Plant scientists unravel a molecular switch to stimulate leaf growth

State-of-the-art techniques

To unravel a biological process on a molecular level, scientists typically develop plants in which genes are switched on or off. Studying the effect of these "aberrant" situations on plant growth can in some cases resolve the function of these genes. However, this approach often is like finding a needle in a haystack. Plant scientists of VIB and Ghent University therefore used various state-of-the-art techniques to study the effect of the "aberrant" molecular situation on all genes and all proteins at once. As such, the researchers could elucidate the function of AN3 in the model plant Arabidopsis.

Unpacking DNA to switch on gene activity

All cells of a particular plant contain the same genetic information, which is stored in their DNA. DNA is packed in a condensed structure, the chromatin. When certain genes need to be activated, the chromatin will be unpacked to make specific DNA regions accessible. This process is mediated by so-called "chromatin remodeling" complexes. An international team of scientists led by Dirk Inzé of VIB and Ghent University demonstrated that AN3 functions as part of a chromatin remodeling complex. More precisely, AN3 recruits the chromatin remodeling complex towards specific DNA regions that harbor cell division genes. As long as AN3 is active and keeps recruiting the chromatin remodeling complex, cells retain their division activity, resulting in plant organs with increased size. The AN3 protein complex regulates the length of the cell division phase in the leaf and hence the transition from cell division towards cell specialization.

This research was performed in collaboration with the University of Pennsylvania (USA), the French "Institut de Biologie des Plantes," the Polish University of Warsaw and the Polish Academy of Sciences. The obtained insights can now be used to orchestrate plant breeding activities more efficiently, for example towards higher plant productivity.