Molecular cloning and expression of the early auxin-responsive Aux/IAA gene family in Nicotiana tabacum.
Early auxin-regulated tobacco cDNAs, belonging to the Aux/IAA gene family have been isolated by screening of a cDNA library prepared from auxin-treated suspension-grown etiolated seedlings of Nicotiana tabacum. The probes used were either RT-PCR fragments or an insert resulting from mRNA differential display selection. All of them possessed the structural features which characterize the Aux/IAA gene products. The auxin response of three distinct Nt-iaa subclasses has been characterized in terms of kinetics, dose-response and specificity as several plant hormones and chemicals have been tested for their ability to alter Nt-iaa mRNA accumulation. Differences of auxin responses have been observed between the Nt-iaa analysed, revealing significant differences of regulation. The effect of the protein synthesis inhibitor cycloheximide suggested that Nt-iaa2.3, Nt-iaa4.3 and strictly related genes can be classified as primary auxin-responsive genes and Nt-iaa28 as a late one. The steady-state mRNA level of these Nt-iaa has also been determined in organs of tobacco plants.
Dargeviciute
A
A
Institut des Sciences végétales, CNRS, Gif sur Yvette, France.
Roux
C
C
Decreux
A
A
Sitbon
F
F
Perrot-Rechenmann
C
C
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003513:Cycloheximide; D018076:DNA, Complementary; D018744:DNA, Plant; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D008969:Molecular Sequence Data; D009280:Naphthaleneacetic Acids; D010937:Plant Growth Regulators; D010947:Plants, Toxic; D014026:Nicotiana / Q000235:genetics*
D018076:DNA, Complementary; D018744:DNA, Plant; D007210:Indoleacetic Acids; D009280:Naphthaleneacetic Acids; D010937:Plant Growth Regulators; D003513:Cycloheximide