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Reporter: Sixue Chen
Professor of Biology
Director of Proteomics and Mass Spectrometry
Cancer and Genetics Research Complex
University of Florida (UF)
Email: schen@ufl.edu
Report title: guard cell 'omics reported mpk4 complexes and CO2 response
Report time: 09:00 am, November 11, 2019
Address: Shuhua multi function hall, College of life science and technology
Associate: Zhang Dabing
Background:
Human population is expected to reach 9 billion by 2050, and global crop productivity needs to increase by 70% to feed the growing population. Unfortunately, pathogen infection and other adverse environmental conditions have posed grand challenges to crop yield and food security. Stomatal pores are major entry points of bacteria pathogens. How stomatal guard cells respond to pathogen invasion and other environmental factors (e.g., rising CO2 levels) is an important and interesting question. Mitogen activated protein kinase 4 (MPK4) is a multifunctional kinase that regulates various signaling events in plant defense, growth, light response and cytokinesis. We discovered that MPK4 is highly abundant in guard cells. How it plays a role in stomatal immunity is not known. Here we introduce an experimental system that combines genetic engineering of kinase activity and quantitative proteomics to rapidly study the signaling networks of MPK4. Proteomics analysis revealed that MPK4 activation affects multiple pathways (e.g., metabolism, redox regulation, jasmonic acid biosynthesis and stress responses). Furthermore, MPK4 activation also increased protein phosphorylation in the phosphoproteome, from which putative MPK4 substrates were identified. Using protein kinase assay, we validated that a transcription factor and a regulatory protein were indeed phosphorylated by MPK4. We demonstrated the utility of proteomics and phosphoproteomics in elucidating kinase dynamics and and identification of downstream substrates. As CO2 levels affect stomatal immunity and stomatal movement, we studied CO2 signaling using hyphenated metabolomics technologies. A new signaling pathway involving jasmonic acid was discovered. Future directions in signal crosstalk and data integration will be discussed.
Reporter information:
Professor Sixue Chen completed his Ph.D. in Shanghai, China and postdoctoral studies in Germany, Denmark, and University of Pennsylvania, USA. He is the Colonel Allen R. and Margret G. Crow Professor in Department of Biology, and Director of Proteomics and Mass Spectrometry at Interdisciplinary Center for Biotechnology Research of University of Florida, USA. Dr. Chen’s areas of expertise fall in Biochemistry, Plant Metabolism, Functional Genomics, Proteomics, Metabolomics, and Mass Spectrometry. He learned mass spectrometry when he was collaborating with a senior chemist at the Danish Royal Veterinary and Agricultural University 20 years ago. Dr. Chen carried out a lot of small molecule work at that time. Since joining University of Pennsylvania in 2001, he has worked on many different projects using proteomics and mass spectrometry. Dr. Chen has accumulated experience with different separation and fractionation technologies, different HPLC instruments including the nanoflow ultra performance LC, as well as mass spectrometers. During his tenure as the Proteomics Facility Director at the Danforth Center in Missouri, USA, Dr. Chen has developed a high throughput protein identification technology. Dr. Chen has successfully administered projects, trained students and scientists, collaborated with other researchers, and produced more than 200 peer-reviewed publications. At University of Florida, Dr. Chen has established three major research projects: plant guard cell hormone and CO2 signaling, stomatal innate immunity and glucosinolate metabolism. These projects have been funded by the US National Science Foundation, Department of Agriculture and National Institute of Health. Based on findings from large-scale “omics” studies, many novel, testable hypotheses have been derived. Another major component of Dr. Chen’s research program has been hypothesis driven and testing, i.e., characterizing molecular, biochemical and physiological functions of specific genes and proteins in plant interaction with the environment. The integration of hypothesis generation and hypothesis driven research will ultimately lead to a holistic view of cellular molecular networks that connect environmental factors to physiological and phenotypic output. Dr. Chen serves as Associate Editor of Metabolomics, Associate Editor of Frontiers in Plant Proteomics, Editorial Advisory Board Member of Journal of Proteome Research, Editorial Board Member of Journal of Proteomics, and Review Editor of Frontiers in Plant Metabolism and Chemodiversity.
Representative papers in recent five years:
1. Zhang, T., Chhajed, S., Schneider, J.D., Feng, G., Silveira, J.A., Song, W., Chen, S. (2019) Proteomic characterization of MPK4 signaling network and putative substrates. Plant Molecular Biology ( doi.org/10 .1007/s11103-019-00908-9)
2. Geng, S., Yu, B., Zhu, N., Dufresne, C., Chen, S. (2017) Metabolomics and proteomics of Brassica napus guard cells in response to low CO2. Frontiers in Molecular Biosciences-Metabolomics 4, 51.
