[Identification of Aux/IAA gene family in Atractylodes lancea and their response to auxin].

Using the whole-genome data of Atractylodes lancea, members of the auxin(Aux)/indole-3-acetic acid(IAA) gene family were identified and characterized, and the effects of 1-naphthaleneacetic acid(NAA) treatment on the expression levels of this gene family were investigated, providing a foundation for further studies on the functions of the A. lancea Aux(AlAux)/IAA gene family. Members of the AlAux/IAA gene family were identified from the A. lancea whole-genome data using TBtools-Ⅱ. Bioinformatics software was employed to analyze the physicochemical properties of the encoded proteins, construct a phylogenetic tree, and predict conserved motifs and gene structures. Tissue-cultured seedlings of A. lancea were used as experimental materials, and key genes of the AlAux/IAA gene family were screened by transcriptome sequencing. The expression of key AlAux/IAA genes was analyzed after one month of NAA treatment. A total of 53 AlAux/IAA genes were identified from the A. lancea genome. Most AlAux/IAA proteins were localized in the nucleus, lacked transmembrane domains, and exhibited negative hydrophobicity. Among them, 44 AlAux/IAA genes were predicted to encode functional Aux/IAA transport proteins. Transcriptome sequencing and RT-qPCR analyses showed that the AlAux/IAA family genes exhibited spatiotemporal expression specificity, and different members displayed varying response times and intensities to NAA treatment. Tissue-specific expression analysis revealed that the AlAux/IAA gene family was generally highly expressed in flowers. This study identified the Aux/IAA gene family members in A. lancea, preliminarily analyzed their sequence characteristics, and examined their expression features in response to Aux. It is speculated that AlAux/IAA13 and AlAux/IAA38 may be involved in rooting and bud growth and development during the subculture process of A. lancea tissue-cultured seedlings. These results provide a theoretical basis for elucidating the molecular mechanisms of AlAux/IAA gene function and Aux-mediated regulation of rhizome growth in A. lancea.