The PINOID protein kinase regulates organ development in Arabidopsis by enhancing polar auxin transport.
The PINOID protein kinase regulates organ development in Arabidopsis by enhancing polar auxin transport.
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发表时间：
2001-10
期刊：
影响因子：
4.6
通讯作者：
René Benjamins;Ab Quint;D. Weijers;P. Hooykaas;R. Offringa
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作者：
René Benjamins;Ab Quint;D. Weijers;P. Hooykaas;R. Offringa
拟南芥pinoid突变体与极性生长素运输被破坏的pin形成突变体表现出强烈的表型相似性。 PINOID 基因最近被克隆并被发现编码一种蛋白质丝氨酸/苏氨酸激酶。在这里，我们表明，PINOID 基因可由生长素诱导，并且蛋白激酶存在于子叶、叶和花器官的原基中以及发育器官中或邻近分生组织的维管组织中。在组成型 CaMV 35S 启动子 (35S::PID) 的控制下，PINOID 的过表达会导致在对生长素敏感性或转运发生改变的突变体中也观察到的表型。高表达 35S::PID 幼苗的一个显着特征是初生根分生组织频繁崩溃。这一事件触发了侧根的形成，这一过程最初在这些幼苗中受到抑制。当幼苗在极性生长素转运抑制剂（例如萘基邻苯二甲酸（NPA））的存在下生长时，分生组织组织和初生根的生长都得到了挽救。此外，PINOID cDNA在表皮特异性LTP1启动子控制下的异位表达为PINOID的NPA敏感性作用提供了进一步的证据。这里给出的结果表明，PINOID 起到极性生长素运输的正调节作用。我们认为，PINOID 参与器官形成过程中响应局部生长素浓度的极性生长素转运的微调。
Arabidopsis pinoid mutants show a strong phenotypic resemblance to the pin-formed mutant that is disrupted in polar auxin transport. The PINOID gene was recently cloned and found to encode a protein-serine/threonine kinase. Here we show that the PINOID gene is inducible by auxin and that the protein kinase is present in the primordia of cotyledons, leaves and floral organs and in vascular tissue in developing organs or proximal to meristems. Overexpression of PINOID under the control of the constitutive CaMV 35S promoter (35S::PID) resulted in phenotypes also observed in mutants with altered sensitivity to or transport of auxin. A remarkable characteristic of high expressing 35S::PID seedlings was a frequent collapse of the primary root meristem. This event triggered lateral root formation, a process that was initially inhibited in these seedlings. Both meristem organisation and growth of the primary root were rescued when seedlings were grown in the presence of polar auxin transport inhibitors, such as naphthylphtalamic acid (NPA). Moreover, ectopic expression of PINOID cDNA under control of the epidermis-specific LTP1 promoter provided further evidence for the NPA-sensitive action of PINOID. The results presented here indicate that PINOID functions as a positive regulator of polar auxin transport. We propose that PINOID is involved in the fine-tuning of polar auxin transport during organ formation in response to local auxin concentrations.