Progress 10/01/06 to 09/30/11
Outputs
OUTPUTS: In the first year, this project generated three outputs in the form of a new technique, meeting abstracts, and presentations at professional conferences. A new technique to culture soybean rust fungus in the laboratory using detached soybean leaves was developed. We published four abstracts from the 2006 National Soybean Rust Symposium and the 2007 annual American Phytopathological Society meeting. The research results have also been presented to members of the State Soybean and Small Grain Promotion Board, and shared with scientific communities at the 2007 National Soybean Rust Symposium. This project generated three outputs in the second year in the form of research papers and meeting abstracts, presentations at professional conferences, and the identification of plant introduction soybean lines that are resistant to Louisiana Asian soybean rust isolate. We published one paper in Plant Disease, two abstracts from the 2008 annual American Phytopathological Society meeting and one from the 13th International Biotechnology Symposium. In the third year, this project generated three outputs in the form of meeting proceeding/abstracts, presentations at national and international meetings, and the identification and characterization of genes differentially expressed during rust infection. We published one paper in 2009 World Soybean Research Conference Meeting Proceedings and three abstracts from the 2009 annual American Phytopathological Society meeting and APS Southern Division Meeting. This project generated three outputs in the fourth year. These include identifying two soybean lines that showed high levels of resistance to soybean rust spores from Louisiana, meeting abstracts, one invited symposium talk and a poster presentation at national meetings, and the identification and characterization of genes differentially expressed during rust infection. We published three abstracts from the annual American Phytopathological Society meeting and submitted one manuscript in 2010. In the last year, this project generated three outputs in the form of two additional recombinant inbred sister lines that showed high levels of resistance to soybean rust spores from Louisiana, meeting abstracts, oral and poster presentations at regional and national meetings, and the identification of several soybean lines that showed high levels of tolerance to Cercospora leaf blight disease in field evaluations. We published two abstracts at the annual APS meeting. PARTICIPANTS: Zhi-Yuan Chen, PI; Sunjung Park, Ashok Chanda, Josielle Rezende and Mala Ganiger, graduate students; Nicole Hazard and Yenjit Raruang, research associates; Poom Preedakoon, Wanida Seehachai, Allessandro Fortunato, intern students; Collaborators: Dr. Raymond Schneider, Dept of Plant Pathology and Crop Physiology, LSU AgCenter; Dr. Boyd Padgett, Macon Ridge Research Station, LSU AgCenter; Dr. Blair Buckley, Red River Research Station, LSU AgCenter; Dr. David Walker, soybean breeder, USDA-ARS, IL. TARGET AUDIENCES: other researchers, crop consultants, and soybean producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In the past five years, we have made the following impacts: 1) We developed a detached leaf assay that enabled us to study the fungus, its interaction with host, and its virulence on different soybean accessions under laboratory conditions all year round. This has led to a significant increase in our research progress on this disease. 2) We found that soybean rust spores could survive the typical Louisiana winter conditions and initiate a new cycle of infection in the next growing season, suggesting that soybean rust disease will persist in Louisiana. 3) Over 20 proteins induced or suppressed in soybean leaves during rust infection have also been identified through proteomics. Some of the up-regulated proteins appeared to be involved in host defense (such as the PR10 protein and chalcone isomerase [CHI]) or in response to stress (such as ascorbate peroxidase). Determining the functions of these differentially expressed proteins will shed light on how rust infects soybean and how the host responds to rust infection, which can provide new control measures for our soybean growers; 4) The induction of some of the proteins can be detected as early as 10 hr after rust infection, indicating their importance in soybean defense against rust infection. Up-regulating the expression of such proteins at an earlier time or a higher level through genetic engineering may provide a new solution to control soybean rust disease. A manuscript summarizing this accomplishment is being prepared. 5) We screened 18 soybean lines against Louisiana Asian soybean rust spores. Two of the lines showed high levels of resistance. Identification of rust resistant soybean lines will accelerate the development of rust resistant commericial soybean lines to combat soybean rust disease; 6) Preliminarily real time PCR analysis showed high induction of the PR10 and CHI transcripts at early stages of fungal infection, indicating their potential involvement in host resistance. A manuscript summarizing this accomplishment has been submitted to a journal; 7) We are comparing protein profile differences between rust resistant and susceptible soybean lines. Our data showed that susceptible soybean lines can induce most of the upregulated genes seen in resistant lines, but at a slower pace, indicating the time of expression in critical in determine whether a pathogen can establish in a host; 8) We have developed molecular probes that can specifically recognize C. kikuchii through collaboration with Dr. Ray Schneider. This technique allowed us to detect C. kikuchii infection long before the disease symptoms appear; and 9) We are comparing protein profile differences of C. kikuchii to identify proteins differentially expressed under light. These genes have the potential to be involved in the biosynthesis of cercosporin toxin. Knocking out/down the production of cercosporin toxin can significantly reduce the disease severity and the crop loss associated with the disease.
