The Significance of Genetically Modifying Glutamate in Plants
As the population continues to grow and food production becomes more difficult due to weather patterns, disease, and lack of nutrient rich land, better solutions are needed. It is the hope of many scientists all over the world that genetically modifying plants and animals will assist with the challenges that we face, specifically wipe out genetic and infectious disease, improve drought resistance, boost nutrient efficiency, and prolong shelf life.
In fact, this is already being done. However, it’s an ongoing learning and innovating process and in some cases licensing restrictions exist (which our technology overcomes). It’s not just the constant discovery of scientific knowledge that researchers are inundated with, but the technology continues to change and improve.
Traditional crop breeding techniques are challenging and remain a lengthy process. Older generation transgenic technologies produce GMOs with permanent heterologous genes inserted.
Conversely, advanced gene editing technologies enable plant biotechnologists with the ability to make targeted knockouts and insertions. This scarless gene editing means no heterologous genes are left in the plant genome, producing a non-GMO crop simplifying the process and possibly shortening timelines.
The Role of Glutamate in Plants
Glutamate is an amino acid that contributes to metabolism, regulation, and signaling pathways within plant cells. It is a precursor for other amino acids that contribute to a multitude of reactions as well as a precursor for chlorophyll synthesis.1
Figure 1 shows glutamate synthesis pathways as well as metabolism in plants. This balanced pathway is a perfect opportunity to take advantage of gene editing tools that have the potential to increase plant growth.
Editing Glutamate In Tomatoes
A recent study on hydroponically grown tomatoes suggested a decline in glutamate following nitrate starvation; therefore, there is a connection that could be manipulated to improve plant growth for agricultural purposes. The potential might seem obvious, but finding the right target within the different possible pathways will bring obstacles without a doubt.
Another possible opportunity to enhance food production is through the chlorophyll synthesis. A recent study found an increased glutamate concentration in the leaves of red tomatoes compared to the green fruit. 1
More research is needed, but if the glutamate accumulation towards the end of ripening is due to the end of chlorophyll synthesis, then gene editing in this pathway could lead to longer storage and longer lasting freshness in tomatoes and possibly other produce.
As the precursor for both amino acids (arginine and proline), glutamate regulates a range of stresses such drought induced stress, salinity, low and high temperatures, and heavy metals. 1 As climate change and increased stress placed on agriculture, genetic editing capabilities to overcome these challenges will be extremely useful.
Additionally, arginine plays a role in nitrogen storage which could be a practical approach to plant growth when a nitrogen source is scarce. Finding the optimal targets within these pathways is necessary to get the desired outcome.
Novel Tools For Gene Editing In Plants
Novel gene editing proteins such as, Cas9, transcription activator-like effector nucleases (TALEN), and zinc-finger nucleases (ZFN) target specific genes in a deliberate manner. This is compared to previous tools that randomly insert, delete, or cause a frameshift in the sequence being edited; dramatically altering gene function.
Figure 2 shows the Cas-CLOVER gene editing system. As opposed to the use of a single guide RNA (gRNA) for sequence-specific gene editing (like in CRISPR), the Cas-CLOVER system utilizes a dual gRNA in addition to the Clo51 nuclease activity that requires dimerization of subunits associated with each guide RNA. This allows for more stringent DNA cleavage. Using two gRNA makes the Cas-CLOVER gene editing system highly restricted and only functional when the paired gRNAs coexist.
Companies like Demeetra recognize the impact that more sophisticated gene editing tools have on the future of agriculture and the world as a whole. The validated Cas-CLOVER activity in plants is exciting for crop trait development as it opens up numerous opportunities.
We’re offering clear commercial freedom to operate and simple accessible licenses to researchers. Demeetra is especially interested in special collaborations with academic groups that can result in traits which can ultimately be adopted commercially to enhance food production while being mindful of the environment. The future of agriculture will rely on science more than ever.
If you’d like to learn more about Cas-CLOVER, please contact us to schedule a meeting online.
- Forde, B. G., & Lea, P. J. (2007). Glutamate in plants: Metabolism, regulation, and signalling. Journal of Experimental Botany, 58(9), 2339–2358. https://doi.org/10.1093/jxb/erm121