RNA-Seq Analysis of Developing Nasturtium Seeds (Tropaeolum majus): Identification and Characterization of an Additional Galactosyltransferase Involved in Xyloglucan Biosynthesis
RNA-Seq Analysis of Developing Nasturtium Seeds (Tropaeolum majus): Identification and Characterization of an Additional Galactosyltransferase Involved in Xyloglucan Biosynthesis
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DOI：
10.1093/mp/sss032
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发表时间：
2012-09-01
期刊：
影响因子：
27.5
通讯作者：
Pauly, Markus
中科院分区：
文献类型：
--
作者：
Jensen, Jacob K.;Schultink, Alex;Pauly, Markus
利用454和Illumina测序方法进行了深度测序，以发现与木聚糖生物合成有关的新基因。从发育中的水仙(Tropaeolum Majus)种子中产生大量非岩藻糖化的木葡聚糖作为种子储藏聚合物。除了已知的木葡聚糖生物合成基因外，还发现了一个先前未知的木葡聚糖半乳糖基转移酶。对一个在相应同源基因(AT5G62220)中有缺陷的拟南芥突变系的分析表明，该基因与先前描述的木葡聚糖半乳糖基转移酶MUR3没有冗余，但在不同位置的木葡聚糖半乳糖基取代是必需的。该基因命名为木葡聚糖L侧链半乳糖基转移酶第2位，与MUR3属于同一糖基转移酶家族47亚类。一个在MUR3(-3.1)和XLT2中都有缺陷的双突变导致了一个含有木葡聚糖的拟南芥植株，该植株基本上只由木糖基单位组成，没有进一步的替换。
A deep-sequencing approach was pursued utilizing 454 and Illumina sequencing methods to discover new genes involved in xyloglucan biosynthesis. cDNA sequences were generated from developing nasturtium (Tropaeolum majus) seeds, which produce large amounts of non-fucosylated xyloglucan as a seed storage polymer. In addition to known xyloglucan biosynthetic genes, a previously uncharacterized putative xyloglucan galactosyltransferase was identified. Analysis of an Arabidopsis thaliana mutant line defective in the corresponding ortholog (AT5G62220) revealed that this gene shows no redundancy with the previously characterized xyloglucan galactosyltransferase, MUR3, but is required for galactosyl-substitution of xyloglucan at a different position. The gene was termed XLT2 for Xyloglucan L-side chain galactosylTransferase position 2. It represents an enzyme in the same subclade of glycosyltransferase family 47 as MUR3. A double mutant defective in both MUR3 (mur3.1) and XLT2 led to an Arabidopsis plant with xyloglucan that consists essentially of only xylosylated glucosyl units, with no further substitutions.