Molecular and functional characterization of ferulate-5-hydroxylase in Populus tomentosa

Wenting Jiang,Xiangning Jiang,Qiqi Zeng,Yan Jiang,Ying Gai

doi:10.1007/s13562-020-00574-9

Wenting Jiang, Xiangning Jiang + Show 3 more

Open Access

https://doi.org/10.1007/s13562-020-00574-9

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Abstract

Ferulate-5-hydroxylase (F5H) is a key rate-limiting enzyme for the conversion of guaiacyl monolignol (G-monolignol) to syringyl monolignol (S-monolignol) in the specific synthetic lignin pathway, through the catalysis of the 5-hydroxylation of S-monolignol precursors ferulic acid, conifer aldehyde, and coniferyl alcohol. In this study, we cloned the F5H gene of Populus tomenta (PtoF5H), whose product has a highly conserved domain of P450-dependent monooxygenase family. Subcellular localization result demonstrated that PtoF5H protein is an endoplasmic reticulum (ER) resident protein. Furthermore, the PtoF5H was transformed into tobacco in the form of sense- and antisense-, showed that the proportion of S-monolignol increased when PtoF5H gene was overexpressed, suggesting PtoF5H could be used as a target gene for modifying lignin composition. These findings provide further insight into the function of PtoF5H.

Highlights

The PtoF5H was transformed into tobacco in the form of sense- and antisense, showed that the proportion of S-monolignol increased when PtoF5H gene was overexpressed, suggesting PtoF5H could be used as a target gene for modifying lignin composition
Lignin is an aromatic polymer that widely exists in the secondary cell wall of vascular plants
Despite lignin play an important role in the normal physiology of plants, the polymer interferes with the use of biomass by humans, the interactions between lignin and cell polysaccharides greatly impede the conversion of these polymers for industrial and agricultural purposes (Kim et al 2015; Weng et al 2008)

Summary

Introduction

Lignin is an aromatic polymer that widely exists in the secondary cell wall of vascular plants. Despite lignin play an important role in the normal physiology of plants, the polymer interferes with the use of biomass by humans, the interactions between lignin and cell polysaccharides greatly impede the conversion of these polymers for industrial and agricultural purposes (Kim et al 2015; Weng et al 2008) To overcome this challenge, many strategies to reduce lignin content or alter lignin composition and structure have been implemented with the overall goal of increasing cell wall degradability (Anderson et al 2015), in this process, plant genetic engineering provides the opportunity to improve the structure and composition of plant secondary cell walls. When sense- and antisense- vectors were constructed and transformed into tobacco to analyze the changes of the lignin content ratio, GC–MS (Gas Chromatography–Mass Spectrometer) analysis suggested that F5H affected the lignin G/S ratio

Materials and methods

Results and discussion

Compliance with ethical standards