Molecular cloning, bioinformatics analysis, and transient expression of MdAux/IAA28 in apple (Malus domestic)

The Aux/IAA gene family, as one of the auxin primary response genes, played an important role in the auxin signaling pathway. In this study, Apple MdAux/IAA28 gene (Genbank ID: XP_ 028945375.1) was selected for the expression analysis, gene cloning, and functional validation. qRT-PCR (Real-time quantitative reverse transcription polymerase chain reaction) of different apple fruit developmental periods showed that the expression of MdAux/IAA28 reached the highest at 60 DAF (days after full flowering) and the lowest at 120 DAF. The subcellular localization revealed that MdAux/IAA28 protein was localized to the nucleus, this result confirmed that MdAux/IAA28 protein played a crucial role in the cellular transduction pathway. Moerover, the result of the GUS (beta-glucuronidase) activity assay demonstrated that MdAux/IAA28 protein was mainly expressed in seeds, which was consistent with the result of qRT-PCR. These results also suggested that MdAux/IAA28 gene might regulate the fruits development and ripening by involving in the seeds formation. In conclusion, this work might provide a deeper understanding of interconnections between MdAux/IAAs structure and function.

Automated summary

The study focused on the expression and function of the Apple MdAux/IAA28 gene in apple fruit development, suggesting its involvement in fruit development and ripening through seed formation. The subcellular localization of MdAux/IAA28 protein in the nucleus was confirmed, highlighting its significance in cellular transduction pathways during fruit development.