Pod Corn Is Caused by Rearrangement at the Tunicate1 Locus
Pod Corn Is Caused by Rearrangement at the Tunicate1 Locus
复制标题
DOI：
10.1105/tpc.112.100537
复制
发表时间：
2012-07-01
期刊：
影响因子：
11.6
通讯作者：
Martienssen, Robert
中科院分区：
文献类型：
--
作者：
Han, Jong-Jin;Jackson, David;Martienssen, Robert
豆荚玉米（Zea mays var tunicata）曾被认为是栽培玉米的祖先，并因其神奇的特性而受到前哥伦布文化的珍视。Tunicate1 （Tu1）是一种荚果玉米显性突变，其籽粒完全包裹在叶状颖片中。在这里，我们发现Tu1编码一个在叶片中表达的MADS盒子转录因子，其5‘调控区通过1.8 mb的染色体反转融合到花序中表达的一个基因的3’区域。这两个基因被进一步复制，说明了通过重组分离的经典衍生等位基因，并且Tu1转基因以剂量依赖的方式与这些衍生等位基因相互作用。在幼穗原基中，TU1蛋白核定位于小穗对分生组织基部的特定细胞中。Tu1分支决定缺陷类似于ramosa突变体中的缺陷，它们编码在这些相同细胞中表达的调节蛋白，这解释了近100年前发现的双突变体的协同作用。图1重排在大刍动物祖先中没有发现，是在玉米驯化后出现的。
Pod corn (Zea mays var tunicata) was once regarded as ancestral to cultivated maize, and was prized by pre-Columbian cultures for its magical properties. Tunicate1 (Tu1) is a dominant pod corn mutation in which kernels are completely enclosed in leaflike glumes. Here we show that Tu1 encodes a MADS box transcription factor expressed in leaves whose 5' regulatory region is fused by a 1.8-Mb chromosomal inversion to the 3' region of a gene expressed in the inflorescence. Both genes are further duplicated, accounting for classical derivative alleles isolated by recombination, and Tu1 transgenes interact with these derivative alleles in a dose-dependent manner. In young ear primordia, TU1 proteins are nuclearly localized in specific cells at the base of spikelet pair meristems. Tu1 branch determination defects resemble those in ramosa mutants, which encode regulatory proteins expressed in these same cells, accounting for synergism in double mutants discovered almost 100 years ago. The Tu1 rearrangement is not found in ancestral teosinte and arose after domestication of maize.