Instituto de Biología Molecular y Celular de Plantas (UPV-CSIC), Universidad Politécnica de Valencia, Avda de los Naranjos s/n, 46022 Valencia, Spain.
Plant Cell Physiol. 2010 Mar;51(3):435-47. doi: 10.1093/pcp/pcq009. Epub 2010 Jan 16.
The genetic and phenotypic characterization of a new tomato (Solanum lycopersicum) insertional mutant, Arlequin (Alq) is reported. Alq mutant plants were affected in reproductive development and their sepals were homeotically converted into fleshy fruit-like organs. Molecular analysis demonstrated that a single copy of T-DNA was present in the mutant genome while genetic analysis confirmed that the mutant phenotype co-segregated with the T-DNA insertion and was inherited as a monogenic semi-dominant trait. The histological and scanning electron microscope analyses revealed cell identity changes in both external and internal tissues of Alq sepals. Flowers developed by Alq homozygous plants showed a severe mutant phenotype, since after fruit set, not only did the sepals become succulent but they also followed a ripening pattern similar to that of normal fruits. From a metabolic viewpoint, Alq sepals also behaved like a fruit, as they acquired the properties of a sink that acted alternatively and independently to the fruit. In fact, expression of regulatory genes controlling tomato fruit ripening was detected in Alq sepals at similar levels to those observed in mature fruits. Furthermore, the Alq mutation inhibited the development of the abscission zone in tomato flowers indicating that the JOINTLESS gene is regulated by ALQ. Results from the genetic and developmental characterization of the Alq tomato mutant suggest that the ALQ gene participates in the regulatory pathway controlling fruit ripening of tomato.
报告了一种新的番茄（Solanum lycopersicum）插入突变体 Arlequin（Alq）的遗传和表型特征。Alq 突变体植物在生殖发育中受到影响，其萼片同源转化为肉质果实状器官。分子分析表明，突变体基因组中存在一个 T-DNA 拷贝，而遗传分析证实突变表型与 T-DNA 插入共分离，并作为单基因半显性性状遗传。组织学和扫描电子显微镜分析显示 Alq 萼片中内外组织的细胞身份发生了变化。Alq 纯合子植物发育的花朵表现出严重的突变表型，因为在果实形成后，不仅萼片变得多汁，而且它们还遵循类似于正常果实的成熟模式。从代谢的角度来看，Alq 萼片也表现得像果实一样，因为它们获得了作为替代和独立于果实的汇的特性。事实上，在 Alq 萼片中检测到控制番茄果实成熟的调节基因的表达水平与在成熟果实中观察到的相似。此外，Alq 突变抑制了番茄花朵离层区的发育，表明 JOINTLESS 基因受 ALQ 调控。Alq 番茄突变体的遗传和发育特征表明，ALQ 基因参与了控制番茄果实成熟的调控途径。
