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Browsing by Author "Puranik, Swati"

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    Abiotic stress-responsive expression of wali1 and wali5 genes from wheat
    (Landes Bioscience, 2012) Garg, Bharti; Puranik, Swati; Tuteja, Narendra; Prasad, Manoj
    Two cDNA clones, encoding Aluminum-responsive wali1 and wali5, were identified in dehydration stress-specific cDNA library from wheat. Their sequence variations and structural dissimilarities indicated them to be non-homologous genes. Expression of both genes was induced by various abiotic stresses as well as in response to plant hormones and oxidative molecules. Further, they were expressed differentially in shoot and root tissues of wheat seedlings, their transcripts being specifically abundant in roots. Previously characterized as being only Aluminum treatment induced, this report proposes them as novel candidates for stress-responsive studies.
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    cDNA-AFLP analysis reveals differential gene expression in response to salt stress in foxtail millet (Setaria italica L.)
    (Springer, 2008) Jayaraman, Ananthi; Puranik, Swati; Rai, Neeraj Kumar; Vidapu, Sudhakar; Sahu, Pranav Pankaj; Lata, Charu; Prasad, Manoj
    Plant growth and productivity are affected by various abiotic stresses such as heat, drought, cold, salinity, etc. The mechanism of salt tolerance is one of the most important subjects in plant science as salt stress decreases worldwide agricultural production. In our present study we used cDNA-AFLP technique to compare gene expression profiles of a salt tolerant and a salt-sensitive cultivar of foxtail millet (Seteria italica) in response to salt stress to identify early responsive differentially expressed transcripts accumulated upon salt stress and validate the obtained result through quantitative real-time PCR (qRT-PCR). The expression profile was compared between a salt tolerant (Prasad) and susceptible variety (Lepakshi) of foxtail millet in both control condition (L0 and P0) and after 1 h (L1 and P1) of salt stress. We identified 90 transcript-derived fragments (TDFs) that are differentially expressed, out of which 86 TDFs were classified on the basis of their either complete presence or absence (qualitative variants) and 4 on differential expression pattern levels (quantitative variants) in the two varieties. Finally, we identified 27 non-redundant differentially expressed cDNAs that are unique to salt tolerant variety which represent different groups of genes involved in metabolism, cellular transport, cell signaling, transcriptional regulation, mRNA splicing, seed development and storage, etc. The expression patterns of seven out of nine such genes showed a significant increase of differential expression in tolerant variety after 1 h of salt stress in comparison to salt-sensitive variety as analyzed by qRT-PCR. The direct and indirect relationship of identified TDFs with salinity tolerance mechanism is discussed.
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    Comparative transcriptome analysis of contrasting foxtail millet cultivars in response to short-term salinity stress
    (Elsevier, 2011) Puranik, Swati; Jha, Sarita; Srivastava, Prem S.; Sreenivasulu, Nese; Prasad, Manoj
    Soil salinity represents a major abiotic stress that adversely affects crop growth and productivity. In this study, 21-day-old seedlings of two foxtail millet (Setaria italica) cultivars differing in salt tolerance were found to also differ in lipid peroxidation, ion balance and activity of antioxidative enzymes (glutathione reductase and catalase) under short-term salinity stress (250 mM NaCl for 1-48 h). With the aim of better understanding the molecular mechanisms underlying plant responses to short-term salinity stress, two suppression subtractive hybridization cDNA libraries (forward and reverse) were constructed of these cultivars. A total of 249 non-redundant ESTs was identified by random EST sequencing and grouped into 11 functional categories. Macroarray analysis of these clones showed that 159 (63.9%) were differentially expressed (≥ 2-fold) in response to salinity stress, with 115 (72.3%) up and 44 (27.7%) down-regulated. A data search of transcriptional profiling under salinity stress in other species revealed that 81 (51%) of the 159 differentially expressed transcripts found in foxtail millet have not been reported in previous studies. Hence, these new transcripts may represent untapped gene sources allowing specific responses to short-term salt-stress in an orphan crop known to possess a natural adaptation capacity to abiotic stress. Quantitative real-time PCR of 21 highly up-regulated (≥2.5-fold) transcripts showed temporal variation in expression in both cultivars under salinity. Among them, several transcription factors and signalling genes were preferentially expressed in the tolerant cultivar. These results suggest that the tolerant cultivar possesses more effective signal-perception mechanisms for metabolic adjustments in plants under harsh saline conditions. Our findings provide evidence that the unknown genes identified in this study, in addition to several known genes, may play important roles in stress tolerance mechanisms present in foxtail millet.
