Seasons and shape: inflorescences from autumn to summer.

Flowering plants organize their reproductive organs within specialized structures named inflorescences. Plasticity in the architecture of these inflorescences allows adaptation to the environment during flowering, ultimately determining reproductive output and yield. Inflorescence development relies on meristems, hubs of pluripotent cells that direct organogenesis. In recent years, laboratory studies have uncovered the response of meristems and their resulting inflorescences to environmental cues such as temperature, which is subject to both unpredictable and seasonal fluctuations. In this review, we explore the mechanisms through which temperature regulates inflorescence development in both model and crop species, principally from the Brassicaceae family. We follow the trajectory of the apical meristem through the seasons, from acquisition of reproductive identity to arrest and including branch outgrowth, highlighting the current understanding of the mechanisms through which temperature influences development. While the role of temperature in regulating the floral transition has been well established, we emphasize significant gaps in our understanding of how subsequent developmental transitions are controlled. Furthermore, we find that many key gene networks underpinning inflorescence development were initially characterized in Arabidopsis under controlled laboratory conditions. However, recent studies in other Brassicaceae species and crops have revealed that our understanding of gene function in the field context remains limited, posing a challenge for breeding efforts aimed at climate resilience.