Syringyl lignin biosynthesis is directly regulated by a secondary cell wall master switch
Open Access
- 26 July 2010
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 107 (32), 14496-14501
- https://doi.org/10.1073/pnas.1009170107
Abstract
Lignin is a major component of plant secondary cell walls and is derived from p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) monolignols. Among higher plants, S lignin is generally considered to be restricted to angiosperms, which contain the S lignin-specific cytochrome P450-dependent monooxygenase, ferulic acid/coniferaldehyde/coniferyl alcohol 5-hydoxylase (F5H). The transcription factor MYB58 directly regulates expression of monolignol pathway genes except for F5H. Here we show that F5H expression is directly regulated by the secondary cell wall master switch NST1/SND1, which is known to regulate expression of MYB58. Deletion of NST1 expression in Medicago truncatula leads to a loss of S lignin associated with a more than 25-fold reduction of F5H expression but only around a 2-fold reduction in expression of other lignin pathway genes. A detailed phylogenetic analysis showed that gymnosperms lack both F5H and orthologs of NST1/SND1. We propose that both F5H and NST1 appeared at a similar time after the divergence of angiosperms and gymnosperms, with F5H possibly originating as a component of a defense mechanism that was recruited to cell wall biosynthesis through the evolution of NST1-binding elements in its promoter.Keywords
This publication has 46 references indexed in Scilit:
- Convergent Evolution of Syringyl Lignin Biosynthesis via Distinct Pathways in the Lycophyte Selaginella and Flowering PlantsPlant Cell, 2010
- Discovery of Lignin in Seaweed Reveals Convergent Evolution of Cell-Wall ArchitectureCurrent Biology, 2009
- A Battery of Transcription Factors Involved in the Regulation of Secondary Cell Wall Biosynthesis in ArabidopsisPlant Cell, 2008
- Independent origins of syringyl lignin in vascular plantsProceedings of the National Academy of Sciences of the United States of America, 2008
- The MYB46 Transcription Factor Is a Direct Target of SND1 and Regulates Secondary Wall Biosynthesis in ArabidopsisPlant Cell, 2007
- NAC Transcription Factors, NST1 and NST3, Are Key Regulators of the Formation of Secondary Walls in Woody Tissues ofArabidopsisPlant Cell, 2007
- SND1, a NAC Domain Transcription Factor, Is a Key Regulator of Secondary Wall Synthesis in Fibers ofArabidopsisPlant Cell, 2006
- Interactive Tree Of Life (iTOL): an online tool for phylogenetic tree display and annotationBioinformatics, 2006
- MAFFT version 5: improvement in accuracy of multiple sequence alignmentNucleic Acids Research, 2005
- A new mathematical model for relative quantification in real-time RT-PCRNucleic Acids Research, 2001