Anthocyanin accumulation is responsible for red pigmentation in plum peel and affected by light and temperature. We investigated the effects of temperature and LED light (400−800 nm, with following red: green: blue ratio 20.9: 75.7: 3.4 respectively) with total radiant flux adjusted at 150 mol m⁻² s⁻¹ on anthocyanin accumulation in postharvest ‘Akihime’ plum peel and found that 20 °C/light could induce anthocyanin concentration and therefore improve red coloration. However, no significant anthocyanin accumulation was detected in the peel of plums treated with 30 °C or under dark conditions. RNA-Seq and qRT-PCR analysis showed that the transcript levels of anthocyanin accumulation-related genes, including phenylalanine ammonialyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumaroyl:CoA-ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) and glutathione S-transferase (GST) in the peel were upregulated by 20 °C/light treatment. Transcription factors differentially regulated by temperature and light were identified. A homolog of peach anthocyanin MYB activator, namely PsMYB10.1, was lowly expressed in the peel of unpigmented fruit but significantly upregulated by 20 °C/light treatment. The function of PsMYB10.1 was verified by transient overexpression in Nicotiana tabacum leaves, resulting in strong anthocyanin accumulation when co-infiltrated with PsbHLH3. Dual luciferase assays further showed that PsMYB10.1 activated the promoters of the anthocyanin biosynthetic genes PsANS, PsUFGT and PsGST. These results suggest that appropriate temperature and light regimes at postharvest can induce anthocyanin accumulation in the peel of ‘Akihime’ plum by activating the expression of the positive regulator PsMYB10.1 and consequently the genes involved in biosynthesis and transportation of anthocyanin.

花青素的积累导致李子皮中的红色色素沉着，并受光和温度的影响。我们研究了温度和LED灯（400-800 nm，以下分别为红色：绿色：蓝色比率20.9：75.7：3.4）以及总辐射通量调整为150 mol m ^-2 s ^-1时对采后花青素积累的影响。秋姬的李子皮，发现20°C /光可以诱导花青素浓度，从而改善红色。但是，在30°C或黑暗条件下处理的李子皮中未检测到明显的花色苷积聚。RNA-Seq和qRT-PCR分析表明，花青素积累相关基因（包括苯丙氨酸解氨酶（PAL））的转录水平），肉桂酸-4-羟化酶（C4H），4-香豆酰基：CoA连接酶（4CL），查尔酮合酶（CHS），查尔酮异构酶（CHI），黄烷酮3-羟化酶（F3H），二氢黄酮醇4-还原酶（DFR），花青素合酶（ANS），UDP葡萄糖：类黄酮3-O-葡萄糖基转移酶（UFGT）和谷胱甘肽S-转移酶（GST）通过20°C /光照处理可将果皮中的）上调。鉴定了受温度和光差异调节的转录因子。桃花色苷MYB激活剂的同系物，即PsMYB10.1，在未着色水果的果皮中低表达，但在20°C /光照下显着上调。PsMYB10.1的功能已通过烟草叶片中的瞬时过表达而得到验证，当与PsbHLH3共同渗入时，会导致强烈的花色苷积聚。双重荧光素酶测定进一步表明PsMYB10.1激活了花色苷生物合成基因PsANS，PsUFGT和PsGST的启动子。这些结果表明，采后适当的温度和光照方式可以通过激活正调控因子PsMYB10.1的表达，从而激活花青素的生物合成和运输基因，从而诱导'Akihime'李子皮中花青素的积累。