NOTICES 
33175 
1. Wil! the introduction of recombin- 
ant DNA from a specific plant patho- 
gen in E. coli K12 lead to the develop- 
ment of strains with enhanced viru- 
lence to man or animals? 
2. Will strains of E. coli be converted 
into plant pathogens? 
3. Will the use of plant pathogens as 
HV systems result in hazards to 
plants? 
With the relatively minor reserva- 
tions documented below, the commit- 
tee agreed that the answer to all three 
questions was “No”. First we would 
point out that there is no evidence 
that genetic information transferred 
from plant pathogenic organisms 
would enhance the capability of 
strains of E. coli to harm man, animals 
cr plants. There are a very small 
number of possible exceptions to this 
generalization. These include a few 
species of bacteria which have been 
found in association with plants or 
which have been described as weak or 
minor plant pathogens and which may 
be closely related to forms causing dis- 
ease in man. Also, plant pathogens 
such as the ergot fungus, arid certain 
molds that produce aflatoxins on 
stored plant products are likely to be 
banned on the grounds that they pro- 
duce potent, albeit non-polypeptide, 
toxins. 
Provided that the use of plant path- 
ogens as HV systems is not undertaken 
with the objective of deliberately cre- 
ating forms with increased virulence 
and host range beyond that which 
occurs by natural genetic exchange 
(these are expressly prohibited by the 
guidelines) we see no hazard from 
such systems to plants. 
1. Without dissent, the committee 
agreed on a classification of plant 
pathogens on the basis of hazard to 
agriculture. 
We have placed all plant pathogens 
into a single class with two subgroups. 
This reflects our opinion that recom- 
binant DNA research with plant path- 
ogens has a negligible risk. The two 
subgroups take account of existing 
federal and state quarantine regula- 
tions. We propose that this classifica- 
tion be appendix C in the guidelines. 
HAZARD CLASSIFICATION OF PLANT 
PATHOGENS 
Class 1A— Plant pathogens not in 
class IB. 
Class IB— All organisms that are 
subject to quarantine restrictions for 
any of the following reasons: 
(i ) Plant pathogens not known to 
occur in the United States. 
(ii.) Plant pathogens that are not 
widely distributed throughout the eco- 
logical range cf their hosts. 
(iii) Plant pathogens subject to fed- 
eral or state eradication or suppression 
programs. 
All plant pathogens require state 
and federal (USDA 1 ) permits for ship- 
ment across state lines. 
2. Specific recommendations. The 
lack of an accepted definition of ex- 
changers caused us some difficulty in 
our discussions. A majority of the com- 
mittee favor a liberal definition that 
would exclude all gram negative bacte- 
ria from the guidelines. However, since 
this decision has still to be made by 
the RAC and Dr. Fredrickson some of 
our recommendations had to reflect 
two alternatives: (i) On the basis that 
most gram negative forms wouid be 
excluded we present rationale for in- 
cluding gram negative plant pathogens 
in this exclusion; (ii) on the basis that 
prokaryotic exchangers might be de- 
fined in a less liberal fashion, or that 
there might be a long lag period 
before plant pathologists can present 
evidence satisfying whatever exchange 
criteria are established, we present ra- 
tionale for adopting minimal contain- 
ment levels for all phytopathogenic 
bacteria namely P1 + EK2 or P2 + EK1. 
Ill B la. Shotgun experiments using 
the E. coli K12 host-vector systems. 
(2) Prokaryotic DNA recombinants, 
(p. 49602 FR 42 No. 187, Sept. 27. 
1977). We propose that the minimum 
containment levels adopted for other 
bacteria be applicable to phytopatho- 
genic bacteria, namely F1 + EK2 or 
P2 + EK1. 
(i) Modify line 7 to read; "biochemi- 
cal, genetic, and/or pathogenic proper- 
ties. 
(ii) Delete the words "and plant 
pathogens” from line 5 of the second 
paragraph. 
