Transcriptional Control of SET DOMAIN GROUP 8 and CAROTENOID ISOMERASE during Arabidopsis Development
Transcriptional Control of SET DOMAIN GROUP 8 and CAROTENOID ISOMERASE during Arabidopsis Development
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DOI：
10.1093/mp/ssp092
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发表时间：
2010-01-01
期刊：
影响因子：
27.5
通讯作者：
Pogson, Barry J.
中科院分区：
文献类型：
--
作者：
Cazzonelli, Christopher I.;Roberts, Andrea C.;Pogson, Barry J.
类胡萝卜素是光合作用、光保护和产生类胡萝卜素衍生的激素如ABA和独脚金内酯所需的色素。类胡萝卜素生物合成途径在番茄红素之后分叉以产生β-和β-类胡萝卜素，并且该分支对于确定类胡萝卜素组成是关键的。在这里，我们展示了如何分支点可以调节染色质修饰组蛋白甲基转移酶，设置域组8（SDG 8）靶向类胡萝卜素异构酶（CRTISO）。SDG 8是在幼苗发育期间、叶片、茎尖和一些花器官中维持CRTISO允许表达所必需的。CRTISO和SDG8启动子显示重叠的报告基因活性的组织特异性模式。有趣的是，与花椰菜花叶病毒35S启动子（CaMV35s）和CRTIS0启动子相比，CRTIS0在不同株系之间表现出更大的变异性，这可能是由于染色体位置效应。CRTISO启动子的调节部分取决于SDG8的存在或不存在。SDG 8（类胡萝卜素和叶绿体调节（ccr 1））和CRTISO（ccr 2）的敲除导致改变的类胡萝卜素组成，并且这可以使用CaMV 35 s或CRTISO启动子在ccr 2中恢复。相比之下，在ccr 1背景下使用CaMV 35 S或CRTISO启动子通过CRTISO过表达的不同程度的GUS表达和类胡萝卜素互补表明，CRTISO启动子和开放阅读框对于SDG 8介导的CRTISO表达是必需的。
Carotenoids are pigments required for photosynthesis, photoprotection and the production of carotenoid-derived hormones such as ABA and strigolactones. The carotenoid biosynthetic pathway bifurcates after lycopene to produce epsilon- and beta-carotenoids and this branch is critical for determining carotenoid composition. Here, we show how the branch point can be regulated by the chromatin-modifying histone methyltransferase, Set Domain Group 8 (SDG8) targeting the carotenoid isomerase (CRTISO). SDG8 is required to maintain permissive expression of CRTISO during seedling development, in leaves, shoot apex, and some floral organs. The CRTISO and SDG8 promoters show overlapping tissue-specific patterns of reporter gene activity. Interestingly, CRTISO showed atypical reporter gene expression in terms of greater variability between different lines compared to the Cauliflower Mosaic Virus 35S promoter (CaMV35s) and epsilon LCY promoters, potentially due to chromosomal position effects. Regulation of the CRTISO promoter was dependent in part upon the presence or absence of SDG8. Knockouts of SDG8 (carotenoid and chloroplast regulation (ccr1)) and CRTISO (ccr2) result in altered carotenoid composition and this could be restored in ccr2 using the CaMV35s or CRTISO promoters. In contrast, varying degrees of GUS expression and carotenoid complementation by CRTISO overexpression using CaMV35S or CRTISO promoters in the ccr1 background demonstrated that both the CRTISO promoter and open reading frame are necessary for SDG8-mediated expression of CRTISO.