Why pruning encourages plants to thrive
Teams of collaborators from the University of York in the UK and the University of Calgary, Canada combined their expertise in molecular genetics and computer modeling to make an important discovery that helps explain why the pruning encourages plants to grow.
Understanding the action and interaction of these hormones can inform horticultural practices designed to change patterns of branching in various crops.
The research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Natural Sciences and Engineering Research Council of Canada (NSERC).
Directed by Professors and Ottoline Leyser Przemyslaw Prusinkiewicz and published in the journal PNAS, the investigation showed that all the tips of the shoots of a plant can influence the growth of others.
Professor Leyser, York University, Department of Biology, said: “It is well known that the main growing shoot of a plant can inhibit the growth of buds below – that’s why we prune to encourage growth of the branches . What interests us is exactly as in the main stem can have this effect.
“It has been known since 1930 that the plant hormone auxin is released from the plant actively growing tip and is carried by the main stem where it has an indirect effect on outbreaks to inhibit branching. There are a number of ways in which the hormone exerts this effect and found a new path that works. ”
Research suggests that for a tip of the outbreak to be active, must be able to export auxin into the main stem. But if large amounts of auxin already exist in the main stem, the export of an additional terminal bud can not be established.
Professor Leyser said: “The use of this mechanism, all shoot tips of a plant to compete, so the top and bottom ends can influence the growth of others. This allows for the strongest branches grow more vigorously, wherever located in the plant. The main stem dominates especially because it was there first, rather than its position at the top of the plant. ”
The teams went on to show that the plant hormone recently discovered strigolactone, works, at least in part, so it is harder to establish new routes of auxin transport tips, strengthening competition between sources of auxin and reduced branching.
The research also involved scientists from the Department of Forest Genetics and Plant Physiology Swedish University of Agricultural Sciences.
Provided by the University of York