Arabidopsis XTH4 and XTH9 Contribute to Wood Cell Expansion and Secondary Wall Formation1[OPEN]

被引：52

作者：

Kushwah, Sunita ^{[1
]}

Banasiak, Alicja ^{[1
,5
]}

Nishikubo, Nobuyuki ^{[1
,6
]}

Derba-Maceluch, Marta ^{[1
]}

Majda, Mateusz ^{[1
,7
]}

Endo, Satoshi ^{[1
,8
]}

Kumar, Vikash ^{[1
]}

Gomez, Leonardo ^{[2
]}

Gorzsas, Andras ^{[3
]}

McQueen-Mason, Simon ^{[2
]}

Braam, Janet ^{[4
]}

Sundberg, Bjorn ^{[1
]}

Mellerowicz, Ewa J. ^{[1
]}

机构：

[1] Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, S-90183 Umea, Sweden

[2] Univ York, Ctr Novel Agr Prod, Dept Biol, York YO10 5DD, N Yorkshire, England

[3] Umea Univ, Dept Chem, SE-90187 Umea, Sweden

[4] Rice Univ, Dept Biosci, Houston, TX 77005 USA

[5] Univ Wroclaw, Inst Expt Biol, Ul Kanonia 6-8, PL-50328 Wroclaw, Poland

[6] Oji Forest & Prod Co Ltd, Chuo Ku, 4-7-5 Ginza, Tokyo 1040061, Japan

[7] John Innes Ctr, Cell & Dev Biol, Norwich Res Pk, Norwich NR4 7UH, Norfolk, England

[8] Univ Tokyo, Dept Biol Sci, Grad Sch Sci, Tokyo 1130033, Japan

来源：

PLANT PHYSIOLOGY | 2020年 / 182卷 / 04期

基金：

瑞典研究理事会;

关键词：

MICROTUBULE-ASSOCIATED PROTEIN; FT-RAMAN-SPECTROSCOPY; PEA STEM SEGMENTS; XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE; ENDOXYLOGLUCAN TRANSFERASE; COVALENT LINKAGE; ELONGATION ZONE; CICER-ARIETINUM; ROOT ELONGATION; HYBRID ASPEN;

D O I：

10.1104/pp.19.01529

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Xylem cell expansion and fiber intrusive tip growth require the activity of enzymes that rearrange xyloglucan in cell walls, and their deficiency not only affects cell expansion but alters subsequent secondary wall formation via cell wall integrity-sensing mechanisms. Xyloglucan is the major hemicellulose of dicotyledon primary cell walls, affecting the load-bearing framework with the participation of xyloglucan endo-transglycosylase/hydrolases (XTHs). We used loss- and gain-of function approaches to study functions of XTH4 and XTH9 abundantly expressed in cambial regions during secondary growth of Arabidopsis (Arabidopsis thaliana). In secondarily thickened hypocotyls, these enzymes had positive effects on vessel element expansion and fiber intrusive growth. They also stimulated secondary wall thickening but reduced secondary xylem production. Cell wall analyses of inflorescence stems revealed changes in lignin, cellulose, and matrix sugar composition indicating an overall increase in secondary versus primary walls in mutants, indicative of higher xylem production compared with the wild type (since secondary walls were thinner). Intriguingly, the number of secondary cell wall layers compared with the wild type was increased in xth9 and reduced in xth4, whereas the double mutant xth4x9 displayed an intermediate number of layers. These changes correlated with specific Raman signals from the walls, indicating changes in lignin and cellulose. Secondary walls were affected also in the interfascicular fibers, where neither XTH4 nor XTH9 was expressed, indicating that these effects were indirect. Transcripts involved in secondary wall biosynthesis and cell wall integrity sensing, including THESEUS1 and WALL ASSOCIATED KINASE2, were highly induced in the mutants, indicating that deficiency in XTH4 and XTH9 triggers cell wall integrity signaling, which, we propose, stimulates xylem cell production and modulates secondary wall thickening. Prominent effects of XTH4 and XTH9 on secondary xylem support the hypothesis that altered xyloglucan affects wood properties both directly and via cell wall integrity sensing.

引用

页码：1946 / 1965

页数：20