular markers, large-scale transcriptome and proteome studies, identification of candidate genes for trait improvement, whole genome sequencing and the current interest by various public and private sector companies in commercial-scale cultivation, which highlights the revival of Jatropha as a sustainable energy crop. The information generated from molecular markers, transcriptome profiling and whole genome sequencing could accelerate the genetic upgradation of J. curcas through molecular breeding.
    Plant Cell Reports 05/2011; 30(9):1573-91. DOI:10.1007/s00299-011-1083-1 · 3.07 Impact Factor
  • G Raja Krishna Kumar · Nalini Eswaran · T Sudhakar Johnson ·
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    ABSTRACT: A method for isolating transcriptionally active RNA for downstream applications from diverse tissues of Jatropha curcas, a plant rich in latex, lipids, waxes, polysaccharide, polyphenols, and secondary metabolites, is described. The described method uses alkaline borate buffer during tissue homogenization to negate the formation of viscous gel observed in guanidium-salt-containing methods. By this method, quality RNA was extracted from leaf, immature inflorescence, endosperm, and root tissues with yields ranging from 1.80 to 7.80mg/100mg fresh weight (FW). The total RNA obtained was found to be suitable for poly(A)(+)RNA purification, complementary DNA (cDNA) synthesis, cloning of full-length cDNA, and cDNA library construction.
    Analytical Biochemistry 02/2011; 413(1):63-5. DOI:10.1016/j.ab.2011.01.046 · 2.22 Impact Factor
  • Alok Varshney · T. Sudhakar Johnson ·
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    ABSTRACT: Jatropha curcas L. (Physic nut) is a commercially important non-edible oil seed crop known for its use as an alternate source of biodiesel. In order to investigate the morphogenic potential of immature embryo, explants from four developmental stages were cultured on medium supplemented with combinations of auxins and cytokinins. It was found that the size of embryo is critical for the establishment of callus. Immature embryos (1.1–1.5cm) obtained from the fruits 6weeks after pollination showed a good response of morphogenic callus induction (85.7%) and subsequent plant regeneration (70%) with the maximum number of plantlets (4.7/explant) on Murashige and Skoog’s (MS) medium supplemented with IBA (0.5mgl−1) and BA (1.0mgl−1). The above medium when supplemented with growth adjuvants such as 100mgl−1 casein hydrolysate+200mgl−1 l-glutamine+8.0mgl−1 CuSO4 resulted in an even higher frequency of callus induction (100%). Plant regeneration (90%) with the maximum number of plantlets (10/explant) was achieved on MS medium supplemented with 500mgl−1 polyvinyl pyrrolidone+30mgl−1 citric acid+1mgl−1 BA+0.5mgl−1 Kn+0.25mgl−1 IBA. It was observed that plantlet regeneration could occur either through organogenesis of morphogenic callus or via multiplication of pre-existing meristem in immature embryos. The age of immature embryos and addition of a combination of growth adjuvants to the culture medium appear to be critical for obtaining high regeneration rates. Well-developed shoots rooted on half-strength MS medium supplemented with 0.5mgl−1 IBA and 342mgl−1 trehalose. The rooted plants after acclimatization were successfully transferred to the field in different agro-climatic zones in India. This protocol has been successfully evaluated on five elite lines of J. curcas. KeywordsEnergy crop-Immature embryo- Jatropha curcas -Morphogenesis-Plant regeneration-Tree-borne oil seed
    Plant Biotechnology Reports 04/2010; 4(2):139-148. DOI:10.1007/s11816-010-0129-0 · 1.19 Impact Factor
  • Ajay C. Deore · T. Sudhakar Johnson ·
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    ABSTRACT: A simple, high-frequency and reproducible protocol for induction of adventitious shoot buds and plant regeneration from leaf-disc cultures of Jatropha curcas L. has been developed. Adventitious shoot buds were induced from very young leaf explants of in vitro germinated seedlings as well as mature field-grown plants cultured on Murashige and Skoog’s (MS) medium supplemented with thidiazuron (TDZ) (2.27μM), 6-benzylaminopurine (BA) (2.22μM) and indole-3-butyric acid (IBA) (0.49μM). The presence of TDZ in the induction medium has greater influence on the induction of adventitious shoot buds, whereas BA in the absence of TDZ promoted callus induction rather than shoot buds. Induced shoot buds were multiplied and elongated into shoots following transfer to the MS medium supplemented with BA (4.44μM), kinetin (Kn) (2.33μM), indole-3-acetic acid (IAA) (1.43μM), and gibberellic acid (GA3) (0.72μM). Well-developed shoots were rooted on MS medium supplemented with IBA (0.5μM) after 30days. Regenerated plants after 2months of acclimatization were successfully transferred to the field without visible morphological variation. This protocol might find use in mass production of true-to-type plants and in production of transgenic plants through Agrobacterium/biolistic-mediated transformation.
    Plant Biotechnology Reports 04/2008; 2(1):7-11. DOI:10.1007/s11816-008-0042-y · 1.19 Impact Factor