Zhang Chengcai, Ren Huadong, Yao Xiaohua, Wang Kailiang, Chang Jun
Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, China.
Front Plant Sci. 2022 Feb 25;13:804968. doi: 10.3389/fpls.2022.804968. eCollection 2022.
Flavonoids influence the flavor and nutritional value of pecan nuts. However, limited information is available regarding the molecular mechanisms underlying pecan flavonoid biosynthesis. Here, we used a high ("YLC28") and a low ("Oconee") flavonoid content cultivar as the research objects. The changes in flavonoid content and the gene transcription patterns during kernel development were identified. Different accumulation patterns of total flavonoids (TF) and condensed tannins (CT) were observed between the two cultivars. The contents of TF and CT in "YLC28" were 1.76- and 2.67-fold higher levels than that of "Oconee" on 150 days after full bloom of female flowers, respectively. In total, 30 RNA-Seq libraries were constructed and sequenced. The upregulated genes in "YLC28" were highly enriched in flavonoid-related pathways. Thirty-three structural genes were identified, and the expression of two , one , one , and one exhibited high correlation ( ≥ 0.7, < 0.01) with the condensed tannin content in "YLC28." A putative MYB transcription factor, CIL1093S0100, might act as a flavonoid biosynthesis repressor during kernel development. Altogether, these results will be useful for uncovering the molecular mechanisms of flavonoid biosynthesis and subsequently accelerating quality pecan breeding.
黄酮类化合物影响山核桃的风味和营养价值。然而，关于山核桃黄酮类化合物生物合成的分子机制的信息有限。在这里，我们以高黄酮含量品种（“YLC28”）和低黄酮含量品种（“Oconee”）作为研究对象。确定了果仁发育过程中黄酮类化合物含量和基因转录模式的变化。观察到两个品种之间总黄酮（TF）和缩合单宁（CT）的积累模式不同。雌花盛开150天后，“YLC28”中TF和CT的含量分别比“Oconee”高1.76倍和2.67倍。总共构建并测序了30个RNA-Seq文库。“YLC28”中上调的基因在黄酮类相关途径中高度富集。鉴定出33个结构基因，其中两个、一个、一个和一个的表达与“YLC28”中的缩合单宁含量表现出高度相关性（≥0.7，<0.01）。一个假定的MYB转录因子CIL1093S0100可能在果仁发育过程中作为黄酮类生物合成的抑制因子。总之，这些结果将有助于揭示黄酮类生物合成的分子机制，并随后加速优质山核桃育种。
