Key message

The Larix leptolepis SPL-like gene LaSPL9 was identified. Additionally, premiR156b and LaSPL9 expression patterns during somatic embryogenesis and the effects of gibberellin and salicylic acid on their transcription revealed the post-transcriptional regulatory functions of the miR156–LaSPL9 module.

Abstract

A full-length cDNA sequence of a SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL) gene was isolated from Japanese larch (Larix leptolepis) and designated as LaSPL9. The cDNA comprised 2735 bp, including a 1779-bp open reading frame encoding a protein (592 amino acids) with conserved SBP domains. The LaSPL9 promoter region included several gibberellin (GA)- and salicylic acid (SA)-inducible elements. Further analyses revealed that LaSPL9 mRNA is targeted by miR156. An examination of the LaSPL9-GFP fusion protein in tobacco leaf epidermal cells indicated that LaSPL9 is a nuclear protein. Additionally, LaSPL9 expression was induced by GA and the miR156b precursor (premiR156b) transcript accumulation was inhibited by SA. Moreover, abscisic acid (ABA) was identified as the main factor down-regulating LaSPL9 expression during the early stage of somatic embryogenesis (SE), which can induce premiR156b expression. Furthermore, LaSPL9 transcription peaked at 10 days, implying it might encode an important regulator of early embryonic pattern formation. The LaSPL9 transcript level subsequently decreased gradually and was lowest at 42 days, which is consistent with the gradual increase in miR156 expression during SE. The miR156–LaSPL9 module might regulate SE in L. leptolepis by responding to ABA. Overall, our results provide evidence that miR156–LaSPL9 is important for the crosstalk between GA and SA pathways during SE.

中文翻译：

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miR156调控日本落叶松（Larix leptolepis）中SPL样基因LaSPL9的表达。

关键信息

在兴安落叶松SPL样基因LaSPL9被确定。此外，体细胞胚胎发生期间的premiR156b和LaSPL9表达模式以及赤霉素和水杨酸对其转录的影响揭示了miR156– LaSPL9模块的转录后调控功能。

抽象

从日本落叶松（Larix leptolepis）中分离到一个SQUAMOSA启动子结合蛋白（SPL）基因的全长cDNA序列，命名为LaSPL9。该cDNA包含2735 bp，包括一个1779 bp的开放阅读框，编码带有保守SBP结构域的蛋白质（592个氨基酸）。该LaSPL9启动子区域包括几个赤霉素（GA） -和水杨酸（SA）诱导型元件。进一步的分析表明，LaSPL9 mRNA被miR156靶向。对烟叶表皮细胞中LaSPL9-GFP融合蛋白的检查表明，LaSPL9是一种核蛋白。此外，LaSPL9GA诱导了大肠杆菌的表达，SA抑制了miR156b前体（premiR156b）的转录积累。此外，脱落酸（ABA）被认为是在体细胞胚发生（SE）的早期下调LaSPL9表达的主要因素，它可以诱导premiR156b的表达。此外，LaSPL9转录在10天达到峰值，这表明它可能编码早期胚胎模式形成的重要调控因子。所述LaSPL9转录水平随后逐渐下降，并在42天，这是与SE过程中miR156表达的逐渐增加一致最低。该miR156- LaSPL9模块可能在调控SE L.落叶松通过回应ABA。总体而言，我们的结果提供了证据，证明miR156– LaSPL9对于SE期间GA和SA途径之间的串扰很重要。