Expansins are conserved in conifers and expressed in hypocotyls in response to exogenous auxin.
Differential display reverse transcription-polymerase chain reaction was used to detect the induction of gene expression during adventitious root formation in loblolly pine (Pinus taeda) after treatment with the exogenous auxin indole-3-butyric acid. A BLAST search of the GenBank database using one of the clones obtained revealed very strong similarity to the alpha-expansin gene family in angiosperms. A near-full-length loblolly pine alpha-expansin sequence was obtained using 5'- and 3'-rapid amplification of cDNA end cloning, and the deduced amino acid sequence was highly conserved relative to those of angiosperm expansins. Northern analysis indicates that alpha-expansin mRNA expression increases 50- to 100-fold in the base of hypocotyl stem cuttings from loblolly pine seedlings in response to indole-3-butyric acid, with peak expression occurring 24 to 48 h after induction.
Department of Biochemistry, Microbiology, and Molecular Biology, The University of Maine, Orono 04469, USA. keithh@maine.edu
K W
KW
Hutchison
P B
PB
Singer
S
S
McInnis
C
C
Diaz-Sala
M S
MS
Greenwood
D000595:Amino Acid Sequence; D001483:Base Sequence; D002455:Cell Division; D018744:DNA, Plant; D018546:Hypocotyl / Q000187:drug effects / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000494:pharmacology; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D018517:Plant Roots / Q000254:growth & development; D012639:Seeds / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014197:Trees / Q000254:growth & development / Q000378:metabolism
D018744:DNA, Plant; D007210:Indoleacetic Acids; D010940:Plant Proteins; C095825:expansin protein, plant