Alterations in the light environment can significantly influence soybean morphology and yield formation; however, the effects and mechanisms of different light qualities on these aspects require further investigation. Consequently, we selected soybean cultivars with marked differences in light sensitivity as test materials, conducted experiments with red, blue, and green light qualities against a blue light background, and analyzed parameters related to leaf photosynthetic capacity, chlorophyll fluorescence, morphological characteristics, biomass, and yield variations following different light quality treatments. The results showed that following far-red light treatment, soybean plants exhibited significant shade avoidance syndrome, internode elongation, increased plant height, and a marked reduction in both root and leaf biomass, as well as total biomass. Furthermore, there was a substantial reduction in photosynthetic capacity. This indicated that far-red light exerts an inhibitory effect on soybean growth and yield formation. Red light has basically no regulatory effect on plant morphology and yield, while green light has a yield-increasing effect, but there was a cultivar effect. This study not only enhances our understanding of the mechanisms through which light quality regulates plant photosynthesis but also lays a scientific foundation for future crop light environment management and for the further exploration of light quality’s regulatory potential on crop growth.

Exposing wheat (Triticum aestivum L.) seeds to a combination of light and low temperatures for 4–6 weeks, followed by transferring to speed breeding (SB) conditions, has been demonstrated to effectively reduce generation time in winter wheat. To reveal the underlying mechanisms of accelerated generation advancement in winter wheat, we investigated changes in transcriptome and the subsequent responses in plant growth, flowering of germinated seeds vernalized at 4 °C with white exposure (VL) or under dark conditions (VD) for 4 weeks before sowing, and subsequent growth under SB conditions. Germinated seeds without vernalization were directly sown under SB conditions and served as controls (Control). The results showed that, compared with Control and VD, VL significantly expedited vernalization, resulting in early flowering for around 6 days and accelerated ripening of progeny seeds for 13 days with a higher germination index and vigor index. The transcriptomic analysis revealed that the differently expressed genes (DEGs) involved in GA synthesis and its signal transduction both participated in the light-induced speed vernalization and the subsequent rapid growth and development of winter wheat. The MADS-box transcription factors, especially VRN-A1 and MADS55, might play a vital role in the light- and low-temperature-induced early flowering. Our results stress the importance of light in vernalization and lay the groundwork for further elucidating the mechanisms underlying the light-induced speed vernalization of winter wheat.