The sequence and structure of grape SBP-box-like18 (VvSPL18) were identified and characterized to explore its regulatory roles during grape berry development and ripening. Homologous conservation across diverse plant species was observed, and its potential function and modulated roles in grapes were investigated. The results showed that VvSPL18 has an ORF sequence of 1,137 bp, encodes 378 amino acids, and is located on chromosome 14 of grapevine. VvSPL18 has the closest relationship with its homolog in soybeans. The promoter of VvSPL18 contains cis-elements responsive to gibberellins (GA) and salicylic acid (SA), indicating that this gene might respond to these hormones involved in the modulation of grape berry. VvSPL18 is mainly distributed in the nucleus. Expression profiles showed that VvSPL18 is highly expressed only at the veraison stage of the grape berry and is slightly expressed in other phases. RNA-seq data also revealed that VvSPL18 might participate in the modulation of grape berry development and ripening. Treatment with diverse hormones demonstrated that abscisic acid (ABA) had almost no effect on its expression, whereas naphthalene acetic acid (NAA) significantly upregulated its expression at the veraison stage. We also found that VvSPL18 has a GA-responsive cis-element but no NAA-responsive cis-element. GA could promote the expression of VvSPL18 with a peak at an earlier stage than NAA, suggesting that VvSPL18 responds faster to GA than to NAA. This result indicates that VvSPL18 might modulate berry development at this phase through an ABA-independent pathway, and it might directly respond to GA, but indirectly to NAA. Our findings provide insights into the functions of VvSPL18 in mediating grape berry development and ripening.

中文翻译：

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VvSPL18 的特性及其在葡萄浆果发育和成熟过程中对外源激素的响应

鉴定并表征了葡萄 SBP-box-like18 (VvSPL18) 的序列和结构，以探索其在葡萄浆果发育和成熟过程中的调控作用。观察到不同植物物种的同源保护，并研究了其在葡萄中的潜在功能和调节作用。结果表明，VvSPL18的ORF序列为1,137 bp，编码378个氨基酸，位于葡萄藤14号染色体上。VvSPL18 与其在大豆中的同源物关系最密切。VvSPL18 的启动子包含响应赤霉素 (GA) 和水杨酸 (SA) 的顺式元件，表明该基因可能响应这些参与葡萄浆果调节的激素。VvSPL18 主要分布在细胞核中。表达谱显示 VvSPL18 仅在葡萄浆果的转色阶段高表达，在其他阶段略有表达。RNA-seq 数据还显示 VvSPL18 可能参与调节葡萄浆果的发育和成熟。用不同的激素处理表明脱落酸 (ABA) 对其表达几乎没有影响，而萘乙酸 (NAA) 在 veraison 阶段显着上调其表达。我们还发现 VvSPL18 具有 GA 响应顺式元件但没有 NAA 响应顺式元件。GA 可以促进 VvSPL18 的表达，并在比 NAA 更早的阶段出现峰值，表明 VvSPL18 对 GA 的反应比对 NAA 的反应更快。该结果表明 VvSPL18 可能通过不依赖 ABA 的途径调节该阶段的浆果发育，它可能直接响应 GA，但间接响应 NAA。我们的研究结果提供了对 VvSPL18 在介导葡萄浆果发育和成熟中的功能的见解。