TELEPHONE (216) 264-1021 
DEPARTMENT OF 
PLANT PATHOLOGY 
April 20, 1978 
Dr. Donald Frederikson, Director 
National Institures of Health 
Bethesda, 
Maryland 20014 
• f 
Dear Dr. Frederickson: 
I understand that the Recombinant DNA Advisory Committee will 
be meeting in the near future to consider the recommendations of 
the NIH-NSF-USDA workshop on risk assessment of plant pathogens. 
As a phytobacteriologist who is actively working in the area of 
bacterial genetics, I would like to add my opinion to those already 
expressed. I fully support the classification of plant pathogens 
set forth by the workshop participants and believe that recombinant 
DNA experiments with plant pathogenic bacteria (except those which 
are also known animal pathogens) do not present a greater risk to 
plant and animal health than experiments with any other group of 
bacteria. I am concerned, however, that the La Jolla Working Group's 
recommendations for exempted experiments, which the workshop endorsed, 
may present problems if the forthcoming list of "gene exchangers" 
(Recommendation IV) is not sufficiently broad. The problems arising 
from a narrow definition of gene exchangers have been outlined in 
Dr. N. J. Panopoulos' letter of April 14, 1978 to you and the advisory 
committee. I agree with Dr. Panopoulos' views and would like to 
emphasize some of the points that he has made. 
In the past, research on plant pathogens has been directed mainly 
toward controlling diseases using empirical approaches rather than 
understanding the basic biology of the pathogens themselves. As a 
result these organisms are not well characterized from a genetic or 
biochemical standpoint. Developing a genetic system for these organisms 
by classical techniques has been a luxury that few plant pathologists 
could afford. This is especially true today in view of conservative 
agricultural research priorities and increased emphasis on fiscal 
[Appendix A — 287] 
