Cloning and expression of AeMYB4 gene related to stolon development of Amana edulis / 中国中药杂志

Stolon is an important organ for reproduction and regeneration of Amana edulis. Previous analysis of transcriptome showed that MYB was one of the most active transcription factor families during the development of A. edulis stolon. In order to study the possible role of MYB transcription factors in stolon development, the authors screened out an up-regulated MYB gene named AeMYB4 was by analyzing the expression profile of MYB transcription factors. In the present study, sequence analysis demonstrated that AeMYB4 contained an open reading frame of 756 bp encoding 251 amino acids, and domain analysis revealed that the predicted amino acids sequence contained two highly conserved SANT domains and binding sites for cold stress factor CBF. By multiple sequence alignment and phylogenetic analysis, it is indicated that AeMYB4 clustered with AtMYB15 from Arabidopsis thaliana, belonging to subgroup S2 of R2 R3-MYB. And most of the transcription factors in this subfamily are related to low temperature stress. The GFP-AeMYB4 fusion protein expression vector for subcellular localization was constructed and transferred into Agrobacterium tumefaciens to infect the leaves of Nicotiana benthamiana, and the results showed the protein was located in the nucleus. To investigate the transcriptional activation, the constructed pGBKT7-AeMYB4 fusion expression vector was transferred into Y2 H Gold yeast cells, which proved that AeMYB4 was a transcription activator with strong transcriptional activity. Real-time quantitative PCR was used to detect the expression of AeMYB4 gene in three different development stages of stolon and in leaves, flowers, and bulbs of A. edulis, which indicated that AeMYB4 transcription factor was tissue-specific in expression, mainly in the stolon development stage, and that the expression was the most active in the middle stage of stolon development, suggesting that AeMYB4 gene may play an important role in stolon development. This study contributes to the further research on the function of AeMYB4 transcription factor in stolon development of A. edulis.

Selection and validation of reference genes for quantitative Real-time PCR analysis in Amana edulis / 中国中药杂志

Amana edulis is a traditional Chinese medicinal plant with low propagation coefficient. In recent years, the increasing demands of A. edulis lead to a shortage of its wild resources. In order to analyze the expression of related functional genes in A. edulis, the selection of suitable internal reference genes is crucial to improve the accuracy of experimental results. Eight genes(ACT, TUA, CYP, GAPDH, UBQ, UBI, EF1a, UBC)were chosen as candidate reference genes based on the RNA-Seq. Real-time fluorescence quantitative technique was used to detect the expression level of candidate internal reference genes in different organs(bulb, leaf, flo-wer) and stolons at different development stages of A. edulis. Then GeNorm, NormFinder, BestKeeper softwares and RefFinder website were used for a comprehensive analysis of the expression stability of the candidate genes.The results showed that among the 8 candidate reference genes, the variation range of Ct value of UBC was the smallest, and the expression level was stable, which was suitable for an reference gene. GeNorm and NormFinder software analysis showed that UBC and UBI were the optimal reference genes. BestKeeper analysis showed that CYP and UBC expression were relatively stable. Comprehensive evaluation of RefFinder website showed that UBC and UBI were the most stable genes, and ACT displayed the lowest stability in all software evaluation, indicating UBC and UBI were suitable for reference genes. Additionally, the most stable UBC, UBI and the most unstable ACT were used as internal reference genes to detect the expression of GBSS gene in A. edulis, and expression pattern of GBSS gene was the same under the calibration of UBC and UBI. The expression data of GBSS gene confirmed that UBC and UBI genes were reliable for A. edulis qRT-PCR as internal reference genes. The results would benefit future studies on related gene expression of A. edulis.