Macadamia ternifolia Transcriptome or Gene expression. Macadamia ternifolia

Macadamia ternifolia is a valuable oil-producing nut crop in the world. The husk is frequently regarded as a low-grade material because the metabolic profile of the husk is still unknown. In order to explore the industrial significance of husk, this study performed metabolic and transcriptomic analyses at various development stages of the husk. The qualitative and quantitative metabolic data analysis identified 596 metabolic substances including several species of phenolic acids, flavonoids, lipids, organic acids, amino acids and derivatives, nucleotides and derivatives, alkaloids, lignans, and coumarins, terpenoids, tannins, and others. However, phenolic acids and flavonoids were predominant and their abundance levels were significantly altered across different development stages of the husk. Comparative transcriptome analysis revealed that expression patterns of phenolic acid and flavonoid pathway genes were significantly changed with husk growth. In particular, the expression of PAL, C4H, 4CL, CHS, CHI, F3H, and FLS had dynamic differences at various development stages of the husk. Our integrative metabolomic and transcriptomic analyses identified key metabolic substances, characterized their abundance level, and further discussed the regulatory mechanism of phenolic and flavonoid biosynthesis in the husk of M. ternifolia. Our results provide new insight into biological profiles of the husk of M. ternifolia and help to elucidate the molecular mechanisms of phenolic and flavonoid biosynthesis in the husk of M. ternifolia for a better valorization.三叶澳洲坚果（Macadamia ternifolia）是全球极具价值的油料坚果作物。其果壳常被视为低价值副产物，因目前对该果壳的代谢组特征仍未明确。为探究该果壳的工业应用潜力，本研究针对其不同发育阶段的果壳开展了代谢组学与转录组学联合分析。经定性与定量代谢组学分析，本研究共鉴定出596种代谢物，涵盖酚酸、类黄酮、脂质、有机酸、氨基酸及其衍生物、核苷酸及其衍生物、生物碱、木脂素、香豆素、萜类、鞣质等多个类别。其中酚酸与类黄酮为优势代谢物，且其丰度水平随果壳发育进程发生显著改变。比较转录组学分析结果显示，参与酚酸与类黄酮生物合成通路的基因表达模式随果壳生长显著变化。具体而言，PAL、C4H、4CL、CHS、CHI、F3H及FLS等关键基因在果壳不同发育阶段的表达量呈现动态差异。本研究通过代谢组学与转录组学整合分析，鉴定出核心代谢物并明确其丰度特征，进一步阐明了三叶澳洲坚果果壳中酚类与类黄酮生物合成的调控机制。本研究结果为三叶澳洲坚果果壳的生物学特性提供了全新认知，有助于阐明其果壳中酚类与类黄酮生物合成的分子机制，进而实现该副产物的高效增值利用。