CqRVE5-CqHAI3 is the potential key gene module regulating pre-harvest sprouting in quinoa

The CqRVE5 - CqHAI3 gene module is a key regulator of seed germination at harvest, and it negativelyregulates germination by infl uencing starch metabolism. Quinoa is a crop that is both resistant to adversity and highly nutritious. Pre-harvest sprouting (PHS) significantly affects quinoa yield and quality, underscoring the need to understand the mechanisms underlying quinoa's resistance to PHS. In this study, the quinoa R157 exhibited significantly greater resistance to PHS than S222. Quinoa resistance to PHS is closely associated with gibberellin/abscisic acid (GA/ABA), amylase activity, and starch metabolism. Weighted gene co-expression network analysis (WGCNA) identified the transcription factor CqRVE5 and its target gene, CqHAI3, as key regulators of PHS resistance in quinoa. Both genes exhibit similar expression patterns, with preferential expression in seeds, and both are localized to the nucleus. The CqRVE5 and CqHAI3 genes were overexpressed in Arabidopsis thaliana. In the transgenic seeds, GA/ABA levels, amylase activity, and starch degradation rates were all reduced, leading to decreased germination capacity, indicating that both CqRVE5 and CqHAI3 negatively regulate arabidopsis seed germination. Further studies have shown that CqRVE5 can bind to the promoter region of the CqHAI3 gene and activate its expression. In summary, CqRVE5-CqHAI3 may be an important module regulating seed germination at the harvest stage. This study proposes a new potential mechanism underlying PHS regulation, offering novel insights into PHS resistance.