Rice phenolics efflux transporter 2 (PEZ2) plays an important role in solubilizing apoplasmic iron
Rice phenolics efflux transporter 2 (PEZ2) plays an important role in solubilizing apoplasmic iron
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DOI：
10.1080/00380768.2011.637305
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发表时间：
2011-12-01
影响因子：
2
通讯作者：
Nishizawa, Naoko K.
中科院分区：
文献类型：
--
作者：
Bashir, Khurram;Ishimaru, Yasuhiro;Nishizawa, Naoko K.
铁是植物必需的微量营养素；然而，尽管铁在土壤中含量丰富，但在中性到碱性土壤中并不容易获得。植物分泌原儿茶酸(PCA)和咖啡酸(CA)等酚类物质，以吸收和利用根表面沉淀的质外体铁。然而，植物体内酚类物质的合成和分泌还没有得到很好的表征。我们鉴定并鉴定了一种水稻(Oryza sativa L.)木质部汁液和根分泌物中的PCA和CA含量减少的突变体，因此我们将其命名为酚类物质外排零2(Pez2)。PEZ2定位于洋葱(Allium cepa L.)的质膜在非洲爪哇卵母细胞中表达的表皮细胞和转运的PCA。PEZ2在靠近根尖的全根中有表达。同样，在叶片中也观察到了强烈的表达。随着木质部汁液中PCA和CA含量的减少，pez2植株的木质部Fe含量也较低。这些结果表明，PEZ2参与了水稻质外体铁的增溶作用。
Iron (Fe) is an essential micronutrient for plants; however, despite its abundance in soils it is not readily available in neutral to alkaline soils. Plants secrete phenolics, such as protocatechuic acid (PCA) and caffeic acid (CA), to absorb and utilize precipitated apoplasmic Fe from root surfaces. However, the synthesis and secretion of phenolics have not been well characterized in plants. We have identified and characterized a rice (Oryza sativa L.) mutant with reduced amounts of PCA and CA in xylem sap and root exudates; hence we named it phenolics efflux zero 2 (pez2). PEZ2 localized to the plasma membrane in onion (Allium cepa L.) epidermal cells and transported PCA when expressed in Xenopus laevis oocytes. PEZ2 expression was observed in whole root near root tips. Similarly, strong expression was observed in leaves. In line with reduced amounts of PCA and CA in xylem sap, the xylem Fe concentration was also low in pez2 plants. These results suggest that PEZ2 is involved in solubilization of apoplasmic Fe in rice.