Grant Information
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|---|---|---|
| 212 - Pathogens and Nematodes Affecting Plants | 1820 - Soybean | 1040 - Molecular biology | 40% |
| 212 - Pathogens and Nematodes Affecting Plants | 1820 - Soybean | 1100 - Bacteriology | 40% |
| 212 - Pathogens and Nematodes Affecting Plants | 999 - Citrus, general/other | 1100 - Bacteriology | 10% |
| 212 - Pathogens and Nematodes Affecting Plants | 999 - Citrus, general/other | 1160 - Pathology | 10% |
Bacterial blight is a common soybean disease significantly threatening the soybean industry worldwide. The bacterial pathogen that causes this disease injects virulence proteins, called effectors, directly into the soybean cells to subvert plant immunity and promote bacterial infection. Although plants have evolved resistant (R) genes to recognize effectors, rapid evolution of these effectors has allowed the pathogens to successful defeat the R-mediated plant defense. This has resulted in the "boom-and-bust" phenomenon of using crop varieties carrying R genes in agricultural practice. Therefore, it is extremely important to understand the dynamic arms race between pathogen effectors and plant defense mechanisms in order to design novel disease intervention methods in a sustainable manner. This project is designed to address this important, yet largely uncharacterized problem. One of the key effectors produced by the causal agent of soybean bacterial blight is called HopZ1. We have identified two forms of HopZ1: HopZ1a can be recognized by a soybean R gene and triggers defense response; HopZ1b was evolved from a HopZ1a-like ancestor but can evade soybean recognition. Therefore, these HopZ1 variants serve as an excellent model system to understand pathogen effector evolution during the arms race with soybean. In this project, we will investigate how HopZ1 facilitates bacterial infection by attacking specific soybean proteins and how HopZ1b, co-evolved with soybean defense system, avoid recognition. A combination of genetics, genomics, biochemistry and cell biology approaches, especially the cutting edge genome-scale analysis including next generation DNA sequencing, will be employed to answer these questions. Findings from this research will significantly benefit the soybean industry by providing guidance and insights into the development of novel management strategies for bacterial blight. Since effector proteins are essential virulence factors of a large variety of parasites including bacteria, fungi, oomycetes, insects and nematodes, this knowledge will also advance our general understanding on the pathogenesis of other endemic and invasive pathogens infecting various economically important crops.
The goal of my research program is to understand the pathogenesis of microbial pathogens in economically important crops. I am particularly interested in the effector proteins which are essential virulence factors delivered from the pathogens into the plant hosts. While it is well accepted that effectors exert essential virulence functions by subverting host immunity, the molecular mechanisms underlying the arms race between effectors and plant defense system remain largely unknown. Using the natural Pseudomonas syringae pv. glycinea (Pgy) - soybean pathosystem, my research has been focusing on understanding the function and evolution of the type III secreted effector HopZ1. In this project, we will characterize the interaction between HopZ1 and two direct targets of HopZ1 in soybean. Objectives:
Expected Outputs: Bacterial blight caused by Pseudomonas syringae is one of the most common diseases of soybean and a major threat to the soybean oil industry. This project will directly benefit the industry by providing guidance and insights into the development of sustainable management strategies against this significant disease of an important crop and biofuel feedstock. This project also has broad impact on general understanding of microbial pathogenesis. Effectors are essential virulence factors produced by a large variety of parasites including bacteria, fungi, oomycetes, insects and nematodes. Therefore, knowledge obtained from this research will provide important implications on the pathogenesis of other endemic and invasive pathogens infecting economically important crops. For example, the PI has established collaboration with Dr. Georgios Vidalakis and the Citrus Research Board to study the function of effectors in the severe citrus bacterial diseases including Huanglongbing and citrus stubborn disease. From the perspective of education, this multidisciplinary program serves as an excellent training ground for postdoc, graduate and undergraduate students. The PI will incorporate the proposed research and findings into her teaching activities, which will enhance the learning outcomes and promote students' interests into scientific research. New findings will be disseminated through conference proceedings, journal articles, seminar presentations and other outreach activities of the PI.
This project is a multidisciplinary program employing a combination of genetics, genomics, biochemistry and cell biology approaches. In addition to the traditional molecular genetic and cloning techniques, cutting edge genome-scale analysis including next generation Illumina sequencing will be used to analyze transcriptome profiles and identify DNA sequences binding to specific transcription regulating proteins. Collaborations with biostatisticians will facilitate data analysis. The PI also has established collaborations with experts in relevant fields, such as Dr. Xuemei Chen (chromatin-mediated gene regulation) and Dr. Yinsheng Wang (posttranslational modification of proteins), whose expertise will ensure the successful execution of this project. The impact of this project can be evaluated by publications in high-impact journals, invited presentations by the PI and other participants of this project, and successful acquisition of extramural research funding.
Target Audience
Effectors are essential virulence factors produced by a large variety of parasites including bacteria, fungi, oomycetes, insects and nematodes. My group has been focusing our research on understanding the virulence functions of bacterial and oomycete effetors. Knowledge obtained from this research will provide broad implications on microbial pathogenesis, especially the mechanisms by which endemic and invasive pathogens infecting economically important crops, such as soybean, tomato, potatoand citrus. During this final reporting period of the project, results from our researchhave been disminated through conference presentations, research seminars, and classroom lectures given by the PI Wenbo Ma and the graduate student and postdoc working in her laboratory. Wenbo Ma teaches a large upper-level undergraduate course (Introductory Microbiology, 240 students) and two core graduate courses (Bacterial Diseases of Plants, and Microbial Genetics) every year at UCR.
Changes / Problems
Nothing Reported
Training & Professional Development
Funds from this project helped support the training and research activities of several Ph.D students andpostdoc researchers as well as two undergraduate assistance Thomas Forest and Francisco Hernandez. Through this project, the students/postdocs gained excellent training not only in molecular biology, cell biology, plant pathology, but also biochemistry and biophysics. They get the opportunities to work with real world problems and interact with stakeholders such as citrus growers. This project also supports the classroom teaching activities of the PI Wenbo Ma including both graduate and undergraduate courses.
Dissemination Streams
The knowledge obtained from this project has been published in research and commentarypapers in a highly regarded scientific journal, including Nature, Nature Plants, and Frontier in Microbiology. The results have also been disseminated through numerous presentations given by the PI Wenbo Ma and her collaborators in local, national and international scientific conferences. There are frequent communications between the research lab/lab members and citrus commodity on research related to citrus Huanglongbing.
Next Reporting Steps
Nothing Reported