Rationale: Plant pathogenic bacteria 
include diverse organisms principally 
in the genera Agrobacterium. Coryne- 
bacterium, Eiwinia^ Pseudo- monas, 
and Xanthomonas. A number of the 
plant pathogenic species are soil-in- 
habitants and are widely distributed 
throughout the United States. In gen- 
eral tney cause economic loss only 
when environmental conditions are fa- 
vorable and available control practices 
are not used. A number of bacteria 
that cause foliage diseases can exist as 
epiphytes on a variety of non host 
plants as well as on their susceptible 
hosts. Other bacteria such as the 
pathogen that causes halo blight of 
beans are seed-transmitted, do not sur- 
vive in soil for long periods of time 
and can be controlled by the use of 
pathogen-free seed. The mechanisms 
by which plant pathogenic bacteria 
produce disease in plants may involve 
enzymes which attack substrates in 
plants such as pectic compounds. Such 
'Address to obtain application tx> import 
or move a plant pest or pathogen: Plant Im- 
portation arid Technical Support Staff, 
Plant Protection and Quarantine Programs. 
An'inal and Plant Health Inspection Serv- 
ice, USDA, Federal Center Building, Hyatls- 
ville, Md. 20782. 
enzymes would not be harmful to man 
or animals. Similarly certain growth 
promoting compounds and compounds 
that interfere with specific physiologi- 
cal functions in plants, e.g. polysac- 
charides that block movement of 
water, are not known to cause injury 
to man. 
Certain bacteria which are not 
known to cause disease in plants but 
which are commonly present as epi- 
phytes on leaves (Leben, C., 1965 Ann. 
Rev. Phytopath. 3:209-230) have been 
associated with diseases of man, i.e. 
Erwinia herbicola also designated as 
Enterobacler agglomerans (Starr, M. 
P. and Chatterjee, A. R., 1972, Ann. 
Rev. Microbiol. 26:389-426). However, 
there is a diversity of strains that have 
been obtained from plants and there is 
no conclusive evidence that the types 
widespread in plants are the same 
strains associated with certain infec- 
tions in man. 
Similarly it has been reported that a 
bacterium similar to a pathogen of 
onions (.Pseudomonas cepacia ) has 
been associated with a disease of man 
(Ederer, G. M. & Matsen, J. M., 1972, 
J. Infect. Dis. 125:613-618; Snell, J. J. 
S., Hill, L. R., LaPage, S. P. & Curtis, 
M. A., 1972, Internat. Symp. Systemat. 
may not have useable vectors. 
III.B. 3c. Plant host-vector systems, 
(p. 49603). 
(i) Delete second paragraph. "Whole 
plants or plant * * * at this time”. 
Rationale: This paragraph is confus- 
ing. Its intent was to define practical 
size or scale limits to physical contain- 
ment rather than limits to biological 
containment. The committee conclud- 
ed that the discussion of physical con- 
tainment in the preceding paragraph 
makes this redundant. 
(ii) Delete last sentence of fourth 
paragraph "However, if the source of 
the DNA is itself pathogenic * * * 
shall be carried out under P3 condi- 
tions” and substitute: “If the vector is 
an unmodified virus the experiments 
shall also be carried out under P2 con- 
ditions”. 
Rationale: This committee has reas- 
sessed the risk to man, animals, and 
plants from plant pathogenic agents. 
In this context we are concerned prin- 
cipally with the risk cf DNA from 
plant pathogens to plants. This para- 
graph now reflects our lowered assess- 
ment of these risks. 
(iii) Delete paragraph five. Experi- 
ments on * * ’are not met. 
Rationale: As for (ii). 
(iv) Modify final paragraphs to read 
“* * * permit a decrease of one step in 
the physical containment to PI.” 
Rationale: The survival of plant pro- 
toplasts (see table 1) and undifferenti- 
ated cultured plant cells outside their 
laboratory environment is zero be- 
cause of their extremely exacting 
growth requirements and fragility. 
FEDERAL REGISTER, VOL. 43, NO. 146— FRtDAY, JULY 28, 1978 
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