Publications
- Ganiger, M. C., Walker, D. R., and Chen, Z. -Y. 2011. Differences in responses and protein profiles of soybean near isogenic lines (NILs) to Phakopsora pachyrhizi inoculation. Phytopathology 101:S58.
- Chanda, A. K., Chen, Z. -Y., and Schneider, R. W. 2011. Functional characterization of two genes involved in cercosporin biosynthesis in Cercospora kikuchii. Phytopathology 101:S30.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: This project generated three outputs in the form of identifying two soybean lines that showed high levels of resistance to soybean rust spores from Louisiana, meeting abstracts, one invited symposium talk and a poster presentation at national meetings, and the identification and characterization of genes differentially expressed during rust infection. We have published three abstracts at the annual American Phytopathological Society meeting in 2010. PARTICIPANTS: Zhi-Yuan Chen, PI; Sunjung Park, graduate student (Ph. D); Ashok Chanda, graduate student (Ph. D); Josielle Rezende, visiting scholar, and Yenjit Raruang, research associate. Organization: Department of Plant Pathology and Crop Physiology. TARGET AUDIENCES: Soybean breeders, growers, researchers and crop consultants in the area of soybean production. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
1) We started testing the closely-related soybean lines that were provided by USDA soybean breeder, Dr. David Walker, for their difference in soybean rust resistance, and have identified at least two of the soybean lines with high levels of resistance to rust infection compared with their closely-related counterpart lines. These lines provided us with ideal material for understanding soybean rust disease resistance mechanism and for developing new soybean lines with enhanced resistance to rust disease and other fungal diseases. 2) We have continued our characterization of the two previously identified rust infection-induced soybean proteins: the pathogenesis-related protein 10 (PR10) protein and chalcone isomerase [CHI]). These proteins were induced and identified using proteomics as early as 10 hr after rust inoculation, indicating their importance in soybean defense against rust infection. Real time PCR analysis also showed high induction of corresponding transcripts at early stages of rust infection. Up-regulating the expression of such proteins at an earlier time or at a higher level through genetic engineering may provide a new solution to the control of this disease. A virus induced gene silencing approached has been adopted to further verify the importance of these genes in conferring soybean rust disease resistance. A manuscript summarizing this accomplishment has been submitted to a journal. 3) We have compared protein profile differences of Cercospora kikuchii, the casual agent of cercospora leaf blight disease (the #1 disease of soybean in southern US) and purple seed stain in soybean, and identified several proteins that were specifically upregulated when the fungal culture was grown under light conditions as compared with dark conditions. Three genes with the potential of encoding key enzymes involved in the biosynthesis of cercosporin toxin have been cloned and their role in the toxin biosynthesis is being investigated through insertional mutagenesis. Knocking out/down the production of cercosporin toxin can significantly reduce the disease severity and the crop loss associated with the disease.
Publications
- Park, S., Chen, Z.-Y., Ganiger, M. C., and Fortunato, A. A. 2010. Protein profile differences between soybean accessions resistant and susceptible to soybean rust (Phakopsora pachyrhizi). Phytopathology 100:S96.
- Chen, Z. -Y., Park, S., and Zhang, C. 2010. Proteomics in identifying potential markers for developing broad spectrum resistance. Phytopathology 100:S164.
