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Summary: Wheat needs different durations of vernalization, which accelerates flowering by exposure to cold temperature, to ensure reproductive development at the optimum time, as that is critical for adaptability and high yield. TaVRN1 is the central flowering regulator in the vernalization pathway and encodes a MADS‐box transcription factor (TF) that usually works by forming hetero‐ or homo‐dimers. We previously identified that TaVRN1 bound to an MADS‐box TF TaSOC1 whose orthologues are flowering activators in other plants. The specific function of TaSOC1 and the biological implication of its interaction with TaVRN1 remained unknown. Here, we demonstrated that TaSOC1 was a flowering repressor in the vernalization and photoperiod pathways by overexpression and knockout assays. We confirmed the physical interaction between TaSOC1 and TaVRN1 in wheat protoplasts and in planta, and further validated their genetic interplay. A Flowering Promoting Factor 1‐like gene TaFPF1‐2B was identified as a common downstream target of TaSOC1 and TaVRN1 through transcriptome and chromatin immunoprecipitation analyses. TaSOC1 competed with TaVRT2, another MADS‐box flowering regulator, to bind to TaVRN1; their coding genes synergistically control TaFPF1‐2B expression and flowering initiation in response to photoperiod and low temperature. We identified major haplotypes of TaSOC1 and found that TaSOC1‐Hap1 conferred earlier flowering than TaSOC1‐Hap2 and had been subjected to positive selection in wheat breeding. We also revealed that wheat SOC1 family members were important domestication loci and expanded by tandem and segmental duplication events. These findings offer new insights into the regulatory mechanism underlying flowering control along with useful genetic resources for wheat improvement. [ABSTRACT FROM AUTHOR]

The Chinese tallow tree (Triadica sebifera) is an economically important plant on account of its ornamental value and oil-producing seeds. Leaf colour is a key characteristic of T. sebifera, with yellow-, red- and purple-leaved varieties providing visually impressive displays during autumn. In this study, we performed metabolomic and transcriptomic analyses to gain a better understanding of the mechanisms underlying leaf colour development in purple-leaved T. sebifera at three stages during the autumnal colour transition, namely, green, hemi-purple, and purple leaves. We accordingly detected 370 flavonoid metabolites and 10 anthocyanins, among the latter of which, cyanidin-3-xyloside and peonidin-3-O-glucoside were identified as the predominant compounds in hemi-purple and purple leaves. Transcriptomic analysis revealed that structural genes associated with the anthocyanin biosynthetic pathway, chlorophyll synthesis pathway and carotenoid synthesis pathway were significantly differential expressed at the three assessed colour stages. Additionally, transcription factors associated with the MYB-bHLH-WD40 complex, including 22 R2R3-MYBs, 79 bHLHs and 44 WD40 genes, were identified as candidate regulators of the anthocyanin biosynthetic pathway. Moreover, on the basis of the identified differentially accumulated anthocyanins and key genes, we generated genetic and metabolic regulatory networks for anthocyanin biosynthesis in T. sebifera. These findings provide comprehensive information on the leaf transcriptome and three pigments of T. sebifera, thereby shedding new light on the mechanisms underlying the autumnal colouring of the leaves of this tree., (© 2024 Scandinavian Plant Physiology Society.)