MYB is one of the largest transcription factor families in plants. Among them, the R3-MYB transcription factor RADIALIS (RAD) plays a very important role in the flowers development in Antirrhinum majus. In this study, a R3-MYB gene similar to RAD was found by analyzing the genome of A. majus, which was named AmRADIALIS-like 1 (AmRADL1). The gene function was predicted through bioinformatics. The relative expression levels in different tissues and organs of wild-type A. majus were analyzed by qRT-PCR. AmRADL1 was overexpressed in A. majus, and the transgenic plants were analyzed by morphological observation and histological staining. The results showed that the open reading frame (ORF) of AmRADL1 gene was 306 bp in length, encoding 101 amino acids. It has typical SANT domain, and the C-terminal contains a CREB motif, which was highly homologous to tomato SlFSM1. The results of qRT-PCR showed that AmRADL1 was expressed in roots, stems, leaves and flowers, and the expression level was higher in flowers. Further analysis of its expression in different floral organs showed that AmRADL1 had the highest expression in carpel. The results of histological staining analysis of the transgenic plants showed that compared with the wild type, although the size of the carpel cells of the transgenic plants did not change significantly, the placenta area in the carpel became smaller and the number of cell decreased. In summary, AmRADL1 may be involved in the regulation of carpel development, but the specific mechanism of action in carpel remains to be further studied.
MYB是植物中最大的转录因子家族之一，其中R3-MYB转录因子RADIALIS (RAD)在金鱼草(Antirrhinum majus)花发育过程中具有十分重要的作用。本研究对金鱼草基因组进行分析，发现1个与RAD结构相似的R3-MYB基因，将其命名为AmRADIALIS-like 1(AmRADL1)。进一步通过生物信息学预测基因功能，利用qRT-PCR分析AmRADL1在野生型金鱼草不同组织器官中的相对表达量，对过表达AmRADL1的转基因金鱼草进行形态学观察和组织学染色分析。结果表明，AmRADL1基因开放阅读框(open reading frame，ORF)长度为306 bp，编码101个氨基酸，具有典型的SANT结构域，C末端含有CREB motif，与番茄(Solanum lycopersicum)SlFSM1同源性较高。qRT-PCR结果表明，AmRADL1在根、茎、叶和花中均有表达，其中在花中表达量较高；进一步分析其在不同花器官中的表达量差异，发现AmRADL1在心皮中表达最高。转基因金鱼草植株的组织学染色分析结果显示，与野生型相比，转基因植株的心皮细胞大小没有明显的变化，但心皮中胎座区域变小，细胞数目减少。综上所述，AmRADL1可能参与调控心皮发育，但在心皮中的具体作用机制还有待进一步研究。.
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