- Chanda, A. K., Chen, Z. -Y., and Schneider, R. W. 2010. Possible functions of light-induced proteins in cercosporin biosynthesis by Cercospora kikuchii. Phytopathology 100:S22.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: This project generated three outputs in the form of meeting proceeding/abstracts, presentations at national and international meetings, and the identification and characterization of genes differentially expressed during rust infection. We have successfully published one paper in 2009 World Soybean Research Conference Meeting Proceedings and three abstracts at the 2009 annual American Phytopathological Society meeting and APS Southern Division Meeting. PARTICIPANTS: Zhi-Yuan Chen, PI; Sunjung Park, graduate student; Ashok Chanda, graduate student; Mala Ganiger, graduate student, Yenjit Rarung, research associate. TARGET AUDIENCES: other researchers, crop consultants, and soybean producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
1) We have preliminarily characterized two previously identified rust infection-induced soybean proteins: the pathogenesis-related protein 10 (PR10) protein and chalcone isomerase [CHI]). These proteins were induced as early as 10 hr after rust inoculation using proteomics, indicating their importance in soybean defense against rust infection. Real time PCR analysis also showed high induction of corresponding transcripts at early stages of rust infection. Up-regulating the expression of such proteins at an earlier time or at a higher level through genetic engineering may provide a new solution to the control of this disease. A manuscript summarizing this accomplishment has been submitted to a journal. 2) We have compared protein profile differences between rust resistant and susceptible soybean lines. Our data showed that susceptible soybean lines can induce most of the upregulated genes seen in resistant lines, but at a slower pace, indicating the time of expression in critical in determine whether a pathogen can establish in a host. 3) We have developed molecular probes to detect Cercospora leaf blight pathogen of soybean. DNA probes that can specifically recognize Cercospora kikuchii (the causal agent for Cercospora leaf blight), but not its close relatives such as Cercospora sojina, has been developed through collaboration with Dr. Ray Schneider. This technique allowed us to detect C. kikuchii infection before the disease symptoms appear.
Publications
- Park, S., and Chen, Z. -Y. 2009. Investigating soybean-Phakopsora pachyrhizi interactions using proteomics. The 2009 World Soybean Research Conference VIII meeting proceedings, August 14, 2009 (Beijing, China).
- Chanda, A. K., Chen, Z. -Y., and Schneider, R. W. 2009. Comparison of protein profiles between light- and dark-grown Cercospora kikuchii. Phytopathology 99:S20.
- Park, S., Ganiger, M. C., Fortunato, A. A., and Chen, Z. -Y. 2009. Proteomic analysis of soybean accessions resistant and susceptible to soybean rust (Phakopsora pachyrhizi), APS Soybean Rust Symposium Abstract.
- Park, S., Xie, Y.-R., Raruang, Y., and Chen, Z. -Y. 2009. Proteomic analysis of soybean accessions resistant and susceptible to Phakopsora pachyrhizi urediniospores from Louisiana. Phytopathology 99:S99.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: This project generated three outputs in the form of research papers and meeting abstracts, presentations at professional conferences, and the identification of plant introduction soybean lines that are resistant to Louisiana asian soybean rust isolate. We have successfully published one paper in Plant Disease, two abstracts at the 2008 annual American Phytopathological Society meeting and one at the 13th International Biotechnology Symposium. PARTICIPANTS: Zhi-Yuan Chen, PI; Sunjung Park, graduate student; Ashok Chanda, graduate student; Nicole Hazard, research associate. TARGET AUDIENCES: other researchers, crop consultants, and soybean producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
1) We determined that asian soybean rust spores could survive in Southern Louisiana winter conditions based on our simulated laboratory studies and verified from collected overwintered infected kudzu samples. This study indicated that asian soybean rust will be a continuous threat to our soybean producers, reinforcing an earlier prediction based on computer models that asian soybean rust disease will come and stay. 2) We identified and sequenced over two dozen differentially expressed proteins (at least 2-fold) between control soybean leaves and leaves inoculated with rust spores. Some of the up-regulated proteins appeared to be involved in host defense (such as the PR10 protein and chalcone isomerase [CHI]) or in response to stress (such as ascorbate peroxidase). We have also found that induction of some of these proteins after asian soybean rust infection can be observed as early as 10 hr after inoculation using proteomics, indicating their importance in soybean defense against rust infection. Up-regulating the expression of such proteins at an earlier time or at a higher level through genetic engineering may provide a new solution to the control of this disease. A manuscript summarizing this accomplishment is being prepared. Determining the identities and functions of these differentially expressed proteins will shed light on how rust infects soybean and how the host responds to rust infection, which can provide new control measures for our soybean growers. 3) We have obtained 18 soybean lines showing levels of resistance to asian soybean rust in studies conducted by others from the US Soybean Germplasm collection. We have screened these lines twice, both in the greenhouse and using the detached soybean leaf assay against Louisiana asian soybean rust spores. Our data showed that two of the lines were the most resistant to this disease. Identification of rust resistant soybean lines will accelerate the development of rust resistant commericial soybean lines, which are lacking right now. This will provide our soybean producers with a more cost effective and enviromental friendly way over fungicide applications to control asian rust disease.