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    Comprehensive genome-wide survey, genomic constitution and expression profiling of the NAC transcription factor family in foxtail millet (Setaria italica L.)
    (PLOS, 2013) Puranik, Swati; Sahu, Pranav Pankaj; Mandal, Sambhu Nath; Suresh B., Venkata; Parida, Swarup K.; Prasad, Manoj
    The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet) that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI), with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants.
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    Development and utilization of novel intron length polymorphic markers in foxtail millet [Setaria italica (L.) P. Beauv.]
    (NRC Res Press, 2011) Gupta, Sarika; Kumari, Kajal; Das, Jyotirmoy; Lata, Charu; Puranik, Swati; Prasad, Manoj
    Introns are noncoding sequences in a gene that are transcribed to precursor mRNA but spliced out during mRNA maturation and are abundant in eukaryotic genomes. The availability of codominant molecular markers and saturated genetic linkage maps have been limited in foxtail millet (Setaria italica (L.) P. Beauv.). Here, we describe the development of 98 novel intron length polymorphic (ILP) markers in foxtail millet using sequence information of the model plant rice. A total of 575 nonredundant expressed sequence tag (EST) sequences were obtained, of which 327 and 248 unique sequences were from dehydration- and salinity-stressed suppression subtractive hybridization libraries, respectively. The BLAST analysis of 98 EST sequences suggests a nearly defined function for about 64% of them, and they were grouped into 11 different functional categories. All 98 ILP primer pairs showed a high level of cross-species amplification in two millets and two nonmil- lets species ranging from 90% to 100%, with a mean of ∼97%. The mean observed heterozygosity and Nei’s average gene diversity 0.016 and 0.171, respectively, established the efficiency of the ILP markers for distinguishing the foxtail millet accessions. Based on 26 ILP markers, a reasonable dendrogram of 45 foxtail millet accessions was constructed, demonstrating the utility of ILP markers in germplasm characterizations and genomic relationships in millets and nonmillets species.
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    The DNA-binding activity of an AP2 protein is involved in transcriptional regulation of a stress-responsive gene, SiWD40, in foxtail millet
    (Elsevier, 2012) Mishra, Awdhesh Kumar; Puranik, Swati; Bahadur, Ranjit Prasad; Prasad, Manoj
    A differentially expressed transcript, encoding a putative WD protein (Setaria italica WD40; SiWD40), was identified in foxtail millet. Tertiary structure modeling revealed that its C-terminus possesses eight blade β-propeller architecture. Its N-terminal has three α-helices and two 310-helices and was highly induced by different abiotic stresses. The SiWD40:GFP fusion protein was nuclear localized. Promoter analysis showed the presence of many cis-acting elements, including two dehydration responsive elements (DRE). A stress-responsive SiAP2 domain containing protein could specifically bind to these elements in the SiWD40 promoter. Thus, for the first time, we report that DREs probably regulate expression of SiWD40 during envi- ronmental stress. Molecular docking analysis revealed that the circumference of the β‐propeller structure was involved in an interaction with a SiCullin4 protein, supporting the adaptability of SiWD40 to act as a scaf- fold. Our study thus provides a vital clue for near future research on the stress-regulation of WD proteins.
