In JoVE (3)
- Electron Cryotomography of Bacterial Cells
- Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography
- Specific and Accurate Detection of the Citrus Greening Pathogen Candidatus liberibacter spp. Using Conventional PCR on Citrus Leaf Tissue Samples
Articles by Jian Chen in JoVE
Electron Cryotomography of Bacterial Cells Songye Chen1, Alasdair McDowall1,2, Megan J. Dobro1, Ariane Briegel1,2, Mark Ladinsky1,2, Jian Shi2, Elitza I. Tocheva1, Morgan Beeby1,2, Martin Pilhofer1,2, H. Jane Ding1, Zhuo Li1,2, Lu Gan1, Dylan M. Morris1, Grant J. Jensen1,2 1Division of Biology, California Institute of Technology - Caltech, 2Howard Hughes Medical Institute, California Institute of Technology - Caltech We illustrate here how to use electron cryotomography (ECT) to study the ultrastructure of bacterial cells in near-native states, to "macromolecular" (~4 nm) resolution.
Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography Hui-Wen Cheng*1,2, Sudeshna Fisch*1, Susan Cheng1, Michael Bauer1, Soeun Ngoy1, Yiling Qiu1, Jian Guan1, Shikha Mishra1, Christopher Mbah1, Ronglih Liao1 1Cardiac Muscle Research Labratory, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, 2Cardiovascular Department, Chang Gung Memorial Hospital Right ventricle (RV) dysfunction is critical to the pathogenesis of cardiovascular disease, yet limited methodologies are available for its evaluation. Recent advances in ultrasound imaging provide a noninvasive and accurate option for longitudinal RV study. Herein, we detail a step-by-step echocardiographic method using a murine model of RV pressure overload.
Specific and Accurate Detection of the Citrus Greening Pathogen Candidatus liberibacter spp. Using Conventional PCR on Citrus Leaf Tissue Samples Huan Chen*1,2, Ian Arthur Palmer*1, Jian Chen1,2, Ming Chang1,2, Stephen L. Thompson3, Fengquan Liu2, Zheng Qing Fu1 1Department of Biological Sciences, University of South Carolina, 2Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, 3Department of Instructions and Teacher Education, University of South Carolina Citrus Greening is a particularly destructive disease affecting citrus crops globally. Presented here is a simple method using PCR and genomic DNA extraction of citrus leaf tissue for the accurate and precise identification of the citrus greening pathogen, Candidatus liberibacter spp.
Other articles by Jian Chen on PubMed
A Bacterial Type III Effector Targets the Master Regulator of Salicylic Acid Signaling, NPR1, to Subvert Plant Immunity Cell Host & Microbe. Dec, 2017 | Pubmed ID: 29174403 Most plant bacterial pathogens rely on type III effectors to cause diseases. Although it is well known that the plant hormone salicylic acid (SA) plays an essential role in defense, whether the master regulator of SA signaling, NPR1, is targeted by any plant pathogen effectors is unknown. SA facilitates the reduction of cytosolic NPR1 oligomers into monomers, which enter the nucleus and function as transcriptional coactivators of plant defense genes. We show that SA promotes the interaction between the Pseudomonas syringae type III effector AvrPtoB and NPR1. In the presence of SA, AvrPtoB mediates the degradation of NPR1 via the host 26S proteasome in a manner dependent on AvrPtoB's E3 ligase activity. Intriguingly, we found that NPR1 plays an important role in MAMP-triggered immunity (MTI), inducing the expression of MTI marker genes. Thus, this work uncovers a strategy in which AvrPtoB targets NPR1 and represses NPR1-dependent SA signaling, thereby subverting plant innate immunity.
Measurement of Cyclic GMP During Plant Hypersensitive Disease Resistance Response Methods in Molecular Biology (Clifton, N.J.). 2018 | Pubmed ID: 29332293 Cyclic guanosine-3',5'-monophosphate (cGMP) is recognized as an important second messenger in plants, mediating intracellular signal in important physiological processes, including the hypersensitive disease resistance response induced by avirulent pathogens. In this context, the analysis of cGMP levels in infected plants requires an accurate and specific detection method allowing its quantification. Here, we describe an assay based on the Alphascreen technology, developed for animal cells and further adapted and optimized for the detection of cGMP in plants. The method is applied for the measurement of cGMP in Arabidopsis thaliana plants challenged with an avirulent strain of Pseudomonas syringae pv. tomato. This protocol includes the extraction of cGMP, the assay procedure and the calculation of cGMP concentration.