Insight into the Molecular Mechanism of Flower Color Regulation in Rhododendron latoucheae Franch: A Multi-Omics Approach

Peng Xiao; Hui Zhang; Qiulin Liao; Ninghua Zhu; Jiaao Chen; Lehan Ma; Minhuan Zhang; Shouyun Shen

doi:10.3390/plants12162897

Insight into the Molecular Mechanism of Flower Color Regulation in Rhododendron latoucheae Franch: A Multi-Omics Approach

Plants (Basel). 2023 Aug 8;12(16):2897. doi: 10.3390/plants12162897.

Authors

Peng Xiao^{1

2

3}, Hui Zhang^{1

2

3}, Qiulin Liao^{1

2

3}, Ninghua Zhu⁴, Jiaao Chen^{1

2

3}, Lehan Ma^{1

2

3}, Minhuan Zhang^{1

2

3}, Shouyun Shen^{1

2

3}

Affiliations

¹ College of Landscape Architecture, Central South University of Forestry and Technology, Changsha 410004, China.
² Hunan Provincial Big Data Engineering Technology Research Center of Natural Reserve and Landscape Resource, Changsha 410004, China.
³ Institute of Human Settlements and Green Infrastructure, Central South University of Forestry and Technology, Changsha 410083, China.
⁴ College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China.

Abstract

Rhododendron latoucheae Franch. (R. latoucheae) is a valuable woody plant known for its high ornamental value. While purple flowers are a distinct and attractive variant phenotype of R. latoucheae, the underlying mechanism regulating its flower color is still poorly understood. To investigate the molecular regulatory mechanism responsible for the variation in flower color, we selected plants with white-pink and purple petals as the object and conducted analyses of metabolites, key genes, and transcription factors associated with flower color. A combined metabolome-transcriptome analysis was performed, and the expression of key genes was subsequently verified through qRT-PCR experiments. The results of our study demonstrated a significant enrichment of differential metabolites in the flavonoid metabolic pathway. Changes in anthocyanin content followed the same trend as the observed flower color variations, specifically showing significant correlations with the contents of malvidin-3-O-glucoside, dihydromyricetin, gallocatechin, and peonidin-3-O-glucoside. Furthermore, we identified three key structural genes (F3GT1, LAR, ANR) and four transcription factors (bHLH130, bHLH41, bHLH123, MYB4) that are potentially associated with the biosynthesis of flavonoid compounds, thereby influencing the appearance of purple flower color in R. latoucheae.

Keywords: Rhododendron latoucheae; flavonoids; flower color regulation; metabolism group; transcriptome.

Grants and funding

This work was supported by the Hunan Forestry Science and Technology Tackling and Innovation Funding Project #1 under grant LKY202327. Central Finance Forestry Science and Technology Promotion Demonstration Project (XLK202213).