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Chalivendra S.C.,Colorado State University | Chalivendra S.C.,Valent BioSciences Corporation | Lopez-Casado G.,Cornell University | Lopez-Casado G.,University of Malaga | And 12 more authors.
Journal of Experimental Botany | Year: 2013

Although self-incompatibility (SI) in plants has been studied extensively, far less is known about interspecifc reproductive barriers. One interspecifc barrier, known as unilateral incongruity or incompatibility (UI), occurs when species display unidirectional compatibility in interspecifc crosses. In the wild tomato species Solanum pennellii, both SI and self-compatible (SC) populations express UI when crossed with domesticated tomato, offering a useful model system to dissect the molecular mechanisms involved in reproductive barriers. In this study, the timing of reproductive barrier establishment during pistil development was determined in SI and SC accessions of S. pennellii using a semi-in vivo system to track pollen-tube growth in developing styles. Both SI and UI barriers were absent in styles 5 days prior to flower opening, but were established by 2 days before flower opening, with partial barriers detected during a transition period 3-4 days before flower opening. The developmental expression dynamics of known SI factors, S-RNases and HT proteins, was also examined. The accumulation of HT-A protein coincided temporally and spatially with UI barriers in developing pistils. Proteomic analysis of stigma/styles from key developmental stages showed a switch in protein profiles from cell-division-associated proteins in immature stigma/styles to a set of proteins in mature stigma/ styles that included S-RNases, HT-A protein and proteins associated with cell-wall loosening and defense responses, which could be involved in pollen-pistil interactions. Other prominent proteins in mature stigma/styles were those involved in lipid metabolism, consistent with the accumulation of lipid-rich material during pistil maturation. © 2012 The Author. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved.

Kumar V.,Jaypee University of Information Technology | Shitiz K.,Jaypee University of Information Technology | Chauhan R.S.,Jaypee University of Information Technology | Sood H.,Jaypee University of Information Technology | Tandon C.,Amity Institute of Biotechnology
Journal of Plant Biochemistry and Biotechnology | Year: 2016

Picrosides, the terpenoids synthesized by Picrorhiza kurroa, have ample usage in medicine. Identification of the regulatory enzymes involved in picroside biosynthesis needs to be explored for improving the level of these secondary metabolites. Current efforts are based on the analysis of secondary metabolism in picroside biosynthesis but its interpretation is limited by the lack of information on the involvement of primary metabolic pathways. The present study investigated the connection of primary metabolic enzymes with the picrosides levels in P. kurroa. The results showed changes in the catalytic activities as well as in the gene expression profiles of hexokinase, pyruvate kinase, isocitrate dehydrogenase, malate dehydrogenase, and NADP+-malic enzyme in congruence with picroside-I content under different conditions of P. kurroa growth, which indicates the role of these enzymes in the accumulation of picrosides. The significant correlation coefficients (p < 0.05) observed between gene expression and enzyme activity underline the role of integrative studies for a better understanding of connecting links between metabolic pathways leading to picroside biosynthesis. This is apparently the first report on the involvement of glycolytic and TCA cycle enzymes in the accumulation of picrosides in P. kurroa. © 2015, Society for Plant Biochemistry and Biotechnology.

Sun Q.,University of Delaware | Madan B.,Amity Institute of Biotechnology | Tsai S.-L.,National Taiwan University of Science and Technology | Delisa M.P.,Cornell University | Chen W.,University of Delaware
Chemical Communications | Year: 2014

For the first time, artificial cellulosome structures were created on DNA scaffolds based on zinc finger protein (ZFP)-guided assembly. These resulting two-component cellulosome structures exhibited enhancement in cellulose hydrolysis compared to the non-complexed mixture depending on the number of CBMs and cellulases assembled. This journal is © The Royal Society of Chemistry.

Kumar V.,Jaypee University of Information Technology | Sharma N.,Jaypee University of Information Technology | Shitiz K.,Jaypee University of Information Technology | Singh T.R.,Jaypee University of Information Technology | And 3 more authors.
Plant Cell, Tissue and Organ Culture | Year: 2015

Picroside-I (P-I) is a member of the iridoid glycosides family of natural products, which are used to treat liver disorders. The growing medicinal need for this benign compound has stimulated the present study to identify genes important for the biosynthesis of P-I. In this study, molecular screens have been generated using gene expression patterns obtained by quantitative RT-PCR which have extended the knowledge of genes associated with P-I biosynthesis. A total of 13 genes encoding the rate limiting enzymes of different pathways, were analyzed by qRT-PCR in Picrorhiza kurroa shoots collected at 0, 10, 20, 30 and 40 days. The results showed that five of the genes (HK, DXPS, ISPD, HMGR and PMK) are supposed to be essential for P-I biosynthesis up to 20 days while DAHPS and G-10-H, in conjunction might assist P-I biosynthesis between 20 and 30 days of P. kurroa growth. This is apparently the first report on the molecular aspects of different pathways integrated in P-I biosynthesis. Moreover, principal component analysis prediction also corroborated the genes selection by identifying genes signatures for different samples (collected at different time intervals) and supported the link between samples and gene expression patterns. Overall, this study capitalizes on dynamic gene expression patterns obtained in response to the P-I stimuli under different stages of P. kurroa growth which are likely to define the regulatory steps in P-I biosynthesis. © 2015 Springer Science+Business Media Dordrecht

Shukla S.,Institute of Cytology and Preventive Oncology ICMR | Mahata S.,Institute of Cytology and Preventive Oncology ICMR | Shishodia G.,Institute of Cytology and Preventive Oncology ICMR | Pande S.,Institute of Cytology and Preventive Oncology ICMR | And 8 more authors.
Indian Journal of Medical Research | Year: 2014

Background & objectives: High-risk human papilloma virus (HR-HPV) infection and its integration in host genome is a key event in malignant transformation of cervical cells. HPV16 being a dominant HR-HPV type, we undertook this study to analyze if viral load and physical state of the virus correlated with each other in the absence of other confounding variables and examined their potential as predictors of progressive cervical lesions. Methods: Both, viral load and integration status of HPV16 were determined by real time URR PCR and estimation of E2:E6 ratio in a total of 130 PGMY-RLB -confirmed, monotypic HPV16-infected cervical DNA samples from biopsies of cytology-confirmed low grade (LSIL, 30) and high grade (HSIL, 30), and invasive carcinoma, (squamous cell carcinoma SCC, 70) cases. Results: Investigation of DNA samples revealed a gradual increase in HPV16 viral load over several magnitudes and increased frequency of integration from LSIL to HSIL and HSIL to invasive cancer in relation to the severity of lesions in monotypic HPV16-infected cervical tissues. In a substantial number of precancer (11/60) and cancer cases (29/70), HPV16 was detected in concomitant mixed form. The concomitant form of HPV16 genome carried significantly higher viral load. Interpretation & conclusions: Overall, viral load and integration increased with disease severity and could be useful biomarkers in disease progression, at least, in HPV16-infected cervical pre-cancer and cancer lesions.

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