“Ligand receptor pairs that regulate stem cell niches in plant stems"

Venue: New Seminar Room, James Hutton Institute, Invergowrie 

Host: Professor Paul Birch

Abstract

The cambium is the stem cell niche in eudicot plants from which xylem and phloem tissues are derived through tightly controlled cell division and differentiation. However, the specific factors that maintain cambial stem cells have been elusive. We reveal that the TDIF-PXY signalling pathway, known to regulate cell division and differentiation in the cambium, controls the expression of PLTtranscription factors within the Arabidopsis thaliana cambial zone. Our data demonstrate that these PLT genes constitute the long-sought-after stem cell identity factors within the actively dividing cambial meristem.

Interestingly, while monocot species lack a cambium, they retain homologs of these regulatory genes. Ongoing efforts in barley reveal surprising conservation, yet subfunctionalization of TDIF-PXY signalling. Our analysis suggests repurposing of this signalling pathway in the different angiosperm lineages to control distinct zones of cell proliferation. This work thus provides insight into the regulation of different stem architectures in monocots and dicots.