3. Libault, M., Chen, S. (2016) Plant single cell type systems biology. Frontiers in Plant Science 7:35.
4. Geng, S., Misra, B.B., de Armas, E., Huhman, D.V., Alborn, H.T., Sumner, L.W., 5. Chen, S. (2016) Jasmonate-mediated stomatal closure under elevated CO2 revealed by time-resolved metabolomics. The Plant Journal 88(6), 947-962. doi: 10.1111/tpj.13296.
5. Parker, J., Balmant, K., Zhu, F., Zhu, N., Chen, S. (2015) cysTMTRAQ - An integrated proteomics method for identification of thiol-based redox proteins. Molecular and Cellular Proteomics 14, 237-242.
6. Misra, B.B., Assmann, S.M., Chen, S. (2014) Plant single cell and single cell-type metabolomics. Trends in Plant Science 19, 637-646
Reporter: Cai Qiang
Professor, doctoral Advisor
School of life sciences, Wuhan University
State Key Laboratory of Hybrid Rice
Email: Qiang.cai @ whu.edu.cn
Report title: small RNAs and extracellular viruses: new mechanisms of cross species communication
Report time: 10:00 am, November 11, 2019
Address: Shuhua multi function hall, College of life science and technology
Associate: Zhang Dabing
Background:
The damage of pathogens to plants seriously affects the yield of food crops. In the process of pathogens infecting plants, cell communication between pathogens and plants involves the transport and exchange of substances across cell boundaries, which plays an important role in regulating plant disease resistance and pathogen toxicity. Previous studies have focused on the transport and exchange of proteins, such as the entry of effectors from pathogens into plant cells to regulate plant disease resistance. Recently, it has been found that small RNA (sRNA) can be transferred Bi directionally between host and pathogen, which can induce gene silencing across the border and participate in the regulation of host immune response and pathogen pathogenicity. However, it is not clear whether endogenous sRNA in the host plays a role in disease resistance through cross-border gene silencing and the mechanism of cross-border sRNA transport. Our study shows that in the process of Botrytis cinerea infection, plant cells secrete a kind of nanoscale lipid vesicles (exosomes) to the outside of the cell, transport their endogenous sRNA to the fungal cells, and target to cut the mRNA expression of pathogenic toxic genes, so as to achieve the role of defense against fungal invasion. It is the first time that exosome mediated cross species gene silencing is found as a new mechanism of host disease resistance and immunity in the plant pathogen interaction system. At the same time, it also puts forward new ideas and ideas for plant pest control.
Reporter information:
Cai Qiang, PhD, professor and doctoral supervisor of School of life sciences, Wuhan University. In September 2014, under the guidance of Mr. Zhang Dabing, he received a doctor's degree in developmental biology from Shanghai Jiaotong University. From December 2014 to August 2019, he engaged in postdoctoral research in Professor Jin Hailing's laboratory, University of California, riverside, USA. Now the State Key Laboratory of Hybrid Rice (Wuhan University) has set up a laboratory to study the following areas: 1) small RNA (sRNA) regulates the interaction mechanism between plant and pathogen. We used rice and Arabidopsis as materials to analyze the regulatory mechanism of sRNA in plant pathogen interaction, especially the role of sRNA transport in this process, through genomics, genetics, molecular and biochemical methods. 2) The role of cell communication in plant immunity and growth and development. Tetraspanins are a class of transmembrane proteins that are conserved in evolution and widely exist in all higher organisms. They participate in intercellular material exchange (exosome mediated), cell recognition, migration, adhesion and fusion. We systematically studied the biological functions of Tetraspanins and their "companion" proteins in cell communication, and their roles in plant immunity and development.
Representative papers in recent five years:
Published papers (* corresponding authors)
1. Qiang Cai, Baoye He, and Hailing Jin. (2019). A safe ride in extracellular vesicles – small RNA trafficking between plant hosts and pathogens. Current Opinion in Plant Biology. 52:140-148.
2. Qiang Cai, Lulu Qiao, Ming Wang, Baoye He, Feng-Mao Lin, Jared Palmquist, Hsien-Da Huang, and Hailing Jin. (2018). Plants send small RNAs in extracellular vesicles to fungal pathogen to silence virulence genes. Science. 360(6393):1126-1129.
3. Qiang Cai, Baoye He, Karl-Heinz Kogel and Hailing Jin. (2018). Cross-kingdom RNA trafficking and environmental RNAi-nature’s blueprint for modern crop protection strategies. Current Opinion in Microbiology. 46:58-64.
4. Qiang Cai*, Zheng Yuan*, Mingjiao Chen, Changsong Yin, Zhijing Luo, Xiangxiang Zhao, Wanqi Liang, Jianping Hu & Dabing Zhang. (2014). Jasmonic acid regulates spikelet development in rice. Nature Communications. 5:3476.
