The Poplar MYB Transcription Factors, PtrMYB3 and PtrMYB20, are Involved in the Regulation of Secondary Wall Biosynthesis

McCarthy, Ryan L.
Zhong, Ruiqin
Fowler, Scott
Lyskowski, David
Piyasena, Hasanthi
Carleton, Kara
Spicer, Charles
Ye, Zheng-Hua

Department of Plant Biology, University of Georgia, Athens, GA 30602, USA

*Corresponding author: E-mail, [email protected]; Fax, +1-706-542-1805

Received March 28, 2010

Accepted April 23, 2010

Plant and Cell Physiology 51(6):p 1084-1090, June 2010. | DOI: 10.1093/pcp/pcq064

Dicot wood is mainly composed of cellulose, xylan and lignin, and its formation requires the coordinated regulation of their biosynthesis. In this report, we demonstrate that the poplar wood-associated MYB transcriptional activators, PtrMYB3 and PtrMYB20, activate the biosynthetic pathways of cellulose, xylan and lignin when overexpressed in Arabidopsis and they are also able to activate the promoter activities of poplar wood biosynthetic genes. We also show that PtrMYB3 and PtrMYB20 are functional orthologs of Arabidopsis MYB46 and MYB83, and their expression is directly activated by poplar PtrWND2, suggesting their involvement in the regulation of wood formation in poplar.