Forest & Fruit Tree Research Institute, Shanghai Academy of Agriculture Sciences, Shanghai, 201403, China.
College of Horticulture, Hebei Agricultural University, Baoding, Hebei, 071001, China.
Plant J. 2021 Dec;108(6):1644-1661. doi: 10.1111/tpj.15532. Epub 2021 Oct 29.
Brown coloration and a rough appearance as russet and semi-russet (partial russet) are features unique to the popular Asian sand pear (Pyrus pyrifolia Nakai). The degree of russeting is different between different genotypes. Russeting is sensitive to water fluctuations, where excessive rainwater can trigger/stimulate its development. However, the molecular mechanism of russeting is currently unclear. Here, we employed multi-omics, i.e., metabolomics, transcriptomics, and proteomics, and analyzed the effect of different sand pear genotypes and artificial rainfall on russeting of pear fruits. This led to the identification of 79, 64, and 29 differentially produced/expressed metabolites, transcripts, and proteins that are involved in the biosynthesis of suberin, phenylpropane, cutin, and waxes. Further analysis of these differentially expressed genes and their encoded proteins revealed that four of them exhibited high expression at both transcript and protein levels. Transient expression of one such gene, PbHHT1 (accession number 103966555), which encodes ω-hydroxypalmitate-O-feruloyl transferase, in young green non-russet fruits triggered premature suberization in the russeting pear genotypes. This coincided with increased production of 16-feruloyloxypalmitic acid, a conjugated compound between phenols and esters during the polymerization for suberin formation. Collectively, our data from the combined three omics demonstrate that russeting in sand pear is a complex process involving the biosynthesis and transport of suberin and many other secondary metabolites.
棕色的外观和粗糙的外观，如锈褐色和半锈褐色（部分锈褐色），是受欢迎的亚洲砂梨（Pyrus pyrifolia Nakai）的独特特征。不同基因型之间的锈斑程度不同。锈斑对水分波动敏感，过多的雨水会引发/刺激其发展。然而，锈斑的分子机制目前尚不清楚。在这里，我们采用了多组学，即代谢组学、转录组学和蛋白质组学，分析了不同砂梨基因型和人工降雨对梨果实锈斑的影响。这导致鉴定了 79、64 和 29 种差异产生/表达的代谢物、转录物和蛋白质，这些代谢物、转录物和蛋白质参与了角质层、类木质素、蜡质的生物合成。对这些差异表达基因及其编码蛋白的进一步分析表明，其中 4 个在转录和蛋白水平均表现出高表达。瞬时表达一个这样的基因 PbHHT1（登录号 103966555），其编码 ω-羟棕榈酸-O-阿魏酰转移酶，在年轻的非锈褐色绿色非锈褐色果实中触发了锈褐色梨基因型的过早角质化。这与 16-阿魏酰氧棕榈酸的产生增加相一致，16-阿魏酰氧棕榈酸是在角质层形成过程中酚类和酯类聚合形成的共轭化合物。总的来说，我们来自三种组学的综合数据表明，砂梨的锈斑是一个涉及角质层和许多其他次生代谢物的生物合成和运输的复杂过程。
