Department of Biology, University of Puget Sound, Tacoma, WA 98416, USA.
New Phytol. 2010 Apr;186(1):239-50. doi: 10.1111/j.1469-8137.2009.03141.x. Epub 2010 Jan 13.
Flower reversion is the result of genetic or environmental effects that reverse developmental steps in the transition from the vegetative to the reproductive phase in plants. Here, we describe peculiar floral abnormalities, homeotic conversions, and flower reversion in several wild-type accessions of the natural allopolyploid Arabidopsis suecica. Microscopy was used to illustrate the phenotype in detail and we experimented with varying photoperiod lengths to establish whether or not the phenotype was responsive to the environment. We also profiled the transcriptional activity of several floral regulator genes during flower reversion using real-time PCR. We showed that the frequency of floral reversion was affected by day length and the position of the flower along the inflorescence axis. In reverting flowers we found unusual gene expression patterns of floral promoters and inflorescence maintenance genes, including lower mRNA levels of AGAMOUS-LIKE-24 (AGL-24), APETALA1 (AP1), and SHORT VEGETATIVE PHASE (SVP), and higher mRNA levels of SUPRESSOR OF CONSTANS1 (SOC1) compared with normal flowers. We conclude that the floral reversion frequency in A. suecica is susceptible to photoperiod changes, and that the floral abnormalities coincide with the competing expression of floral promoters and floral repressors in reverting floral tissue.
花逆转是遗传或环境效应的结果，这些效应逆转了植物从营养生长到生殖生长阶段的发育步骤。在这里，我们描述了几个野生型拟南芥瑞典亚种中特有的花异常、同型异位转化和花逆转。显微镜用于详细说明表型，我们还尝试了不同的光周期长度，以确定表型是否对环境有反应。我们还使用实时 PCR 分析了花逆转过程中几个花调控基因的转录活性。我们表明，花逆转的频率受日照长度和花序轴上花的位置的影响。在逆转的花朵中，我们发现了花启动子和花序维持基因的异常表达模式，包括 AGL-24、AP1 和 SVP 的 mRNA 水平降低，以及 SOC1 的 mRNA 水平升高，与正常花朵相比。我们得出的结论是，拟南芥瑞典亚种的花逆转频率易受光周期变化的影响，并且花异常与逆转花组织中花启动子和花抑制子的竞争表达一致。
