PIIS1674205220304299

Plants utilize light signals detected by photoreceptors to manage growth and defense against competitors.
A low red to far-red (R:FR) light ratio signifies competition, sensed by phytochrome B (phyB), stimulating growth hormones (auxin, gibberellins) for shade avoidance.
Other important photoreceptors include cryptochromes, phototropins, and UVR8, which regulate plant growth and defense by interacting with major regulatory nodes like COP1/SPA ligase complex and PIF transcription factors.
The study reviews mechanisms linking photoreceptors with growth and defense, offering insights for agricultural improvement of crops.

High plant densities lead to resource competition, requiring plants to adapt physiologically.
Shaded plants tend to elongate, maximizing light capture.
Competition for light is intense due to its directional availability.
Plants have evolved strategies for shade avoidance by altering growth patterns upon detecting shading signals.

SAS comprises responses to low R:FR ratios identified by research in 1990s.
Photoreceptors provide a multicolor and directional view of light in the canopy.
Key responses to realized shade include elongation growth, leaf hyponasty, negative phototropism, and improved light foraging.

Detect changes in R:FR ratios, signaling plant proximity via reflected far-red light.
Play important roles in detecting reflected FAR signals and adjusting growth behavior.

Sensitive to blue and UV-A light, controlling phototropic responses and plant acclimation and growth adjustments.

Manage shade responses, modulating the synthesis of growth hormones in shaded conditions.

Regulates UV-B response and plant morphological adaptation, enhancing resistance while controlling stress responses.

Plants must balance growth (light foraging) with defense against herbivores and pathogens.
High density heightens competition, resulting in growth-defense trade-offs where rapid growth conflicts with robust defense mechanisms.

Light signaling impacts physiological responses including auxin biosynthesis involved in expansion and elongation through PIF interaction. Growing evidence indicates crosstalk between growth and defense mechanisms mediated by jasmonate and light.

Understanding photoreceptor mechanisms can improve plant resilience and stress tolerance, optimizing crop production strategies.
Researchers can apply findings from Arabidopsis to enhance crop species, particularly in terms of light management in dense planting and greenhouse systems.

The research emphasizes understanding the intricate balance between plant growth and defense responses, revealing potential applications in agricultural practices. Further research should strive to manipulate and optimize photoreceptor signaling pathways for crop improvement.