Identification, expression analysis of quinoa betalain biosynthesis genes and their role in seed germination and cold stress

ABSTRACT

Betalains provide Chenopodium quinoa bright color, and the key enzyme genes for betalain biosynthesis include CYP76AD, DODA, and GTs. In this study, 59 CqCYP76AD, CqDODA and CqGTs genes in quinoa were identified and characterized by gene structural characteristics, phylogenetic relationships and gene expression patterns. The CqCYP76AD genes were divided into ɑ, β and γ types, CqDODA into ɑ and β types, and CqGTs into CqcDOPA5GT, CqB5GT and CqB6GT types according to phylogenetic relationships. The analysis of co-linearity identified eight pairs of duplicated genes which were subjected to purifying selection during evolution. CqCYP76AD and CqDODA, as well as CqcDOPA5GT and CqB5GT may have been evolutionarily linked in genetic inheritance, based on gene location and gene structure study. The tissue expression specificity of CqCYP76AD, CqDODA, and CqGTs genes in response to seed germination and cold stress was studied by RNA-Seq data. The genes CqCYP76AD, CqDODA, and CqGTs were involved in betalain biosynthesis and cold stress. CqCYP76AD, CqDODA, CqcDOPA5GT and CqB5GT gene sequences were consistent in the eight quinoa samples and showed significant variations in expression. In contrast, the inconsistency between changes in gene expression and betalain accumulation indicates that other factors may influence betalain biosynthesis in quinoa. This study offers the theoretical basis for the roles of the CqCYP76AD, CqDODA, and CqGTs genes in betalain biosynthesis and cold stress in quinoa, as well as a guide for the full utilization of betalains in quinoa plants.

KEYWORDS:

• Chenopodium quinoa
• betalain biosynthesis
• gene identification
• gene cloning
• expression analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contribution

F.G. and S.W. designed the experiments. F.Y. and X.Y. carried out all the experiments. F.Y. analyzed the data, and wrote the manuscript. S.W., Z.L., W.L., and F.G reviewed and edited the manuscript. All authors have read and agreed to the published version of the manuscript.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15592324.2023.2250891

Additional information

Funding

This work was supported by the Natural Science Foundation of China (NO. 31960417).