Growth, development, and survival are essential processes shared by all plants on earth. Identifying the determinants of these three functions is key to understanding the limits to plant life and production in a world marked by a changing climate (high CO2, higher temperature) and an agriculture that must cope with increasingly stressful environments and face the rising food and non-food demand.
The idea that carbon is a major determinant of these functions is straightforward. Carbon is an essential building block of growth and a source of energy for metabolism. There is abundant evidence that plant functioning is dictated at least partially by carbon. Three different illustrations are : (i) plant biomass accumulation is strongly related to intercepted radiation and cumulated photosynthesis (Monteith and Moss, 1977) and this is the basis of several, successful crop models; (ii) mutations in carbon metabolism have drastic effects on growth (Pantin et al., 2011); (iii) long lasting stress periods that cause severe reductions in photosynthesis may lead to C starvation and associated mortality from inability to maintain metabolism, repair embolism, or fend off attack by pathogens (McDowell, 2011)). All of these processes have fundamental regulation at the molecular level, with impacts manifest at the whole plant.
In contrast, there is also a plethora of examples where neither growth, nor development or survival responses to environmental stresses involve C uptake and storage, but are more determined by sink characteristics, (Körner, 2003; Sala, 2009; Muller et al. 2011), hydraulic constraints (Ryan and Yoder, 1997, Tyree, 2003; Pantin et al. 2011 or biotic agents (Raffa et al., 2008). The science challenge thus lies in the interpretation of apparently conflicting information within an integrated theory (McDowell et al., 2011; Tardieu et al., 2011).
The question we would like to see addressed in this topic is thus: is growth, development and survival under stressful environments (e.g. drought, high temperature, low temperature, high CO2, mineral deficiency) related to the efficiency of C capture, the rate of C metabolism, the regulation of its partitioning and its transport within the plants, and the capacity of the plant to actively store C and prevent starvation? A series of connected questions could be:
- how can scientists provide convincing experimental and modeling evidence of C limitation or lack thereof?
- where does the carbon go, and what controls it, under severe and/or long term stresses when photosynthesis is near zero (source limitation) or growth is near zero (sink limitation) ?
- how can we provide evidence of (and how to model) feedbacks between expansive growth (in volume) and structural growth (in matter) ?
- how can molecular biology contribute to these questions, for instance with markers and system level analysis of starvation, reprogramming of metabolism, etc ?
- what can we expect from the observation of genetic as well as environmental gradients ?
- are annual crops substantially different than trees with regard to their dependence on C management ?
We would like to welcome contributions, including primary data, synthesis, or opinions, addressing these issues or related ones, from the widest possible community of ecologist, ecophysiologists, molecular biologists, geneticists and modelers.
Körner C (2003) J Ecol 91: 4– ; McDowell N (2011) Plant Physiol 155: 1051- ; McDowell NG et al. (2011) Trends Ecol Evol 26: 523– ; Monteith JL, Moss CJ (1977) Phil Trans Roy Soc Lond B 281: 277 –294; Muller B et al. (2011) J Exp Bot 62: 1715- ; Pantin F
Growth, development, and survival are essential processes shared by all plants on earth. Identifying the determinants of these three functions is key to understanding the limits to plant life and production in a world marked by a changing climate (high CO2, higher temperature) and an agriculture that must cope with increasingly stressful environments and face the rising food and non-food demand.
The idea that carbon is a major determinant of these functions is straightforward. Carbon is an essential building block of growth and a source of energy for metabolism. There is abundant evidence that plant functioning is dictated at least partially by carbon. Three different illustrations are : (i) plant biomass accumulation is strongly related to intercepted radiation and cumulated photosynthesis (Monteith and Moss, 1977) and this is the basis of several, successful crop models; (ii) mutations in carbon metabolism have drastic effects on growth (Pantin et al., 2011); (iii) long lasting stress periods that cause severe reductions in photosynthesis may lead to C starvation and associated mortality from inability to maintain metabolism, repair embolism, or fend off attack by pathogens (McDowell, 2011)). All of these processes have fundamental regulation at the molecular level, with impacts manifest at the whole plant.
In contrast, there is also a plethora of examples where neither growth, nor development or survival responses to environmental stresses involve C uptake and storage, but are more determined by sink characteristics, (Körner, 2003; Sala, 2009; Muller et al. 2011), hydraulic constraints (Ryan and Yoder, 1997, Tyree, 2003; Pantin et al. 2011 or biotic agents (Raffa et al., 2008). The science challenge thus lies in the interpretation of apparently conflicting information within an integrated theory (McDowell et al., 2011; Tardieu et al., 2011).
The question we would like to see addressed in this topic is thus: is growth, development and survival under stressful environments (e.g. drought, high temperature, low temperature, high CO2, mineral deficiency) related to the efficiency of C capture, the rate of C metabolism, the regulation of its partitioning and its transport within the plants, and the capacity of the plant to actively store C and prevent starvation? A series of connected questions could be:
- how can scientists provide convincing experimental and modeling evidence of C limitation or lack thereof?
- where does the carbon go, and what controls it, under severe and/or long term stresses when photosynthesis is near zero (source limitation) or growth is near zero (sink limitation) ?
- how can we provide evidence of (and how to model) feedbacks between expansive growth (in volume) and structural growth (in matter) ?
- how can molecular biology contribute to these questions, for instance with markers and system level analysis of starvation, reprogramming of metabolism, etc ?
- what can we expect from the observation of genetic as well as environmental gradients ?
- are annual crops substantially different than trees with regard to their dependence on C management ?
We would like to welcome contributions, including primary data, synthesis, or opinions, addressing these issues or related ones, from the widest possible community of ecologist, ecophysiologists, molecular biologists, geneticists and modelers.
Körner C (2003) J Ecol 91: 4– ; McDowell N (2011) Plant Physiol 155: 1051- ; McDowell NG et al. (2011) Trends Ecol Evol 26: 523– ; Monteith JL, Moss CJ (1977) Phil Trans Roy Soc Lond B 281: 277 –294; Muller B et al. (2011) J Exp Bot 62: 1715- ; Pantin F
