Costa Rica: Biodiversity and Biotechnology at the Crossroads
by Ana Sittenfeld, Ana M. Espinoza and Griselda Arrieta
Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica
Paper prepared for the Biodiversity & Biotechnology Conference
Center for Interdisciplinary Studies, Washington University School of Law’s
Washington University, St. Louis, Missouri, April 4-6, 2003
Introduction
Costa Rica, as many other tropical countries is at the crossroads of agricultural
biotechnology and biodiversity conservation. On one hand, agricultural expansion, has resulted in
the last decades in poor natural resource management, still using a model based on plentiful use
of agrochemicals to maximize productions, with potential adverse effects on biodiversity and
health (Mateo 1996, Sittenfeld and Espinoza, 2002). On the other hand, Costa Rica is one of the
twenty countries with the greatest biodiversity and has enjoyed a long history of conservation of
its natural resources. A National System of Conservation Areas, comprises today over 25% of the
national territory and is the main attraction for tourism, which generated US$1,249 million in
2000 (9% of GDP) indicating that protected areas are contributing substantially to the economy
(Proyecto Estado de la Nación, 2000). Imports of agrochemicals increased by a factor of ten
between 1990 and 1996, and there was no significant increase in crop yields per hectare in the
last decade. The use of pesticides in Costa Rica has lead to increasing numbers of poisoned field
workers. The challenge for Costa Rica is to decide whether to continue with unsustainable
agricultural practices, or to explore other alternatives such as the introduction of genetically
modified (GM) crops and other biotechnologies that might offer opportunities to reduce the use
of agrochemicals and increase yields. However, as any other new technologies they require a
careful consideration to potential environmental effects, including gene flow from GM plants to
natural variants. Having a quarter of its territory separated for wildland protection, and realizing
that only 15 percent of the soils are adequate for agriculture, Costa Rica needs to find ways to
take advantage of both the technology and its biodiversity. If Costa Rica is to conserve its
biodiversity, it is imperative for the country to design and implement innovative strategies to link
conservation and biotechnology, leading to increase agricultural production on less land, with
lower pesticide use, and to maximize the benefits of using in an intelligent manner
biological/genetic resources from wildlands.
Linking biodiversity and biotechnology: The Rice Biotechnology Program
Rice is a very important staple crop for Costa Rica, providing approximately 25% of the
daily caloric intake to the population. Rice production faces several phytosanitary constraints that
include the rice hoja blanca virus disease (RHBV) and weeds, among others. The distribution of
this viral disease is limited to tropical America, and there is no natural resistance to RHBV
among indica rice varieties. Because of a lack of resistance or tolerance to these factors, the use
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of pesticides has increased costs, which reduces profit margins and competitiveness of rice
production in Costa Rica. An alternative approach, therefore, would be to use non-conventional
strategies, such as the genetic transformation of commercial rice varieties with RHBV antiviral
genes for conferring resistance to the virus and to the herbicide PPT (ammonium glufosinate), in
order to perform a more effective weed control in post-emergence. The production and
deployment to farmers of transgenic rice with these traits, and a biodiversity inventory and
characterization of wild rice relatives and weedy rice biotypes within the country, together with
an assessment and monitoring of any potential environmental impacts before commercial release
represent the main research activities performed by the Rice Biotechnology Program of the
Centro de Investigación en Biología Celular y Molecular (RBP-CIBCM) of the Universidad de
Costa Rica (UCR) (Sittenfeld et al., 2001). Since this is the first transgenic crop locally produced
that addresses production constraints not considered by private and public research institutions in
developed countries, the RBP-CIBCM has faced many challenges. These include basic research
leading to the transformation of local germplasm, while at the same time considering the
biodiversity assessment, regulatory and intellectual property (IP) issues necessary for a successful
commercialization of the new variety. Transgenic rice varieties, resistant to RHBV and produced
by RBP-CIBCM, represent the first transgenic crop to be deregulated for commercial release in
the country that responds to phytosanitary constraints specific to tropical America.
