Increasing crop yields is one of the goals of plant scientists and increasing the efficiency of how plants transport sugars, proteins and other organic nutrients between different parts of the plant is one of the strategies they are investigating. To this end, understanding the factors that affect short and long distance transport inside a plant could allow them to breed more productive crops by directing transport of nutrients to specific parts of the plants.
Researchers at the University of Cambridge in the UK, led by Yrjö Helariutta, and the University of Bordeaux in France, led by Emmanuelle Bayer, say they have now taken an important step in this direction with the discovery of Phloem Unloading Modulator (PLM), a new gene that affects nutrient trafficking by altering the channels connecting neighbouring plant cells called plasmodesmata.
The study, published in Nature Plants, shows that Arabidopsis thaliana mutant plants missing the PLM gene release more substances from the phloem (a specialized tissue for long distance transport) at the tips of their roots. The researchers employed fluorescent protein as a proxy for macromolecules and saw that the PLM gene had a clear controlling effect on the amount of phloem unloading.
Reference: Dawei Yan, Shri Ram Yadav, Andrea Paterlini, William J. Nicolas, Jules D. Petit, Lysiane Brocard, Ilya Belevich, Magali S. Grison, Anne Vaten, Leila Karami, Sedeer el-Showk, Jung-Youn Lee, Gosia M. Murawska, Jenny Mortimer, Michael Knoblauch, Eija Jokitalo, Jonathan E. Markham, Emmanuelle M. Bayer, Ykä Helariutta, Sphingolipid biosynthesis modulates plasmodesmal ultrastructure and phloem unloading. Nature Plants.
The French members of the team are from the Laboratoire de Biogenèse Membranaire (UMR 5200, CNRS, Université de Bordeaux) and the Bordeaux Imaging Centre, Plant Imaging Platform, (UMS 3420, INRA-CNRS-INSERM, University of Bordeaux).