Leaf and shoot apical meristem transcriptomes of quinoa (Chenopodium quinoa Willd.) in response to photoperiod and plant development

Our study focused on identifying key genes regulating flowering time and photoperiod response in quinoa. We examined the timing of photoperiod-induced floral transition and analyzed transcriptomes in photoperiod-sensitive and -insensitive quinoa accessions' leaf and shoot apical meristems. Histological analysis showed that floral transition in quinoa initiates two to three weeks after sowing. We found four groups of differentially expressed genes annotated in the QQ74-V2 reference genome that responded to plant development and floral transition, (i) 222 genes responsive to photoperiod in leaves, (ii) 1,812 genes differentially expressed between accessions under long-day conditions in leaves, (iii) 57 genes responding to developmental changes between weeks under short-day conditions in leaves, and (iv) 911 genes responding to floral transition within the shoot apical meristem. Interestingly, among numerous candidate genes, two putative FT orthologues and others (e.g., SOC1, COL, AP1) have been reported as key regulators of flowering time in other species. Additionally, we used co-expression networks to associate novel transcripts to a putative biological process based on the annotated genes within the same co-expression cluster. The candidate genes in this study would benefit quinoa breeding by identifying and integrating their beneficial haplotypes in crossing programs to develop adapted cultivars to diverse environmental conditions. We examined the timing of photoperiod-induced floral transition and analyzed transcriptomes in photoperiod-sensitive and -insensitive quinoa accessions' leaf and shoot apical meristems. Histological analysis revealed floral transition initiating two to three weeks after sowing. Differentially expressed genes were categorized in the QQ74-V2 reference genome, encompassing 222 genes responsive to photoperiod in leaves, 1,812 genes under long-day conditions, 57 genes during short-day conditions, and 911 genes during floral transition in shoot apical meristems. Notably, among numerous candidates, two putative FT orthologues and others (e.g., SOC1, COL, AP1) implicated in flowering time regulation in various species were identified. Co-expression networks associated novel transcripts with putative biological processes based on annotated genes in the same cluster. The candidate genes identified have potential applications in quinoa breeding, facilitating the incorporation of beneficial haplotypes in crossbreeding programs to develop