VASCULAR-RELATED NAC-DOMAIN7 is involved in the differentiation of all types of xylem vessels in Arabidopsis roots and shoots
VASCULAR-RELATED NAC-DOMAIN7 is involved in the differentiation of all types of xylem vessels in Arabidopsis roots and shoots
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DOI：
10.1111/j.1365-313x.2008.03533.x
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发表时间：
2008-08-01
期刊：
影响因子：
7.2
通讯作者：
Demura, Taku
中科院分区：
文献类型：
--
作者：
Yamaguchi, Masatoshi;Kubo, Minoru;Demura, Taku
拟南芥NAC结构域转录因子VASCULAR-RELATED NAC-DOMAIN 7（VND 7）在调控根原生木质部导管分化中起关键作用。为了更详细地了解VND 7在导管分化中的作用机制，我们在酵母（酿酒酵母）、拟南芥和烟草中进行了广泛的分子分析。CV.亮黄2（烟草BY-2）细胞。在酵母和拟南芥中证实了VND 7的转录激活活性，并且显示C-末端区域是VND 7转录激活所必需的。在天然VND 7启动子的控制下，C-末端截短的VND 7蛋白的表达导致根中的后生木质部导管和气生器官中的导管以及根中的原生木质部导管的正常发育受到抑制。在大多数分化血管中，VND 7的表达模式与VND 2至VND 5的表达模式重叠。此外，酵母双杂交测定揭示了VND 7通过其N-末端（包括NAC结构域）与其他VND蛋白形成同源二聚体和异源二聚体的能力。VND 7在烟草BY-2细胞中的异源表达表明，VND 7的稳定性可以通过蛋白酶体介导的降解来调节。总之，这些数据表明，VND 7调节根和芽中所有类型的导管的分化，可能与VND 2至VND 5和其他调节蛋白合作。
The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), plays a pivotal role in regulating the differentiation of root protoxylem vessels. In order to understand the mechanisms underscoring the function of VND7 in vessel differentiation in more detail, we conducted extensive molecular analyses in yeast (Saccharomyces cerevisiae), Arabidopsis, and Nicotiana tabacum L. cv. Bright Yellow 2 (tobacco BY-2) cells. The transcriptional activation activity of VND7 was confirmed in yeast and Arabidopsis, and the C-terminal region was shown to be required for VND7 transcriptional activation. Expression of the C-terminus-truncated VND7 protein under the control of the native VND7 promoter resulted in inhibition of the normal development of metaxylem vessels in roots and vessels in aerial organs, as well as protoxylem vessels in roots. The expression pattern of VND7 overlapped that of VND2 to VND5 in most of the differentiating vessels. Furthermore, a yeast two-hybrid assay revealed the ability of VND7 to form homodimers and heterodimers with other VND proteins via their N-termini, which include the NAC domain. The heterologous expression of VND7 in tobacco BY-2 cells demonstrated that the stability of VND7 could be regulated by proteasome-mediated degradation. Together these data suggest that VND7 regulates the differentiation of all types of vessels in roots and shoots, possibly in cooperation with VND2 to VND5 and other regulatory proteins.