Transcriptomic and metabolomic analysis of autumn leaf color change in Fraxinus angustifolia

Abstract

Fraxinus angustifolia is a type of street tree and shade tree with ornamental value. It has a beautiful shape and yellow or reddish purple autumn leaves, but its leaf color formation mechanism and molecular regulation network need to be studied. In this study, we integrated the metabolomes and transcriptomes of stage 1 (green leaf) and stage 2 (red-purple leaf) leaves at two different developmental stages to screen differential candidate genes and metabolites related to leaf color variation. The results of stage 1 and stage 2 transcriptome analysis showed that a total of 5,827 genes were differentially expressed, including 2,249 upregulated genes and 3,578 downregulated genes. Through functional enrichment analysis of differentially expressed genes, we found that they were involved in flavonoid biosynthesis, phenylpropanoid biosynthesis, pigment metabolism, carotene metabolism, terpenoid biosynthesis, secondary metabolite biosynthesis, pigment accumulation, and other biological processes. By measuring the metabolites of Fraxinus angustifolia leaves, we found the metabolites closely related to the differentially expressed genes in two different periods of Fraxinus angustifolia, among which flavonoid compounds were the main differential metabolites. Through transcriptome and metabolomics data association analysis, we screened nine differentially expressed genes related to anthocyanins. Transcriptome and qRT-PCR results showed that these nine genes showed significant expression differences in different stages of the sample, and we speculate that they are likely to be the main regulatory factors in the molecular mechanism of leaf coloration. This is the first time that we have analyzed the transcriptome combination metabolome in the process of leaf coloration of Fraxinus angustifolia, which has important guiding significance for directional breeding of colored-leaf Fraxinus species and will also give new insights for enriching the landscape.

Integrated Metabolome and Transcriptome Analyses Provide New Insights into the Leaf Color Changes in Osmanthus fragrans cv. ‘Wucaigui’

“…Twenty-six metabolites, including anthocyanins, proanthocyanidins, and flavonoids, were simultaneously detected and quantified in different colored leaf species of A. mandshuricum [14]. Recently, 118 compounds were identified in the red and purple leaves of F. angustifolia, and the high contents of flavonoids indicate that they may be the main substances causing leaf color changes [16]. In this study, 26 carotenoids, 51 anthocyanins, and 2 chlorophyll, including zeaxanthin, lutein, α-carotene, and β-carotene, were identified in the processes of O. fragrans 'Wucaigui' leaf color changes (Tables 1-3).…”

The correlation between autumnal landscape colors and environmental factors and the analysis of ecological service functions in subtropical urban scenic forests

“…However, young tree leaves with a red color in tropical regions are the result of physiological causes (Wang et al, 2023), such as scavenging reactive oxygen species and defense against photoinhibition. Researchers observed that differences in relative humidity and light availability are related to autumn phenological variation.…”

Transcriptomic Analysis of Green Leaf Plants and White–Green Leaf Mutants in Haworthia cooperi var. pilifera

“…(maple) [28]. Transcriptome analysis of green leaves and red-purple leaves from Fraxinus angustifolia showed that there were nine differentially expressed genes related to anthocyanins [29]. However, research on the change in leaf color has been limited, especially in succulent plants.…”