Integration of Light and Auxin Signaling in Shade Plants: From Mechanisms to Opportunities in Urban Agriculture

Abstract

With intensification of urbanization throughout the world, food security is being threatened by the population surge, frequent occurrence of extreme climate events, limited area of available cultivated land, insufficient utilization of urban space, and other factors. Determining the means by which high-yielding and high-quality crops can be produced in a limited space is an urgent priority for plant scientists. Dense planting, vertical production, and indoor cultivation are effective ways to make full use of space and improve the crop yield. The results of physiological and molecular analyses of the model plant species Arabidopsis thaliana have shown that the plant response to shade is the key to regulating the plant response to changes in light intensity and quality by integrating light and auxin signals. In this study, we have summarized the major molecular mechanisms of shade avoidance and shade tolerance in plants. In addition, the biotechnological strategies of enhancing plant shade tolerance are discussed. More importantly, cultivating crop varieties with strong shade tolerance could provide effective strategies for dense planting, vertical production, and indoor cultivation in urban agriculture in the future.

Effects of light spectrum on the morphophysiology and gene expression of lateral branching in Pepino (Solanum muricatum)

“…Red and blue light maximizes photosynthetic performance and is therefore essential for normal plant growth and development (Kharshiing and Sinha, 2016). In addition, most plants can regulate shade avoidance response by sensing blue and red wavelengths (Xie et al, 2022;Zeidler, 2022). Therefore, blue and red light is essential for plant photomorphogenesis and photosynthetic traits.…”

Shade responses and resistant mechanisms in Spatholobus suberectus

“…Plant hormones interact with COP1 and HY5 and integrate into the light signaling network [ 27 , 28 ]. It was reported that under shade, auxin/IAA and GA were activated to promote stem elongation, MeJA was repressed to attenuate limited resources reallocating to defense, and ABA was increased to repress branching [ 22 , 29 ].…”

The New Green Challenge in Urban Planning: The Right Genetics in the Right Place

“…This aspect is not always transversal for all habitats since it strongly depends on the subarea considered and is specific to the different cultural typologies: for example, the surface can be high in an urban park, medium in an urban garden and/or roadside/traffic islands, and low in the roof/terrace/balcony context. In urban parks, it is possible to plant those species that have high dimensions of aerial parts and roots, such as arboreal ones; however, in roadsides, traffic islands or buildings' terraces and balconies, the choice is more oriented toward plants able to grow in limited surfaces and, consequently, toward the selection of varieties with limited size [104,105].…”