Qiu Yujie, Cai Chengcheng, Mo Xu, Zhao Xinyi, Wu Lijuan, Liu Fan, Li Rui, Liu Chen, Chen Ji, Tian Mengliang
College of Agronomy, Sichuan Agricultural University, Chengdu, China.
Front Plant Sci. 2023 Aug 23;14:1220507. doi: 10.3389/fpls.2023.1220507. eCollection 2023.
L. is a rare orchid plant with high medicinal and ornamentalvalue, and extremely few genetic species resources are remaining in nature. In the normal purple flower population, a type of population material with a white flower variation phenotype has been discovered, and through pigment component determination, flavonoids were preliminarily found to be the main reason for the variation.
This study mainly explored the different genes and metabolites at different flowering stages and analysed the flower color variation mechanism through transcriptome- and flavonoid-targeted metabolomics. The experimental materials consisted of two different flower color phenotypes, purple flower (PF) and white flower (WF), observed during three different periods.
The results identified 1382, 2421 and 989 differentially expressed genes (DEGs) in the white flower variety compared with the purple flower variety at S1 (bud stage), S2 (chromogenic stage) and S3 (flowering stage), respectively. Among these, 27 genes enriched in the ko00941, ko00942, ko00943 and ko00944 pathways were screened as potential functional genes affecting flavonoid synthesis and flower color. Further analysis revealed that 15 genes are potential functional genes that lead to flavonoid changes and flower color variations. The metabolomics results at S3 found 129 differentially accumulated metabolites (DAMs), which included 8 anthocyanin metabolites, all of which (with the exception of delphinidin-3-o-(2'''-o-malonyl) sophoroside-5-o-glucoside) were found at lower amounts in the WF variety compared with the PF variety, indicating that a decrease in the anthocyanin content was the main reason for the inability to form purple flowers. Therefore, the changes in 19 flavone and 62 flavonol metabolites were considered the main reasons for the formation of white flowers. In this study, valuable materials responsible for flower color variation in D. nobile were identified and further analyzed the main pathways and potential genes affecting changes in flavonoids and the flower color. This study provides a material basis and theoretical support for the hybridization and molecular-assisted breeding of
兜唇石斛是一种珍稀的兰花植物，具有很高的药用和观赏价值，自然界中现存的遗传物种资源极少。在正常的紫色花群体中，发现了一种具有白花变异表型的群体材料，通过色素成分测定，初步发现黄酮类化合物是导致变异的主要原因。
本研究主要探索不同开花阶段的差异基因和代谢产物，并通过转录组和黄酮类靶向代谢组学分析花色变异机制。实验材料包括在三个不同时期观察到的两种不同花色表型，即紫色花（PF）和白色花（WF）。
结果表明，在S1（花蕾期）、S2（显色期）和S3（开花期），白花品种与紫花品种相比，分别鉴定出1382、2421和989个差异表达基因（DEG）。其中，筛选出27个富集在ko00941、ko00942、ko00943和ko00944途径中的基因作为影响黄酮类化合物合成和花色的潜在功能基因。进一步分析表明，有15个基因是导致黄酮类化合物变化和花色变异的潜在功能基因。S3期的代谢组学结果发现了129种差异积累代谢物（DAM），其中包括8种花青素代谢物，与PF品种相比，所有这些代谢物（除了飞燕草素-3-o-（2'''-o-丙二酰）槐糖苷-5-o-葡萄糖苷）在WF品种中的含量都较低，这表明花青素含量的降低是无法形成紫色花的主要原因。因此，19种黄酮和62种黄酮醇代谢物的变化被认为是形成白花的主要原因。在本研究中，鉴定出了负责铁皮石斛花色变异的有价值材料，并进一步分析了影响黄酮类化合物和花色变化的主要途径和潜在基因。本研究为……的杂交和分子辅助育种提供了物质基础和理论支持。
