A type 5 acid phosphatase gene from Arabidopsis thaliana is induced by phosphate starvation and by some other types of phosphate mobilising/oxidative stress conditions
A type 5 acid phosphatase gene from Arabidopsis thaliana is induced by phosphate starvation and by some other types of phosphate mobilising/oxidative stress conditions
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DOI：
10.1046/j.1365-313x.1999.00562.x
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发表时间：
1999-09-01
期刊：
影响因子：
7.2
通讯作者：
Paz-Ares, J
中科院分区：
文献类型：
--
作者：
del Pozo, JC;Allona, I;Paz-Ares, J
低磷可利用性是许多土壤的常见状况，已知会刺激植物的磷酸酶活性；然而，这种反应的分子细节仍然是未知的。对拟南芥（Arabidopsis thaliana）磷酸饥饿诱导酸性磷酸酶（AtACP5）的n端区域进行了纯化和测序，并克隆了其cDNA和相应的基因组DNA。cDNA的核苷酸序列预测AtACP5是一个338个氨基酸长的前体，带有一个信号肽。发现AtACP5与已知的紫色酸性磷酸酶有关，特别是与哺乳动物5型酸性磷酸酶有关。紫色酸性磷酸酶含有一个双核金属中心，它与紫色酸性磷酸酶的其他相似之处还包括：与金属配体结合有关的所有残基的保存，以及对酒石酸盐抑制的抗性。此外，与其他5型酸性磷酸酶一样，AtACP5也表现出过氧化活性。北方杂交实验以及对含有AtACP5:GUS翻译融合物的转基因植物的GUS活性测定表明，AtACP5不仅对磷酸盐饥饿有反应，而且对ABA和盐胁迫也有反应。在H202r诱导的衰老叶片和氧化应激过程中也有表达，但在百草枯和水杨酸诱导下不表达。考虑到AtACP5的双重功能，因为它同时具有磷酸酶和过氧化活性，我们认为AtACP5可能参与植物逆境或衰老部位的磷酸盐动员和活性氧代谢。
Low phosphorous availability, a common condition of many soils, is known to stimulate phosphatase activity in plants; however, the molecular details of this response remain mostly unknown. We purified and sequenced the N-terminal region of a phosphate starvation induced acid phosphatase (AtACP5) from Arabidopsis thaliana, and cloned its cDNA and the corresponding genomic DNA. The nucleotide sequence of the cDNA predicted that AtACP5 is synthesised as a 338 amino acid-long precursor with a signal peptide. AtACP5 was found to be related to known purple acid phosphatases, especially to mammal type 5 acid pnospnarases. Other similarities with purple acid phosphatases, which contain a dinuclear metal centre, include the conservation of all residues involved in metal ligand binding and resistance to tartrate inhibition. In addition, AtACP5, like other type 5 acid phosphatases, displayed peroxidation activity. Northern hybridisation experiments, as well as in sifu glucuronidase (GUS) activity assays on transgenic plants harbouring AtACP5:GUS translational fusions, showed that AtACP5 is not only responsive to phosphate starvation but also to ABA and salt stress. It is also expressed in senescent leaves and during oxidative stress induced by H202r but not by paraquat or salicylic acid. Given its bifunctionality, as it displays both phosphatase and peroxidation activity, we propose that AtACP5 could be involved in phosphate mobilisation and in the metabolism of reactive oxygen species in stressed or senescent parts of the plant.