Through identifying and selecting SDV alleles in winter cereals flowering time and yield may be stabilized under warming climates, increasing the resilience of cereal crops. By conducting comparative transcriptomics for six Pooideae species, five SDV- and one SD-responsive, Schubert et al. identify gene clusters linked to SDV and propose a conserved molecular network across the Pooideae. This approach demonstrates the merit and potential of using cross-species comparisons now possible through advances in pan-genomics (Fig. 1). This cross-species approach has the potential to accelerate our understanding of plant adaptation as Schubert et al. have already demonstrated how it can be used to identify conserved molecular signalling hubs. This echoes recent advances regarding the multiple origins of spring VRN1 alleles across the Hordeum genus, highlighting the convergent recruitment of an adaptive solution (Mascher et al., 2025). Interestingly, the central SDV-responsive gene cluster contains well-known grass floral-development genes: VERNALIZATION 2 (VRN2), FLOWERING LOCUS T-LIKE 9 (FTL9), FRUITFULL2 (FUL2) and GENERAL REGULATORY FACTOR 14h (GF14h). The identification of these genes immediately suggests common points of regulation between SDV and V. This is of huge interest for cereal crop development as characterizing whether and how SDV intersects with V will not only contribute to understanding crop adaptation and evolution but will also aid the development of elite crop varieties to confer flowering competency with minimum reliance on low temperature. To this end, the functional characterization of GF14h via CRISPR mutants enables Schubert et al. to propose an SDV-aware flowering model for the Pooideae grasses. This highlights the role of GF14h in regulating SDV, where it promotes the expression of VRN2 and FTL4 under long days (LDs) before SDV to repress reproductive development. Then, following SDV, repression is released, and the floral promotion signal is integrated through the formation of the FT1 florigen activation complex (FT1-FAC), which is also the central complex involved in V responsiveness. Notable overlap with the well-established regulatory pathway of V in crops is clear. During V, VRN1 is expressed under low temperatures and represses VRN2, enabling the expression of active FT1. VRN2 is also repressed by SDs and by LDs after the chilling V (Dubcovsky et al., 2006). Furthermore, the role of VRN1 as a downstream regulator of FAC and the regulatory role of PPD1 promoted by LDs after V has been included in the SDV model. Recently, FT3, a homologue of FT1 (component of the FAC complex), has been reported to function as a temperature-sensitive SD florigen in bread wheat (Gauley et al., 2025) and so may also fit into this pathway. Understanding the molecular intersections of V and SDV is of great importance to the potential of adapting plants from V at higher latitudes to SDV at lower latitudes and for balancing the relative importance of each of these pathways within crops species for optimal local adaptation. Phytohormones, such as auxin, gibberellin and cytokinin, play crucial roles in regulating plant growth and development by acting as endogenous signalling molecules and coordinating with exogenous factors (Mishra et al., 2022). For example, auxin is known for its role in regulating inflorescence, lateral root initiation, vascular tissue differentiation and leaf expansion. It has also been found to affect flowering time, floret number and whole spike development (Salisbury, 1955; Wang et al., 2001; Mishra et al., 2022). The regulation of auxin on plant growth and development is mainly caused by its differential distribution. Interestingly, the second gene cluster identified by Schubert et al. contained a homologue of the auxin transport gene, ABCB9-like, which is downregulated under SDV conditions. In addition, other studies have also found that exogenous auxin application repressed flowering in SD plants (Cooke, 1954). This suggests the possible role of auxin in plants' reproductive development response to photoperiod during SDV. Another gene identified by Schubert et al. in the second cluster is the cytokinin signalling gene, PHP3. Similar to auxin, cytokinin levels and distribution are affected by the photoperiod (Macháčková et al., 1993). This discovery, for the first time, reveals a broader view that links auxin transportation and cytokinin signalling to the molecular network of SDV, suggesting that these phytohormones potentially coordinate floral initiation with photoperiodic signalling during SDV. This may be one of the physiologically ancient and conserved strategies used to achieve flowering competency after the expansion of Pooideae species from lower to higher latitude regions, where the photoperiod cue of V is distinct from SDV. This adaptive strategy provides a direction for developing SDV-responsive crop varieties by manipulating hormone-related genes. Given the vulnerability of major cereal crops to unreliable and unpredictable autumn and winter temperatures, the findings of Schubert et al. provide a needed and welcome new breeding target. Through identifying and selecting SDV alleles in winter cereals, flowering time and yield may be stabilized under warming climates, increasing the resilience of cereal crops. SDV genes are conserved across diverse Pooideae species, but in some species, they may have been recruited to multiple pathways. The characterization presented strongly suggests that the major winter cereal crops wheat and barley contain relevant SDV genes. A detailed characterization is now needed to identify which alleles need to be selected for functional validation and to gain an understanding of how manipulating the balance of SDV to V may impact final yield potential. Interestingly, recent work has identified that in barley and bread wheat, VRN2 has roles beyond the V pathway, with respect to tiller outgrowth in barley (Montardit-Tarda et al., 2025) and secondary tiller emergence rate and coleoptile tillers in bread wheat (Hirsz et al., 2026). Continued functional understanding of V genes will provide a comprehensive framework that integrates SDV and V with plant growth and development beyond flowering regulation. The phenotypic characterization, transcriptomics approach and computational analysis used by Schubert et al. provide a framework for how to study a wider range of species, identifying more phenotypic-specific molecular networks and characterizing adaptive trait evolution. However, it must be acknowledged that the collection, cultivation and development of genomic resources for such diverse grasses is certainly not trivial. YS was supported by BBSRC ISP ‘BBSRC Institute Strategic Programme: Delivering Sustainable Wheat (DSW)’ (BB/X011003/1). The New Phytologist Foundation remains neutral with regard to jurisdictional claims in maps and in any institutional affiliations.
Song et al. (Fri,) studied this question.