Interview with Dr. Sofia Valenzuela: Global potential of forest biotechnology

By Daniel Norero

September 5, 2019

A group of 15 leading scientists in forest biotechnology research recently published a letter in the Science Magazine, calling on international forest certification programs to review and modify their standards that exclude genetically modified (GM) and gene-edited trees.

Although the review wont take place until October, researchers believe its necessary to raise their voices through this and other initiatives, such as a public petition managed by the Alliance for Science and signed by more than 1000 people last January.

Among the scientists who signed the letter, the only Latin American was Sofía Valenzuela, who is a biochemist from the University of Chile with a PhD in Natural Resources (TU Braunschweig, Germany). She works as a professor on the faculty of forestry sciences at the University of Concepcion and also as a researcher at the Biotechnology Center of the same university. In addition, she engages in science communication and activism in favor of gender equality in science and participated in the 2016 Alliance for Science Global Leadership Fellows Program executive session.

Taking advantage of her expertise in the field, I conducted an interview in which Dr. Valenzuela explains in more detail research under way globally and in Latin America on GM and gene-edited trees, their potential in the context of climate change and the challenges of the field.

Question: Since the commercialization of GM crops began in the mid-1990s, they have made significant progress in research, commercial and consumer approvals around the world. However, this same recombinant DNA technology applied to the forestry sector didnt experience the same commercial growth. What factors are behind this uneven development of genetic engineering in the agricultural and forestry sector?

Answer: The development of GM trees takes several years, almost three decades; however, its acceptance and therefore its use in commercial plantations has been complex. On the one hand, most forestry companies are nationally and internationally certified and the certifying entities dont allow the use of GM trees in their production chain. Since 1988, nearly 1500 field trials have been carried out using GM trees, most of them in the United States and Brazil. The poplar corresponds to the species with the highest number of trials, followed by eucalyptus and pine. The traits that have been modified are growth, content and type of lignin, herbicide tolerance, reproductive development and cold tolerance, just to mention the main ones. These trials have been developed by both private entities and universities, among which we can mention Arborgen, Oregon State University and Futuragene. Some trials that have been able to advance on a larger scale correspond to Bt poplar in China (2003) and in 2014, Futuragene in Brazil obtained permission to commercialize GM eucalyptus with higher yield.

On the other hand, there has been a lot of debate regarding the use of GM trees. Some people think that when we talk about GM trees, we talk about forests, which they associate with nature and say that nature shouldn’t be modified. In reality, the main objective is the use of these species in forest plantations. Otherwise, there is fear—unfounded—that unlike agricultural crops, GM trees will be planted for more than a decade, which would entail a greater environmental risk—mainly “gene flow.” Others argue that the main traits used in agriculture for the production of GM crops—herbicide tolerance and Bt, or both—arent of great economic relevance for the forestry sector. Despite these public concerns, there is sufficient scientific evidence that GM trees have no major negative impact on the environment or human/animal health. In fact, if GM forest species were allowed for commercial plantation purposes, we could have higher productivity per hectare, which would reduce the pressure for more land for plantations.

This is why, led by Dr. Steve Strauss of Oregon State University, we made the letter and a petition that has been signed by more than 1000 people, so that the use of GM or genetically edited trees is changed and accepted. We are sure that there is scientific evidence to allow the use of these trees, and this may bring benefits to society, but especially small and medium farmers, who will have the opportunity to have better trees for their plantations.

Dr. Sofía Valenzuela

Q: Aside from the famous case of genetic modification of the Hawaiian papaya tree, which saved the Islands’ farms from the ringspot virus without having to use conventional control methods, which trees for food or industrial use are commercially approved or already planted in the world? What socioeconomic and environmental impact have they generated?

A: It is necessary to differentiate fruit trees from forest species for commercial purposes. In the case of fruit trees there is a greater acceptance, both from producers, farmers and even consumers. There are several studies with GM fruit trees, including some of them ready to be marketed, especially in the USA,  given that the genetic modifications used confer tolerance to diseases or pathogens in fruit species.  This implies reducing both the use of pesticides and losses in production while maintaining a fruit industry that could be threatened by pathogens, which will be increasingly frequent in the face of the climate change scenario. Its likely that given the commercial and social impact that these trees or fruit species have, it will be easier for them to be accepted and commercialized by both farmers and consumers. In the case of forest trees for commercial purposes, it has been, for some reason that I fail to understand, much more complex to gain acceptance and use.

