Subject: Controlling A. tumefaciens

From: "Peter L. Schuerman" <[email-masked]>
Date: Mon, 1 May 1995 13:51:31 -0700

Using Agrobacterium tumefaciens as a means of introducing DNA 
into plant cells necessitates actually infecting plant 
segments (explants) with the bacterium.  If the next step in 
the process involves culturing the explant, the residual bacteria
can be a serious problem, as they will grow unchecked in the 
plant growth medium.  This problem is dealt with by using 
antibiotics, but often this is not 100% effective, and the 
antibiotics may have undesirable effects on the plant tissue.
 
I'm writing an article on these problems.  As I understand it, 
these difficulties plague many researchers, yet they are often 
not discussed in journal publications.  I think it would be 
good, especially for those new to the field, to know more 
about these aspects of plant transformation.  I am told that 
these difficulties are especially salient with regard to woody 
plants, or plants which are otherwise difficult to culture.
 
If you have had problems controlling the growth of A. 
tumefaciens in a plant transformation experiment, or have had 
undesirable effects on your plant material due to antibiotics, 
please contact me.  I would appreciate discussing this, and, 
if you are interested, perhaps interviewing you for the article.
 
                  `.`.    //   
         . - ~ ~-.__`.`-.//     Peter L. Schuerman
     .-~   . - ~  }~ ~ ~-.~-.        Crown Gall Group / Pomology
   .' .-~      .-~       :/~-.~-./:       University of California
  /_~_ _ . - ~                 ~-.~-._
                                   ~-.~._    _   
                           . - ~ ~-. __`.`-./ ~-.-~-_         
[email-masked] .-~   . - ~  }~ ~ ~-.~   -.   \_.
                      .' .-~      .-~     _- :/ -. ~.   ~:
                     /_~_ _ . - ~        :.   .  . :   ~ -.~-._
                                           :      ._ _: _  
                                            ~ ~\_.-

---

From: [email-masked] (Alan McHughen)
Date: 2 May 1995 15:13:00 GMT

While developing more efficient transformation efficiencies for flax, one 
of the parameters we investigated was length of co-culture period (flax 
hypocotyls + Agrobacterium *in vitro*). Traditionally, 2-3 days of such 
coculture is standard, largely due to the overgrowth of Agrobacterium 
observed with longer durations. We noted a better transformation 
efficiency in the hypocotyls cocultured for longer periods when the Agro 
did NOT overgrow the plant tissue. Because this non-overgrowth was a 
relatively rare event, the overall efficiency was low, however. 

Dr J-Z Dong, a postdoc in the lab at the time, started culturing the 
cocultivated hypocotyl + Agrobacterium on a piece of filter paper overlay 
on the culture medium; this dramatically reduced the Agrobacteria 
growth, enabling co-culture periods of up to 12 days. We eventually 
determined our most efficient co-culture period using this method for 
recovery of transgenic plants to be seven days. The use of the filter 
paper overlay to control Agrobacteria (and other aspects of this work) is 
recorded in Dong and McHughen; Plant Science 88:61-71 (1993). 

From Ancha  Srinivasan Sun May  7 17:06:51 EDT 1995
Article: 6258 of bionet.plants
Newsgroups: bionet.plants
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From: Ancha  Srinivasan
Subject: Ph.D. Crop Sci./6 yr. Exp./Seeks Intl. Agric. R&D Position
Sender: [email-masked]
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Date: Mon, 1 May 1995 07:32:48 GMT
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To whom it may concern:

I am a researcher from India working at the Japan International
Research Center for Agricultural Sciences. My contract here will expire
by October 1995. I wish to broaden my exposure to agric. research and 
development activities by working at a reputed institution.  I would be
grateful if you could consider the following resume and inform me of any
potential opportunities. I am willing to relocate to any place, if the
position is challenging. Please feel free to pass this information 
along to anyone else who might be interested. Thank you very much for 
your time, interest and consideration.