Publications
- Park, S., Chen, Z.-Y., Chanda, A. K., Schneider, R. W., and Hollier, C. 2008. Viability of Phakopsora pachyrhizi urediniospores under simulated southern Louisiana winter conditions. Plant Disease 92:1456-1462
- Chen, Z. -Y., Brown, R. L., and Cleveland, T. E. 2008. Identifying genes/proteins to enhance crop resistance to fungal pathogens through proteomics and RNAi gene silencing. J. Biotechnology 136S: S218.
- Park, S., Chen, Z. -Y., Chanda, A. K., and Hazard, N. 2008. Identification of pathogen-responsive proteins from soybean leaves during interaction of soybean and Phakopsora pachyrhizi using proteomics. Phytopathology 98: S120.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: This project generated three outputs in the form of new technique development, meeting abstracts, and presentations at professional conferences. I developed a new technique to culture soybean rust fungus in the laboratory using detached soybean leaves. We have successfully published four abstracts at the 2006 National Soybean Rust Symposium and the 2007 annual American Phytopathological Society meeting. The research results have also been presented to members of the State Soybean and Small Grain Promotion Board, and shared with scientific communities at the 2007 National Soybean Rust Symposium.
PARTICIPANTS: Zhi-Yuan Chen, PI; Sunjung Park, graduate student; Ashok Chanda, graduate student; Nicole Hazard, research associate. Organization: Department of Plant Pathology and Crop Physiology.
TARGET AUDIENCES: other researchers, crop consultants, and soybean producers
Impacts
1)The development of new technique to maintain soybean rust fungus using detached soybean leaves has enabled us to study the fungus, its interaction with host, and its virulence on different soybean accessions under laboratory and greenhouse conditions all year round. This has led to an significant increase in our research progress on this disease. 2) We found that the spore viability of Phakopsora pachyrhizi, the causal agent of soybean rust disease, varies depending on the temperature and the duration of exposure to the temperature. Treatment of rust spores under simulated LA winter conditions reduced not only spore viability, but also virulence. We also found that rust spores remained viable and produced new infection even after exposing to simulated LA winter conditions for as long as two months. This study indicates that soybean rust spores could survive the typical Louisiana winter conditions and initiate a new cycle of infection in the next growing season. This
reinforced earlier predictions based on computer models that soybean rust disease will come and will stay. 3) Over 20 proteins induced or suppressed in soybean leaves during rust infection have also been identified. Partial amino acid sequences have been obtained using LC-MS/MS. The induction of some of the proteins can be detected as early as 10 hr after rust infection, indicating their importance in soybean defense against rust infection. Up-regulating the expression of such proteins at an earlier time or a higher level through genetic engineering may provide a new solution to control soybean rust disease.
Publications
- Chen, Z.-Y., Park, S., Hazard, N., Mumma, E. P., and Schneider, R. W. 2006. Proteome anlysis of greenhouse-grown soybean plants inoculated with Phakopsora pachyrhizi. Page 6 in: Proceedings, 2006 National Soybean Rust Symposium, Nov. 29-Dec. 1, 2006. St. Louis, MO.
- Park, S., Hazard, N., Chanda, A. K., and Chen, Z.-Y. 2006. Viability of Phakopsora pachyrhizi urediniospores under simulated winter conditions. Page 7 in: Proceedings, 2006 National Soybean Rust Symposium, Nov. 29-Dec. 1, 2006. St. Louis, MO.
- Chanda, A. Chen, Z.-Y, and Schneider, R. W. 2007. Identification of cercosporin biosynthesis-related proteins through a proteomic approach. Phytopathology 97:S19.
- Park, S., Hazard, N., Chanda, A., and Chen, Z.-Y. 2007. Protein profile changes in soybean leaves upon Phakopsora pachyrhizi infection. Phytopathology 97:S90.
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