Nitric Oxide Functions as a Positive Regulator of Root Hair Development
Nitric Oxide Functions as a Positive Regulator of Root Hair Development
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DOI：
10.4161/psb.1.1.2398
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发表时间：
2006-01-01
影响因子：
2.9
通讯作者：
Lamattina, Lorenzo
中科院分区：
文献类型：
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作者：
Cristina Lombardo, Maria;Graziano, Magdalena;Lamattina, Lorenzo
根表皮由两种细胞组成：毛细胞（或毛细胞）和无毛细胞（或非毛细胞）。在莴苣（Lactuca sativa cv.大急流城水培法生长的植株，根表皮不形成根毛。添加10 μ M硝普钠（SNP），一氧化氮（NO）供体，导致几乎所有的根皮细胞分化成根毛。用合成的生长素1-萘乙酸（NAA）处理显示出显著增加的根毛形成（RHF），这被特异性NO清除剂羧基-PTIO（cPTIO）阻止。在拟南芥中，两个突变体已被证明是有缺陷的NO生产和显示改变的表型，其中NO是牵连。拟南芥nos 1在NO合酶结构基因（NOS 1）中具有突变，并且nia 1 nia 2双突变体不具有硝酸还原酶（NR）活性。我们观察到这两个突变体的根毛发育能力受到影响。根毛伸长显着减少nos 1和nia 1 nia 2突变体以及cPTIO处理的野生型植物。用荧光探针DAF-FM-DA和RHF检测的根系内源NO含量之间存在相关性。在拟南芥中，以及在莴苣中，cPTIO阻断NAA诱导的根毛伸长。总之，这些结果表明：（1）NO是导致RHF的过程中的关键分子，（2）NO参与了导致RHF的生长素信号级联。
The root epidermis is composed of two cell types: trichoblasts (or hair cells) and atrichoblasts (or non-hair cells). In lettuce (Lactuca sativa cv. Grand Rapids var. Rapidmor oscura) plants grown hydroponically in water, the root epidermis did not form root hairs. The addition of 10 mu M sodium nitroprusside (SNP), a nitric oxide (NO) donor, resulted in almost all rhizodermal cells differentiated into root hairs. Treatment with the synthetic auxin 1-naphthyl acetic acid (NAA) displayed a significant increase of root hair formation (RHF) that was prevented by the specific NO scavenger carboxy-PTIO (cPTIO). In Arabidopsis, two mutants have been shown to be defective in NO production and to display altered phenotypes in which NO is implicated. Arabidopsis nos1 has a mutation in an NO synthase structural gene (NOS1), and the nia1 nia2 double mutant is null for nitrate reductase (NR) activity. We observed that both mutants were affected in their capacity of developing root hairs. Root hair elongation was significantly reduced in nos1 and nia1 nia2 mutants as well as in cPTIO-treated wild type plants. A correlation was found between endogenous NO level in roots detected by the fluorescent probe DAF-FM DA and RHF. In Arabidopsis, as well as in lettuce, cPTIO blocked the NAA-induced root hair elongation. Taken together, these results indicate that: (1) NO is a critical molecule in the process leading to RHF and (2) NO is involved in the auxin-signaling cascade leading to RHF.