Lycium ruthenicum Murr. is an important ecological and economic species in the Qaidam Basin of Qinghai–Tibet Plateau. Its black fruits (BF) are rich in anthocyanins, which have health-promoting properties for humans and thus provide nutritional benefits for this plant. Although the fruit quality of natural white fruit (WF) is affected by the disappearance of pigmentation in phenotypes, this phenomenon provides an opportunity to unravel the complex color metabolic networks. In this study, anthocyanin profiling confirmed that WF was formed due to anthocyanin loss. Transcriptome analysis of BF and WF revealed 101,466 unigenes, 261 of which were identified as the putative homologs of color-related genes in other species. Genes encoding the enzymes involved in flavonoid biosynthesis were also identified systematically. The structural gene expression levels of chalcone synthase ( CHS ), chalcone isomerase ( CHI ), flavonoid 3′5′-hydroxylase ( F3′5′H ), dihydroflavonol 4-reductase ( DFR ), anthocyanidin synthase ( ANS ), and anthocyanidin 3-O-glucosyltransferase ( UFGT ) were highly similar and significantly positively correlated with anthocyanin accumulation rate in BF. In particular, F3′5′H , UFGT , ANS , and DFR expression levels in BF were 2391, 119, 96, and 85 times higher than those in WF at S3 (35 days after anthesis), respectively. This result strongly suggests that the low expression of these genes in WF is responsible for the anthocyanin loss. Meanwhile, the expression patterns of the anthocyanin regulatory genes were also investigated by qRT-PCR. Mass sequencing data were obtained and annotated by deep sequencing and provided a platform for future function and molecular biological research on L. ruthenicum Murr.

中文翻译：

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转录组分析提供了对野生枸杞果实颜色发展的见解。来自青藏高原

Lycium ruthenicum Murr。是青藏高原柴达木盆地重要的生态经济物种。它的黑色果实 (BF) 富含花青素，对人类具有促进健康的特性，从而为这种植物提供营养价值。尽管天然白色水果 (WF) 的果实品质受到表型色素沉着消失的影响，但这种现象为解开复杂的颜色代谢网络提供了机会。在这项研究中，花青素分析证实 WF 是由于花青素损失而形成的。BF 和 WF 的转录组分析揭示了 101,466 个 unigenes，其中 261 个被鉴定为其他物种中颜色相关基因的推定同源物。还系统地鉴定了编码参与类黄酮生物合成的酶的基因。查尔酮合酶（CHS）、查尔酮异构酶（CHI）、黄酮类3'5'-羟化酶（F3'5'H）、二氢黄酮醇4-还原酶（DFR）、花色素合酶（ANS）和花色素3的结构基因表达水平-O-葡萄糖基转移酶（UFGT）高度相似，与BF中花青素积累率呈显着正相关。特别是，在S3（开花后35天），BF中F3'5'H、UFGT、ANS和DFR的表达水平分别是WF的2391、119、96和85倍。该结果强烈表明这些基因在 WF 中的低表达是花青素丢失的原因。同时，还通过 qRT-PCR 研究了花青素调控基因的表达模式。