Huang Qichun, Liu Jimin, Hu Chengxiao, Wang Nina, Zhang Lan, Mo Xiaofang, Li Guoguo, Liao Huihong, Huang Hongming, Ji Sufeng, Chen Dongkui
College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Institute of Horticulture, Guangxi Academy of Agricultural Sciences, Nanning 530007, China.
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning 530007, China.
Genomics. 2022 Mar;114(2):110291. doi: 10.1016/j.ygeno.2022.110291. Epub 2022 Feb 6.
Citrus fruits exhibit vivid color and are favored extensively. However, the biochemical and molecular mechanism of Citrus Reticulata Blanco fruits coloring, especially the effect of transplantation on fruits coloring, is unclear. Herein, RNA-Seq and carotenoids profiling were applied to investigate the effect of transplantation on Orah mandarin fruits coloring. Transplantation induces fruit color shallowing, Ca and ACC level declining and IAA level increasing. Transplantation induced variation in fruit skin and pulp carotenoids, mainly β-citraurin as one of the important pigments of citrus peel. 2253 up-regulated genes, 1103 down-regulated genes in skin and 815 up-regulated genes, 534 down-regulated genes in pulp of transplanted tree fruits were identified by RNA-Seq. The DEGs involved hormone signal, carotenoids biosynthesis and TFs such as MYB and bHLH family TFs. The carotenoid cleavage dioxygenase gene (Ciclev10028113m.g) is positively correlated with β-citraurin and regulated directly and/or indirectly by MYB1R1, PIF4, ACC and IAA. Integrative analyses revealed potential molecular insights into Orah mandarin peel color variation during transplantation.
柑橘类水果色泽鲜艳，广受喜爱。然而，柑橘（Citrus Reticulata Blanco）果实着色的生化和分子机制，尤其是移栽对果实着色的影响尚不清楚。在此，采用RNA测序（RNA-Seq）和类胡萝卜素分析来研究移栽对奥哈橘（Orah mandarin）果实着色的影响。移栽导致果实颜色变浅、钙和乙烯前体1-氨基环丙烷-1-羧酸（ACC）水平下降以及生长素（IAA）水平上升。移栽引起果实果皮和果肉类胡萝卜素的变化，主要是β-柠乌素，它是柑橘果皮的重要色素之一。通过RNA测序鉴定出移栽树果实的果皮中有2253个上调基因、1103个下调基因，果肉中有815个上调基因、534个下调基因。差异表达基因涉及激素信号、类胡萝卜素生物合成以及MYB和bHLH家族转录因子等转录因子。类胡萝卜素裂解双加氧酶基因（Ciclev10028113m.g）与β-柠乌素呈正相关，并受到MYB1R1、光敏色素互作因子4（PIF4）、ACC和IAA的直接和/或间接调控。综合分析揭示了奥哈橘在移栽过程中果皮颜色变化的潜在分子机制。
