LONG-DISTANCE SUGAR SIGNALLING

Abstract

The orchestration of a plant’s growth and development is dependent on an complex web of signalling pathways, with sugars emerging as a central player. Plants are autotrophic organisms which means that they rely on sugars that are derived from photosynthesis, which are crucial for the plant’s growth. Recent studies have emphasised the evolution of mechanisms that allow the plant to perceive sugars, revealing their dual role in metabolism and signalling. Sugar signalling allows the plants to integrate external as well as internal cues, maintaining nutrient homeostasis and respond to stresses. There is evidence of many environmental stresses that utilise sugar signals. Some examples are drought, salt and cold stress. Short-distance sugar signalling mechanisms have been well documented; however, long-distance sugar signalling remains largely unexplored. The lack of studies exploring long-distance sugar signals could be attributed to the fact that signalling networks are very complex and are often interconnected with different signalling networks making it difficult to study especially when talking about long-distance signalling. Sugars are dynamic molecules which means that changes in their levels is rapid when responding to changes in environmental stimuli. A lot of these signalling sugar pathways work intracellularly so putting them in the context of long-distance signalling makes it a lot more complicated. In this literature review I researched the established short-distance sugar signalling pathways, shed light on the mechanisms that orchestrate physiological responses in plants and investigated if there is any evidence of these signalling pathways working in the long-distance context. Also, in this review I suggest that the crosstalk between sugar signalling pathways and other signalling pathways and molecules could contribute to long-distance sugar signalling.