Genome-wide identification of polyamine metabolism and ethylene synthesis genes in Chenopodium quinoa Willd. and their responses to low-temperature stress.

BACKGROUND: Quinoa (Chenopodium quinoa Willd.) is valued for its nutritional richness. However, pre-harvest sprouting poses a significant threat to yield and grain quality. This study aims to enhance our understanding of pre-harvest sprouting mitigation strategies, specifically through delayed sowing and avoiding rainy seasons during quinoa maturation. The overarching goal is to identify cold-resistant varieties and unravel the molecular mechanisms behind the low-temperature response of quinoa. We employed bioinformatics and genomics tools for a comprehensive genome-wide analysis of polyamines (PAs) and ethylene synthesis gene families in quinoa under low-temperature stress. RESULTS: This involved the identification of 37 PA biosynthesis and 30 PA catabolism genes, alongside 227 ethylene synthesis. Structural and phylogenetic analyses showcased conserved patterns, and subcellular localization predictions indicated diverse cellular distributions. The results indicate that the PA metabolism of quinoa is closely linked to ethylene synthesis, with multiple genes showing an upregulation in response to cold stress. However, differential expression within gene families suggests a nuanced regulatory network. CONCLUSIONS: Overall, this study contributes valuable insights for the functional characterization of the PA metabolism and ethylene synthesis of quinoa, which emphasize their roles in plant low-temperature tolerance and providing a foundation for future research in this domain.

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

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, ß and γ types, CqDODA into ɑ and ß 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.

[Comparison of arbutin contents from Bergenia purpurascens in Yunnan].

OBJECTIVE: To determine arbutin contents in different populations of Bergenia purpurascens in Yunnan province, for screening out the best resource and best part of B. purpurascens. METHOD: The SB-C18 column was used with methanol-water (15: 85) as the mobile phase, at the flow rate of 1 mL x min(-1) and column temperature of 30 degrees C, and 282 nm was selected as the detected wavelength. RESULT: There were much significant differences in arbutin contents among various parts of the same B. population. The sequence of parts from high to low was lamina > petiole > root > rhizome. Arbutin contents in laminae of different B. populations were different at the most significant level and varied between 6.36% and 1.51%. Arbutin contents in rhizomes of different B. populations were also dignificantly different at varied between 1.72% and 0.40%. CONCLUSION: Lamina is the best part for extracting arbutin. B. population distributed in Laojunshan mountain in Lanping county is the best resource for arbutin exploitation in B. purpurascens.