Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Department of Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Plant Signal Behav. 2012 Jul;7(7):807-10. doi: 10.4161/psb.20606. Epub 2012 Jul 1.
Arabidopsis TCPs are a family of basic helix loop helix (bHLH)-type transcription factors. Previous studies suggested that antagonistic activities of class I TCPs and class II TCPs are correlated with cell proliferation. We have recently shown that the class I TCPs AtTCP14 and AtTCP15 promote typical cytokinin (CK) responses in Arabidopsis, and proposed that they mediate the effect of CK on cell divisions. To further study the role of AtTCP14 and AtTCP15 in plant development, we expressed them in tomato plants. AtTCP14 and AtTCP15-expressing tomato plants were semi-dwarf, had a reduced apical dominance and developed ectopic meristems on leaflet petioles. CK application to tomato seedlings promoted axillary bud outgrowth and this effect was enhanced in the transgenic AtTCP14 and AtTCP15 overexpressing plants. The results of this study extend our previous suggestion that AtTCP14 and AtTCP15 modulate the plant sensitivity to CK.
拟南芥 TCP 蛋白是一类碱性螺旋-环-螺旋(bHLH)转录因子。先前的研究表明，I 类 TCP 蛋白和 II 类 TCP 蛋白的拮抗活性与细胞增殖相关。我们最近发现 I 类 TCP 蛋白 AtTCP14 和 AtTCP15 促进拟南芥中典型细胞分裂素(CK)的响应，并提出它们介导 CK 对细胞分裂的影响。为了进一步研究 AtTCP14 和 AtTCP15 在植物发育中的作用，我们在番茄植物中表达了它们。表达 AtTCP14 和 AtTCP15 的番茄植株呈半矮化，顶端优势减弱，并且在小叶叶柄上形成异位分生组织。CK 处理番茄幼苗促进侧芽生长，而在过表达转基因 AtTCP14 和 AtTCP15 的植株中，这种作用得到增强。这项研究的结果扩展了我们之前的假设，即 AtTCP14 和 AtTCP15 调节植物对 CK 的敏感性。
