Photoperiod, Light Quality, and Intensity: Integrated Signalling and Hormonal Crosstalk in the Spatiotemporal Control of Plant Vascular Development

Light acts as both the primary energy source for photosynthesis and a pivotal environmental signal that orchestrates plant growth and developmental transitions. The plant vascular system, comprising xylem, phloem, and cambium, dynamically adjusts its development in response to light intensity, quality, and photoperiod. This review synthesises current knowledge on how light signalling regulates cambial activity, xylem and phloem differentiation, and secondary cell wall formation. We elaborate on the molecular interplay between light signalling components and key vascular developmental regulators. Understanding these mechanisms is crucial for deciphering plant adaptation to variable light environments and holds significant potential for enhancing crop resilience and woody biomass yield in the context of global climate change.