Ectopic Expression of an Esterase, Which is a Candidate for the Unidentified Plant Cutinase, Causes Cuticular Defects in Arabidopsis thaliana
Ectopic Expression of an Esterase, Which is a Candidate for the Unidentified Plant Cutinase, Causes Cuticular Defects in Arabidopsis thaliana
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DOI：
10.1093/pcp/pcp173
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发表时间：
2010-01-01
影响因子：
4.9
通讯作者：
Hara-Nishimura, Ikuko
中科院分区：
文献类型：
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作者：
Takahashi, Kentaro;Shimada, Tomoo;Hara-Nishimura, Ikuko
角质酶是一种酯酶，降解聚酯角质，植物角质层的主要成分。虽然角质酶活性已在花粉中检测到，编码这种酶的基因尚未确定。在这里，我们报告的鉴定和表征拟南芥CDEF 1（角质层破坏因子1），一个新的候选基因编码角质酶。CDEF 1编码蛋白质的GDSL脂肪酶/酯酶家族的成员，尽管真菌和细菌角质酶属于与GDSL脂肪酶/酯酶家族不同的/水解酶超家族。根据AtGenExpress微阵列数据，CDEF 1主要在花粉中表达。由35 S启动子驱动的CDEF 1的异位表达引起器官的融合，包括叶、茎和花，并增加表面渗透性。超微结构分析表明，转基因植株的角质层经常被破坏，变得不连续。用绿色荧光蛋白（GFP）标记的CDEF 1的亚细胞分析表明，该蛋白质被分泌到叶片的细胞外空间。重组CDEF 1蛋白具有酯酶活性。这些结果与角质酶从细胞分泌并直接降解角质层中的聚酯一致。在成熟花粉和花粉管中检测到CDEF 1启动子活性，表明CDEF 1参与了花粉管对柱头的穿透。此外，我们发现CDEF 1在侧根出现的区域表达，这表明CDEF 1降解细胞壁组分以促进侧根的出现。我们的研究结果表明，CDEF 1是一个未知的植物角质酶的候选基因。
Cutinase is an esterase that degrades the polyester cutin, a major component of the plant cuticle. Although cutinase activity has been detected in pollen, the genes encoding this enzyme have not been identified. Here, we report the identification and characterization of Arabidopsis CDEF1 (cuticle destructing factor 1), a novel candidate gene encoding cutinase. CDEF1 encodes a member of the GDSL lipase/esterase family of proteins, although fungal and bacterial cutinases belong to the / hydrolase superfamily which is different from the GDSL lipase/esterase family. According to the AtGenExpress microarray data, CDEF1 is predominantly expressed in pollen. The ectopic expression of CDEF1 driven by the 35S promoter caused fusion of organs, including leaves, stems and flowers, and increased surface permeability. Ultrastructural analysis revealed that the cuticle of the transgenic plants was often disrupted and became discontinuous. Subcellular analysis with green fluorescent protein (GFP)-tagged CDEF1 showed that the protein is secreted to the extracellular space in leaves. The recombinant CDEF1 protein has esterase activity. These results are consistent with cutinase being secreted from cells and directly degrading the polyester in the cuticle. CDEF1 promoter activity was detected in mature pollen and pollen tubes, suggesting that CDEF1 is involved in the penetration of the stigma by pollen tubes. Additionally, we found CDEF1 expression at the zone of lateral root emergence, which suggests that CDEF1 degrades cell wall components to facilitate the emergence of the lateral roots. Our findings suggest that CDEF1 is a candidate gene for the unidentified plant cutinase.