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    Dynamics of defense related components in two contrasting genotypes to tomato upon infection with tomato leaf curl New Delhi virus
    (Springer, 2012) Sahu, Pranav Pankaj; Rai, Neeraj Kumar; Puranik, Swati; Roy, Anirban; Khan, Moinuddin; Prasad, Manoj
    Tomato leaf curl virus (ToLCV) disease is a serious threat for tomato cultivation in the tropics and subtropics. Despite serious efforts no immune commercial varieties or F(1) hybrids are available till date. In this study, the interaction between Solanum lycopersicum and ToLCV was characterized on molecular and biochemical basis. RNA silencing mediated by short interfering RNA (siRNA) and reactive oxygen species (ROS) has been proposed as central components of plant adaptation to several stresses. A comparative RNA interference study between two contrasting tomato genotypes, LA1777 (tolerant) and 15SBSB (susceptible) infected with Tomato Leaf Curl New Delhi Virus (ToLCNDV) revealed relatively higher accumulation of siRNA in the leaves of tolerant genotype. In LA1777, ToLCNDV produced chlorotic as well as necrotic areas at the inoculation sites 5-10 days post-inoculation. Caspase-9- and caspase-3-like activities were significantly increased in response to ToLCNDV infection in LA1777 at inoculated region. Activities of antioxidant enzymes involved in the detoxification of ROS were examined in both systemic and localized area of infection, and their expression level was further validated through quantitative real-time PCR of the corresponding transcripts. Expression patterns of three genes encoding pathogenesis-related proteins showed higher accumulation in tolerant genotype. Tolerance against the ToLCNDV in LA1777 can be attributed to the higher siRNA accumulation, localized cell death, altered levels of antioxidant enzymes and activation of pathogenesis-related genes at different durations of virus infection. Based on these direct and indirect evidences, we have proposed a putative mechanism for ToLCNDV tolerance in the tolerant genotype.
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    Electrophoretic mobility shift assay reveals a novel recognition sequence for Setaria italica NAC protein
    (Landes Bioscience, 2011) Puranik, Swati; Kumar, Karunesh; Srivastava, Prem S.; Prasad, Manoj
    The NAC (NAM/ATAF1,2/CUC2) proteins are among the largest family of plant transcription factors. Its members have been associated with diverse plant processes and intricately regulate the expression of several genes. Inspite of this immense progress, knowledge of their DNA-binding properties are still limited. In our recent publication,1 we reported isolation of a membrane-associated NAC domain protein from Setaria italica (SiNAC). Transactivation analysis revealed that it was a functionally active transcription factor as it could stimulate expression of reporter genes in vivo. Truncations of the transmembrane region of the protein lead to its nuclear localization. Here we describe expression and purification of SiNAC DNA-binding domain. We further report identification of a novel DNA-binding site, [C/G][A/T][T/A][G/C]TC[C/G][A/T][C/G][G/C] for SiNAC by electrophoretic mobility shift assay. The SiNAC-GST protein could bind to the NAC recognition sequence in vitro as well as to sequences where some bases had been reshuffled. The results presented here contribute to our understanding of the DNA-binding specificity of SiNAC protein.
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    Epigenetic mechanisms of plant stress responses and adaptation
    (Springer, 2013) Sahu, Pranav Pankaj; Pandey, Garima; Sharma, Namisha; Puranik, Swati; Muthamilarasan, Mehanathan; Prasad, Manoj
    Epigenetics has become one of the hottest topics of research in plant functional genomics since it appears promising in deciphering and imparting stress-adaptive potential in crops and other plant species. Recently, numerous studies have provided new insights into the epigenetic control of stress adaptation. Epigenetic control of stress-induced phenotypic response of plants involves gene regulation. Growing evidence suggest that methylation of DNA in response to stress leads to the variation in phenotype. Transposon mobility, siRNA-mediated methylation and host methyltransferase activation have been implicated in this process. This review presents the current status of epigenetics of plant stress responses with a view to use this knowledge towards engineering plants for stress tolerance.
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    Involvement of host regulatory pathways during geminivirus infection: a novel platform for generating durable resistance
    (Springer, 2014) Sahu, Pranav Pankaj; Sharma, Namisha; Puranik, Swati; Muthamilarasan, Mehanathan; Prasad, Manoj
    Geminiviruses are widely distributed throughout the world and cause devastating yield losses in almost all the economically important crops. In this review, the newly identified roles of various novel plant factors and pathways participating in plant–virus interaction are summarized with a particular focus on the exploitation of various pathways involving ubiquitin/26S proteasome pathway, small RNA pathways, cell division cycle components, and the epigenetic mechanism as defense responses during plant–pathogen interactions. Capturing the information on these pathways for the development of strategies against geminivirus infection is argued to provide the basis for new genetic approaches to resistance.
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    Molecular cloning and characterization of a membrane associated NAC family gene, SiNAC from foxtail millet [Setaria italica (L.) P. Beauv.]
