Sibdas Ghosh, Ph.D.

Professor & Department Chair

Email: sghosh@dominican.edu

Office: Science Center # 228

Phone: (415) 482-3583

Fax:  (415) 482-1972

Academic Area

Biology

Educational Backgound

• B.Sc. Botany, 1974, City College, University of Calcutta, Calcutta, India.
• B.Sc. Plant Physiology & Biochemistry, 1978, University of Lancaster, Lancaster, UK.
  
• M.Sc. Crop Physiology, 1979, University of Reading, Reading, UK.
• Ph.D. Molecular Biology, 1989, University of Waterloo, Waterloo, Ontario, Canada.
• Postdoctoral Fellow, 1989-1990, Los Alamos National Laboratory & Plant Genetic Engineering Laboratory, Los Alamos,NM
  

Teaching and Research Interests

Research In Progress

• Soil Bacteria Promoting Plant Growth     
• Paclobutrazol: A Growth Retardant
• Cadmium Toxicity in Plants
• Sudden Oak Death
• Fish Parasites
• Weed Free Feed/Horse Manure
• Biodiversity of Bees in National Parks

Research Interests

• Effects of Environmental Stress on Gene Expression and on the Dynamics of Protein Synthesis in the Photosynthetic Apparatus,
  
• Molecular Aspects of Membrane Turnover,
• Plant-Microbial Interactions
  
• Methods of Development in Bioanalytical and Separations Chemistry.  

Current research focuses on four projects:

• Project I  PLANT ADAPTATION:  Adaptation of plants to environmental stresses including high light, high temperatures and drought
• Project II MEMBRANE BIOCHEMISTRY:  Structural and functional integrity of membranes during senescence and stress, and increase crop
  
• Project III INOCULATION TECHNOLOGY:  Increase crop production by developing efficacious yet environmentally non-detrimental fertilizers/fungicides
  
• Project IV STUDY OF SUDDEN OAK DEATH (Supported by The Conserving California Landscapes Initiative, Resource Legacy Fund = $60,000):  Developing protection of oak trees effected by fungal pathogen Phytopthora ramorum

Project I:

The immediate research effort entails a comprehensive analysis of the regulation of antioxidative enzymes at the transcriptional, translational and posttranslational levels in chloroplasts during environmental stress and senescence.  The above mentioned corn-sorghum-soybean-peanut model system will be used to examine the regulation of the reactive oxygen species scavenging system in chloroplasts in relation to tolerance of the plant to oxidative stress.  In particular, superoxide dismutase and ascorbate peroxidase will be used as marker enzymes.  The antibodies directed against these enzymes and cDNA probes are available for me to investigate the developmental and/or stress regulation of ascorbate peroxidase at both in vivo and in vitro levels.

Project II:

This project characterizes the mechanisms by which membranes lose structural and functional integrity under adverse environmental conditions.  The fate of thylakoid lipid and protein catabolites once they are formed within the bilayer is largely  unknown.  Recently, lipid-protein particles that are enriched in lipid and protein catabolites have been isolated from the cytosol of plant tissue.  Lipid-protein particles with essentially similar properties can also be formed in vitro from isolated membranes under conditions in which phospholipid catabolism is activated.  It has been proposed that these particles are formed by blebbing from membranes and may serve as a vehicle for removing destabilizing catabolites from membrane bilayers.  We are currently characterizing lipid-protein particles from the stroma of intact chloroplasts that have properties consistent with their prospective involvement in the removal of destabilizing catabolites from thylakoids.

Project III:

Microorganisms are precious resources for mankind.  Recent studies have shown that some of them can be used as microbial fertilizers or as biocontrol agents for fungal diseases or as both fertilizers and biocontrol agents.  Farmers currently have the choice between natural fertilizers (non-polluters) or synthetic organic fertilizers (expensive and polluters).  They also have a choice between biocontrol agents (non-polluters) and chemical control measures, for example organic arsenic fungicides (expensive and polluters).  However, the detailed information on how these choices could be explored, not only to save money but also to practice agriculture in a manner friendly to our environment, must be researched and developed. The goals of the proposed research are to isolate plant growth promoting soil bacteria native to Wisconsin and then answer the following questions:  1.  How do the growth promoting bacteria isolated from soil samples from several locations in Wisconsin improve growth and development of economically important crops?  2.  Is the early establishment of seedling growth in the presence of soil bacteria sufficient to overcome environmental stresses?  Finally, this work will evaluate the potential to develop bacterial-inocula (natural fertilizers) for field and commercial applications.