5. Huanhuan Wang*, Liang Zhang*, Qiang Cai*, Wei Fan, Yun Hu, Ling Li, Zhenming Jin, Taotao Wang, Qianming Huang, Zhijing Luo, Mingjiao Chen, Dabing Zhang & Zheng Yuan. (2015). MADS32 interacts with B-function proteins and regulates rice flower development. Journal of Integrative Plant Biology. 57(5):504-13.
6. Yun Hu, Wanqi Liang, Changsong Yin, Xuelian Yang, Baozhe Ping, Anxue Li, Ru Jia, Mingjiao Chen, Zhijing Luo, Qiang Cai, Xiangxiang Zhao, Dabing Zhang & Zheng Yuan. (2015). Interactions of OsMADS1 with Floral Homeotic Genes in Rice Flower Development. Molecular Plant. 8(9):1366-84.
Reporter: Chen Chengcheng
Long term appointment of associate professor
School of agriculture and biology, Shanghai Jiaotong University
Email: cgchen@msu.edu
Report title: mechanisms and spatial regulation of chloroplast division
Report time: 11:00 am, November 11, 2019
Address: Shuhua multi function hall, College of life science and technology
Associate: Zhang Dabing
Background:
Chloroplast is the site of photosynthesis in plants. In the process of plant growth and development, the number of chloroplasts needs to be increased to meet the growing material and energy needs of plants, and ensure that the daughter cells formed by cell division can inherit the same number of chloroplasts. The increase of chloroplast number is mainly realized by chloroplast division, which is carried out by the division device located in the center of chloroplast in the way of binary division. The apparatus consists of FtsZ ring, endoplast division ring, drp5 ring and exoplast division ring on the cytoplasm side of the outer membrane. The division of chloroplast starts from the aggregation and assembly of FtsZ ring at the division site. For a long time, the regulatory mechanism of how chloroplast division apparatus accurately locates in chloroplast division site and keeps dynamic change is not very clear. We found that the chloroplast cleavage protein arc3 can inhibit the polymerization of FtsZ loop at the non cleavage site, so that the loop and the whole cleavage apparatus can only assemble at the cleavage site. In addition, some arc3 were recruited to the division sites to increase the dynamic change ability of the division apparatus, which may promote the division of chloroplast. This study reveals the molecular regulation mechanism of chloroplast division localization, and has important implications for elucidating the regulation mechanism of cell division (mainly mediated by FtsZ protein) in prokaryotes.
Reporter information:
Chen Cheng, Ph.D., head of School of agriculture and biology, Shanghai Jiaotong University, is an associate professor and project leader (PI). In 2012, he graduated from the State Key Laboratory of plant physiology and biochemistry of China Agricultural University with Professor Yuan Ming as his supervisor. During his doctoral study, he went to the laboratory of Professor William J. Lucas of the University of California, Davis for joint training. From April 2014 to October 2019, I worked as a postdoctoral researcher in the laboratory of Professor Katherine w. osteryong of Michigan State University, USA. my main research direction is the molecular mechanism of plant chloroplast organelle division regulation. In the end of October 2019, he will return to China to set up the laboratory, and will focus on the following research areas in the future: 1) molecular mechanism of chloroplast division. Arabidopsis thaliana and green algae will be taken as the research objects to reveal the regulation mechanism of chloroplast division device assembly, localization and dynamic changes. 2) The molecular control mechanism of the coordination between organelle and cell division. Chloroplast organelles will be taken as the research object to explore the molecular mechanism of how plants coordinate cell division and organelle division. 3) Objective to study the regulation mechanism of the occurrence, division and differentiation of non green plastids such as amyloplasts. Amyloplast is one of the non green plastids, which is mainly responsible for the long-term storage of starch in cells. Amyloplasts are mainly found in roots, endosperm (such as rice, wheat and corn), tubers (such as potato) and tuberous roots (such as sweet potato and cassava). Research on non green plastids such as amyloplasts is not only of great scientific significance, but also of great agricultural and economic value.
Representative papers in recent five years:
Published papers (* corresponding authors)
1. Chen, C.*, Cao, L., Yang, Y., Porter, K. and Osteryoung, K.W.* (2019). ARC3 Activation by PARC6 Promotes FtsZ-Ring Remodeling at the Chloroplast Division Site. The Plant Cell 31: 862–885.
2. Chen, C., MacCready, J.S., Ducat, D.C. and Osteryoung, K.W.* (2018). The Molecular Machinery of Chloroplast Division. Plant Physiology 176(1), 138–151.
3. Zhang, M. #, Chen, C. #, Froehlich, J.E., terbush, A.D. and Osteryoung, K.W. (2016). Roles of Arabidopsis parc6 in coordination of the chloroplast division complex and negative regulation of FtsZ assembly. Plant physics 170 (1), 250 – 262
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