Peptide GOLVEN10 alters root development and noduletaxis

For many years, biologists argued about whether plants have peptide hormones like animals have, and ever since it was first shown that plant peptides do have hormone-like functions, I’ve said a little cheer as new functions are discovered (Yay plants!). A few years ago, Sonali Roy and colleagues wrote an excellent Teaching Tool on this topic (Small and mighty: Peptide hormones in plant biology) which I encourage you to read and share. Here, Roy et al. demonstrate a new role for the GOLVEN10 peptide in Medicago truncatula. Previous work identified roles for GOLVEN (GLV) peptides in root development; GLV overexpression leads to a wavy root and golven means “waves” in Dutch. The authors found that in Medicago, GLV10 is expressed in nodule-initiation sites and under the control of the NODULE INCEPTION (NIN) transcription factor. They found that application of GLV10 peptide to roots caused a decrease in nodule number, independent of effects on the symbiont. Interestingly, they also found a shift in position of the nodules and lateral roots along the root axis away from the root base, and that GLV10-treated roots had more, shorter cortical cells. Consistent with this finding, analysis of genes regulated by GLV10 showed that cell-cycle and cytoskeleton-related genes are differentially expressed. Thus, GLV10 is a regulator of nodule placement, or, by analogy to phyllotaxis, “nodultaxis”. (Summary by Mary Williams @PlantTeaching) Plant J. 10.1111/tpj.16626