The proposed study has four phases:  (i) to isolate plant growth-promoting soil bacteria from different locations in Wisconsin, (ii) to investigate their ability to promote growth of crop plants important to Wisconsin (corn, alfalfa), (iii) to determine their antibiosis ability against a broad spectrum of fungi, and (iv) to evaluate the potential to develop bacterial inocula (natural fertilizer) for field and commercial applications to replace organic fertilizer (artificial) which has potentially negative environmental effects.  At present, three students are working on these projects.  We already have isolated five strains of bacteria.

Interestingly, we have also found that these bacteria contain an enzyme 1-aminoacyclopropane-1-carboxylic acid (ACC) deaminase activity.  The enzyme ACC deaminase may be responsible, to some extent, for the ability of the bacterium to promote plant growth.  Following the binding of these bacteria to the plant seed coat the bacterial ACC deaminase may bind and hydrolyze ACC from the germinating seed.  Consequently, this would lower the level of ACC and also the level of ethylene (a plant hormone that inhibits plant growth and causes ageing) because ACC is the immediate precursor of ethylene in plants.  Plants treated with mutant bacterial strains which lack ACC deaminase enzyme, as predicted, produce high levels of ethylene and show slower growth than those plants treated with normal plant growth promoting soil bacteria strains.

Project IV:

Sudden Oak Death was discovered in Marin County six years ago, and speculatively triggered by a non-native fungus, sudden oak death is jeopardizing 11 million acres of woodland from Southern California to Oregon.  The disease has been confirmed in trees from Big Sur to northern Sonoma County and as far inland as the Sonoma-Napa border.  Marin and Santa Cruz counties have been the hardest hit. 

A report commissioned by the California Oak Mortality Task Force (January 2001), and focused on study sites in China Camp State Park and the Marin Municipal Water District (MMWD) land, reveals high levels of SOD infection and mortality.  For China Camp State Park, 35.4% of the 293 coast live oaks in the ten study sites exhibited SOD in March 2000, increasing to 38.6% in March 2001.  The mortality level due to the disease was 7.8% in March 2000, compared to 14.7% in March 2001, representing the death of 17 trees within a year. 

In MMWD, infection levels for coast live oak were 16.3% and 18.9% in 2000 and 2001, respectively; mortality increased from 5.6% to 8.4%.  Studies of black oak at these sites reveal 21% infection and 16% mortality; for tan oaks in MMWD the crisis is even bleaker with 55% infection and 15% mortality. 

So grave is the crisis that the federal government earmarked $3.5 million last year and $3.2 million this year to stop the spreading of the disease in California.  The California Oak Mortality Task Force, established in 2000, has a two-year $10 million budget for research, monitoring and management, firefighting (the dead and dying trees create an extreme fire hazard), and education efforts.

Investigators and Locations: Dr. Sibdas Ghosh, (Ph.D. in Molecular Plant Physiology & Biochemistry, University of Waterloo, Ontario, Canada), Chair of the Department of Natural Sciences and Mathematics is the lead investigator of the Sudden Oak Death Project at the Dominican University of California.  This project is being carried out on the Dominican campus located in San Rafael (Marin County) with the support from The Resources Legacy Fund. Dr. Anusree Ganguly (Ph.D. in Chemistry, Southern Illinois University at Carbondale, Illinois), Assistant Professor of Chemistry, and Dr. James Namnath (Ph.D. in Chemistry, University of Southern California University, Los Angeles, California), Lecturer of Environmental Studies at the Dominican University of California, are in the co-principal investigators of this project.  This report includes sudden oak death studies conducted over the past 12 months at the Dominican University of California, by both faculty and students.     

