Liao Yingying, Zhao Wenwen, Wang Yu, Zhao Sumeiqi, Gu Shiqin, Zhang Chao, Peng Jiqing, Sheng Song, Wang Sen
Central South University of Forestry and Technology, Changsha, 410004, China.
Yuelushan Laboratory, Hunan Agricultural University, Qiushi Building, Furong District, No. 1, Nongda Road, Furong District, Changsha, Hunan Province, China.
Sci Rep. 2025 Aug 9;15(1):29125. doi: 10.1038/s41598-025-14216-4.
Flower color serves as a pivotal ornamental trait in plants, significantly impacting their aesthetic value. H macrophylla is particularly esteemed for its large, vibrant flowers and the remarkable variability in color it exhibits. In this study, the MYB gene family within H. macrophylla was comprehensively examined, resulting in the identification of 72 MYB genes through genomic screening utilizing the Hidden Markov Model (HMM) method. A physicochemical analysis revealed a diverse range of properties among these proteins, with sizes varying from 65 to 770 amino acids; notably, six of these proteins were classified as stable. Predominantly, MYB proteins were localized within the nucleus, although some were also detected in other organelles, indicating a multifaceted role in cellular function. Phylogenetic analysis established that 13 MYB genes from H. macrophylla can be categorized into five distinct subfamilies based on the classifications observed in Arabidopsis thaliana, suggesting their involvement in the biosynthetic pathways of anthocyanins and proanthocyanidins. Expression analysis indicated a significant correlation between specific R2R3-MYB transcription factors, particularly HmMYB54, and the accumulation of anthocyanins during various flowering stages. qPCR results showed that the expression of HmMYB54 was consistent with the accumulation trend of 'Forever Summer' colors in hydrangea, while HmMYB61 was just the opposite, which was consistent with RNAseq, suggesting that they regulated the formation of 'Foever Summer' blue flowers positively and negatively, respectively. A proposed regulatory model has been articulated to elucidate the mechanisms by which these MYB genes affect flower color, particularly through their interactions with essential structural genes in the anthocyanin biosynthesis pathway. Thus, this study not only enhances the understanding of the genetic basis of flower coloration in H. macrophylla but also highlights the adaptive significance of MYB transcription factors in response to environmental challenges.
花色是植物中关键的观赏性状，对其美学价值有重大影响。大叶绣球尤其因其硕大、鲜艳的花朵以及所展现出的显著颜色变异性而备受推崇。在本研究中，对大叶绣球中的MYB基因家族进行了全面检测，通过利用隐马尔可夫模型（HMM）方法进行基因组筛选，鉴定出了72个MYB基因。理化分析揭示了这些蛋白质具有多样的特性，其大小从65个氨基酸到770个氨基酸不等；值得注意的是，其中六种蛋白质被归类为稳定型。主要地，MYB蛋白定位于细胞核内，不过在其他细胞器中也检测到了一些，这表明其在细胞功能中具有多方面的作用。系统发育分析表明，根据拟南芥中的分类，大叶绣球的13个MYB基因可分为五个不同的亚家族，这表明它们参与了花青素和原花青素的生物合成途径。表达分析表明，特定的R2R3 - MYB转录因子，特别是HmMYB54，与不同开花阶段花青素的积累之间存在显著相关性。qPCR结果显示，HmMYB54的表达与绣球花‘无尽夏’颜色的积累趋势一致，而HmMYB61则相反，这与RNA测序结果一致，表明它们分别对‘无尽夏’蓝色花朵的形成起正向和负向调控作用。已阐明了一个拟议的调控模型，以解释这些MYB基因影响花色的机制，特别是通过它们与花青素生物合成途径中关键结构基因的相互作用。因此，本研究不仅增进了对大叶绣球花色遗传基础的理解，还突出了MYB转录因子在应对环境挑战方面的适应性意义。
