Effects of Elevated Carbon Dioxide on Photosynthesis and Carbon Partitioning: A Perspective on Root Sugar Sensing and Hormonal Crosstalk

Abstract

Plant responses to atmospheric carbon dioxide will be of great concern in the future, as carbon dioxide concentrations ([CO2]) are predicted to continue to rise. Elevated [CO2] causes increased photosynthesis in plants, which leads to greater production of carbohydrates and biomass. Which organ the extra carbohydrates are allocated to varies between species, but also within species. These carbohydrates are a major energy source for plant growth, but they also act as signaling molecules and have a range of uses beyond being a source of carbon and energy. Currently, there is a lack of information on how the sugar sensing and signaling pathways of plants are affected by the higher content of carbohydrates produced under elevated [CO2]. Particularly, the sugar signaling pathways of roots are not well understood, along with how they are affected by elevated [CO2]. At elevated [CO2], some plants allocate greater amounts of sugars to roots where they are likely to act on gene regulation and therefore modify nutrient uptake and transport. Glucose and sucrose also promote root growth, an effect similar to what occurs under elevated [CO2]. Sugars also crosstalk with hormones to regulate root growth, but also affect hormone biosynthesis. This review provides an update on the role of sugars as signaling molecules in plant roots and thus explores the currently known functions that may be affected by elevated [CO2].

Transitioning to the Next Phase: The Role of Sugar Signaling throughout the Plant Life Cycle

“…The whole life cycle of the plant is considered here (Box 1), including step changes (such as floral transition) as well as more gradual processes (such as leaf senescence). Because of space limitations, sugar signaling in root development (Thompson et al, 2017) is not specifically covered. While this Update focuses on sugars as signals for carbon availability, it should be kept in mind that sugar signals also interact with nitrogen (e.g.…”

Silencing of OsCV (chloroplast vesiculation) maintained photorespiration and N assimilation in rice plants grown under elevated CO2

“…A range of anthropogenic factors is rapidly increasing atmospheric CO 2 , causing significant changes in global temperature and thereby precipitation patterns (Gamage et al 2018). Since the industrial revolution, global atmospheric CO 2 concentrations have increased rapidly, rising from 280 to 400 ppm (Tans & Keeling, ; Thompson, Gamage, Hirotsu, Martin, & Saman, ). CO 2 directly affects plant metabolism in general and photosynthesis in particular (Dusenge, Duarte, & Way, ).…”

Elevated CO2‐induced improvement of mycorrhization – which players lie in‐between?

“…To date, the responses of plants to e[CO 2 ] were mainly seen in respect to their rather ‘global’ positive effects, such as increase of growth, above‐ground biomass, and yield due to enhanced photosynthesis (Thompson et al ., ). Negative effects have, however, also been described that have serious consequences for plant growth.…”

“…Many physiological processes might be regulated indirectly, and the way in which e[CO 2 ] affects root function is still not entirely understood. However, it was already known that e[CO 2 ] can affect the acquisition of soil nutrients (Thompson et al ., ). With this new paper from Zhou et al .…”