Analysis of the transcriptome of green and mutant golden-yellow leaves of Acer palmatum Thunb. using high-throughput RNA sequencing

Acer palmatum Thunb. (maple) is one of the most popular and important decorative plants in the World. The visual attributes of its leaf colour display provide ornamental value and so are widely used in landscape gardening. Although the genes encoding chlorophyll (Chl) synthases and some related enzymes have been well characterised, no Chl synthase mutants have yet been fully studied. In this study, a leaf colour mutant (m1), which has golden-yellow leaves in Spring and Summer, was compared with wide-type (WT) plants, which have a green leaf colour. These plants were used to explore the mechanism of the mutation by studying the relationships between the different leaf colours and Chl, carotenoid, and anthocyanin concentrations and by combining the Illumina sequencing platform with an analysis of differentially expressed genes (DEGs). There were 48,436 unigenes and 1,913 DEGs, of which 784 were up-regulated and 1,129 were down-regulated genes in m1 compared to WT plants. Some DEGs were related to the formation of leaf colour and to resistance to biotic or abiotic stresses such as pathogens, heat, or pests. This study will help to improve our understanding of the mechanism responsible for the m1 Chl-mutant in A. palmatum Thunb. and other plants.