A pectin glucuronyltransferase gene is essential for intercellular attachment in the plant meristem.
Intercellular attachment is an essential process in the morphogenesis of multicellular organisms. A unique mutant, nolac-H18 (nonorganogenic callus with loosely attached cells), generated by T-DNA transformation using leaf-disk cultures of haploid Nicotiana plumbaginifolia, lost the ability to form tight intercellular attachments and adventitious shoots. The gene tagged with T-DNA, named NpGUT1 (glucuronyltransferase 1), was similar to the gene for the catalytic domains of animal glucuronyltransferases and was expressed predominantly in shoot and root apical meristems. The transformation of NpGUT1 complemented the nolac-H18 mutation, and the expression of antisense NpGUT1 RNA produced crumbled shoots. The mutation caused defects in the glucuronic acid of rhamnogalacturonan II of pectin, which drastically reduced the formation of borate cross-linking of rhamnogalacturonan II. NpGUT1, which encodes a unique glucuronyltransferase, is a glycosyltransferase gene identified in pectin biosynthesis and is essential for intercellular attachment in plant meristems and tissues.
Iwai
Hiroaki
H
Institute of Biological Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
Masaoka
Nobutaka
N
Ishii
Tadashi
T
Satoh
Shinobu
S
D000595:Amino Acid Sequence; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis; D002448:Cell Adhesion; D002473:Cell Wall / Q000737:chemistry; D019281:Dimerization; D005808:Genes, Recessive; D014453:Glucuronosyltransferase / Q000235:genetics / Q000502:physiology*; D006238:Haploidy; D018519:Meristem / Q000166:cytology / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010368:Pectins / Q000096:biosynthesis*; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D018520:Plant Shoots; D016372:RNA, Antisense / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D018749:RNA, Plant / Q000096:biosynthesis; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology*
D002241:Carbohydrates; D010940:Plant Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D018749:RNA, Plant; D010368:Pectins; C111364:galactosylgalactoylxylosylprotein 3-beta-glucuronosyltransferase; D014453:Glucuronosyltransferase