New York State College of Agriculture and Life Sciences 
a Statutory College of the State University 
Cornell University 
Department of Plant Pathology 
334 Plant Science Building, Ithaca, N. Y. 14853 
February 19, 1976 
Dr. Donald S. Fredrickson, Director 
National Institutes of Health 
Building 1, Room 124 
Bethesda, Maryland 20014 
Dear Dr. Fredrickson: 
After reading the background material and listening to a 1 1/2 day presentation 
on the moral and public safety aspects of recombinant DNA research I have come to 
the conclusion that the rules promulgated by the NIH present a reasonable approach 
to this very complex and important problem. I personally have reservations concerning 
the risk to benefit ratio of this type of research and thus I feel that a go-slow, 
conservative attitude is warranted; to my mind the proposed guidelines reflect this 
concern. It is obvious too, that this is research which is world-wide in scope; rules 
established in this country will undoubtedly be used as a guide elsewhere to establish 
similar restrictions. 
I would like to make a few specific comments about certain forms of research with 
higher plants, which might eventually enter into these studies. As treated in the 
guidelines, plants have only a peripheral role, but with a few significant advances 
they could well become very important in recombinant ENA studies . I 'm not referring 
to the cloning of higher plant ENA and incorporating such DNA into bacteria; that 
eventuality is well covered by the guidelines. Rather, I'm concerned with the in- 
corporation of foreign DNA into the genome of higher plants. At the present time 
this is just a dream, as the experimental work in this area has yet to demonstrate 
conclusively the stable incorporation of foreign DNA into the genome of higher plants. 
As a vehicle for introducing foreign DNA, plant viruses might well play a role. 
Unfortunately (for these studies) most plant viruses contain RNA rather than DNA. 
There is however, one small group of five DNA plant viruses. These viruses are normally 
transmitted by aphids, but may also be transfered by mechanical inoculation. It is the 
property of aphid transmissibility which gives me some reservations as to the applicability 
of the guidelines. The physical containment guidelines are designed to prevent bacteria 
from getting out of the facility; thus, negative air pressures are specified, and the 
guidelines were merely extended to include plant studies. Negative pressures are certainly 
satisfactory for most plant studies except in those cases where insect-borne plant 
viruses are a part of the experimental procedure. Here tightly screened greenhouse 
facilities with positive air pressures plus antechamber entry rooms are normally used to 
avoid drawing insects into the greenhouse. Routine fumigations are also employed to 
keep the facility insect-free. 
[ 472 ] 
