A GH3-like gene, LaGH3, isolated from hybrid larch (Larix leptolepis x Larix olgensis) is regulated by auxin and abscisic acid during somatic embryogenesis
A GH3-like gene, LaGH3, isolated from hybrid larch (Larix leptolepis x Larix olgensis) is regulated by auxin and abscisic acid during somatic embryogenesis
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从杂种落叶松 (Larix leptolepis x Larix olgensis) 中分离出的 GH3 样基因 LaGH3 在体细胞胚胎发生过程中受到生长素和脱落酸的调节
DOI：
10.1007/s00468-019-01904-8
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Qi Li-wang
中科院分区：
文献类型：
--
作者：
Zhang Li-feng;Lan Qian;Han Su-ying;Qi Li-wang
关键信息鉴定了杂种落叶松（Larix leptolepis × Larix olgensis）的Gretchen Hagen 3样基因LaGH3，并分析了脱落酸（ABA）和吲哚-3-乙酸（IAA）对其转录水平和体细胞胚胎发生过程中表达模式的影响。杂交落叶松（Larix leptolepis×Larix olgensis）并命名为LaGH3。该 cDNA 长度为 2053 bp，包含一个 1848 bp 开放阅读框，编码 615 个氨基酸的预测蛋白，其特征为 GH3 蛋白家族的四个保守基序：P 环、α5、α6 和 β8-β9。使用改进的 TAIL-PCR 技术克隆了 LaGH3 的 5' 侧翼启动子区域。在该区域，我们鉴定了几种生长素和脱落酸 (ABA) 诱导元件。表达分析表明，LaGH3 受吲哚-3-乙酸诱导，其转录物积累受 ABA 抑制。进一步的实验表明，ABA是体细胞胚胎发生早期LaGH3下调的主要因素，生长素的缺失则略微降低了LaGH3的表达。随着体细胞胚胎的快速发育，LaGH3转录本逐渐增加，并在28天达到峰值，然后随着体细胞胚胎的成熟而下降。我们认为LaGH3转录本的水平部分代表了落叶松体细胞胚胎发育过程中内源生长素的动态。综上所述，我们的结果证明 GH3 基因通过在体细胞胚胎发育过程中维持生长素稳态，在生长素和 ABA 之间的串扰中发挥重要作用。
Key messageA Gretchen Hagen 3-like gene,LaGH3from hybrid larch (Larix leptolepis × Larix olgensis), was identified, and the effects of abscisic acid (ABA) and indole-3-acetic acid (IAA) on its transcriptional levels and expression patterns during somatic embryogenesis were analyzed.AbstractA full-length cDNA sequence of a Gretchen Hagen 3 (GH3) gene was isolated from hybrid larch (Larix leptolepis×Larix olgensis) and designatedLaGH3. The cDNA was 2053 bp in length and contained an 1848-bp open-reading frame encoding a predicted protein of 615 amino acids, characterized by four conserved motifs of the GH3 protein family: P-loop, α5, α6, and β8–β9. The 5′-flanking promoter region ofLaGH3was cloned using an improved TAIL-PCR technique. In this region, we identified several auxin- and abscisic acid (ABA)-inducible elements. Expression analysis showed thatLaGH3was induced by indole-3-acetic acid and that its transcript accumulation was inhibited by ABA. Further experiments demonstrated that ABA was the main factor inLaGH3downregulation during the early stage of somatic embryogenesis, although the absence of auxin decreasedLaGH3expression slightly.LaGH3transcripts gradually increased and peaked at 28 days with the rapid development of somatic embryos and then declined as the somatic embryos matured. We suggest that the level ofLaGH3transcripts partly represents the dynamics of endogenous auxin during somatic embryo development in larch. Taken together, our results provide evidence that GH3 genes play important roles in the crosstalk between auxin and ABA by maintaining auxin homeostasis during somatic embryo development.