Yours sincerely,

Ancha Srinivasan

Resume follows:

                            ANCHA SRINIVASAN
          Japan International Research Center for Agricultural Sciences
            Okinawa Subtropical Station, Maezato, Ishigaki, 907 JAPAN
                Tel: +81 9808 34190 (Off.) +81 9808 37793 (Home)  
            Fax: +81 9808 20614 E-Mail: [email-masked]
  
OBJECTIVE  A challenging agric. R&D position, with an opportunity to 
           apply my experience and develop new skills

EDUCATION  Ph.D. Crop Science 1988  University of Cambridge, UK.
           M.S.  Agronomy     1984  3.89/4.00 OGPA Indian Agric. Res. Inst.
           B.S.  Agriculture  1981  4.00/4.00 OGPA A.P. Agric. Univ. India

HONORS/    Cambridge University Research Scholarship
AWARDS     Overseas Research Students' Award in U.K.
           First rank in ICAR Senior Research Fellowship in India 
           Gold Medal in M.S. Agronomy
           Award of Junior and Senior Research Fellowships by
            the Indian Council of Agricultural Research (ICAR)
           Second rank in M.S. Agronomy in India;
           First rank in B.S. Agriculture, A.P., India;  
           Scholarships throughout the career since age 10
           Letter of appreciation from the late Prime Minister of 
             India, Mrs. Indira Gandhi
           Several travel grants and awards throughout the career

EXPERIENCE      
1993-present  Visiting Scientist, Japan International Research Center 
              for Agricultural Sciences. Independent research on heat
              tolerance of food legumes
1992-1993     Govt. of Japan Science and Technology Agency Fellow, 
              Hokkaido National Agric. Exp. Stn., Sapporo, Japan. Mechanisms  
              of chilling tolerance in confectionery soybean 
1989-1991     Postdoc. International Crops Research Institute for the
              Semi-Arid Tropics (ICRISAT), India. Mechanisms of cold
              tolerance in chickpeas during reproductive growth
1984-1988     Research Fellow, Dept. of Plant Sciences, University of
              Cambridge. Genetic and physiological constraints for seed 
              development in oilseed rape
1983-1984     Research Scholar, Indian Agricultural Research Institute
              Energy balance in upland rice-based cropping systems
1981-1983     Research Scholar, Indian Agricultural Research Institute
              Phosphorus management in pigeonpea-based intercropping systems
1977-1981     Undergraduate, Andhra Pradesh Agric. Univ., Bapatla, INDIA
              Resource constraint analysis in sugarcane-based cropping systems

SKILLS
1. LAB.: Plant histology, Histochemistry, Light & scanning electron microscopy
      X-radiography, Autoradiography, Liquid scintillation counting
      High performance Liquid Chromatography, Gas chromatography
      Determination of chemical composition of plants and soils
      Conversant with Atomic Absorption Spectrophotometer, Chlorophyll
      Fluorimeter, Microtomes, etc. Experience in using growth rooms &
      incubators, hydroponics, etc.
2. FIELD: Development and evaluation of cropping systems; Integrated weed
      management; Crop responses to fertilizers and abiotic stresses;
      Planning and lay out of field experiments; Field Plot technique;
      Experience with  all field operations; Measurements of light 
      interception, photosynthesis, water status of soils and plants; 
3. COMPUTING: Ability to use software on mainframe and personal computers 
      (IBM and Apple Macintosh) for word processing, graphics and 
      statistical analysis
4. MANAGERIAL: Ability to (a) lead people to execute the plan of work 
      successfully, (b) design, formulate and coordinate research 
      projects, and  (c) plan, conduct and report research in peer-
      reviewed journals; Active interest in applications of 
      biotechnology and other new technologies; Strong interpersonal 
      and communication skills, etc. 
5. LINGUISTIC: Working knowledge of English, Telugu & Hindi; Limited 
      knowledge of Japanese.

PROFESSIONAL AFFILIATIONS:
   Member of the American Society of Agronomy; Crop Science Society 
   of America; Institute of Biology, London; Cambridge Philosophical
   Society; Cambridge Commonwealth  Society; International Working 
   Group on Flowering, Belgium; British  Plant Growth Regulator
   Group; Indian Society of Agronomy; Development Education Exchange
   Service of F.A.O. of the U.N.;
   Registered as a volunteer with Volunteers in Technical Assistance,
    Arlington, USA. 

FOREIGN COUNTRIES VISITED: 
    U.K., Japan, Hong Kong, Singapore, France, Spain, The Netherlands, 
    Germany, Poland, Ireland

PUBLICATIONS/PRESENTATIONS:
    Research and review articles in national & international journals 
    (Crop Science; Euphytica; Journal of Agric. Sci., Camb. etc.); 
    Presentations in international Conferences in Poland, Canada, etc. 
     
REFERENCES: Available upon request.