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TBL 10 is required for O ‐acetylation of pectic rhamnogalacturonan‐I in Arabidopsis thaliana
Author(s) -
Stranne Maria,
Ren Yanfang,
Fimognari Lorenzo,
Birdseye Devon,
Yan Jingwei,
Bardor Muriel,
Mollet JeanClaude,
Komatsu Takanori,
Kikuchi Jun,
Scheller Henrik V.,
Sakuragi Yumiko
Publication year - 2018
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/tpj.14067
Subject(s) - arabidopsis , acetylation , cell wall , arabidopsis thaliana , mutant , pectin , biochemistry , xyloglucan , pseudomonas syringae , biotic stress , apoplast , botrytis cinerea , chemistry , wild type , biology , abiotic stress , botany , gene
Summary O ‐Acetylated pectins are abundant in the primary cell wall of plants and growing evidence suggests they have important roles in plant cell growth and interaction with the environment. Despite their importance, genes required for O ‐acetylation of pectins are still largely unknown. In this study, we showed that TRICHOME BIREFRINGENCE LIKE 10 ( AT 3G06080 ) is involved in O ‐acetylation of pectins in Arabidopsis ( Arabidopsis thaliana ). The activity of the TBL 10 promoter was strong in tissues where pectins are highly abundant ( e.g . leaves). Two homozygous knock‐out mutants of Arabidopsis, tbl10‐1 and tbl10‐2 , were isolated and shown to exhibit reduced levels of wall‐bound acetyl esters, equivalent of ~50% of the wild‐type level in pectin‐enriched fractions derived from leaves. Further fractionation revealed that the degree of acetylation of the pectin rhamnogalacturonan‐I ( RG ‐I) was reduced in the tbl10 mutant compared to the wild type, whereas the pectin homogalacturonan ( HG ) was unaffected. The degrees of acetylation in hemicelluloses ( i.e . xyloglucan, xylan and mannan) were indistinguishable between the tbl10 mutants and the wild type. The mutant plants contained normal trichomes in leaves and exhibited a similar level of susceptibility to the phytopathogenic microorganisms Pseudomonas syringae pv. tomato DC 3000 and Botrytis cinerea ; while they displayed enhanced tolerance to drought. These results indicate that TBL 10 is required for O ‐acetylation of RG ‐I, possibly as an acetyltransferase, and suggest that O ‐acetylated RG ‐I plays a role in abiotic stress responses in Arabidopsis.