A newly discovered plant gene could be modified to increase crop yields, according to a new paper published on 10 June in Nature Plants. The gene may influence how plants transport sugars, proteins, and other key organic nutrients between different parts of the plant that could provide the key to boosting crop production (1).
Understanding the factors that affect nutrient transport in plants could help plant biologist develop strategies to sustainably increase crop yields. To this end, scientists from the University of Cambridge and the University of Bordeaux have discovered the so-called Phloem Unloading Modulator (PLM), a gene that helps control the movement of nutrients throughout plants.
More specifically, the gene makes changes to the tiny nutrient-transport channels between plant cells called plasmodesmata. These nanoscale channels are found along the cell wall barrier linking plant cells and allow them to transfer essential substances. And according to the authors, some of these plasmodesmata have a modified cytoplasmic sleeve that results in higher rates of nutrient trafficking.
The study was based on Arabidopsis thaliana or thale cress, a small flowering plant of the mustard family that is often used as a model organism in biology. Interestingly, the researchers observed that A. thaliana plants without the PLM gene release more substances from their root tips from an area called the phloem.
They came to this conclusion by examining different cell interfaces in the roots of seedling plants. In addition, molecular and genetic investigations showed that PLM is involved in making sphingolipids, a class of lipids associated with plant development and responses to the environment.
Moreover, by observing the plasmodesmata on the nano-scale, they discovered that plants without PLM only had one type of plasmodesmata instead of the two types that are normally found — and this type has a very narrow cytoplasmic sleeve that is actually more conductive.
So, the authors suggest that blocking the activity of the PLM gene in other plant species could potentially relieve a “trafficking bottleneck”, essentially speeding up the transfer of nutrients from the vascular system of plants into rapidly growing tissues in the roots — where they are most needed.
And more importantly, could present an environmentally friendly way of boosting crop production — which could reduce the use of fertilisers while increasing crop yields. It may even be possible to direct the transport of nutrients to specific parts of the plant such as seeds or fruit.
The global population is expected to reach 10 billion by 2050 leading to higher demands for food production. In fact, overall food production will need to increase by as much as 70 per cent between now and 2050 to meet the projected future food demands. However, climate change will also continue to cause increasingly more frequent agricultural challenges that threaten global food security.
Effective plant breeding programmes and genetically modified crops have the potential to improve agricultural productivity, lower the need for pesticides, and reduce poverty. Perhaps, scientists will eventually be able to increase food production from agricultural crops by fully decoding plant DNA.
(1) Yan, D. et al. Sphingolipid biosynthesis modulates plasmodesmal ultrastructure and phloem unloading. Nature Plants (2019). DOI: 10.1038/s41477-019-0429-5