Overexpression of PeRHD3 alters the root architecture in Populus.
Overexpression of PeRHD3 alters the root architecture in Populus.
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DOI：
10.1016/j.bbrc.2012.06.083
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发表时间：
2012-07
影响因子：
3.1
通讯作者：
Meng Xu;W. Xie;Minren Huang
中科院分区：
文献类型：
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作者：
Meng Xu;W. Xie;Minren Huang
不定根对于重要经济木本物种的营养繁殖至关重要。更好地了解促进或阻碍生根的遗传和生理机制将提高树木成功商业化应用的潜力。根毛缺陷3（RHD3）是一种大的GTP结合蛋白，在植物中广泛表达。我们以前的微阵列研究确定了属于RHD3家族的基因的差异表达模式不定根的发展过程中硬枝扦插，并表明，RHD3基因参与不定根在杨树。在这项研究中，我们克隆和鉴定了两个杨树RHD3基因的cDNA，命名为PeRHD3a和PeRHD3b。在根、茎、叶和叶柄中检测到这两个基因编码的转录本。为了表征这些基因的细胞功能，使用根癌农杆菌（Agrobacterium tumifaciens）用将靶基因的表达置于强组成型启动子花椰菜花叶病毒35S（Pro35S）启动子控制下的载体转化白杨。PeRHD3a转基因株系和PeRHD3b转基因株系表现出非常相似的表型特征。在白杨植株中过量表达PeRHD3a或PeRHD3b导致仅形成单个突出的不定根，侧根发达，根尖特征异常，根毛更长且更丰富。这些结果表明，RHD 3可能控制不定根和侧根的形成，以及通过调节各向异性的细胞扩张根毛的发展。
Adventitious rooting is essential for the vegetative propagation of economically important woody species. A better understanding of the genetic and physiological mechanisms that promote or hinder rooting will enhance the potential for successful commercial deployment of trees. ROOT HAIR DEFECTIVE 3 (RHD3), a large GTP-binding protein, is ubiquitously expressed in plants. Our previous microarray study identified differential expression patterns of genes belonging to the RHD3 family during adventitious root development from hardwood cuttings, and indicated that the RHD3 genes were involved in adventitious rooting in Populus. In this study, we cloned and characterized cDNAs of the two Populus RHD3 genes, designated as PeRHD3a and PeRHD3b. Transcripts encoded by the two genes were detected in roots, stems, leaves and petioles. To characterize the cellular functions of the genes, Agrobacterium tumifaciens was used to transform poplar with a vector that places expression of the target gene under the control of the strong constitutive promoter, Cauliflower Mosaic Virus 35S (Pro35S) promoter. Both PeRHD3a transgenic lines and PeRHD3b transgenic lines showed very similar phenotypic characteristics. Overexpression of PeRHD3a or PeRHD3b in poplar plants resulted in the formation of only a single prominent adventitious root with well-developed lateral roots, characteristic abnormalities in the root tip, and longer and more plentiful root hairs. These results imply that RHD3 may control adventitious and lateral root formation, as well as root hair development by regulating anisotropic cell expansion.