Q: Among the various developments of GM trees that you have seen or investigated, which ones stand out for their potential or are in advanced phases of research/field trials? Which countries could be the first to take advantage of them on their lands?

A: Most of the research on forest trees has been in poplar, where different genetic modifications have been made. Many of them are focused on obtaining trees with more cellulose and less lignin, which increases productivity per hectare—more cellulose/ha. In this case, many field trials have been carried out and different events have been obtained with a greater production of cellulose—without changes in the tree phenotype—so this would be a case that could be marketed promptly.

However, there are also studies to have disease-tolerant trees and for better tolerance of environmental conditions, such as drought. It has worked with other species such as eucalyptus, poplar, chestnut, just to name a few. Some companies like Arbogen conducted cold-tolerant eucalyptus tests in the USA; China a few years ago planted Bt poplar; in Brazil Futuragene obtained permission to market a eucalyptus with better wood quality. Moreover, this technology could be used in the future for the control of invasive plant species. In the short term and seeing the investment, bets that are being made that possibly China will one of the first countries where GM trees will be authorized and result in commercial plantations.

Q: Regarding the new techniques of genome editing like CRISPR, are there countries advancing in new developments with this technology? Is there any ongoing debate whether they will be regulated as GMOs or “natural mutants,” as is the case in Europe for agricultural crops?

A: With applications in the forestry sector there are many advances with this technology in China and the USA, mainly, where they have investigated in poplar. As in the case of agricultural crops, for trees edited with CRISPR/Cas it is the same debate. I think this could be a new opportunity to have edited trees in plantations. It has been a long battle to have GM trees commercially, after almost three decades we havent succeeded in authorizing their use. I see that the genome editing opens a new door for us to have these trees in commercial plantations. It is not that someone wants to replace all plantations with GM trees, but they can be a good alternative in specific cases. Like agricultural crops, its one of the alternatives. What is requested is that the option of its use be given.

Q: At the Latin American and Chilean level, what biotechnological forestry developments are being carried out? Do you lead any at the University of Concepción?

A: In Latin America, research in forest biotechnology has focused mainly on the development of biotechnological tools that support forest breeding programs and shorten the selection times of the best trees. The first investigations focused on the development of micropropagation techniques, followed with the use of molecular markers for both clonal genotyping and for marker-assisted breeding. Nowadays, progress is being made with the use of genomic selection, GWAS and genome sequencing of forest species, as well as in the validation of candidate genes associated with different traits of interest, which will be the basis for GM trees in the medium term—once we have the legislation that allows it.

In Brazil, a GM eucalyptus has already been generated. There is progress and if we could have the authorization to use these trees we would be conducting more studies in the area. In our case, we are investigating the use of genomic selection in forest species of interest in Chile. Also in the validation of candidate genes that confer tolerance to abiotic conditions—cold and drought. For now we use the Arabidopisis model plant and next year we hope to have the option of validating them in poplar at the laboratory level, with the authorization of Agricultural and Livestock Service (SAG). For this reason, I am currently in the laboratory of Dr. Vincent Chiang, at Northeast Forestry University in Harbin, China, with whom we are collaborating in this area.

Q: In the context of climate change, population growth and the need to produce more using less land, what new useful features could forest biotechnology offer to meet these challenges?

A: Today the concept of bioeconomy is increasingly imposed, where we could replace the use of fossil fuel with renewable natural resources, with trees as one of them. With these, we can obtain not only cellulose, but many biomaterials from cellulose, lignin and hemicelluloses, the three main components of wood. At the same time, wood is an excellent building material, not only for houses, but also for buildings. Therefore, we may need more area to meet these needs. An alternative is to look for more land for this, and another is to obtain trees that have a better quality of wood (for different goals) and are more productive, healthy and tolerant of extreme environments—drought, cold, heat, salinity. This can be done—and there are already some examples—with GM trees or developed through gene editing.

