IGT/LAZY genes are differentially influenced by light and required for light-induced change to organ angle

Light at the end of the tunnel: integrating signaling pathways in the coordination of lateral root development

Root system architecture (RSA) encompasses a range of physical root attributes, including the lateral roots (LRs), root hairs and adventitious roots, in addition to the primary or main root. This overall structure is a crucial trait for efficient water and mineral capture alongside providing anchorage to the plant in the soil and is vital for plant productivity and fitness. RSA dynamics are dependent upon various environmental cues such as light, soil pH, water, mineral nutrition and the belowground microbiome. Among these factors, light signaling through HY5 significantly influences the flexibility of RSA by controlling different signaling pathways that converge at photoreceptors-mediated signaling, also present in the 'hidden half'. Furthermore, several phytohormones also drive the formation and emergence of LRs and are critical to harmonize intra and extracellular stimuli in this regard. This review endeavors to elucidate the impact of these interactions on RSA, with particular emphasis on LR development and to enhance our understanding of the fundamental mechanisms governing the light-regulation of LR growth and physiology.

Genetic regulation of the root angle in cereals

The root angle plays a critical role in efficiently capturing nutrients and water from different soil layers. Steeper root angles enable access to mobile water and nitrogen from deeper soil layers, whereas shallow root angles facilitate the capture of immobile phosphorus from the topsoil. Thus, understanding the genetic regulation of the root angle is crucial for breeding crop varieties that can efficiently capture resources and enhance yield. Moreover, this understanding can contribute to developing varieties that effectively sequester carbon in deeper soil layers, supporting global carbon mitigation efforts. Here we review and consolidate significant recent discoveries regarding the molecular components controlling root angle in cereal crop species and outline the remaining research gaps in this field.