Studies have shown that herbivores, like the locust
shown here, are not likely to eat plants that have
absorbed metals such as zinc. The plant on the right,
which had not absorbed zinc, was quickly devoured.

+ Pollutants become benign, useful
+ can be used to generate
biodegradable material from
renewable resources
+ could develop environmentally
safe manufacturing and disposal
+ leaves soil intact
conventional methods)
+ it's passive, solar
energy driven
+ useful in treating a wide
variety of
contaminants and sites
+ less expensive (almost 1/10
the cost of the more laborious
traditional methods!)
+ more efficient and less
+ it's a natural solution!
+ increased land value of
brownfield sites
+ hyperaccumulators are
unattractive to insects and
have a reduced chance of
fungal and bacterial infections
+ genetically engineered
phytoremediators could lead to
plants with higher levels of
dietary metals and
- Social response and controversy
(ethical contention may lead to
criminal activity)
- possible release of the stored
contaminants through either
transpiration or incineration
- possibly disastrous effects on the
food chain
- transgenic varieties may lead
to uncontrollable infectious
- genetic alterations may cause
immunity to pesticides and
- the process is limited to relatively
shallow contamination sites and
is dependent on the adaptability if
the plant
Several protest groups have launched intense and at times violent
propaganda against any form of genetic alteration (including
biotechnological enhancements!)
necessary breakthroughs
major barrier is lack of basic knowledge about the process, molecular genetics and biochemical
mechanisms of adaptive metal tolerance in plants

perfection of a genetic engineering process

genes responsible for desirable characteristics must be located in specifically designated plants

the reproductive biology of the plant and the distribution of its sexually compatible relatives
must be known because the introgression of genetic information from one plant to another is
only possible if the two plants are sexually compatible and if their hybrid offspring are viable

must understand impact of introduced trait