Suppression of Peroxisome Biogenesis Factor 10 Reduces Cuticular Wax Accumulation by Disrupting the ER Network in Arabidopsis thaliana
Suppression of Peroxisome Biogenesis Factor 10 Reduces Cuticular Wax Accumulation by Disrupting the ER Network in Arabidopsis thaliana
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DOI：
10.1093/pcp/pcp152
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发表时间：
2009-12-01
影响因子：
4.9
通讯作者：
Nishimura, Mikio
中科院分区：
文献类型：
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作者：
Kamigaki, Akane;Kondo, Maki;Nishimura, Mikio
过氧化物酶体生物合成因子10（PEX10）是过氧化物酶体基质蛋白输入机制的一个组成部分。为了分析PEX10的生理功能，我们使用了转基因AtPEX10i拟南芥植物，由于RNA干扰抑制了PEX10基因的表达。AtPEX10i植物叶片上有苍白的斑块，和异常的花器官，这是典型的表皮蜡缺陷突变体。角质层蜡质的定量分析表明，AtPEX10i植物中的蜡质量确实低于对照植物。这一结果通过AtPEX10i的甲苯胺蓝染色和扫描电子显微镜分析得到证实。已知CER1、CER4、WAX2和SHN1基因负责拟南芥中蜡的生物合成。其中，CER1，CER4和WAX2被发现定位于内质网（ER）。在AtPEX10i植物中，这些基因的表达被下调，并且CER1、CER4和WAX2被错误定位到胞质溶胶中。我们还发现AtPEX10i植物在内质网形态上有缺陷。基于这些结果，我们提出，PEX10是必不可少的ER形态的维持和CER1，CER4，WAX2和SHN1基因的表达，这有助于角质蜡的生物合成。
Peroxisome biogenesis factor 10 (PEX10) is a component of the peroxisomal matrix protein import machinery. To analyze the physiological function of PEX10, we used transgenic AtPEX10i Arabidopsis plants that had suppressed expression of the PEX10 gene due to RNA interference. AtPEX10i plants had patches of paleness on leaves, and abnormal floral organs that were typical of cuticular wax-deficient mutants. Quantitative analysis of cuticular wax revealed that the amount of wax in AtPEX10i plants was indeed lower than that in control plants. This result was confirmed by toluidine blue staining and scanning electron microscopic analysis of AtPEX10i. The CER1, CER4, WAX2 and SHN1 genes are known to be responsible for wax biosynthesis in Arabidopsis. Of these, CER1, CER4 and WAX2 were found to be localized on the endoplasmic reticulum (ER). In AtPEX10i plants, the expression of these genes was down-regulated, and CER1, CER4 and WAX2 were mislocalized to the cytosol. We also found that AtPEX10i plants had defects in ER morphology. Based on these results, we propose that PEX10 is essential for the maintenance of ER morphology and for the expression of CER1, CER4, WAX2 and SHN1 genes, which contribute to the biosynthesis of cuticular wax.