RNA-sequencing analysis reveals novel genes involved in the different peel color formation in eggplant

Jing Li; Senlin Jiang; Guobin Yang; Yanwei Xu; Lujun Li; Fengjuan Yang

doi:10.1093/hr/uhad181

RNA-sequencing analysis reveals novel genes involved in the different peel color formation in eggplant

Hortic Res. 2023 Sep 4;10(10):uhad181. doi: 10.1093/hr/uhad181. eCollection 2023 Oct.

Authors

Jing Li^{1

2

3}, Senlin Jiang¹, Guobin Yang¹, Yanwei Xu¹, Lujun Li¹, Fengjuan Yang^{1

2

3}

Affiliations

¹ College of Horticulture Science and Engineering, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai'an, Shandong 271018, China.
² Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region), Ministry of Agriculture and Rural Affairs, Tai'an, Shandong 271018, China.
³ Shandong Collaborative Innovation Center for Fruit and Vegetable Production with High Quality and Efficiency, Shandong Agricultural University, Tai'an, Shandong 271018, China.

Abstract

Eggplant (Solanum melongena L.) is a highly nutritious vegetable. Here, the molecular mechanism of color formation in eggplants was determined using six eggplant cultivars with different peel colors and two SmMYB113-overexpressing transgenic eggplants with a purple peel and pulp. Significant differentially expressed genes (DEGs) were identified by RNA-sequencing analysis using the following criteria: log₂^{(sample1/sample2)} ≥ 0.75 and q-value ≤ 0.05. Two analytical strategies were used to identify genes related to the different peel color according to the peel color, flavonoids content, delphinidins/flavonoids ratio, and the content of anthocyanins. Finally, 27 novel genes were identified to be related to the color difference among eggplant peels and 32 novel genes were identified to be related to anthocyanin biosynthesis and regulated by SmMYB113. Venn analysis revealed that SmCytb5, SmGST, SmMATE, SmASAT3, and SmF3'5'M were shared among both sets of novel genes. Transient expression assay in tobacco suggested that these five genes were not sufficient for inducing anthocyanin biosynthesis alone, but they play important roles in anthocyanin accumulation in eggplant peels. Yeast one-hybrid, electrophoretic mobility shift assay and dual-luciferase assays indicated that the expression of the five genes could be directly activated by SmMYB113 protein. Finally, a regulatory model for the mechanism of color formation in eggplant was proposed. Overall, the results of this study provide useful information that enhances our understanding of the molecular mechanism underlying the different color formation in eggplant.