TY - JOUR
T1 - TRICHOME BIREFRINGENCE and its homolog AT5G01360 encode plant-specific DUF231 proteins required for cellulose biosynthesis in arabidopsis
AU - Bischoff, Volker
AU - Nita, Silvia
AU - Neumetzler, Lutz
AU - Schindelasch, Dana
AU - Urbain, Aurélie
AU - Eshed, Ravit
AU - Persson, Staffan
AU - Delmer, Deborah
AU - Scheible, Wolf Rudiger
PY - 2010/6
Y1 - 2010/6
N2 - The Arabidopsis (Arabidopsis thaliana) trichome birefringence (tbr) mutant has severely reduced crystalline cellulose in trichomes, but the molecular nature of TBR was unknown. We determined TBR to belong to the plant-specific DUF231 domain gene family comprising 46 members of unknown function in Arabidopsis. The genes harbor another plant-specific domain, called the TBL domain, which contains a conserved GDSL motif known from some esterases/lipases. TBR and TBR-like3 (TBL3) are transcriptionally coordinated with primary and secondary CELLULOSE SYNTHASE (CESA) genes, respectively. The tbr and tbl3 mutants hold lower levels of crystalline cellulose and have altered pectin composition in trichomes and stems, respectively, tissues generally thought to contain mainly secondary wall crystalline cellulose. In contrast, primary wall cellulose levels remain unchanged in both mutants as measured in etiolated tbr and tbl3 hypocotyls, while the amount of esterified pectins is reduced and pectin methylesterase activity is increased in this tissue. Furthermore, etiolated tbr hypocotyls have reduced length with swollen epidermal cells, a phenotype characteristic for primary cesa mutants or the wild type treated with cellulose synthesis inhibitors. Taken together, we show that two TBL genes contribute to the synthesis and deposition of secondary wall cellulose, presumably by influencing the esterification state of pectic polymers.
AB - The Arabidopsis (Arabidopsis thaliana) trichome birefringence (tbr) mutant has severely reduced crystalline cellulose in trichomes, but the molecular nature of TBR was unknown. We determined TBR to belong to the plant-specific DUF231 domain gene family comprising 46 members of unknown function in Arabidopsis. The genes harbor another plant-specific domain, called the TBL domain, which contains a conserved GDSL motif known from some esterases/lipases. TBR and TBR-like3 (TBL3) are transcriptionally coordinated with primary and secondary CELLULOSE SYNTHASE (CESA) genes, respectively. The tbr and tbl3 mutants hold lower levels of crystalline cellulose and have altered pectin composition in trichomes and stems, respectively, tissues generally thought to contain mainly secondary wall crystalline cellulose. In contrast, primary wall cellulose levels remain unchanged in both mutants as measured in etiolated tbr and tbl3 hypocotyls, while the amount of esterified pectins is reduced and pectin methylesterase activity is increased in this tissue. Furthermore, etiolated tbr hypocotyls have reduced length with swollen epidermal cells, a phenotype characteristic for primary cesa mutants or the wild type treated with cellulose synthesis inhibitors. Taken together, we show that two TBL genes contribute to the synthesis and deposition of secondary wall cellulose, presumably by influencing the esterification state of pectic polymers.
UR - http://www.scopus.com/inward/record.url?scp=77953219973&partnerID=8YFLogxK
U2 - 10.1104/pp.110.153320
DO - 10.1104/pp.110.153320
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C2 - 20388664
AN - SCOPUS:77953219973
SN - 0032-0889
VL - 153
SP - 590
EP - 602
JO - Plant Physiology
JF - Plant Physiology
IS - 2
ER -