    (Springer Science, 2011) Puranik, Swati; Bahadur, Ranjit Prasad; Srivastava, Prem S.; Prasad, Manoj
    The plant-specific NAC (NAM, ATAF, and CUC) transcription factors have diverse role in development and stress regulation. A transcript encoding NAC protein, termed SiNAC was identified from a salt stress subtractive cDNA library of S. italica seedling (Puranik et al., J Plant Physiol 168:280-287, 2011). This single/low copy gene containing four exons and four introns within the genomic-sequence encoded a protein of 462 amino acids. Structural analysis revealed that highly divergent C terminus contains a transmembrane domain. The NAC domain consisted of a twisted antiparallel beta-sheet packing against N terminal alpha helix on one side and a shorter helix on the other side. The domain was predicted to homodimerize and control DNA-binding specificity. The physicochemical features of the SiNAC homodimer interface justified the dimeric form of the predicted model. A 1539 bp fragment upstream to the start codon of SiNAC gene was cloned and in silico analysis revealed several putative cis-acting regulatory elements within the promoter sequence. Transactivation analysis indicated that SiNAC activated expression of reporter gene and the activation domain lied at the C terminal. The SiNAC:GFP was detected in the nucleus and cytoplasm while SiNAC ΔC(1-158):GFP was nuclear localized in onion epidermal cells. SiNAC transcripts mostly accumulated in young spikes and were strongly induced by dehydration, salinity, ethephon, and methyl jasmonate. These results suggest that SiNAC encodes a membrane associated NAC-domain protein that may function as a transcriptional activator in response to stress and developmental regulation in plants.
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    NAC proteins: regulation and role in stress tolerance
    (Cell Press (Elsevier), 2012) Puranik, Swati; Sahu, Pranav Pankaj; Srivastava, Prem S.; Prasad, Manoj
    The plant-specific NAC (NAM, ATAF1,2 and CUC2) proteins constitute a major transcription factor family renowned for their roles in several developmental programs. Despite their highly conserved DNA-binding domains, their remarkable diversification across plants reflects their numerous functions. Lately, they have received much attention as regulators in various stress signaling pathways which may include interplay of phytohormones. This review summarizes the recent prog- ress in research on NACs highlighting the proteins’ potential for engineering stress tolerance against various abiotic and biotic challenges. We discuss regulatory components and targets of NAC proteins in the context of their prospective role for crop improvement strategies via biotechnological intervention.
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    Post-transcriptional and epigenetic arms of RNA silencing: a defense machinery of naturally tolerant tomato plant against Tomato leaf curl New Delhi virus
    (Springer, 2014) Sahu, Pranav Pankaj; Sharma, Namisha; Puranik, Swati; Prasad, Manoj
    Tomato leaf curl disease (ToLCD), caused by strains of Tomato leaf curl virus, is major constraint to tomato production globally. The present study was aimed to understand the mechanisms of ToLCD tolerance in a naturally tolerant tomato cultivar through post-transcriptional and DNA methylation-specific RNA silencing. We evaluated the distribution of virus-derived short-interfering RNAs (siRNAs) throughout the Tomato leaf curl New Delhi virus (ToLCNDV) genome along with DNA methylation patterns in intergenic (IR) and Rep (AC1) regions in two tomato cultivars differing in their ToLCNDV tolerance. The methylation pattern was correlated by expression analysis of key methyltransferases genes. In the tolerant cultivar, higher accumulation of viral IR-specific 24-nucleotides (nt) siRNA and AC1-specific 21-nt siRNA were found. Higher methylation levels were observed in various regions of IR. Additionally, AC1 region which facilitates binding of plant nuclear proteins was hypermethylated. DNA methylation in the key regulating region may control the expression of AC1, AC2, and AC3 genes. Components of RNA silencing and DNA methylation machinery were found to be differentially expressed in both the cultivar of tomato at 21 dpi. Thus, we infer that both viral DNA methylation and siRNA-mediated RNA degradation play an important role in conferring tolerance against Tomato leaf curl New Delhi virus. Due to the inability to achieve field resistance in transgenic tomato by deploying the viral genes, targeting the viral genomic regions through RNAi technology reported here could offer an alternate defense strategy for generating transgenics to prevent yield loss.
