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ZmMYB31 directly represses maize lignin genes and redirects the phenylpropanoid metabolic flux
Author(s) -
Fornalé Silvia,
Shi Xinhui,
Chai Chenglin,
Encina Antonio,
Irar Sami,
Capellades Montserrat,
Fuguet Elisabet,
Torres JosepLluís,
Rovira Pere,
Puigdomènech Pere,
Rigau Joan,
Grotewold Erich,
Gray John,
CaparrósRuiz David
Publication year - 2010
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2010.04363.x
Subject(s) - phenylpropanoid , monolignol , lignin , myb , arabidopsis thaliana , arabidopsis , biosynthesis , biochemistry , promoter , genetically modified crops , chromatin immunoprecipitation , transgene , gene , biology , metabolic pathway , flux (metallurgy) , chemistry , botany , transcription factor , mutant , gene expression , organic chemistry
Summary Few regulators of phenylpropanoids have been identified in monocots having potential as biofuel crops. Here we demonstrate the role of the maize ( Zea mays ) R2R3‐MYB factor ZmMYB31 in the control of the phenylpropanoid pathway. We determined its in vitro consensus DNA‐binding sequence as ACC T / A ACC, and chromatin immunoprecipitation (ChIP) established that it interacts with two lignin gene promoters in vivo . To explore the potential of ZmMYB31 as a regulator of phenylpropanoids in other plants, its role in the regulation of the phenylpropanoid pathway was further investigated in Arabidopsis thaliana . ZmMYB31 downregulates several genes involved in the synthesis of monolignols and transgenic plants are dwarf and show a significantly reduced lignin content with unaltered polymer composition. We demonstrate that these changes increase cell wall degradability of the transgenic plants. In addition, ZmMYB31 represses the synthesis of sinapoylmalate, resulting in plants that are more sensitive to UV irradiation, and induces several stress‐related proteins. Our results suggest that, as an indirect effect of repression of lignin biosynthesis, transgenic plants redirect carbon flux towards the biosynthesis of anthocyanins. Thus, ZmMYB31 can be considered a good candidate for the manipulation of lignin biosynthesis in biotechnological applications.