Q: In Chile, the endemic tree Araucaria Araucana—a very important tree in our culture, especially for the native peoples of the south—was declared endangered last year. Could genetic modification offer a solution to the millenary forests of Araucaria that are disappearing?

A: It could definitely be an alternative. Once the cause that is affecting the Araucaria is known, we could find a solution through genetic engineering or gene editing. This doesnt mean that alternatives can’t also be sought or used in parallel or in conjunction with conventional breeding. This is a case very similar to what happened with the American chestnut in the USA, where the species was affected by a fungus and there were very few specimens. Two options were carried out: one was to generate a hybrid with an Asian chestnut (pathogen tolerant) and the other was the development of a genetically modified chestnut tolerant to the pathogen. And thanks to this, today there are many GM chestnut plants that can be planted, recovering the species

Now, together with creating a GM tree, a lot of research goes hand in hand; for example, knowing the genome of the species, evaluating the effect that the gene or genes will have on the new phenotype and carrying out complete and complex environmental risk and benefit assessments, among many other studies. That is, a GM Araucaria is not going to be done in the laboratory and immediately taken to the field, but it will go through a series of detailed scientific studies before being released to the environment. This is a mechanism that new agricultural crops or forestry varieties arent subjected to when they are obtained by other techniques of conventional breeding.

Q: In mid-2017, the IUFRO Tree Biotechnology Conference was held at the University of Concepción, which suffered vandalism by activists who protested against the “genetic contamination towards native forests” claiming that this type of research ends up “filling the pockets of big companies.” What would be your message for opponents who share this type of fear or objection?

A: Yes, I remember it very well. First, there is a lot of misinformation. For example, a clone is confused with a genetically modified tree, so in Chile there are clonal plantations, but they are not genetically modified. The language is also critical. On the one hand we have commercial plantations and on the other hand we have forests. In order for any [gene flow] contamination to occur in native forests, the species must be sexually compatible, and if we think of the commercial species used in Chile—pine and eucalyptus—they are both exotic, and not compatible with the native species. If one day we could have commercial plantations with GM trees, you can be sure that these will have been rigorously evaluated, much more than any other agricultural crop or non-GM tree, so there will be scientific evidence that they wont cause damage to the environment. In the end, GM trees shouldnt be feared. They arent sinister, they dont cause damage to the environment; on the contrary, they will allow healthier trees with less pesticide application, better management and at the same time a higher productivity per hectare.

Q: Among the 15 scientists who signed the letter in Science, you and Heather Coleman were the only women. In your opinion, what are the causes behind this gender disparity? How can we encourage more women to dedicate themselves to science and your research field?

A: Yes, it is a problem. In the forestry field, the research led by female scientist must be close to 15-20 percent. In fact, if we do a search for forest biotechnology in the WOS, we will see that the main and most cited authors are all men. We noted this low participation (or presence) of researchers during the IUFRO Tree Biotechnology 2017 congress, which we held in Concepción. That was a first step, making visible that the main researchers are men, almost all from the northern hemisphere! This allowed two things. One, that for the first time two women were chosen as deputies in the tree molecular biology section of the IUFRO (2.04.06)—in this case, Heather Coleman and me—and this year four young researchers joined. Secondly, this year’s IUFRO Tree Biotechnology Congress held in Raleigh, NC, USA, included a panel of diversity and the opportunity for young researchers to make oral presentations on their work. We hope those elements will remain in subsequent versions of this congress, with the next to be held in 2021 in China.

This has allowed the community in forest biotechnology to start reflecting on how to have more women in a subject area that is very masculine. One of the missions is to have role models, to give greater visibility to the leading researchers in this field who are young and also to those who belong to minority groups. Its not easy to change the status quo, but for now we are having more actions and support from our male colleagues. For example, some of them have promised not to attend panels comprised solely of men and to support more female researchers, especially when they decide to be mothers, which is a critical stage where the academic careers of women are affected. Though equal numbers of men and women pursue university careers, for some reason the number of women leading research working groups barely reaches 20 percent. We are taking the first steps to reverse the situation. I hope it will not take us a century, as some studies indicate, but that we will be able to have equity in science and forest biotechnology by 2050.