RT Journal Article
SR Electronic
T1 COMPOSITUM 1 (COM1) contributes to the architectural simplification of barley inflorescence via cell wall-mediated and meristem identity signals
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.02.18.952705
DO 10.1101/2020.02.18.952705
A1 N. Poursarebani
A1 C. Trautewig
A1 M. Melzer
A1 T. Nussbaumer
A1 U. Lundqvist
A1 T. Rutten
A1 T. Schmutzer
A1 R. Brandt
A1 A. Himmelbach
A1 L. Altschmied
A1 R. Koppolu
A1 H. M. Youssef
A1 M. Dalmais
A1 A. Bendahmane
A1 N. Stein
A1 Z. Xin
A1 T. Schnurbusch
YR 2020
UL http://biorxiv.org/content/early/2020/03/20/2020.02.18.952705.abstract
AB Grasses have varying inflorescence shapes; however, little is known about the genetic mechanis ms specifying such shapes among tribes. We identified the grass-specific TCP transcription factor COMPOSITUM 1 (COM1) expressed in inflorescence meristematic boundaries of differe nt grasses. COM1 specifies branch-inhibition in Triticeae (barley) versus branch-formation in non-Triticeae grasses. Analyses of cell size, cell walls and transcripts revealed barley COM1 regulates cell growth, affecting cell wall properties and signaling specifically in meristematic boundaries to establish identity of adjacent meristems. COM1 acts upstream of the boundary gene Liguleless1 and confers meristem identity independent of the COM2 pathway. Furthermore, COM1 is subject to purifying natural selection, thereby contributing to specification of the spike inflorescence shape. This meristem identity module has conceptual implications for both inflorescence evolution and molecular breeding in Triticeae.