N this study, except for the T6P synthase homolog TPS (Unigene0013555) that was downregulated in SD19-vs.-LD19, other TPSs had been upregulated at one particular or extra stages during floral transition in L. gratissima (Figure 5E and Supplementary Table S9), displaying that TPS homologs participate in floral transition in L. gratissima along with the T6P signaling pathway is substantially enhanced throughout floral transition. SPL4 was also hugely expressed at SD10, demonstrating that T6P in L. gratissima SAM promoted floral transition by regulating SPL4 expression. HK acts as a catalytic enzyme to catalyze hexose phosphorylation, at the same time as a glucose signal sensor mediating the interaction in between the glucose signaling pathway plus the ABA signaling pathway to regulate plant improvement (Moore et al., 2003; Teng et al., 2008). In this study, HK homologs (Unigene0044869 and Unigene0044870) were upregulated in SD7-vs.-LD7 and SD13-vs.-LD13 (Figure 5E and Supplementary Table S9). We speculate that HK mostly catalyzed hexose phosphorylation to provide an power supply for initiating floral transition at SD7 and acted as a glucose signal sensor to participate in L. gratissima flower development at SD13. In summary, the sugar metabolism-related genes TPS and HK entered the flowering regulatory network via the sugar signaling and hormone signaling pathways to regulate floral transition in L. gratissima.Phytohormones Regulate Floral Transition in L. gratissimaPhytohormones play important regulatory roles in plant development plus the mechanisms of their participation in floral transition in several plants are extensively studied (Shu et al.,Frontiers in Plant Science | www.frontiersin.org2018; Lin et al., 2019; Zhang et al., 2019; Bao et al., 2020). On the other hand, the complex hormone regulatory network of floral transition in perennial woody plants remains unclear. We studied the regulatory patterns of hormones that take part in floral transition in L. gratissima. As one of the most vital phytohormones, the function of GA in regulating floral transition is mainly accomplished via maintaining GA homeostasis and regulating the levels of DELLA, a growth inhibitor within the GA signaling pathway (Bao et al., 2020). GA homeostasis in plants is maintained via coordinating the expression levels on the GA biosynthesis genes, which include GA3OXs and GA20OXs, and the catabolic enzyme genes GA2OXs, thereby regulating floral transition (Mateos et al., 2015; Bao et al., 2020). In this study, homologs of GA2OX1 (Unigene0030732) and GA2OX8 (Unigene0073113) were both upregulated in SD10-vs.-LD10 (Figure 5C and Supplementary Table S9). GA2OXs can catalyze the 2-hydroxylation of bioactive GAs (which include GA1, GA3, GA4, and GA9), IDO Inhibitor drug resulting in decreased levels of bioactive GAs (Rieu et al., 2008). This may perhaps be one of many factors for low GA3 content in shoot apexes and leaves of L. gratissima. The main elements of GA signaling include CB1 Agonist Purity & Documentation things like the GA receptor GID1B as well as the growth inhibitors, DELLAs (Bao et al., 2020). When GA concentrations increase, the DELLA protein forms a GA-GID1B-DELLA complex that undergoes degradation by the ubiquitination pathway, thereby regulating the expression of downstream genes (Bao et al., 2020). The GA signaling pathway mainly promotes floral transition by inducing the expression of SOC1 and LFY (Bl quez et al., 1998; Hou et al., 2014; Bao et al., 2020; Fukazawa et al., 2021). Within this study, RGL3 (Unigene0071862) encoding DELLA had low expression in SD10,.