WUS and STM-based reporter genes for studying meristem development in poplar
WUS and STM-based reporter genes for studying meristem development in poplar
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DOI：
10.1007/s00299-009-0685-3
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发表时间：
2009-06-01
影响因子：
6.2
通讯作者：
Strauss, Steven H.
中科院分区：
文献类型：
--
作者：
Bao, Y.;Dharmawardhana, P.;Strauss, Steven H.
我们描述了一个报告系统的发展，用于监测分生组织启动杨树使用启动子的白杨分生组织活性调控基因WUSCHEL（WUS）和SHOOTMERISTEMLESS（STM）。当使用相近同源物的类似于3 kb的5'侧翼区来驱动GUSPlus基因的表达时，50-60%的转基因事件显示在顶端和腋生分生组织中表达。然而，在其他器官中表达也很常见，包括在叶脉（分别为WUS和STM转基因事件的40%和46%）和积水管（WUS转基因事件的56%）中。在愈伤组织发生和使用体外茎作为外植体的芽再生期间，外植体的组织化学GUS染色显示，在可见的芽发育之前，在将外植体置于愈伤组织诱导培养基上后3-15天开始，表达是可检测的。少数WUS和STM事件还显示在经历次生生长的再生的温室生长植物的形成层、韧皮部或木质部中表达。基于微阵列基因表达数据，白杨WUS的一个paraums可检测到上调在芽的启动，但其他paraums没有。这两个旁系同源的白杨STM下调3倍至6倍，在早期愈伤组织的启动。我们在两个启动子中鉴定了15-35个拷贝的细胞分裂素反应调节剂结合基序（ARR 1AT）和一个拷贝的生长素反应元件（ARR 1 RE）。几个回收的事件可能是有用的研究过程中的初级和次级分生组织的发展，包括治疗旨在刺激分生组织的发展，以促进克隆繁殖和遗传转化。
We describe the development of a reporter system for monitoring meristem initiation in poplar using promoters of poplar homologs to the meristem-active regulatory genes WUSCHEL (WUS) and SHOOTMERISTEMLESS (STM). When similar to 3 kb of the 5' flanking regions of close homologs were used to drive expression of the GUSPlus gene, 50-60% of the transgenic events showed expression in apical and axillary meristems. However, expression was also common in other organs, including in leaf veins (40 and 46% of WUS and STM transgenic events, respectively) and hydathodes (56% of WUS transgenic events). Histochemical GUS staining of explants during callogenesis and shoot regeneration using in vitro stems as explants showed that expression was detectable prior to visible shoot development, starting 3-15 days after explants were placed onto callus inducing medium. A minority of WUS and STM events also showed expression in the cambium, phloem, or xylem of regenerated, greenhouse grown plants undergoing secondary growth. Based on microarray gene expression data, a paralog of poplar WUS was detectably up-regulated during shoot initiation, but the other paralog was not. Both paralogs of poplar STM were down-regulated threefold to sixfold during early callus initiation. We identified 15-35 copies of cytokinin response regulator binding motifs (ARR1AT) and one copy of the auxin response element (AuxRE) in both promoters. Several of the events recovered may be useful for studying the process of primary and secondary meristem development, including treatments intended to stimulate meristem development to promote clonal propagation and genetic transformation.