Expression Analysis of Two NAC Transcription Factors PtNAC068 and PtNAC154 from Poplar
Expression Analysis of Two NAC Transcription Factors PtNAC068 and PtNAC154 from Poplar
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杨树两个NAC转录因子PtNAC068和PtNAC154的表达分析
DOI：
10.1007/s11105-011-0350-1
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发表时间：
2012-04-01
影响因子：
2.1
通讯作者：
Lu, Mengzhu
中科院分区：
文献类型：
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作者：
Han, Xiaojiao;He, Guo;Lu, Mengzhu
NAM/ATAF/CUC (NAC) 家族基因是植物基因组中最大的转录因子家族之一，在发育中的木本组织中广泛表达。在本研究中，我们利用β-葡萄糖醛酸酶（GUS）报告基因系统构建了植物转化载体，并检测了转基因白杨（Populus alba x Populus mudulosa）中来自毛白杨（Populus tomentosa Carr.）的PtNAC068和PtNAC154基因的启动子表达模式。结果表明，PtNAC068和PtNAC154启动子驱动的GUS表达在杨树中可能比在拟南芥中更复杂。组织化学GUS检测表明，PtNAC068启动子驱动的GUS活性主要在茎、叶、叶柄和根的维管组织中，而PtNAC154启动子驱动的GUS活性仅限于茎和叶脉的发育中的次生木质部。通过实时 RT-PCR 测量发现，与 IN2-4 相比，IN5-10 顶点以下连续节间的 PtNAC068 和 PtNAC154 转录水平要高得多，表明 PtNAC068 和 PtNAC154 上调与杨树的次生生长有关。 ProNAC068::GUS转基因植物的节间3-8中的GUS表达比ProNAC154::GUS转基因植物高30倍。 mRNA积累的表达模式和转录水平的差异表明PtNAC068和PtNAC154可能参与血管组织发育的两个不同方面。
NAM/ATAF/CUC (NAC) family genes comprise one of the largest families of transcription factors in plant genomes and are widely expressed in developing woody tissues. In the present study, we constructed plant transformation vectors using the beta-glucuronidase (GUS) reporter gene system and detected the promoter expression patterns derived from the PtNAC068 and PtNAC154 genes of Chinese white poplar (Populus tomentosa Carr.) in transgenic poplars (Populus alba x Populus glandulosa). The results showed that the GUS expression driven by PtNAC068 and PtNAC154 promoters may be more complex in poplar than they are in Arabidopsis. Histochemical GUS assays showed that GUS activity driven by PtNAC068 promoter was mainly in vascular tissues of stems, leaves, petioles, and roots, while that driven by PtNAC154 promoter was confined to the developing secondary xylem of stems and veins of leaves. The transcript level of both PtNAC068 and PtNAC154 in successive internodes below the apex was found to be much higher in IN5-10 compared to that in IN2-4 as measured by real-time RT-PCR, suggesting that PtNAC068 and PtNAC154 upregulation is related to secondary growth in poplar. GUS expression in internodes 3-8 of ProNAC068::GUS transgenic plants was 30-fold higher than that in ProNAC154::GUS transgenic plants. The differences in the expression pattern and transcript level of mRNA accumulation indicate that PtNAC068 and PtNAC154 may be involved in two distinct aspects of vascular tissue development.