Key J L
Bioessays. 1989 Aug-Sep;11(2-3):52-8. doi: 10.1002/bies.950110204.
Auxin, a class of plant hormones which affects a wide array of growth and developmental processes including cell elongation and cell division, alters gene expression in a very rapid, selective, and dramatic way. The relative level of some mRNAs decreases several fold, while that of other mRNAs increases many fold. These changes are mediated, at least in some cases, by very fast (within 5-10 min) modulation by auxin of transcription as measured by run-off transcription assays using nuclei isolated from control and auxin-treated tissues. Rapid turnover of mRNAs following auxin treatment also contributes to large changes in steady state concentration in some cases. The data are suggestive of multiple and complex mechanisms of regulation of expression of those genes which have been studied, using cloned cDNAs for direct quantitation of mRNA steady state levels and relative transcription rats. While there is no definitive evidence that auxin-regulated gene expression mediates any of the growth responses effected by auxin, several lines of evidence are supportive of a very close relationship between these processes. The working hypothesis is that there is a causal relationship between the effects of auxin on gene expression and at least some of the physiological and growth responses to auxin.
生长素是一类植物激素，它影响包括细胞伸长和细胞分裂在内的一系列广泛的生长和发育过程，能以非常快速、选择性和显著的方式改变基因表达。一些mRNA的相对水平会降低数倍，而其他mRNA的相对水平则会增加数倍。这些变化至少在某些情况下是由生长素对转录的非常快速（5 - 10分钟内）的调节介导的，这是通过使用从对照组织和生长素处理的组织中分离的细胞核进行的连续转录分析来测量的。在某些情况下，生长素处理后mRNA的快速周转也导致了稳态浓度的巨大变化。这些数据表明，对于那些已被研究的基因，其表达调控存在多种复杂机制，这些研究使用克隆的cDNA来直接定量mRNA稳态水平和相对转录率。虽然没有确凿证据表明生长素调节的基因表达介导了生长素所产生的任何生长反应，但有几条证据支持这些过程之间存在非常密切的关系。目前的工作假设是，生长素对基因表达的影响与至少一些对生长素的生理和生长反应之间存在因果关系。