In 1990, the RBP-CIBCM started the molecular characterization and sequencing of the
RHBV genome (de Miranda et al., 1996), the development of plant tissue culture protocols for
regeneration of Costa Rican indica rice varieties CR-1821 and CR-527 (Valdez et al., 1996-1997)
and epidemiological studies of RHBV and its insect vector, Tagosodes orizicolus (Homoptera:
Delphacidae). The next phase of the program focused on the development of resistant rice lines
through genetic engineering of the Costa Rican rice cultivars, with RHBV sequences in order to
confer resistance to the RHBV and to the herbicide PPT, by expressing the bar gene. Transgenic
calli, produced in collaboration with Cornell University, were regenerated and evaluated in Costa
Rica for their resistance to the RHBV and PPT under local field conditions, as well as for their
agronomic performance. Progress in the research program is leading to a shift from testing of
concepts and building up experience in production of transgenic plants, to field evaluation and
deployment of modified rice varieties to farmers (Arrieta et al., 2002). Field-testing is just one of
the several steps required before the genetically engineered rice plants produced can be
commercially grown. These steps range from health and environmental risk assessment and
management of transgenic crops under tropical conditions, to the establishment of an IP
management plan dealing with proprietary inputs and technologies used during the genetic
modification of the lines, possible negotiations due to IPRs of third parties enforceable in the
countries where commercialization will take place, and protection of inputs and technologies
developed within the Program (Espinoza et al., 2002). Public opinion surveys to determine levels
of acceptance (Sittenfeld and Espinoza, 2002), together with cost benefit analysis and
negotiations with seed producers, are all important activities for the commercialization and
distribution of the new varieties. The identified steps, which are part of an integrated strategy
developed by RBP-CIBCM, are most probably common to those from other groups working with
transgenic rice in tropical countries.
Primary transformed lines were shown to tolerate toxic concentrations of the herbicide,
while T1 progeny segregates 3:1 as a dominant locus. T2 homozygous lines turned out to be
herbicide resistant under field conditions. In addition, T2 and T3 lines were evaluated for
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morphology, phenology and agronomic performance under field conditions. All experiments
were conducted under the supervision of the Costa Rican National Biosafety Committee (NBC).
The NBC has developed regulations and granted permits for transgenic seed increases for nearly
a decade in the country, but no genetically modified products have yet been deregulated and
released for commercial purposes. At present, new transgenic lines using other RHBV genes and
bar are under development at CIBCM. RBP-CIBCM research agenda is not static, but constantly
searching for scientific improvement, including also studies on the genetic diversity and
reproductive biology of wild rice relatives (Zamora et al, 2001; Quesada et al, 2002) and weedy
rice (Arrieta et al, 2002), aiming towards the development of gene flow experiments. At the same
time, prospecting for new genes from wild rice relatives and other sources is also being
conducted.
Assessment and management of gene flow from GM plants to wild Oryza relatives and to
the weedy rice complex, is one of the most important activities of the program, since Costa Rica
is a biodiversity rich country. The RBP-CIBCM has conducted research to identify, map, and
characterize native relatives of rice that occur in Costa Rica. Populations of three of the four
Oryza species reported for tropical America have been found in natural ecosystems throughout
the country, accounting for three of the six described genome types of Oryza (Zamora et al.,
2002). Inventories for wild rice relatives have provided information for the best locations for the
evaluation of transgenic lines in field trials. At the same time, morphological and molecular
characterization of weedy rice populations allowed the identification of 27 biotypes (Arrieta et
al., 2002). Information on the overlapping of flowering periods between weedy biotypes and
commercial varieties obtained by RBP-CIBCM will be useful to select the weedy rice biotypes
used in field experiments for assessing gene flow from transgenic rice to weedy rice populations
(Arrieta et al., 2002). Preliminary results indicate that the number of potential recipients is low.
The fact that rice is self-pollinated and pollen survives only minutes, suggest that the potential
environmental risks of transgenes could be minimized.
Microbial diversity and biotechnology
Debates over the role of GM plants in agriculture continue in the international
environmental agenda. Transgenic plants containing genes from Bacillus thuringiensis (Bt) have
produced positive reports advocating their use, together with agricultural practices to prevent
ecological consequences, as well as negative reports suggesting environmental impacts for
biodiversity. The RBP-CIBCM has also explored the presence of Bt in wildlands in Costa Rica
(Rodríguez-Sanchez et al., 2003). Bt synthesizes crystalline inclusions that are toxic to
caterpillars (Lepidoptera) and other orders. Materials associated to caterpillars from 16 species,
collected while feeding on 15 different species of host plants in dry, cloud and rain forests located
at the Area de Conservación Guanacaste (ACG) in northwestern Costa Rica, were examined for
presence of Bt. Bt isolates were cultured from host plant leaves, caterpillar guts and from
caterpillar fecal pellets. Caterpillars are among the major herbivores in tropical forests and every
leaf they eat contains a diversity of microbes. This inoculum plus potential food material is added
into the established microbial community within the caterpillar gut, remains there for a few hours
or days and passes on through as fecal pellets that fall to foliage below and to the forest floor.
