A novel wound-inducible extensin gene is expressed early in newly isolated protoplasts of Nicotiana sylvestris.
A cDNA clone (6PExt 1.2) encoding a novel extensin was isolated from a cDNA library made from 6 h old mesophyll protoplasts of Nicotiana sylvestris. The screening was performed with a heterologous probe from carrot. The encoded polypeptide showed features characteristic of hydroxyproline-rich glycoproteins such as Ser-(Pro)4 repeats and a high content in Tyr and Lys residues. The presence of four Tyr-X-Tyr-Lys motifs suggests the possibility for intramolecular isodityrosine cross-links whereas three Val-Tyr-Lys motifs may participate in intermolecular cross-links. The analysis of genomic DNA gel blots using both the N. sylvestris and the carrot clones as probes showed that the 6PExt 1.2 gene belongs to a complex multigene family encoding extensin and extensin-related polypeptides in N. sylvestris as well as in related Nicotianeae including a laboratory hybrid. This was confirmed by the analysis of RNA gel blots: a set of mRNAs ranging in size from 0.3 kb to 3.5 kb was found by the carrot extensin probe. The 6PExt 1.2 probe found a 1.2 kb mRNA in protoplasts and in wounded tissues as well as a 0.9 kb mRNA which seemed to be stem-specific. The gene encoding 6PExt 1.2 was induced by wounding in protoplasts, in leaf strips and after Agrobacterium tumefaciens infection of stems.
Parmentier
Y
Y
Institut de Biologie Moléculaire des Plantes, UPR CNRS 406, Strasbourg, France.
Durr
A
A
Marbach
J
J
Hirsinger
C
C
Criqui
M C
MC
Fleck
J
J
Jamet
E
E
D000595:Amino Acid Sequence; D001483:Base Sequence; D002473:Cell Wall / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D017343:Genes, Plant; D006023:Glycoproteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D010947:Plants, Toxic; D017433:Protein Structure, Secondary; D011523:Protoplasts / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014018:Tissue Distribution; D014026:Nicotiana / Q000166:cytology / Q000235:genetics*
D018076:DNA, Complementary; D006023:Glycoproteins; D010940:Plant Proteins; D012333:RNA, Messenger; C005488:extensin protein, plant