College of Biology and Agricultural Resources, Huanggang Normal University, Huanggang, 438000, Hubei, People's Republic of China.
Sci Rep. 2023 Oct 20;13(1):17912. doi: 10.1038/s41598-023-44779-z.
Rhododendron pulchrum sweet, a member of the Ericaceae family possessing valuable horticultural properties, is widely distributed in the temperate regions. Though serving as bioindicator of metal pollution, the molecular mechanism regulating flowering in R. pulchrum is very limited. Illumina sequencing was performed to identify critical miRNAs in the synthesis of flavonoids at different developmental stages. Totally, 722 miRNAs belonging to 104 families were screened, and 84 novel mature miRNA sequences were predicted. The miR166, miR156, and miR167-1 families were dominant. In particular, 126 miRNAs were significantly differentially expressed among four different flowering stages. Totally, 593 genes were differentially regulated by miRNAs during the flower development process, which were mostly involved in "metabolic pathways", "plant hormone signal transduction", and "mitosis and regulation of biosynthetic processes". In pigment biosynthesis and signal transduction processes, gra-miR750 significantly regulated the expression of flavonoid 3',5'-hydroxylase; aof-miR171a, aof-miR171b, aof-miR171c, cas-miR171a-3p, and cas-miR171c-3p could regulate the expression of DELLA protein; aof-miR390, aof-miR396b, ath-miR3932b-5p, cas-miR171a-3p, aof-miR171a, and aof-miR171b regulated BAK1 expression. This research showed great potentials for genetic improvement of flower color traits for R. pulchrum and other Rhododendron species.
锦绣杜鹃甜美，是杜鹃花科的一员，具有宝贵的园艺特性，广泛分布于温带地区。尽管作为金属污染的生物指示剂，但调控锦绣杜鹃开花的分子机制非常有限。我们通过 Illumina 测序鉴定了不同发育阶段合成类黄酮的关键 miRNA。总共筛选到 722 个属于 104 个家族的 miRNA，并预测了 84 个新的成熟 miRNA 序列。miR166、miR156 和 miR167-1 家族占主导地位。特别是，126 个 miRNA 在四个不同开花阶段的表达水平存在显著差异。总共，593 个基因在花发育过程中受到 miRNA 的差异调控，这些基因主要参与“代谢途径”、“植物激素信号转导”和“有丝分裂和生物合成过程的调控”。在色素生物合成和信号转导过程中，gra-miR750 显著调控类黄酮 3',5'-羟化酶的表达；aof-miR171a、aof-miR171b、aof-miR171c、cas-miR171a-3p 和 cas-miR171c-3p 可以调控 DELLA 蛋白的表达；aof-miR390、aof-miR396b、ath-miR3932b-5p、cas-miR171a-3p、aof-miR171a 和 aof-miR171b 调控 BAK1 的表达。本研究为锦绣杜鹃和其他杜鹃属物种花色性状的遗传改良提供了巨大潜力。
