title: XTH20 and XTH19 regulated by ANAC071 under auxin flow are involved in cell proliferation in incised Arabidopsis inflorescence stems.
abstract: One week after partial incision of Arabidopsis inflorescence stems, the repair process in damaged tissue includes pith cell proliferation. Auxin is a key factor driving this process, and ANAC071, a transcription factor gene, is upregulated in the distal region of the incised stem. Here we show that XTH20 and the closely related XTH19, members of xyloglucan endotransglucosylase/hydrolases family catalyzing molecular grafting and/or hydrolysis of cell wall xyloglucans, were also upregulated in the distal part of the incised stem, similar to ANAC071. XTH19 was expressed in the proximal incision region after 3 days or after auxin application to the decapitated stem. Horizontal positioning of the plant with the incised side up resulted in decreased ProDR 5 :GUS, ANAC071, XTH20, and XTH19 expression and reduced pith cell proliferation. In incised stems of Pro35S :ANAC071-SRDX plants, expression of XTH20 and XTH19 was substantially and moderately decreased, respectively. XTH20 and XTH19 expression and pith cell proliferation were suppressed in anac071 plants and were increased in Pro35S :ANAC071 plants. Pith cell proliferation was also inhibited in the xth20xth19 double mutant. Furthermore, ANAC071 bound to the XTH20 and XTH19 promoters to induce their expression. This study revealed XTH20 and XTH19 induction by auxin via ANAC071 in the distal part of an incised stem and their involvement in cell proliferation in the tissue reunion process.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-8572, Japan.
authors.forename: Weerasak
authors.initials: W
authors.lastname: Pitaksaringkarn
authors.forename: Keita
authors.initials: K
authors.lastname: Matsuoka
authors.forename: Masashi
authors.initials: M
authors.lastname: Asahina
authors.forename: Kenji
authors.initials: K
authors.lastname: Miura
authors.forename: Kimiyo
authors.initials: K
authors.lastname: Sage-Ono
authors.forename: Michiyuki
authors.initials: M
authors.lastname: Ono
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Yokoyama
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nishitani
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ishii
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Iwai
authors.forename: Shinobu
authors.initials: S
authors.lastname: Satoh
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002241:Carbohydrates / Q000737:chemistry; D049109:Cell Proliferation; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D056626:Inflorescence / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000166:cytology / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C568459:ANAC071 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002241:Carbohydrates; D007210:Indoleacetic Acids; D014157:Transcription Factors
keywords: XTH; auxin; incision of stem; pith cell proliferation; tissue reunion; transcription factors