Abstract:Light is one of the most important critical factors that regulate plant growth and development. Photoreceptors perceive the changes in light intensity, direction and photoperiod to regulate the entire lifecycle of plants further. Phytochrome A (PHYA) is the unique far-red light receptor in plants. PHYA is synthesized in the cytosol in the dark; upon light illumination, PHYA is translocated into the nucleus and degraded rapidly. PHYA precisely regulates the transcription network via multiple pathways. Furthermore, post-translational modifications have been shown to play an essential role in modulating the stability and activity of PHYA. The research progress on PHYA-mediated transcription and post-translational modifications of PHYA were summarized, and the application prospects of PHYA in molecular design breeding in crops were also discuss.