Litchi (Litchi chinensis Sonn.) is an important subtropical fruit crop with high economic and nutritional values. Fruit coloration is a sign of litchi fruit ripening and an important external quality traits. Two continuous generations of mutants, named MS1 and MS2, originally derived from cultivar ‘Heli’, exhibited the distinctive characteristic of late maturation of 20 d, with observable delays in coloration. The present study aimed to understand the mechanism underlying maturation difference between ‘Heli’ and its two mutants. An RNA-seq analysis revealed 6,145 differentially expressed genes, mostly identified at the color-breaking stage. The maximum expression levels of some genes involved in anthocyanin biosynthesis and chlorophyll degradation were delayed in the pericarp of the mutants compared with in the original cultivar. Generally, they peaked at earlier stages (S2/S3) in ‘Heli’, compared with later stages (S4/S5) in mutants. Moreover, some hormonal signal receptors, especially those involved in abscisic and ethylene signaling pathways, were also differentially expressed between the original cultivar and the mutant. Transcription factors, including MYB, bHLH, bZIP, and WRKY, correlated with anthocyanin biosynthesis, chlorophyll degradation and abscisic acid signal pathways were identified. The late pigmentation in mutants was related to the fruit ripening program, a complex and comprehensive process. Additionally, we identified novel candidate genes that are involved in the regulation of litchi fruit pigmentation of and gained significant insights into the process of litchi fruit ripening.

荔枝（荔枝）Sonn.）是一种重要的亚热带水果作物，具有很高的经济和营养价值。果实着色是荔枝果实成熟的标志，是重要的外在品质性状。连续两代突变体，命名为 MS1 和 MS2，最初来自栽培品种“Heli”，表现出 20 d 晚熟的独特特征，着色延迟可观察到。本研究旨在了解“合力”及其两个突变体之间成熟差异的潜在机制。RNA-seq 分析揭示了 6,145 个差异表达的基因，大部分在颜​​色破坏阶段被识别。与原始品种相比，突变体果皮中一些参与花青素生物合成和叶绿素降解的基因的最大表达水平有所延迟。一般来说，与突变体的后期（S4/S5）相比，它们在“Heli”的早期阶段（S2/S3）达到峰值。此外，一些激素信号受体，特别是那些参与脱落和乙烯信号通路的受体，在原始品种和突变体之间也存在差异表达。鉴定了与花青素生物合成、叶绿素降解和脱落酸信号通路相关的转录因子，包括 MYB、bHLH、bZIP 和 WRKY。突变体的晚期色素沉着与果实成熟程序有关，这是一个复杂而全面的过程。此外，我们确定了新的候选基因，这些基因参与荔枝果实色素沉着的调控，并对荔枝果实成熟的过程有了重要的了解。一些激素信号受体，特别是那些参与脱落和乙烯信号通路的受体，在原始品种和突变体之间也有差异表达。鉴定了与花青素生物合成、叶绿素降解和脱落酸信号通路相关的转录因子，包括 MYB、bHLH、bZIP 和 WRKY。突变体的晚期色素沉着与果实成熟程序有关，这是一个复杂而全面的过程。此外，我们确定了新的候选基因，这些基因参与荔枝果实色素沉着的调控，并对荔枝果实成熟的过程有了重要的了解。一些激素信号受体，特别是那些参与脱落和乙烯信号通路的受体，在原始品种和突变体之间也有差异表达。鉴定了与花青素生物合成、叶绿素降解和脱落酸信号通路相关的转录因子，包括 MYB、bHLH、bZIP 和 WRKY。突变体的晚期色素沉着与果实成熟程序有关，这是一个复杂而全面的过程。此外，我们确定了新的候选基因，这些基因参与荔枝果实色素沉着的调控，并对荔枝果实成熟的过程有了重要的了解。鉴定了与花青素生物合成、叶绿素降解和脱落酸信号通路相关的转录因子，包括 MYB、bHLH、bZIP 和 WRKY。突变体的晚期色素沉着与果实成熟程序有关，这是一个复杂而全面的过程。此外，我们确定了新的候选基因，这些基因参与荔枝果实色素沉着的调控，并对荔枝果实成熟的过程有了重要的了解。鉴定了与花青素生物合成、叶绿素降解和脱落酸信号通路相关的转录因子，包括 MYB、bHLH、bZIP 和 WRKY。突变体的晚期色素沉着与果实成熟程序有关，这是一个复杂而全面的过程。此外，我们确定了新的候选基因，这些基因参与荔枝果实色素沉着的调控，并对荔枝果实成熟的过程有了重要的了解。