Current Research:

A. To develop a sudden oak death laboratory by acquiring infrastructure necessary to conduct experiments in gaining knowledge to control the pathogen, Phytopthora ramorum;

B. To synthesize and screen antifungal chemicals to control the pathogen responsible for the sudden oak death;

C. To survey oak trees on campus and screening for resistant species of costal live oaks.

A. Sudden Oak Death Laboratory.

While we are waiting for the new science center to be built, we have dedicated a laboratory of 200 ASF for training undergraduate research scholars and conducting all experiments related to the study of sudden oak death.  We have purchased key equipment such as an autoclave, growth chambers, an incubator and a photosynthesis measurement unit with the help of the Conserving California Landscapes Initiative (CCLI) grant to DUC.  This laboratory is complete and now we conduct all our sudden oak death related experiments in the laboratory, which is located in Guzman Hall. 

B. Synthesis and Screening of Antifungal Chemicals:

Synthesis and anti fungal testing of boron compounds are being conducted by the co-pi Dr. Anusree Ganguly in collaboration with the Pi, Dr. Sibdas Ghosh. It is well known that the boron moiety present in heterocyclic boron systems maybe responsible for imparting anti-fungal activity to these compounds.   In addition to 5-chloro-2-nitrophenylboric acid, Dr. Ganguly has successfully completed the synthesis of two other putative anti fungal compounds.  We completed the investigation of these putative antifungal chemicals on the coastal live oak seedlings and have found that these chemicals do not affect seedlings.  We have planned to investigate the effects of these putative fungicides on the causal agent of the sudden oak death, Phytopthora ramorum.  We are waiting to receive the regulatory permit from the state and the federal government to culture the fungus, Phytopthora ramorum.  The antifungal activity will comprise of in vitro testing utilizing Phytophthora ramorum with dose levels (ug per plate) of 0, 0.005, 0.05, 0.5, 5, 50, 500, 1250, 2500, 5000).  It is expected (based on previous preliminary data) that we will see a very strong dose response between 1250-5000 ug per plate concentration for antifungal signal.

C.  Surveying and Screening:

This project is conducted by the co-P.I. Dr. James Namnath in collaboration with the P.I., Dr. Sibdas Ghosh.  We surveyed the 80 acres owned by the Dominican University of California.  We found very few tan oaks (Lithocarpus densiflorus) and a large variety of live oaks (Quercus agrifolia), most of which are the native species.  We observed several apparent incidents of sudden oak death syndrome which were later found not to be due to the putative Phytopthora ramorum, a causal fungal agent of the disease.  The Plant Diagnostics Center, California Department of Food and Agriculture, Sacramento conducted the tests.  We are now collecting acorn from individual marked coastal live oak trees which will be cultivated and monitored for their resistance to the sudden oak death disease (caused by the fungus, Phytopthora ramorum).  Although it is a long-term project to select the disease resistance species, once we find resistant trees, we will collect the germplasm.  This will allow us not only to collect resistant breeding stocks for reforesting as well as to study the underlying disease resistance mechanisms at the molecular and physiological levels.

Drs. Mietek Kolipinski, Sibdas Ghosh, Lauren Quinn, Jim Cunningham:

Project V:

Survey of freshwater fish parasites from Marin County and nearby National Parks, including Point Reyes National Seashore and Golden Gate National Recreation Area.  We are particularly interested in determining what kinds of roundworms and tapeworms parasitize local fishes. Preliminary results indicate that three types of helminth (roundworm) parasites occur in mosquitofish.These helminth parasites have a complex life history, part of which is spent in amhibians and birds, such as herons. This project is leading to new scientific information and scientific discoveries (Mietek Kolipinski, Sibdas Ghosh, Jim Cunningham).

