In their natural environment, plants are dependent on sunlight to supply energy for photosynthesis and face a daily challenge to survive through the night when photosynthesis is no longer possible. Plants are exposed to fluctuating environmental conditions (i.e. light, temperature, water supply, etc.), constraining their growth and development. To buffer these variable and mostly unpredictable periods of carbon supply and demand and sustain the growth of heterotrophic organs, plants can store transitory carbon reserves, which are remobilized to provide energy for maintenance of respiration and growth. By far, the most common reserves are starch and soluble sugars, especially sucrose. Once synthesized, the larger sugars are exported to the non-photosynthetic sink organs (young leaves, roots, tubers, meristems, reproductive organs and seeds) via long-distance transport through the phloem. Efficient source-to-sink transport of sugars is essential for fundamental plant growth processes and enables fine-tuned carbon partitioning across plant organs through the phloem. Depending on the species, the common reserves can be supplemented by fructans, sugar alcohols (e.g., sorbitol and mannitol), raffinose-family oligosaccharides (e.g., raffinose, stachyose, verbascose), mannans, or organic acids (e.g., malate and citrate).
For optimal plant growth, development, fitness and crop production, it is important to efficiently coordinate carbohydrate partitioning. Many regulatory steps, which can inhibit or promote the rate of photosynthetic carbohydrate partitioning, can ensure tight control over this process to avoid periods of starvation. However, despite huge progress over the last three decades in understanding the whole-plant carbon metabolism, knowledge about its regulation is still fragmentary.
This Research Topic welcomes manuscripts understanding whole-plant carbon metabolism, outlining its pathways, regulation and implications on crop yield and quality. In particular, studies shall focus on how processes are linked to the carbon status of the plant and regulated accordingly, allowing the plant to adapt its carbon metabolism to an ever-changing environment. Most of our knowledge regarding pathways, components and regulation of the whole-plant carbon metabolism comes from experiments performed on the model plant species Arabidopsis thaliana, which has proven to be a powerful tool for successful forward genetic screens. This article collection is not limited to model plants but also welcomes studies performed on crop and ornamental plant species.
We encourage the submission of Original Research articles, Mini-Reviews, Perspectives and Opinion articles covering the following topics, but are not limited to:
· Understanding plant carbon metabolism and its adjustments towards a fluctuating environment
· Mechanisms to sense, translocate, store, and metabolize carbon
· Discoveries in the regulation of whole-plant carbohydrate partitioning, phloem loading and sugar transport
· Metabolic profiling studies of plants with defects in carbon metabolism useful to discover new components and/or elucidate their function and possibly regulation
· Implication of the circadian clock and sugar signaling molecules in the regulation of several aspects of plant carbon metabolism
· High-throughput phenotyping for carbon metabolism-related traits and their role in crop yield, quality and resilience