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    Recent advances in plant-virus interaction with emphasis on small interfering RNAs (siRNAs)
    (Springer, 2013) Sharma, Namisha; Sahu, Pranav Pankaj; Puranik, Swati; Prasad, Manoj
    Regulation of several biological functions in plants has now been known to involve diverse RNA silencing pathways. These vital pathways involve various components such as dsRNA, Dicer, RNA-dependent RNA polymerase and Argonaute proteins, which lead to the production of several small RNAs (sRNAs) varying in their sizes. These sRNAs have significant role in the regulation of gene expression at transcriptional and translational levels. Among them, small interfering RNAs (siRNAs; majorly 21, 22 and 24 nt) have been shown to play an important role in plants' resistance against many viruses by inhibiting the viral gene expression. Furthermore, it has also been highlighted that siRNA-mediated methylation of viral DNA confers resistance to various plant DNA viruses. In this review, we have outlined the recent advances made using the siRNA-mediated antiviral strategy, along with methylation-based epigenetic defensive mechanisms as a protective measure against diverse plant viruses.
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    Recent advances in tomato functional genomics: utilization of VIGS
    (Springer, 2012) Sahu, Pranav Pankaj; Puranik, Swati; Khan, Moinuddin; Prasad, Manoj
    Tomato unquestionably occupies a significant position in world vegetable production owing to its world-wide consumption. The tomato genome sequencing efforts being recently concluded, it becomes more imperative to recognize important functional genes from this treasure of generated information for improving tomato yield. While much progress has been made in conventional tomato breeding, post-transcriptional gene silencing (PTGS) offers an alternative approach for advancement of tomato functional genomics. In particular, virus-induced gene silencing (VIGS) is increasingly being used as rapid, reliable, and lucrative screening strategy to elucidate gene function. In this review, we focus on the recent advancement made through exploiting the potential of this technique for manipulating different agronomically important traits in tomato by discussing several case studies.
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    Role of NACs in regulation of abiotic stress responses in plants
    (Bentham Science Publishers, USA, 2012) Puranik, Swati; Prasad, Manoj
    Abiotic stresses such as drought, high salinity and cold are common adverse environmental conditions that significantly influence plant growth and productivity worldwide. NAC domain proteins are important plant-specific transcription factors (TFs) that regulate the expression of many stress-inducible genes. They act both by an ABA-dependent or independent manner and play a critical role in improving abiotic stress tolerance of plants by interacting with cis- element present in the promoter region of various abiotic stress- responsive genes. We summarize recent studies highlighting the structural and functional characters of specific members of this family, the current knowledge on the relation between NACs and their cis-elements, with emphasis on the expression and regulation of NACs in the adaptive responses to abiotic stresses. The progress of the practical and application value of NACs in crop improvement engineering has also been discussed
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    Structure and regulatory networks of WD40 protein in plants
    (Springer, 2012) Mishra, Awdhesh Kumar; Puranik, Swati; Prasad, Manoj
    Plants have been gifted with intricate regulatory networks to carry on with their sessile life form. Often such networks involve delicate association between various proteins. The WD40 proteins, which are present abundantly in several eukaryotes, act as scaffolding molecules assisting proper activity of other proteins. They comprise several stretches of 44–60 amino acid residues and often terminate with a WD dipeptide. They function in several cellular, metabolic and molecular pathways, biologically playing important roles in plant development and also during stress signaling. Moreover, some WD40 (named DWD) proteins also function as substrate receptors in Cullin4 RING dependent E3 ubiquitin ligase mediated proteosomal degradation and DNA damage repair mechanism. In this review, we have discussed the various aspects of these proteins that affect their highly diversified functions in plants.
