Effects of altered lignin biosynthesis on phenylpropanoid metabolism and plant stress

Abstract

Modification of lignin in bioenergy feedstocks has become a common strategy to increase saccharification and biofuel yield. The lignin biosynthetic pathway in several plant species has been dissected and key enzymes have been manipulated in transgenic plants. Recent analyses of lignin-modified plants have shown that decreasing lignin biosynthesis can alter carbon flow within the phenylpropanoid pathway and indirectly affect the synthesis of other secondary metabolites, many of which can play important roles in plant–environment interactions. In addition, lignin modifications have also been shown to induce the expression of various stress response-related genes. Examining and understanding these indirect effects of lignin modification on stress-related processes are essential, since they could ultimately impact the performance of low-lignin bioenergy feedstocks under agronomic field conditions. Recent efforts to characterize such effects will be discussed in this review.

Acknowledgements

The authors would like to acknowledge the anonymous reviews for their helpful comments and suggestions.

Financial & competing interests disclosure

This work was supported by funding from the Southeastern Sun Grant Center (TN, USA) , the US Department of Agriculture-funded Integrated Biomass and Supply Systems center (TN, USA) and the BioEnergy Science Center (TN, USA). The BioEnergy Science Center is a US Department of Energy Bioenergy Research Center supported by the Office of Biological and Environmental Research in the US Department of Energy Office of Science (Washington, DC, USA). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.