"THE SCIENTIFIC COMMUNITY HAS MADE GREAT ADVANCES IN UNDERSTANDING HOW PLANTS RESPOND TO ENVIRONMENTAL STRESS"
Jun 17, 2020
Drought and water scarcity are the main environmental limitations on agriculture. Because of that, we need to develop new varieties of plants that use water more efficiently and tolerate episodes of drought, both with classic methods of improvement and by taking advantage of the molecular techniques of genetic editing. Dr. Pedro L. Rodríguez Egea, of the Institute for Plant Molecular and Cellular Biology of the Spanish National Research Council (CSIC) - Universitat Politècnica de València (UPV), works in this field. His team researches and develops plants that are more resistant to drought and salinity thanks to a technique that consists of suppressing one of the genes of the plant itself in order to increase that resistance.
Today, World Day against Desertification and Drought, we look ahead at some of the topics he will share in his lecture scheduled for 12 November 2020 at the Museu de les Ciències.
- In the International Year of Plant Health, what threats are endangering plants? How does climate change affect them?
Among the many challenges that agriculture faces, we can single out the threats to plants of different pathogens and adverse environmental conditions. There are numerous microorganisms, viroids and phytopathogenic viruses, and some here now like the feared Xylella fastidiosa bacterium. As adverse environmental conditions we can point to excessive cold and heat (low and high temperatures), the excessive salinity of the soil, floods and droughts. Without forgetting too much or too little light, an inadequate supply of mineral nutrients or the presence of environmental pollutants like ozone and other gasses. Climate change can combine several of these factors, for example, the accumulation of greenhouse gasses leads to an increase in temperature and irregular periods of precipitation, whether drought or torrential rain. Nevertheless, the greenhouse effect prior to the industrial revolution enabled life on the planet, without which the average temperature of the surface of the earth would be -20ºC (below zero) instead of the current 14ºC. Lastly, climate change and, basically, globalisation also facilitated the introduction of certain phytopathogenic vectors.
- Your research group is focussed on producing plants with greater resistance to drought and salinity. What does this work involve?
The scientific community has made great advances in understanding how plants respond to environmental stress, particularly the molecular response mechanisms to drought and an excess of salt. As part of this community, we have made an effort to clarify how drought is detected and what kind of signalling the plant produces. Ideally, this will allow us to take advantage of that knowledge to produce plants more resistant to those adverse factors. Basically, building on the basic research on plant models, we would like to use this knowledge to produce more resistant varieties that can improve agriculture.
- The key to the adaptation of plants to drought lies in the plant hormone ABA. What is it, and how does it work?
Plants synthesise hormones (like animals). These are signalling molecules present in small amounts that regulate plant growth and their adaptation to their immediate environment. In particular, ABA (abscisic acid) increases its concentration in drought situations and coordinates the adaptive response. For example, it reduces the transpiration of the plant, boosts the search for water in the soil and protects plant cells against dehydration. This mechanism evolved to permit plants to colonise half the earth and is fundamental in adapting to drought. On a hot, dry day, we think that ABA acts to keep the plant from wilting and brings all its adaptive resources into play.
- By not introducing any genes but rather suppressing one, are we talking about a transgenic plant?
Technically it is possible to modify plants genetically in ways that do not involve the introduction of foreign genes, which is what is known as genetic editing. This is not about being a transgenic organism, but, indeed, an organism modified genetically, although in such a precise way as to be indistinguishable from random mutations which occur in the genome. Our ancestors adopted a production economy based on agriculture and livestock thanks to the selection of genetic modifications that were randomly offered to us. Science allows us to make those modifications in an exact and targeted way.
- What would you say to people who distrust genetic engineering?
To provide accurate, unbiased information to the public, and also to broaden the scientific knowledge of the people, I believe we must overcome these fears with scientific information. Genetic modification of plants is something that is possible and necessary, and genetically modified organisms have been very successfully adopted in the past, from the Neolithic Revolution to the Green Revolution led by Nobel Prize winner Norman Borlaug (agronomist). The consumer distrusts dominant positions in the market, especially in something as sensitive as feeding humanity. Because of that, legislation will be needed that ensures fair access to these resources, especially in areas of need. For example, there are millions of diabetics who need access to insulin (obtained by genetic engineering), and that is perfectly regulated.
- In this 'Green Revolution', what new varieties of plants or cultivars are going to be improved thanks to this technique?
It is possible to improve practically any cultivar. For obvious reasons grains, which comprise the predominant diet on the planet, would be the main targets. This Green Revolution already existed at the end of the 20th century (1960-80), but we have gone from 3 to almost 8 billion people, which demands new improvements. That does not mean that every crop will be modified, only when there are benefits for agriculture, the consumer and our environment.