Dissecting iron deficiency-induced proton extrusion in Arabidopsis roots
Dissecting iron deficiency-induced proton extrusion in Arabidopsis roots
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DOI：
10.1111/j.1469-8137.2009.02908.x
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发表时间：
2009-01-01
期刊：
影响因子：
9.4
通讯作者：
Schmidt, Wolfgang
中科院分区：
文献类型：
--
作者：
Santi, Simonetta;Schmidt, Wolfgang
在这里，我们分析了H+-ATP酶介导的质子穿过根皮细胞质膜（PM）的挤出，铁敏感性质膜H ~+-的诱导和功能拟南芥根中的ATP酶的基因表达分析，并通过使用突变体的表达或功能的一个同源基因进行了研究。此外，最响应的isogenes的表达进行了调查，在自然拟南芥加入已被选定为他们在体内质子挤出activity.Our的数据表明，根际酸化响应铁缺乏主要是由AHA 2介导的，而AHA 1作为管家异构体的功能。Aha 7基因敲除的突变体植物显示根毛的频率降低，表明AHA 7参与了根皮细胞的分化。拟南芥的酸化能力因材料而异，并与AHA 2和IRT 1的高诱导率、高相对生长速率和不受外部铁供应影响的地上部/根比相关，铁响应基因的有效调控和稳定的地上部/根比可能是铁吸收效率的重要特征。
Here, we have analysed the H+-ATPase-mediated extrusion of protons across the plasma membrane (PM) of rhizodermic cells, a process that is inducible by iron (Fe) deficiency and thought to serve in the mobilization of sparingly soluble Fe sources.The induction and function of Fe-responsive PM H+-ATPases in Arabidopsis roots was investigated by gene expression analysis and by using mutants defective in the expression or function of one of the isogenes. In addition, the expression of the most responsive isogenes was investigated in natural Arabidopsis accessions that have been selected for their in vivo proton extrusion activity.Our data suggest that the rhizosphere acidification in response to Fe deficiency is chiefly mediated by AHA2, while AHA1 functions as a housekeeping isoform. The aha7 knock-out mutant plants showed a reduced frequency of root hairs, suggesting an involvement of AHA7 in the differentiation of rhizodermic cells. Acidification capacity varied among Arabidopsis accessions and was associated with a high induction of AHA2 and IRT1, a high relative growth rate and a shoot-root ratio that was unaffected by the external Fe supply.An effective regulation of the Fe-responsive genes and a stable shoot-root ratio may represent important characteristics for the Fe uptake efficiency.