Project VI:

Study to determine the role of horses in spreading non-native plants into natural areas. A de novo sample collection protocol was developed and implemented at DU of C. At the DU of C plant nursery a plant growing enclosure was constructed for conducting the study of plant growth from horse manure.  Students have collected preliminary horse manure samples from the greater San Francisco Bay Area.  The purpose of this study is to determine if non-native plant seeds can viably pass through the digestive system of horses and then germinate and grow to seeding.  In an initial investigation, some plants successfully passed through, sprouted, grew, and produced new seeds at the Dominican University of California nursery. Project participants will build on preliminary results. They will collect and study samples from national parks in north and south California  (Mietek Kolipinski, Sibdas Ghosh, Lauren Quinn).

Project VII:

This project centers on bees, which are an essential component of biodiversity. They have a role as primary pollinators of non-wind pollinated  plants. The richness of the bee community can be directly affected by the conditions of the surrounding environment. Bees often specialize on specific plants or plant communities and are limited by the presence of appropriate plants as food resources in the form of pollen and nectar, the presence of nesting habitat and, in some groups, nest building materials. You will join two other students and field scientists to study the biodiversity of bees from nearby national parks. Opportunity exists to work with bee specialists at Yosemite National Park, in late spring or summer 2006 and to collect and study bees here on campus. (Mietek Kolipinski, Sibdas Ghosh).

Professional Organizations

• Council on Undergraduate Research
  
• National Collegiate Honors Council
• Advisory Council for the Wisconsin Space Grant Consortium
• American Society of Plant Physiologists
  
• International Society of Plant Molecular Biologists
• International Society of Photosynthesis Research
• Plant Growth Regulation Society
• Plant Growth Regulation Society of America

Selected Publications

• Tesar G, S Ghosh, SW Anderson, T Bramorski 2004  (Edited Book) Strategic Technology Management: Building Bridges Between Sciences, Engineering and Business Management, Imperial College Press & World Scientific.
• Ghosh S, JN Penterman, E Madey, LM Baird, JM Frederick, DJ Cummings, F Hall-Glenn, A De Giacomo, S Volk, EB Dumbroff 2003 Paclobutrazol: Its physiological effects and biochemical functions during plant stress.  Physiol Mol Biol Plants 9: 163-173.
• Ghosh S, JN Penterman, RD Little**, R Chavez**, BR Glick 2003 Three newly isolated plant growth-promoting bacilli facilitate the seedling growth of canola, Brassica campestris,  Plant Physiol Biochem 41: 277-281.
• Matthew SD, S Ghosh 2002 Lipid Bodies of Plastids.  Reviews Plant Biochemistry and Biotechnology 1:209-216.
• Ghosh S, S Mahoney**, JN Penterman**, D Peirson,  EB Dumbroff 2001 Ultrastructural and biochemical changes in chloroplasts of Brassica Napus cotyledons during development and senescence. Plant Physiol Biochem 39: 1-8.

Presentations

• Vianney J-M, K Hassler, S Thorng, I McFadden, B Davis, S Ghosh, and M Kolipinski 2005 Role of Large Herbivores in Spreading Non-native Invasive Plants into Natural Areas. Cal-IPC Symposium, California State University, Chico, California.
• Alas M, A Martinez, D Williams, I McFadden, B Davis, M Kolipinski, and S Ghosh 2005 Resource Kit for Management of Non-native Plants in National Parks.  Cal-IPC Symposium, California State University, Chico, California.
• Geltz E, J McHugh, L Baird, S Ghosh, P Thut, and M Kolipinski 2005 Examination of Phytophthora ramorum infection in Camellia. Second Science Symposium: Sudden Oak Death, Monterey, Calfornia.
• Thut P, R Chavez, D Williams, L Baird, M Kolipinski, B Babzik, S Ghosh 2005 SOD Bike Tire Scrubber. Second Science Symposium: Sudden Oak Death, Monterey, California.   
  
• Williams D, L Kawabata, A McClellan, S Ghosh and V Coelho 2005 Photosynthetic pigments in Halimeda tuna and Dictyota sp. collected from various depths in Little Cayman, Cayman Islands. 19th National Conference on Undergraduate Research, Washington and Lee University & Virginia Military Institute, Lexington, Virginia, USA.

Other Interests

International & National Travel, Photography, Soccer, Track, Classical Indian Music

For a full listing of publications and presentations