Genetic dissection of hormonal responses in the roots of Arabidopsis grown under continuous mechanical impedance
Genetic dissection of hormonal responses in the roots of Arabidopsis grown under continuous mechanical impedance
复制标题
DOI：
10.1104/pp.107.115519
复制
发表时间：
2008-04-01
期刊：
影响因子：
7.4
通讯作者：
Rahman, Abidur
中科院分区：
文献类型：
--
作者：
Okamoto, Takashi;Tsurumi, Seiji;Rahman, Abidur
我们研究了乙烯和生长素在机械阻抗过程中调节根的生长和形态的作用，通过开发一个新的生长系统，并使用模式植物拟南芥（Arabidopsis thaliana）。在透析膜覆盖的琼脂平板上水平生长的拟南芥幼苗遇到足够的机械阻抗，因为根表现出特征性的乙烯表型：根生长减少2倍，根直径增加，细胞伸长减少，和异位根毛形成。乙烯生物合成或信号，乙烯抑制剂对机械受阻的根，和转录谱的乙烯响应基因的各种突变体的根表型表征导致我们得出结论，增强乙烯响应在机械阻抗过程中改变根的形态和发育中起着主要作用。此外，水平和垂直生长的根对外源乙烯的不同敏感性表明，乙烯信号在增强乙烯反应中起着至关重要的作用。我们随后证明，增强乙烯反应也影响了根中的生长素反应。两者合计，我们的研究结果提供了一个新的洞察乙烯在机械阻抗过程中改变根形态的作用。
We investigated the role of ethylene and auxin in regulating the growth and morphology of roots during mechanical impedance by developing a new growing system and using the model plant Arabidopsis (Arabidopsis thaliana). The Arabidopsis seedlings grown horizontally on a dialysis membrane-covered agar plate encountered adequate mechanical impedance as the roots showed characteristic ethylene phenotypes: 2-fold reduction in root growth, increase in root diameter, decrease in cell elongation, and ectopic root hair formation. The root phenotype characterization of various mutants having altered response to ethylene biosynthesis or signaling, the effect of ethylene inhibitors on mechanically impeded roots, and transcription profiling of the ethylene-responsive genes led us to conclude that enhanced ethylene response plays a primary role in changing root morphology and development during mechanical impedance. Further, the differential sensitivity of horizontally and vertically grown roots toward exogenous ethylene suggested that ethylene signaling plays a critical role in enhancing the ethylene response. We subsequently demonstrated that the enhanced ethylene response also affects the auxin response in roots. Taken together, our results provide a new insight into the role of ethylene in changing root morphology during mechanical impedance.