Could the green tea help us with the food security?

The fast developing world faces progressing globalisation and increasing number of people. The following pressures us to rise food production and overcome unfavourable environmental conditions, like drought, for growing area of crop plantations. One of the methods to improve grain yields is the creation of genetically modified organisms (GMOs). Although GM crops are recognized as safe by many scientists, there is a lot of controversy over health safety and potential transfer of newly introduced genes to other organisms.

Improving life standards in many countries increase consumption, therefore the companies would like to reach their clients globally. To do so they often combine their efforts by consolidating power into one merged company. A prospective fusion of the biggest GMO and pesticide producer with the biggest pharmaceutical company rises people concerns over food safety and quality. Likely, the law regulations regarding many aspects of trade between countries are being simplified and standardised. This includes production and import of GM crop plants.

Is the use of pesticides and herbicides safe to our health? Are there any other methods which does not interfere with DNA but have similar effect? I may not have ready answers for you now, but hopefully I will give you a little glimpse on how scientists like myself try to find the best solutions.

Plant cell wall is the main barrier protecting the cell from the danger of pathogen attack or environmental changes. It creates a “net” around cells built with complex sugars like cellulose, hemicellulose and pectin. Modulations in composition cause the weakening or strengthening of cell wall. The rigid cell wall can withstand severe weather conditions like heavy rains or strong winds. I will focus on one of the components, pectin. It bonds together other cell wall components creating a “gel”, therefore it is a good target for studies. The ability to design a “gel” is altered by enzymes called pectin methylesterases (PMEs).

The aim of our project was to modulate the activity of PME and see how it influences root development in a model plant, Arabidopsis. Roots are the perfect organ to study as they undergo many processes like cell division, cell differentiation and produce new organs (root branches). The PME activity could be changed using genetic engineering but we found an alternative approach. In our study we used pharmacological tool, polyphenon-60 (PP60), which is a catechin green tea extract. The component of PP60 and green tea called epigallocatechin gallate (EGCG) has been shown to have beneficial impact on our health including lowering risk of cancer and Alzheimer’s disease. In our experimental approach plants were grown on the solid media containing PP60 and the activity of PME was measured. We discovered that PP60 increased the activity of pectin modulating enzymes, roots became short and plants were more resistant to acidic stress. This indicated that green tea extract has a positive effect on plants making them resistant to particular stresses probably due to alterations in pectin composition.

Another ongoing project aim is to study changes in small molecules produced by plants after use of herbicide called isoxaben. Isoxaben is commonly used in vineyards to kill weeds growing around grape-bearing vines. It blocks synthesis of cellulose therefore damaging the cell wall. There is a little knowledge about isoxaben impact on plant metabolism and sugar composition. We have grown plants in liquid media with addition of isoxaben and then measured the content of small molecules produced by the whole plant. This approach will let us understand how the plant metabolism changes and what is the cell wall maintenance mechanism after damages caused by isoxaben.

The results obtained from these studies could be used to advance our knowledge of cell wall maintenance mechanism and herbicides impact on plants as well as contribute to food industry in production of stress resistant fruits and vegetables.

About the Author

Przemyslaw_OciepaPrzemek Ociepa finished his PhD at the University of Southampton. His study involved collaboration with research centres from UK, France, and Norway and was funded by the European Union INTERREG programme and the short-term fellowship award from the European Molecular Biology Organisation. Przemek is interested in improving crop plants for better yield and biofuels production. He likes to organise public engagement and science communication activities outside the lab. Travelling and capturing the beauty of architecture and nature on photographs is his passion too.

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