microRNA319a-Targeted Brassica rapa ssp pekinensis TCP Genes Modulate Head Shape in Chinese Cabbage by Differential Cell Division Arrest in Leaf Regions
microRNA319a-Targeted Brassica rapa ssp pekinensis TCP Genes Modulate Head Shape in Chinese Cabbage by Differential Cell Division Arrest in Leaf Regions
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DOI：
10.1104/pp.113.228007
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发表时间：
2014-02-01
期刊：
影响因子：
7.4
通讯作者：
He, Yuke
中科院分区：
文献类型：
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作者：
Mao, Yanfei;Wu, Feijie;He, Yuke
卷心菜（Brassica oleracea）、白菜（Brassica rapa）和生菜（Lactuca sativa）的叶状头由非常弯曲的叶子组成。这些头的形状通常决定了这些作物的质量，从而决定了它们的商业价值。利用150个大白菜重组自交系群体中头部性状的数量性状位点定位，研究了microrna靶向型油菜（Brassica rapa ssp）基因表达水平之间的关系。pekinensis TEOSINTE BRANCHED1、cycloidea和PCF转录因子4 （BrpTCP4）基因与头形的关系。在这里，我们证明了圆柱形头部形状与相对较低的BrpTCP4-1表达相关，而圆形头部形状与较高的BrpTCP4-1表达相关。在圆型大白菜中，microRNA319 （miR319）的积累和BrpTCP4-1的表达从顶部到叶片中部逐渐减少。BrpMIR319a2的过表达降低了BrpTCP4的表达水平，并导致BrpTCP4转录本在所有叶区均匀分布。BrpTCP4表达的时空变化似乎与顶端和脉间区域的过度生长、叶尖变直以及头部形状从圆形到圆柱形的转变有关。这些结果表明，mir319a靶向的BrpTCP基因通过叶区细胞分化阻滞调控叶头的圆形形状。因此，miR319a和BrpTCP4基因的操作是这些作物头部形状遗传改良的潜在重要工具。
Leafy heads of cabbage (Brassica oleracea), Chinese cabbage (Brassica rapa), and lettuce (Lactuca sativa) are composed of extremely incurved leaves. The shape of these heads often dictates the quality, and thus the commercial value, of these crops. Using quantitative trait locus mapping of head traits within a population of 150 recombinant inbred lines of Chinese cabbage, we investigated the relationship between expression levels of microRNA-targeted Brassica rapa ssp. pekinensis TEOSINTE BRANCHED1, cycloidea, and PCF transcription factor4 (BrpTCP4) genes and head shape. Here, we demonstrate that a cylindrical head shape is associated with relatively low BrpTCP4-1 expression, whereas a round head shape is associated with high BrpTCP4-1 expression. In the round-type Chinese cabbage, microRNA319 (miR319) accumulation and BrpTCP4-1 expression decrease from the apical to central regions of leaves. Overexpression of BrpMIR319a2 reduced the expression levels of BrpTCP4 and resulted in an even distribution of BrpTCP4 transcripts within all leaf regions. Changes in temporal and spatial patterns of BrpTCP4 expression appear to be associated with excess growth of both apical and interveinal regions, straightened leaf tips, and a transition from the round to the cylindrical head shape. These results suggest that the miR319a-targeted BrpTCP gene regulates the round shape of leafy heads via differential cell division arrest in leaf regions. Therefore, the manipulation of miR319a and BrpTCP4 genes is a potentially important tool for use in the genetic improvement of head shape in these crops.