Sohlberg Joel J, Myrenås Mattias, Kuusk Sandra, Lagercrantz Ulf, Kowalczyk Mariusz, Sandberg Göran, Sundberg Eva
Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, Box 7080, S-750 07 Uppsala, Sweden.
Plant J. 2006 Jul;47(1):112-23. doi: 10.1111/j.1365-313X.2006.02775.x. Epub 2006 Jun 1.
Gynoecia of the Arabidopsis mutant sty1-1 display abnormal style morphology and altered vascular patterning. These phenotypes, which are enhanced in the sty1-1 sty2-1 double mutant, suggest that auxin homeostasis or signalling might be affected by mutations in STY1 and STY2, both members of the SHI gene family. Chemical inhibition of polar auxin transport (PAT) severely affects the apical-basal patterning of the gynoecium, as do mutations in the auxin transport/signalling genes PIN1, PID and ETT. Here we show that the apical-basal patterning of sty1-1 and sty1-1 sty2-1 gynoecia is hypersensitive to reductions in PAT, and that sty1-1 enhances the PAT inhibition-like phenotypes of pin1-5, pid-8 and ett-1 gynoecia. Furthermore, we show that STY1 activates transcription of the flavin monooxygenase-encoding gene THREAD/YUCCA4, involved in auxin biosynthesis, and that changes in expression of STY1 and related genes lead to altered auxin homeostasis. Our results suggest that STY1 and related genes promote normal development of the style and affect apical-basal patterning of the gynoecium through regulation of auxin homeostasis.
拟南芥突变体sty1-1的雌蕊表现出异常的花柱形态和改变的维管束模式。这些表型在sty1-1 sty2-1双突变体中增强，表明生长素稳态或信号传导可能受到SHI基因家族成员STY1和STY2突变的影响。生长素极性运输（PAT）的化学抑制严重影响雌蕊的顶基模式，生长素运输/信号基因PIN1、PID和ETT的突变也是如此。在这里，我们表明sty1-1和sty1-1 sty2-1雌蕊的顶基模式对PAT的降低高度敏感，并且sty1-1增强了pin1-5、pid-8和ett-1雌蕊的PAT抑制样表型。此外，我们表明STY1激活参与生长素生物合成的黄素单加氧酶编码基因THREAD/YUCCA4的转录，并且STY1和相关基因表达的变化导致生长素稳态的改变。我们的结果表明，STY1和相关基因通过调节生长素稳态促进花柱的正常发育并影响雌蕊的顶基模式。
