van Rooijen Roxanne, Schulze Stefanie, Petzsch Patrick, Westhoff Peter
Institute of Plant Molecular and Developmental Biology, Heinrich-Heine-University, Duesseldorf, Germany.
Cluster of Excellence on Plant Sciences 'From Complex Traits towards Synthetic Modules', Duesseldorf, Germany.
J Exp Bot. 2020 Feb 19;71(4):1434-1448. doi: 10.1093/jxb/erz509.
In an effort to identify genetic regulators for the cell ontogeny around the veins in Arabidopsis thaliana leaves, an activation-tagged mutant line with altered leaf morphology and altered bundle sheath anatomy was characterized. This mutant had a small rosette area with wrinkled leaves and chlorotic leaf edges, as well as enhanced chloroplast numbers in the (pre-)bundle sheath tissue. It had a bundle-specific promoter from the gene GLYCINE DECARBOXYLASE SUBUNIT-T from the C4 species Flaveria trinervia (GLDTFt promoter) inserted in the coding region of the transcriptional repressor NAC052, functioning in H3K4 demethylation, in front of an alternative start codon in-frame with the natural start codon. Reconstruction of the mutation event of our activation-tagged line by creating a line expressing an N-terminally truncated sequence of NAC052 under control of the GLDTFt promoter confirmed the involvement of NAC052 in leaf development. Our study not only reveals leaf anatomic and transcriptomic effects of an N-terminally truncated NAC052 under control of the GLDTFt promoter, but also identifies NAC052 as a novel genetic regulator of leaf development.
为了鉴定拟南芥叶片中脉周围细胞个体发育的遗传调控因子，对一个叶片形态改变且维管束鞘解剖结构改变的激活标签突变体株系进行了表征。该突变体莲座叶面积小，叶片皱缩，叶边缘黄化，并且（前）维管束鞘组织中的叶绿体数量增加。它在转录抑制因子NAC052的编码区插入了来自C4植物三脉黄顶菊（Flaveria trinervia）的甘氨酸脱羧酶亚基T基因的束特异性启动子（GLDTFt启动子），该启动子在与天然起始密码子框内的另一个起始密码子前发挥作用，参与H3K4去甲基化。通过创建一个在GLDTFt启动子控制下表达NAC052 N端截短序列的株系，重建我们激活标签株系的突变事件，证实了NAC052参与叶片发育过程。我们的研究不仅揭示了在GLDTFt启动子控制下N端截短的NAC052对叶片解剖结构和转录组的影响，还将NAC052鉴定为叶片发育的一个新的遗传调控因子。
