Genetic Engineering Research Center, Bioengineering College, Chongqing University, Key Lab of Functional Gene and New Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, 400030, PR China.
J Exp Bot. 2011 May;62(8):2815-26. doi: 10.1093/jxb/erq455. Epub 2011 Jan 25.
TIR1 and its homologues act as auxin receptors and play a crucial role in auxin-mediated plant development. While the functions of auxin receptor genes have been widely studied in Arabidopsis thaliana, there has been no report on the consequences of TIR1 overexpression in plants that regulate fruit development. Here a putative tomato auxin receptor gene, homologous to Arabidopsis AtTIR1, is reported. This gene, designated as Solanum lycopersicum TIR1 (SlTIR1), was found to be expressed in all the parts of floral buds and flowers at anthesis stages. From bud to anthesis, SlTIR1 expression increases slightly in sepal tissue and decreases dramatically in stamen. From anthesis to post-anthesis when fruit set is expected to occur, the expression of SlTIR1 declines in the ovary and sepal. Overexpression of SlTIR1 results in a pleiotropic phenotype including parthenocarpic fruit formation and leaf morphology. Furthermore, SlTIR1 overexpression altered transcript levels of a number of auxin-responsive genes. The present data demonstrate that the tomato SlTIR1 gene plays an important role at the stages of flower-to-fruit transition and leaf formation.
TIR1 及其同源物作为生长素受体，在生长素介导的植物发育中发挥着关键作用。虽然生长素受体基因的功能已在拟南芥中得到广泛研究，但关于其在调节果实发育的植物中过表达的后果尚无报道。本文报道了一个拟南芥 AtTIR1 的同源物，即番茄生长素受体基因。该基因被命名为 Solanum lycopersicum TIR1（SlTIR1），在花芽和开花期的所有部分都有表达。从芽到开花，SlTIR1 在萼片中的表达略有增加，而在雄蕊中的表达急剧下降。从开花到预期果实形成的后开花期，SlTIR1 在子房和萼片中的表达下降。SlTIR1 的过表达导致了包括单性结实果实形成和叶片形态的多效表型。此外，SlTIR1 的过表达改变了许多生长素响应基因的转录水平。本研究数据表明，番茄 SlTIR1 基因在花到果实的过渡和叶片形成阶段发挥着重要作用。
