In keeping with its name, green biotechnology is a subcategory of biotechnology that conjures imagery of flora and planet-friendly advances. Encompassing the biotechnological application of plants, including agricultural crops; green biotechnology and agricultural biotechnology (AgBiotech) are so mutually inclusive they are increasingly used interchangeably. Recently, interest in green biotechnology has increased significantly, but why is it generating such a buzz?
Green biotechnology is part of the wider movement of ‘going green’. Depletion of finite resources is becoming an increasingly important challenge to address and biotechnological solutions to challenges like crop enhancement and protection are gaining traction.
Researchers have been studying trait discovery and crop protection for some time, but growing pressures from environmental stresses and food security concerns have garnered new and increased interest in these projects.
In it for the long haul
Sustainable development is a key phrase in all areas of ‘going green’, biotechnology included. It is the idea of taking steps to ensure that new developments don’t cause long-term environmental damage or intervening to stop current technologies from doing so. After decades of reliance on non-renewable resources, such as fossil fuels, the green revolution is vital to create alternatives to current damaging practices[1].
Biotechnology offers significant promise in sustainable development. Advances in crop protection, such as genetically modified organism (GMO)-free RNA interference, have the potential to increase the productivity and yield of plant crops enough to address food insecurity.
Already a global issue due to population growth, food security is a challenge exacerbated further by changes in climate altering the environmental conditions for food production. Again, biotechnology has the potential to help us mitigate some of the effects to secure the agricultural future despite evolving climates[2].
Looking for the advantage
Trait discovery, the process of defining the genes or genomic regions responsible for certain traits, allows for selection and genetic engineering, even across species, which can help plants adapt to stresses such as varying environmental pressures[3]. One example of this is the tomato. Accounting for 15% of the world’s vegetable production, the tomato is both an important food crop and an established model organism in AgBiotech research.
As a model organism, the tomato plant has been fully sequenced and many of its traits annotated through quantitative trait locus (QTL) mapping and genome-wide association studies (GWAS). These maps and databases make it possible to more effectively plan agricultural genetic engineering.[4]
The recent advances in biotechnological techniques have led to widespread gathering of genome-wide data and ease of trait engineering using CRISPR-Cas systems. Of course, while the science races ahead, important decisions regarding GM crops are yet to be made.
In the USA, CRISPR-edited plants are accepted as safe and are not subject to a lengthy approval process[3], but the same does not apply within the EU. Due to concerns around transfer of traits and environmental effects, GM products, including plant varieties developed with CRISPR-Cas technology are currently required to undertake a long approval process, increasing associated costs[5]. Research into the safety of trait-engineered crops will need to continue for the foreseeable future, addressing safety concerns to push forward with the new age of green biotechnology.
Increasing defences
Naturally, trait discovery is often applied to the issue of crop protection. When you can pick and choose traits, those that help your product survive stress tend to be at the top of the list.
Stress from abiotic factors such as the weather or biotic factors such as pests can be tackled by engineering resistance within the plant. Modern genetic engineering techniques allow for not only the introduction of genes from genetically incompatible plants but even from other organisms entirely.[4]
Cisgenic strategies of genetic modification, where desirable genes are sourced from a plant that could be used in a traditional cross breed, are widely socially accepted since the resulting plant could have been achieved without genetic modification. The advantage over crossbreeding is that it is possible to limit the transfer to only the desired genes by cisgenesis, as opposed to half the genetic material in a cross. This allows for fine tuning of the genome without carrying over unwanted traits. However, in practice, cisgenesis is mostly limited to single gene transfers, a huge drawback since many plant traits are determined by multiple genes at multiple loci.[4]
CRISPR-Cas systems, on the other hand, are well suited for modifying multi-gene traits. CRISPR-Cas has revolutionized what is possible in AgBiotech and crop protection since it’s development in 2014, the ability to perform targeted genetic modification like never before has unleashed a world of opportunities in the sector.
