Roles of Arabidopsis TBL34 and TBL35 in xylan acetylation and plant growth. (February 2016)

• Record Type: Journal Article
• Authors: Yuan, Youxi; Teng, Quincy; Zhong, Ruiqin; Ye, Zheng-Hua
• Is Part Of: Plant science. Volume 243(2016:Feb.)
• Page Start: 120
• Page End: 130
• Publication Date: 2016-02
• Subjects: Acetylation -- Arabidopsis -- DUF231 -- Secondary wall -- Xylan; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2015.12.007
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: Xylan is one of the major components in lignocellulosic biomass. Xylan is often acetylated at O -2 and/or O -3. TBL34 and TBL35 are two DUF231 proteins. Mutations of TBL34 and TBL35 cause a specific reduction in xylan 3- O -monoacetylation and 2, 3-di- O -acetylation. This study provides genetic evidence for the roles of TBL34 and TBL35 in xylan acetylation. Abstract: Xylan is one of the major polymers in lignocellulosic biomass and about 60% of its xylosyl residues are acetylated at O -2 and/or O -3. Because acetylation of cell wall polymers contributes to biomass recalcitrance for biofuel production, it is important to investigate the biochemical mechanism underlying xylan acetylation, the knowledge of which could be applied to custom-design biomass composition tailored for biofuel production. In this report, we investigated the functions of Arabidopsis TRICHOME BIREFRINGENCE-LIKE 34 (TBL34) and TBL35, two DUF231-containing proteins, in xylan acetylation. The TBL34 gene was found to be specifically expressed in xylem cells in stems and root-hypocotyls, and both TBL34 and TBL35 were shown to be localized in the Golgi, where xylan biosynthesis occurs. Chemical analysis revealed that simultaneous mutations of TBL34 and TBL35 caused a mild decrease in xylan acetyl content and a specific reduction in xylan 3- O -monoacetylation and 2, 3-di- O -acetylation. Furthermore, simultaneous mutations of TBL34, TBL35 and ESKIMO1 ( ESK1 ) resulted in severely collapsed xylem vessels with altered secondary wall structure, and an extremely retarded plant growth. These findings indicate that TBL34 and TBL35 are putative acetyltransferases required for xylan 3- O -monoacetylation and 2, 3-di- O -acetylation and that xylan acetylation is essential for normal secondary wall deposition and plant growth.