Superoxide dismutase multigene family in longan somatic embryos: a comparison of CuZn-SOD, Fe-SOD, and Mn-SOD gene structure, splicing, phylogeny, and expression
Superoxide dismutase multigene family in longan somatic embryos: a comparison of CuZn-SOD, Fe-SOD, and Mn-SOD gene structure, splicing, phylogeny, and expression
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龙眼体细胞胚超氧化物歧化酶多基因家族：CuZn-SOD、Fe-SOD 和 Mn-SOD 基因结构、剪接、系统发育和表达的比较
DOI：
10.1007/s11032-013-9892-2
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发表时间：
2013-10-01
影响因子：
3.1
通讯作者：
Lai, Zhong-Xiong
中科院分区：
文献类型：
--
作者：
Lin, Yu-Ling;Lai, Zhong-Xiong
超氧化物歧化酶是一种重要的抗氧化酶，由多基因家族编码，具有保护机体免受超氧化物损伤的作用。由于该基因家族在植物胚胎中还没有得到系统的描述，因此SODS在龙眼胚胎中的功能还不完全清楚。本研究利用逆转录-聚合酶链式反应和基因末端快速扩增技术，从龙眼胚性愈伤组织中分离到20个编码胞质CSD1a和DlCSD1b、叶绿体DlCSD2a和DlFSD1a、胞质D1FSD1b和线粒体DlMSD的全长基因。每个基因都有多个多聚腺苷酸化位点。DlCSD1a、DlCSD1b、DlCSD2a、DlFSD1a、DlFSD1b和DlMSD基因分别含有8、6、7、6、7和5个长度差异很大的内含子。还克隆了7个在龙眼体细胞胚胎发生过程中表现出功能多样性的不同剪接方式的突变体。每种SOD基因类型都有多个转录起始点(TSS)。TSS的选择影响了5‘-非翻译区的长度，但对蛋白质多样性没有贡献。DlCSD1a、DlCSD2a、DlFSD1a和DlMSD启动子被分离出来，并发现含有许多顺式作用元件，如光、赤霉素、生长素、茉莉酸甲酯、脱水、寒冷和创伤。综合表达谱分析表明，不同类型的SOD在龙眼SE中表现出不同的时空表达模式，在龙眼SE中尤其是在发育的中后期起着关键作用。本研究首次对植物超氧化物歧化酶基因家族进行了全面的分析，包括全长cDNA克隆、基因结构、选择性剪接变异体、系统发育、TSS、启动子分离和表达模式。通过本研究中的比较，可以深入了解SOD亚型在龙眼体细胞胚胎形成过程中的不同功能。
Superoxide dismutases (SODs), which are encoded by a multigene family, are important antioxidant enzymes guarding against superoxide toxicity. Because no systematic characterization of this gene family has been conducted in plant embryos, the function of SODs in longan embryos is not completely clear. In this study, we isolated 20 full-length cDNAs encoding cytoplasmic CSD1a and DlCSD1b, chloroplastic DlCSD2a and DlFSD1a, plastidic DlFSD1b, and mitochondrial DlMSD from longan embryogenic callus using reverse transcription-PCR and rapid amplification of cDNA ends. Each gene possessed multiple polyadenylation sites. The DlCSD1a, DlCSD1b, DlCSD2a, DlFSD1a, DlFSD1b, and DlMSD genes contained eight, six, seven, six, seven, and five introns, respectively, of greatly varying length. Seven variants with different splicing modes, demonstrating functional diversity during longan somatic embryogenesis (SE), were also cloned. Each SOD gene type had multiple transcription start sites (TSSs). The choice of TSS affected the length of the 5'-untranslated region but did not contribute to protein diversity. DlCSD1a, DlCSD2a, DlFSD1a, and DlMSD promoters were isolated and found to contain many cis-acting elements responsive to stimuli such as light, gibberellins, auxin, methyl jasmonate, dehydration, coldness, and wounding. Comprehensive expression profile analysis indicated that different SOD types exhibit different spatial and temporal expression modes and play a key role in longan SE, especially during the middle and later developmental stages. This study represents the first comprehensive analysis of the SOD gene family in plant SE, encompassing full-length cDNA cloning, gene structures, alternatively spliced variants, phylogeny, TSS, promoter isolation, and expression patterns. The comparisons in this study provide insights into diverse functions of SOD isoforms during longan somatic embryo formation.