sentence: EgMYB1 downregulates EgCCR and EgCAD expression ( Legay et al ., 2007 ) , whereas PtoMYB156 downregulates secondary wall formation during xylogenesis in Populus tomentosa via the phenylpropanoid pathway ( Yang et al ., 2017b ) , and overexpression of Maize ZmMYB31 in Arabidopsis thaliana reduces lignin content of transgenic plants , which show a dwarf phenotype ( Fornal é et al ., 2010 ) .