Identification and functional characterization of the distinct plant pectin esterases PAE8 and PAE9 and their deletion mutants.
Identification and functional characterization of the distinct plant pectin esterases PAE8 and PAE9 and their deletion mutants.
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DOI：
10.1007/s00425-014-2139-6
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发表时间：
2014-11
期刊：
影响因子：
4.3
通讯作者：
Pauly M
中科院分区：
文献类型：
--
作者：
de Souza A;Hull PA;Gille S;Pauly M
PAE8和PAE9具有果胶乙酰酯酶活性，它们一起去除了拟南芥叶片中与果胶形成相关的三分之一的细胞壁醋酸酯。在pae8和pae9突变体中，大量的醋酸盐积累在细胞壁中。此外，花序茎高也有所降低。果胶多糖是双子叶被子植物初生细胞壁的重要组成部分。这种多种多样的多糖参与了多种生理过程，包括细胞与细胞间的黏附和发病机制。几种果胶多糖含有直接影响其物理性质的乙酰基，如凝胶能力，这是食品工业的一个重要特征。为了进一步了解果胶乙酰化的生物学作用，采用反向遗传学方法研究了拟南芥果胶乙酰酯酶基因家族(PAE)成员基因的功能。PAE家族的两个成员(PAE8和PAE9)的突变导致细胞壁的醋酸盐含量增加约20%。从突变体中提取的富含果胶鼠李半乳糖醛酸甘油酯(RGI)的高相对分子质量组分增加了醋酸酯含量。此外，pae8突变体在低分子量果胶组分中也显示出更高的醋酸盐含量。Pae8/pae9-2双突变体表现出加性效应，壁醋酸酯含量增加高达37%，表明这两个基因不是多余的，它们作用于不同果胶结构域的乙酰基。突变体pae8和pae8/pae9-2表现出花序生长减慢，突显了果胶乙酰化在植物发育中的作用。当异源表达和纯化时，这两种基因产物在体外都能从相应的突变果胶组分中释放出醋酸酯。PAES在调节果胶聚合物在壁上的乙酰化状态方面发挥着重要作用，突出了质外体代谢对植物细胞和植物生长的重要性。本文的在线版本(doi：10.1007/s00425-0142139-6)包含补充材料，授权用户可以使用。
PAE8 and PAE9 have pectin acetylesterase activity and together remove one-third of the cell wall acetate associated with pectin formation in Arabidopsis leaves. In pae8 and pae9 mutants, substantial amounts of acetate accumulate in cell walls. In addition, the inflorescence stem height is decreased. Pectic polysaccharides constitute a significant part of the primary cell walls in dicotyledonous angiosperms. This diverse group of polysaccharides has been implicated in several physiological processes including cell-to-cell adhesion and pathogenesis. Several pectic polysaccharides contain acetyl-moieties directly affecting their physical properties such as gelling capacity, an important trait for the food industry. In order to gain further insight into the biological role of pectin acetylation, a reverse genetics approach was used to investigate the function of genes that are members of the Pectin AcetylEsterase gene family (PAE) in Arabidopsis. Mutations in two members of the PAE family (PAE8 and PAE9) lead to cell walls with an approximately 20 % increase in acetate content. High-molecular-weight fractions enriched in pectic rhamnogalacturonan I (RGI) extracted from the mutants had increased acetate content. In addition, the pae8 mutant displayed increased acetate content also in low-molecular-weight pectic fractions. The pae8/pae9-2 double mutant exhibited an additive effect by increasing wall acetate content by up to 37 %, suggesting that the two genes are not redundant and act on acetyl-substituents of different pectic domains. The pae8 and pae8/pae9-2 mutants exhibit reduced inflorescence growth underscoring the role of pectic acetylation in plant development. When heterologously expressed and purified, both gene products were shown to release acetate from the corresponding mutant pectic fractions in vitro. PAEs play a significant role in modulating the acetylation state of pectic polymers in the wall, highlighting the importance of apoplastic metabolism for the plant cell and plant growth. The online version of this article (doi:10.1007/s00425-014-2139-6) contains supplementary material, which is available to authorized users.
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影响因子：
4
作者：
Arend, Matthias
通讯作者：
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影响因子：
4.1
作者：
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DOI：
10.1073/pnas.1120429109
发表时间：
2012-01-24
影响因子：
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