The caterpillar-based microbial community may thus be visualized as a diffuse network of shortlived nodes between which microbes move. These results demonstrated that Bt is found in the
same habitat of these caterpillars, associated to the leaf material from which these larvae were
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feeding. Since the gut of caterpillars constitutes a selective habitat for microorganisms, it can be
speculated that Bt isolates unable to colonize the gut could be transient passengers and as a result
are eliminated in the fecal pellets. We postulate that caterpillars contribute to the dispersion of Bt
in their natural ecosystems. Bt might also play a role in limiting forest defoliation, however
further research is needed to better understand the role for Bt in wildlands.
Biological/genetic resources from wildland diversity are mainly used for improving
locally adapted varieties and races, and wild relatives of crops to increase yields. Microbial
diversity is also an important resource to explore for its potential use in improving food
production. In this connection, bacteria in caterpillar guts represent an interesting source of new
enzymes. Although microorganisms from different genera have been isolated from guts and
pupae of tropical caterpillars, little is known about them. Studying enzymatic activities of gut
microbes is a starting point for understanding their metabolic and physiological relationships with
their hosts, and to find enzymes with biotechnological applications. We are using traditional and
biotechnological assays to detect secretion of gelatinases, caseinases, lipases, esterases,
cellulases, xylanases, amylases and chitinases in a collection of bacterial isolates from caterpillar
guts collected at the ACG. Bacterial isolates from caterpillars were more active when compared
to other sources of microbes such as human guts. Chitinolytic activity of isolates was further
studied. At present research using chitinase genes is in progress aiming to generate GM crops
tolerant to insect and fungal diseases.
Public perception of GM crops
Public perception to GM crops is fairly positive in Costa Rica. A nationwide survey of
1000 Costa Rican citizens aged 18 and over conducted in May-June 2001, to assess the existing
level of awareness and perceptions to GM crops, concluded that the national level of awareness
of safety and benefits of GM crops Costa Ricans are more in line with those of the United States
than those of Europeans. The survey found an overall positive acceptance to the use of GM crops
(Sittenfeld and Espinoza, 2002). Between 40 and 50% of Costa Ricans had heard about GM,
thought that GM crops are nutritious, would buy food obtained from GM plants at no price
difference and thought GM crops pose no risks to the environment. Only 21% feared that biotech
food would offer a health risk. About 30% were supportive of research into GM crops. A similar
percentage trusted regulatory institutions. In general, more educated people responded more
positively to GM crops, in terms of acceptance and environmental and food safety issues, while
low income and low education groups answer more frequently that they do not know or simply
do not respond. The latter responses were also higher for women. It is interesting that 55% of
the people surveyed had not heard about GM plants and animals, indicating the importance of
promoting education to provide them with accurate and science-based information.
Conclusions
Although, Costa Rica, a country with a population of 3.9 million, has allocated in the last
decades an important portion of its national budget to education and health (27% and 29%
respectively for year 2000), the effects of globalization, and recent international economic
policies from international agencies has lead to the increase of social and economic differences,
and a delay in sustainable human development, that will affect the capacity of the country to deal
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with complex issues related to agricultural biotechnology. Agriculture has been one of the most
important sectors for the economy of Costa Rica, promoting democracy, national values, and
political stability. Today, the country needs to develop agricultural practices that are friendlier to
native biodiversity, at the same time that research seeks the path of higher productivity, without
intensifying environmental degradation, social integrity or health problems. The research and
possible commercialization of transgenic rice generated by the RBP-CIBCM represents a careful
exercise. Lessons from the RBP-CIBCM indicate that is possible to implement sound science
practices in agreement with environmental concerns, leading the way to the production of
transgenic plants, and the sustainable use of biodiversity at the biodiversity and biotechnology
crossroads.
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