A new hypothesis on the strategy for acquisition of phosphorus in arbuscular mycorrhiza: Up-regulation of secreted acid phosphatase gene in the host plant
A new hypothesis on the strategy for acquisition of phosphorus in arbuscular mycorrhiza: Up-regulation of secreted acid phosphatase gene in the host plant
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DOI：
10.1094/mpmi-18-1046
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发表时间：
2005-10-01
影响因子：
3.5
通讯作者：
Saito, M
中科院分区：
文献类型：
--
作者：
Ezawa, T;Hayatsu, M;Saito, M
通过电泳检测到与球囊霉共生的万寿菊菌根响应性磷酸酶，并通过柱层析纯化，并鉴定为分泌到根际的酸性磷酸酶。通过气相测序仪确定N端氨基酸序列，并通过根据N端氨基酸序列设计的简并引物扩增磷酸酶基因(TpPAP1)的cDNA片段。通过cDNA末端快速扩增技术获得全长cDNA。 TpPAP1来源于宿主，cDNA长1,843 bp，预测多肽开放阅读框为466个氨基酸。系统发育分析表明该基因属于植物高分子量紫色酸性磷酸酶簇。与细叶古孢菌共生的孔雀草中 TpPAP1 的表达分析表明，菌根定植后转录物水平增加了八倍。蛋白质印迹分析显示，与菌根响应性磷酸酶相对应的 57 kDa 蛋白质因菌根定植而增加。本研究提出了一种在丛枝菌根群落中获取磷的新策略，其中真菌伙伴激活植物伙伴低磷适应系统的一部分、磷酸酶分泌，并提高磷吸收的整体效率。
The mycorrhiza-responsive phosphatase of Tagetes patula in symbiosis with Glomus etunicatum was detected by electrophoresis, was purified by column chromatography, and was characterized as acid phosphatase that was secreted into rhizosphere. The N-terminal amino acid sequence was determined by a gas-phase sequencer, and a cDNA fragment of the phosphatase gene (TpPAP1) was amplified by degenerate primers designed based on the N-terminal amino acid sequence. The full-length cDNA was obtained by the rapid amplification of cDNA ends technique. The TpPAP1 was of host origin, and the cDNA was 1,843 bp long with a predicted open reading frame of polypeptide of 466 amino acids. Phylogenetic analysis revealed that the gene fell into the cluster of plant high-molecular-weight purple acid phosphatase. Expression analysis of the TpPAP1 in T patula in symbiosis with Archaeospora leptoticha showed that the levels of transcripts increased eightfold by mycorrhizal colonization. Western blot analysis revealed that the 57-kDa protein corresponding to the mycorrhiza-responsive phosphatase increased by mycorrhizal colonization. The present study proposes a new strategy for acquisition of P in arbuscular mycorrhizal associations in which the fungal partner activates a part of the low-P adaptation system of the plant partner, phosphatase secretion, and improves the overall efficiency of P uptake.