Transgenic tomato plants, for example, have been successfully developed to alter many traits including fruit ripening, fruit shelf life and resistance to pathogens. Refinements to the CRISPR-Cas system, such as new Cas enzymes better adapted to plants and marker-free systems, has led to CRISPR-modified crops becoming a rapidly growing research field[6, 7]. However, as crops produced with CRISPR strategies continue to face long approval processes in Europe, the green biotechnology innovation sector has had to be even more creative.[4]
A new approach
Where there is concern over GM products, resilience can also be achieved by leveraging small RNAs (sRNAs) and RNA interference (RNAi) technologies. This is already an approach used to genetically modify crops to express the double stranded RNAs (dsRNAs) for gene silencing in RNAi. In 2017, SmartStax Pro, a transgenic maize designed to express dsRNA against corn rootworm, was approved for use in the United States. However, there is also the possibility of GM-free RNAi approaches.[8]
Achieving RNA interference without genetic modification involves applying dsRNA or sRNA molecules exogenously. For example, by spraying on the crop for absorption, leading to a change in phenotype without any actual modification to the plant genome. This exogenous application can be used to target plant cells or other organisms within the plant, such as bacteria or fungi. As well as avoiding the need to create a GM product, exogeneous application also makes the RNAi more widely applicable since the plants do not need to be a specific transgenic line.[8]
A key challenge to this approach is the plant cell walls. Rich in cellulose, tough, and varying in thickness, cell walls are a potentially problematic physical barrier to delivery. To overcome this, recent research has leveraged nano molecules as carriers to improve delivery efficacy. While nanoparticles appear very successful, they often require a synthesis step that adds to cost, a consideration from a commercial standpoint.
Other, less costly, application techniques center around inducing mechanical damage to the plant leaves, allowing for easier entry into the cells. High-pressure spraying and brush-mediated application have been successfully used for leaf application on Arabidopsis and N. benthamiana[8-10] and could be a more commercially viable alternative.
With the rise of green biotechnology, access to fast and reliable genomics services is more important than ever. Our genomics team offers support for all aspects of genomics research from the initial design stages through to analysis and interpretation. Our rapid, cost-effective research services solution is tailored exactly to your needs.
Discuss a project with us today and see how we can help you usher in the new age of green biotechnology.
References
- Hebatallah Ahmed Nasser, et al., Pros and cons of using green biotechnology to solve food insecurity and achieve sustainable development goals. Euro-Mediterranean Journal for Environmental Integration, 2021. 6(1): p. 29.
- R. Lake Iain, et al., Climate Change and Food Security: Health Impacts in Developed Countries. Environmental Health Perspectives, 2012. 120(11): p. 1520-1526.
- Emily Waltz, Gene-edited CRISPR mushroom escapes US regulation. Nature, 2016. 532(7599): p. 293-293.
- Christophe Rothan, Isidore Diouf, and Mathilde Causse, Trait discovery and editing in tomato. The Plant Journal, 2019. 97(1): p. 73-90.
- E. Callaway, CRISPR plants now subject to tough GM laws in European Union. Nature, 2018. 560(7716): p. 16.
- Tomáš Čermák, et al., A Multipurpose Toolkit to Enable Advanced Genome Engineering in Plants. The Plant cell, 2017. 29(6): p. 1196-1217.
- Holger Puchta, Applying CRISPR/Cas for genome engineering in plants: the best is yet to come. Current Opinion in Plant Biology, 2017. 36: p. 1-8.
- Athanasios Dalakouras, et al., Genetically Modified Organism-Free RNA Interference: Exogenous Application of RNA Molecules in Plants1 [OPEN]. Plant Physiology, 2019. 182(1): p. 38-50.
- A. Dalakouras, et al., Induction of Silencing in Plants by High-Pressure Spraying of In vitro-Synthesized Small RNAs. Front Plant Sci, 2016. 7: p. 1327.
- Alexandra S. Dubrovina, et al., Induction of Transgene Suppression in Plants via External Application of Synthetic dsRNA. International Journal of Molecular Sciences, 2019. 20(7).
