Delving deeper into the link between sugar transport, sugar signaling, and vascular system development

Abstract

Plant growth and development rely on the transport and use of sugars produced during photosynthesis. Sugars have a dual function as nutrients and signal molecules in the cell. Many factors maintaining sugar homeostasis and signaling are now identified, but our understanding of the mechanisms involved in coordinating intracellular and intercellular sugar translocation is still limited. We also know little about the interplay between sugar transport and signaling and the formation of the vascular system, which controls long‐distance sugar translocation. Sugar signaling has been proposed to play a role; however, evidence to support this hypothesis is still limited. Here, we exploited recent transcriptomics datasets produced in aerial organs of Arabidopsis to identify genes coding for sugar transporters or signaling components expressed in the vascular cells. We identified genes belonging to sugar transport and signaling for which no information is available regarding a role in vasculature development. In addition, the transcriptomics datasets obtained from sugar‐treated Arabidopsis seedlings were used to assess the sugar‐responsiveness of known genes involved in vascular differentiation. Interestingly, several key regulators of vascular development were found to be regulated by either sucrose or glucose. Especially CLE41, which controls the procambial cell fate, was oppositely regulated by sucrose or glucose in these datasets. Even if more experimental data are necessary to confirm these findings, this survey supports a link between sugar transport/signaling and vascular system development.

Impairment of sugar transport in the vascular system acts on nitrogen remobilization and nitrogen use efficiency in Arabidopsis

“…Considering that stem diameter and nutrient contents could account for xylem development and C/N allocation, respectively, our results support a link between both traits. A role for sugars in vasculature development has been proposed for a long time, even if the identification of molecular actors involved starts only to emerge (for review Dinant & Le Hir, 2022). On the other hand, a similar role for amino acids has not been explored so far.…”

Carbohydrate distribution via SWEET17 is critical for Arabidopsis inflorescence branching under drought

“…In addition, pith cells harbor a variety of sugar transporters, as e.g. carbohydrate transporters of the EARLY RESPONSE TO DEHYDRATION SIX-LIKE (ERDL) and SUCROSE TRANSPORTER (STP) families, known to be expressed in the inflorescence stem, show high expression levels in the pith of this organ (Shi et al, 2021; Dinant and Le Hir, 2022). Therefore, the pith and in particular its subcellular sugar distribution may play an important role in plant developmental processes, such as the development of the vascular system, a process that is clearly influenced by sugar signaling and thus by sugar availability and distribution (Dinant and Le Hir, 2022).…”

“…carbohydrate transporters of the EARLY RESPONSE TO DEHYDRATION SIX-LIKE (ERDL) and SUCROSE TRANSPORTER (STP) families, known to be expressed in the inflorescence stem, show high expression levels in the pith of this organ (Shi et al, 2021; Dinant and Le Hir, 2022). Therefore, the pith and in particular its subcellular sugar distribution may play an important role in plant developmental processes, such as the development of the vascular system, a process that is clearly influenced by sugar signaling and thus by sugar availability and distribution (Dinant and Le Hir, 2022). In accordance with suggestions by Dinant and Le Hir (2022), increased SWEET17 expression in the pith allows fructose to be mobilized from vacuoles and serve as carbohydrate source for local sinks such as the xylem tissue (Spicer 2014; Aubry et al, 2022).…”

Impairment of sugar transport in the vascular system acts on nitrogen remobilisation and nitrogen use efficiency in Arabidopsis

“…Considering that stem diameter and nutrient contents could account for xylem development and C/N allocation respectively, our results support a link between both traits. A role for sugars in the vasculature development has been proposed for long, even if the identification of molecular actors involved starts only to emerge (for review Dinant and Le Hir, 2022). On the other hand, a similar role for amino acids has not been explored so far.…”