College of Life Sciences, Jilin Agricultural University, Changchun, 130118, People's Republic of China.
TECON Pharmaceutical Co., Ltd., Suzhou, 215000, People's Republic of China.
Sci Rep. 2024 May 20;14(1):11451. doi: 10.1038/s41598-024-61525-1.
The SMALL ACIDIC PROTEIN (SMAP) gene is evolutionarily indispensable for organisms. There are two copies of the SMAP gene in the Arabidopsis thaliana genome, namely, SMAP1 and SMAP2. The function of SMAP2 is similar to that of SMAP1, and both can mediate 2,4-D responses in the root of Arabidopsis. This study cloned the AtSMAP2 genetic promoter sequence. Two promoter fragments of different lengths were designed according to the distribution of their cis-acting elements, and the corresponding β- glucuronidase (GUS) expression vector was constructed. The expression activity of promoters of two lengths, 1993 bp and 997 bp, was studied by the genetic transformation in Arabidopsis. The prediction results of cis-acting elements in the promoter show that there are many hormone response elements in 997 bp, such as three abscisic acid response elements ABRE, gibberellin response elements P-box and GARE-motif and auxin response element AuxRR-core. Through GUS histochemical staining and qRT‒PCR analysis, it was found that the higher promoter activity of P, compared to P, drove the expression of GUS genes at higher levels in Arabidopsis, especially in the root system. The results provide an important basis for subsequent studies on the regulation of AtSMAP2 gene expression and biological functions.
SMALL ACIDIC PROTEIN（SMAP）基因在进化上对生物是不可或缺的。拟南芥基因组中有两个 SMAP 基因拷贝，即 SMAP1 和 SMAP2。SMAP2 的功能与 SMAP1 相似，都可以介导拟南芥根中的 2,4-D 反应。本研究克隆了 AtSMAP2 基因的启动子序列。根据顺式作用元件的分布设计了两个不同长度的启动子片段，并构建了相应的β-葡萄糖醛酸酶（GUS）表达载体。通过拟南芥的遗传转化研究了这两个长度为 1993bp 和 997bp 的启动子的表达活性。启动子中顺式作用元件的预测结果表明，997bp 中有许多激素反应元件，如三个脱落酸反应元件 ABRE、赤霉素反应元件 P-box 和 GARE-motif 以及生长素反应元件 AuxRR-core。通过 GUS 组织化学染色和 qRT-PCR 分析发现，与 P 相比，P 更高的启动子活性在拟南芥中以更高的水平驱动 GUS 基因的表达，特别是在根系中。这些结果为后续研究 AtSMAP2 基因表达和生物学功能的调控提供了重要依据。
