Science continues to have many frontiers of which the plant kingdom is just one. It continues to provide explanations and explores new capabilities. It helps to explain evolution whilst helping to unravel the understanding of life itself, bit by bit.
Last week the International Association for Plant Biotechnology held its annual congress in Dublin. Presentations displayed the capability of a range of modern technologies which can interact at cellular, plant or environmental level.
There were presentations on how plants directly impact on human health and how modifications to plants can significantly alter the levels of these health-related substances.
For us in the EU, the major limitation to securing the potential benefits of these technologies is the legislative controls which apply to the process of gene manipulation. In many regions of the world it is the product of manipulation that is assessed for its safety to humanity and the environment, but in the EU it is the process which is legislated.
This means that research itself is restricted. But this problem is for the EU itself to change, if it so chooses.
A basic understanding
While the conference was predominantly high-end science it was also apparent that many of these areas are individually specific.
Perhaps the best known of these biotechnologies is GMO, an abbreviation which has come to describe crops which were altered for specific traits through the insertion of genetic material from a different species, ie from bacteria generally.
It is a gene from these bacteria that confers Roundup resistance and/or insect resistance in the global GM crops. This transfer of genetic material from one species to another is known as ‘transgenesis’.
Getting foreign genes into plants was generally done using a gene gun or bacteria. Both were a bit hit and miss and as a result the gene that was being inserted was often marked in some way to enable the trait to be found in the resultant plant without having to take the plant through its lifecycle.
The main bacteria used for transfer is Agrobacterium tumefaciens, which is the pathogen which causes crown gall in trees. Because it is now used to carry genes into a plant it is often referred to a gene jockey.
In recent years there has been a lot more emphasis on more precise mechanisms which can literally switch individual genes on or off to alter the characteristics of an individual variety.
Gene editing is very much the current buzzword and this uses an enzyme to alter individual genes within a plant cell without inserting any external material.
CRISPR/Cas9 is one such technology and this is heralded as having the potential to have a big impact on our capacity to alter gene expression in plants, animals and humans.
However, the recent ruling by the European Court of Justice clarified that gene editing techniques come under the remit of current GMO legislation. This means that this technology has limited use within the EU unless the legislation is changed.
Mutagenesis is any process which alters the genetic information within an organism. It is the result of a mutation which can occur spontaneously in nature (resistance in pests, weeds and diseases), be forced by exposing the organism to specific external agents like radiation and nowadays it can be done experimentally using laboratory procedures to transfer or edit genes.
Sell the benefits
Genetic modification plays an important role in genetics – plant, animal and human. But it is also being used in very many other aspects of science which can be used to help the sustainability of biological systems.
One of the big challenges facing the scientific community is to convince society that modern technology tools are good for society.
A number of speakers commented that one of the roles of the research should be to put forward justifiable cases for research and then again for the results and recommendations. Science has not been good at doing that.
If science cannot succeed in this communication then the EU will remain stagnant.
Natural health substances
“Food is about health care. Medicine is about sick-care.” This was a title of a very interesting paper on the importance of plant-produced substances for human health.
Cathie Martin from the John Innes Centre gave a brief summary of some of the health-relevant chemicals known today and outlined ways in which these could be delivered in a simple food like a tomato.
Cathie used transgenic GM to transfer genes to a tomato as she used this crop as a type of proof of concept to test if we could use plants to deliver elevated quantities of substances like anthocyanins, flavonoids and resveratrol. And her work proved that she could deliver a range of substances with health related benefits.
The modified tomatoes that she produced brought colour changes in conjunction with the chemical changes.
She ended up producing a range of different coloured tomatoes with each colour aligned to a specific targeted health chemical.
These health chemicals occur naturally in other foods but at lower levels. For example, resveratrol is contained in the skin of red grapes and in red wine but with one modified tomato containing the same total quantity as 50 bottles of red wine, the tomato offered a more practical solution.
Cathie also spoke about the option of delivering the benefits via juice from the coloured tomatoes.
While this project is using transgenic traits (sourced from one species and inserted in another) Cathie commented that she believes that anti-GM is now more of a corporate issue than a safety or genetic modification issue.
She is working on the premise that if science can deliver traits that are solely for the benefit of consumers then attitudes may change.
Using fungi to yield-kick spring barley
There were a number of presentations which did not involve gene or DNA alteration – they looked at the beneficial or synergistic coexistence of micro-organisms and plants.
This is not a new theory, but pinning down the species that exhibit these benefits in the field remains a challenge. Such beneficial organisms are known as endophytes and they work inside the plant for its benefit.
Brian Murphy from Trinity College has been working on the consequences of a mix of organisms found to have synergistic effects on barley growth.
Field experiments used endophyte-dressed seed and examined their impact on the yield of three spring barley varieties at different sites in Cork and Kildare.
The specific endophytes were known to help nitrogen metabolism and so the trial used three different N rates (full, half and none) with and without the endophytes.
The results are impressive. Planet appeared to be most responsive and yield increases varied from 10 to 16%. The response level was also impacted by site. In general, the endophyte-treated plots yielded more with less applied nitrogen.Rainfall level impacted on the responses.
The treatment is being tested at many more sites and in a number of countries in 2018.
This is just one example of how biotechnology (understanding biological systems) can be used to enhance crop performance by using natural organisms to aid crop growth. We will watch this story with interest. More yield with less cost has to be a prerequisite for the future.
Photosynthesis is the process of taking energy from the sun and using it to grow plants which produce food and other resources for the world’s population. It is the absolutely critical chemical process for the survival of the human race.
We take it for granted but now scientists are asking if the process can be altered in some way to make it more efficient to help produce more food.
Science has continued to look increasingly deep into the chemical pathways that make up photosynthesis.
This knowledge, coupled with the tools of modern biotechnology, is enabling scientists to look in depth at the different processes.
For Christine Raines from the University of Essex, increasing the levels of photosynthesis efficiency is a primary ambition. She explained that yield is ultimately the conversion of solar energy. Put simply she explained the process as follows:
Within this formula there is no limitation on solar energy and she suggests that we are close to maximising both light interception and harvest index in mainstream crops, but not all crops. So she sees an improvement in light conversion efficiency (photosynthesis) as a significant target area to improve plant yields.
An experiment on carbon dioxide (CO2) enrichment (a technique sometimes used in glasshouse crops) found field yield benefits of up to 16% for soya beans, 15% for wheat and 12% for rice. This shows that there is potential to improve the efficiency of the process.
Christine explained that photosynthesis efficiency has not been used to select for higher yield potential in the past but this is changing.
She indicated that there are a number of ways in which it may be possible to alter efficiency, all of which might target enzymes in the plant cell. She also indicated the possibility of converting C3 crops (a description of the type of photosynthesis mechanism they use) such as cereals, grass, brassicas, beet etc, to C4 crops which can grow faster and more efficiently and occur naturally in crops like maize.