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    Tomato 26S Proteasome subunit RPT4a regulates ToLCNDV transcription and activates hypersensitive response in tomato
    (Nature Publishing Group, 2016) Sahu, Pranav Pankaj; Sharma, Namisha; Puranik, Swati; Chakraborty, Supriya; Prasad, Manoj
    Involvement of 26S proteasomal subunits in plant pathogen-interactions, and the roles of each subunit in independently modulating the activity of many intra- and inter-cellular regulators controlling physiological and defense responses of a plant were well reported. In this regard, we aimed to functionally characterize a Solanum lycopersicum 26S proteasomal subunit RPT4a (SlRPT4) gene, which was differentially expressed after Tomato leaf curl New Delhi virus (ToLCNDV) infection in tolerant cultivar H-88-78-1. Molecular analysis revealed that SlRPT4 protein has an active ATPase activity. SlRPT4 could specifically bind to the stem-loop structure of intergenic region (IR), present in both DNA-A and DNA-B molecule of the bipartite viral genome. Lack of secondary structure in replication-associated gene fragment prevented formation of DNA-protein complex suggesting that binding of SlRPT4 with DNA is secondary structure specific. Interestingly, binding of SlRPT4 to IR inhibited the function of RNA Pol-II and subsequently reduced the bi-directional transcription of ToLCNDV genome. Virus-induced gene silencing of SlRPT4 gene incited conversion of tolerant attributes of cultivar H-88-78-1 into susceptibility. Furthermore, transient overexpression of SlRPT4 resulted in activation of programmed cell death and antioxidant enzymes system. Overall, present study highlights non-proteolytic function of SlRPT4 and their participation in defense pathway against virus infection in tomato.
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    Transcript profiling identifies novel transcripts with unknown functions as primary response components to osmotic stress in wheat (Triticum aestivum L.)
    (Springer, 2013) Garg, Bharti; Puranik, Swati; Misra, Shrilekha; Tripathi, Bhumi Nath; Prasad, Manoj
    Osmotic stress induced by dehydration and salinity, is among the major abiotic stresses that adversely impacts crop productivity and plants often display cultivar-dependent response against osmotic imbalance. To better understand the molecular mechanisms underlying differential responses to dehydration, transcriptome changes of two contrasting wheat (Triticum aestivum L.) cultivars were evaluated in plants grown under unfavorable osmotic conditions. A total of 107 non-redundant transcripts were identified. Of these, most had unknown functions (31; ~30 %) signifying the existence of putative stress-specific genes in wheat, reported here for the first time. Upon comparing with previous transcriptomic studies, 43 (40 %) of the osmotically-responsive transcripts were found not to be documented. These new transcripts may therefore signify unexplored gene sources for specific responses towards short-term osmotic stress in wheat. Through macroarray analysis, 69 (~64 %) transcripts were found to be differentially expressed (≥3-fold) and expression of 14 transcripts (with known or unknown functions) was further confirmed by quantitative real time PCR. Expression analysis of the seven unknown transcripts also revealed their tissue- and stress-specific regulation. Comparative in silico mapping of these 107 wheat transcripts against available mapping data for rice (40; ~37 %), maize (34; ~32 %), and sorghum (33; ~31 %) revealed presence of wheat orthologous sequences in these cereal crops. This study provides an interesting account on several novel genes, besides those with known functions, which may regulate stress response dynamics and thus, may be used as potential candidates to improve stress adaptability through genetic and molecular studies.
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    Transcription factors: modulating plant adaption in the scenario of changing climate
    (Springer, 2013) Puranik, Swati; Prasad, Manoj
    Climate change and the associated environmental constraints have created a challenge to sustain food security and biodiversity globally. The response to adverse environments is a complex process and plants integrate several approaches that allow them to withstand climatic restraints, depending on the timing and length. Changes at the transcriptional level of various genes transduce cellular signals for the synthesis of necessary metabolites. Transcription factors have the principal role for the efficient adaptation capacity of the plants, and present an attractive target category for manipulation and gene regulation. As many biological processes in plants are regulated at the level of transcription, understanding transcription factor function is an important step towards understanding plant responses to environmental conditions. Among them, numerous transcription factors belonging to several large transcription factor families, such as AP2/ERF, bZIP, MYB, MYC, Cys2His2 zinc finger, WRKY, and NAC, have been shown as stress-responsive proteins. They act both by an abscisic acid-dependent and -independent manner, and through their interaction with respective cis-elements of their target genes, play crucial roles in recuperating plant stress tolerance. We highlight the considerable biotechnological progress made towards understanding the molecular stress responses of plants using important transcription factor families. The progress of their practical and application value in crop improvement through genetic engineering is also discussed.

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