PDF(Pubmed)
Abstract：
Macadamia nuts are one of the most important economic food items in the world. Pericarp thickness and flavonoid composition are the key quality traits of Macadamia nuts, but the underlying mechanism of pericarp formation is still unknown. In this study, three varieties with significantly different pericarp thicknesses, namely, A38, Guire No.1, and HAES 900, at the same stage of maturity, were used for transcriptome analysis, and the results showed that there were significant differences in their gene expression profile. A total of 3837 new genes were discovered, of which 1532 were functionally annotated. The GO, COG, and KEGG analysis showed that the main categories in which there were significant differences were flavonoid biosynthesis, phenylpropanoid biosynthesis, and the cutin, suberine, and wax biosynthesis pathways. Furthermore, 63 MiMYB transcription factors were identified, and 56 R2R3-MYB transcription factors were clustered into different subgroups compared with those in Arabidopsis R2R3-MYB. Among them, the S4, S6, and S7 subgroups were involved in flavonoid biosynthesis and pericarp formation. A total of 14 MiMYBs\' gene expression were verified by RT-qPCR analysis. These results provide fundamental knowledge of the pericarp formation regulatory mechanism in macadamia nuts.
摘要：
澳洲坚果是世界上最重要的经济食品之一。果皮厚度和类黄酮成分是澳洲坚果的关键品质性状,但是果皮形成的潜在机制仍然未知。在这项研究中,果皮厚度明显不同的三个品种，即,A38，1号Guire和HAES900，在同一成熟阶段，用于转录组分析，结果表明，它们的基因表达谱存在显着差异。共发现3837个新基因,其中1532个被功能注释。GO,COG,和KEGG分析表明，存在显着差异的主要类别是类黄酮生物合成，苯丙素生物合成，还有角质,suberine,和蜡生物合成途径。此外，鉴定了63个MiMYB转录因子，与拟南芥R2R3-MYB相比，56个R2R3-MYB转录因子聚集到不同的亚群中。其中,S4,S6和S7亚组参与类黄酮生物合成和果皮形成.通过RT-qPCR分析验证了总共14个MiMYBs基因表达。这些结果为澳洲坚果果皮形成调控机制提供了基本知识。
