Maize endosperm-specific transcription factors O2 and PBF network the regulation of protein and starch synthesis
Maize endosperm-specific transcription factors O2 and PBF network the regulation of protein and starch synthesis
复制标题
玉米胚乳特异性转录因子O2和PBF网络对蛋白质和淀粉合成的调控
DOI：
10.1073/pnas.1613721113
复制
发表时间：
2016-09
影响因子：
11.1
通讯作者：
Wu, Yongrui
中科院分区：
文献类型：
--
作者：
Zheng, Xixi;Yang, Jun;Messing, Joachim;Wu, Yongrui
营养品质和产量在作物育种中同样重要，尽管它们有时会出现矛盾。在这项工作中，我们发现这些性状是通过两个转录因子的调节联系在一起的。影响这些转录因子表达的突变可以改善种子的营养品质，但也可以降低籽粒产量和硬度。因此，未来的玉米育种计划应该直接沉默玉米醇溶蛋白基因，而不是通过阻断转录因子。玉米胚乳特异性转录因子opaque 2（O2）和醇溶谷蛋白盒结合因子（PBF）调控贮藏蛋白玉米醇溶蛋白基因。我们发现，他们也控制淀粉合成。与正常基因型相比，PbfRNAi和o2突变体中的淀粉含量分别降低了105%和11%。在双突变体PbfRNAi;o2中，淀粉减少了25%。转录组分析显示，在两个突变体和双突变体中，均有> 1，000个基因受到影响;这些基因主要富集在糖和蛋白质代谢中。丙酮酸正磷酸二激酶1和2（PPDK）和淀粉合成酶III（SSIII）是淀粉生物合成酶复合体中的关键组分。与单突变体相比，双突变体中PPDK 1、PPDK 2和SSIII的表达及其蛋白水平进一步降低。当这些基因的启动子进行了分析，我们发现了一个醇溶谷蛋白盒和O2盒，可以添加反式激活PBF和O2。淀粉合成酶Ⅱ a（SSIIa，编码支链淀粉的另一种淀粉合成酶）和淀粉分支酶1（SBEI，编码两种主要淀粉分支酶之一）不直接受PBF和O2调节，但它们的蛋白质水平在O2突变体中显著降低，并且在双突变体中进一步降低，表明α 2和PbfRNAi可能影响一些其它转录因子或mRNA调节因子的水平，这些转录因子或mRNA调节因子又会影响SSIIa和SBEI的转录物和蛋白质水平。这些发现表明，三个重要的性状营养质量、热量和产量通过相同的转录因子联系在一起。
Significance Nutritional quality and yield are equally important considerations in crop breeding, although they sometimes appear at odds. In this work we made the discovery that these traits are linked through regulation by two transcription factors. Mutations that affect the expression of these transcription factors can improve the nutritional quality of the seed but also can reduce kernel yield and hardness. Therefore future corn-breeding programs should silence zein genes directly, not by blocking transcription factors. The maize endosperm-specific transcription factors opaque2 (O2) and prolamine-box binding factor (PBF) regulate storage protein zein genes. We show that they also control starch synthesis. The starch content in the PbfRNAi and o2 mutants was reduced by ∼5% and 11%, respectively, compared with normal genotypes. In the double-mutant PbfRNAi;o2, starch was decreased by 25%. Transcriptome analysis reveals that >1,000 genes were affected in each of the two mutants and in the double mutant; these genes were mainly enriched in sugar and protein metabolism. Pyruvate orthophosphate dikinase 1 and 2 (PPDKs) and starch synthase III (SSIII) are critical components in the starch biosynthetic enzyme complex. The expression of PPDK1, PPDK2, and SSIII and their protein levels are further reduced in the double mutants as compared with the single mutants. When the promoters of these genes were analyzed, we found a prolamine box and an O2 box that can be additively transactivated by PBF and O2. Starch synthase IIa (SSIIa, encoding another starch synthase for amylopectin) and starch branching enzyme 1 (SBEI, encoding one of the two main starch branching enzymes) are not directly regulated by PBF and O2, but their protein levels are significantly decreased in the o2 mutant and are further decreased in the double mutant, indicating that o2 and PbfRNAi may affect the levels of some other transcription factor(s) or mRNA regulatory factor(s) that in turn would affect the transcript and protein levels of SSIIa and SBEI. These findings show that three important traits—nutritional quality, calories, and yield—are linked through the same transcription factors.
登录
查看更多内容
影响因子：
3.7
作者：
Wu Y;Messing J
通讯作者：
Messing J
影响因子：
3.3
作者：
Wu, Yongrui;Messing, Joachim
通讯作者：
Messing, Joachim
DOI：
10.3410/f.725357467.793507045
发表时间：
2015-06
影响因子：
3.9
作者：
Sinéad Drea;S. Kourmpetli
通讯作者：
Sinéad Drea;S. Kourmpetli
影响因子：
7.4
作者：
Hennen-Bierwagen, Tracie A.;Lin, Qiaohui;Myers, Alan M.
通讯作者：
Myers, Alan M.
影响因子：
6.9
作者：
Chen, Jiang;Yi, Qiang;Huang, Yubi
通讯作者：
Huang, Yubi