A gain-of-function mutation in IAA16 confers reduced responses to auxin and abscisic acid and impedes plant growth and fertility

作者：Rinaldi Mauro A; Liu James; Enders Tara A; Bartel Bonnie; Strader Lucia C^*

来源：Plant Molecular Biology, 2012, 79(4-5): 359-373.

DOI：10.1007/s11103-012-9917-y

• Auxin signaling
• Abscisic acid
• Aux/IAA gain of function
• IAA16

Auxin regulates many aspects of plant development, in part, through degradation of the Aux/IAA family of transcriptional repressors. Consequently, stabilizing mutations in several Aux/IAA proteins confer reduced auxin responsiveness. However, of the 29 apparent Aux/IAA proteins in Arabidopsis thaliana, fewer than half have roles established through mutant analysis. We identified iaa16-1, a dominant gain-of-function mutation in IAA16 (At3g04730), in a novel screen for reduced root responsiveness to abscisic acid. The iaa16-1 mutation also confers dramatically reduced auxin responses in a variety of assays, markedly restricts growth of adult plants, and abolishes fertility when homozygous. We compared iaa16-1 phenotypes with those of dominant mutants defective in the closely related IAA7/AXR2, IAA14/SLR, and IAA17/AXR3, along with the more distantly related IAA28, and found overlapping but distinct patterns of developmental defects. The identification and characterization of iaa16-1 provides a fuller understanding of the IAA7/IAA14/IAA16/IAA17 clade of Aux/IAA proteins and the diverse roles of these repressors in hormone response and plant development.

• 出版日期2012-7