Research Institute for Landscape and Ornamental Plant, College of Landscape Architecture and Art, Northwest A&F University, Yangling, China.
Physiol Plant. 2023 Jan;175(1):e13859. doi: 10.1111/ppl.13859.
Chaenomeles speciosa is a plant with high ornamental value, and the color of its petals deepens obviously under drought stress. To understand the mechanism of drought-induced reddening of C. speciosa petal color, the metabolites and transcriptomics of petals from 4% PEG-8000-treated and control cuttings were analyzed. In this study, the analysis of metabolites revealed the accumulation of anthocyanins in petals of PEG-treated cuttings, indicating anthocyanins might be the reason for the deepening of petal color. By using transcriptomics, we identified CsMYB6 as an overexpressed transcription factor in PEG-treated samples. Transient overexpression and suppression of CsMYB6 revealed that it is a key transcription factor for anthocyanin synthesis. We identified genes related to anthocyanin biosynthesis and constructed a network of drought- and anthocyanin-related genes (such as CsMYB6, CsbHLH111, CsANS, CsDFR, and CsUFGT). Further experiments indicated that CsMYB6 directly interacted with CsbHLH111, and this interaction increased the binding ability of CsMYB6 to the promoter regions of three structural genes of anthocyanin biosynthesis: CsANS, CsDFR, and CsUFGT. Our findings provide a molecular basis and new insight into drought-induced anthocyanin biosynthesis in C. speciosa.
木瓜海棠是一种具有很高观赏价值的植物，其花瓣在干旱胁迫下颜色会明显加深。为了了解干旱诱导木瓜海棠花瓣变红的机制，对 4%PEG-8000 处理和对照插条花瓣的代谢物和转录组进行了分析。在这项研究中，代谢物分析表明 PEG 处理插条花瓣中积累了花色素苷，表明花色素苷可能是花瓣颜色加深的原因。通过转录组学分析，我们鉴定出 CsMYB6 是 PEG 处理样品中过表达的转录因子。CsMYB6 的瞬时过表达和抑制表明，它是花青素合成的关键转录因子。我们鉴定了与花青素生物合成相关的基因，并构建了一个与干旱和花青素相关基因的网络（如 CsMYB6、CsbHLH111、CsANS、CsDFR 和 CsUFGT）。进一步的实验表明，CsMYB6 与 CsbHLH111 直接相互作用，这种相互作用增加了 CsMYB6 与花青素生物合成三个结构基因（CsANS、CsDFR 和 CsUFGT）启动子区域结合的能力。我们的研究结果为木瓜海棠干旱诱导花青素生物合成提供了分子基础和新的见解。
