Manning Kenneth, Tör Mahmut, Poole Mervin, Hong Yiguo, Thompson Andrew J, King Graham J, Giovannoni James J, Seymour Graham B
Warwick Horticulture Research International (HRI), University of Warwick, Wellesbourne, Warwick CV35 9EF, UK.
Nat Genet. 2006 Aug;38(8):948-52. doi: 10.1038/ng1841. Epub 2006 Jul 9.
A major component in the regulatory network controlling fruit ripening is likely to be the gene at the tomato Colorless non-ripening (Cnr) locus. The Cnr mutation results in colorless fruits with a substantial loss of cell-to-cell adhesion. The nature of the mutation and the identity of the Cnr gene were previously unknown. Using positional cloning and virus-induced gene silencing, here we demonstrate that an SBP-box (SQUAMOSA promoter binding protein-like) gene resides at the Cnr locus. Furthermore, the Cnr phenotype results from a spontaneous epigenetic change in the SBP-box promoter. The discovery that Cnr is an epimutation was unexpected, as very few spontaneous epimutations have been described in plants. This study demonstrates that an SBP-box gene is critical for normal ripening and highlights the likely importance of epialleles in plant development and the generation of natural variation.
控制果实成熟的调控网络中的一个主要成分可能是番茄无色非成熟（Cnr）位点的基因。Cnr突变导致果实无色，细胞间粘附力大幅丧失。该突变的性质和Cnr基因的身份此前未知。利用定位克隆和病毒诱导的基因沉默，我们在此证明一个SBP-box（类SQUAMOSA启动子结合蛋白）基因位于Cnr位点。此外，Cnr表型是由SBP-box启动子的自发表观遗传变化导致的。Cnr是一个表观突变这一发现出乎意料，因为在植物中很少有自发表观突变被描述过。这项研究表明一个SBP-box基因对正常成熟至关重要，并突出了表观等位基因在植物发育和自然变异产生中的可能重要性。
