Cellular and Molecular Mechanisms for Elevated CO₂–Regulation of Plant Growth and Stress Adaptation

Abstract

Increases in atmospheric CO2 concentration have exerted significant impacts on plant growth. Numerous studies have reported positive effects of elevated CO2 on plant growth and adaptation to various environmental stresses in many plant species. The mechanisms by which CO2 enrichment regulates plant growth and stress adaptation are not completely understood. There have been some recent exciting advances in elucidating the cellular, metabolic, and molecular basis for increased growth under elevated CO2. At the cellular level, cell growth involving both cell division and cell expansion is stimulated by increasing CO2, which has been associated with increased photosynthetic activities and carbohydrate availability, and also with the expression of genes controlling cell division, cycling, and cell expansion. Proteomic profiling studies identified CO2–regulated proteins mainly involved in photosynthesis, carbon metabolism, energy pathways, molecular chaperones, and antioxidant proteins. Transcriptomic analyses identified several hundreds of genes responsive to elevated CO2 levels, which play roles in cell wall loosening, photosynthesis, respiration, water use, and protein synthesis, as well as stress defense. This paper reviews recent progress in the mechanistic understanding of CO2 regulation of plant growth and stress adaptation at the cellular, metabolic, and molecular levels, and addresses research gaps and future research perspective areas.

Stimulation of Growth and Alteration of Hormones by Elevated Carbon Dioxide for Creeping Bentgrass Exposed to Drought

“…However, the drought‐induced water deficit was less severe for plants grown at elevated CO 2 concentration, suggesting that elevated CO 2 facilitated the maintenance of leaf hydration under drought stress. Reduction in water loss by elevated CO 2 concentration has been attributed to the induction of stomatal closure and reduction in transpiration rate (Ainsworth and Rogers, 2007; Leakey et al, 2009; Yu et al, 2012a; Burgess and Huang, 2014a, 2016; Huang and Xu, 2015). Despite reductions in stomatal conductance and CO 2 influx during drought, elevated CO 2 can increase leaf‐level water use efficiency, defined as the net photosynthesis per unit transpirational water loss, compared with plants grown at ambient CO 2 through upregulation of various enzymes involved in the Calvin cycle (Huang and Xu, 2015).…”

“…Along with possible increases in drought incidence due to global climate changes, atmospheric CO 2 concentrations have been steadily increasing and are expected to double within the next 100 years (Solomon et al, 2007). Elevated atmospheric CO 2 under optimal conditions or interacting with abiotic stress has been shown to influence many aspects of plant development, and most studies have reported positive effects for mitigation of abiotic stress damages in various plant species (Ceulemans and Mousseau, 1994; Ainsworth et al, 2002; Kirkham, 2011; Huang and Xu, 2015), including perennial grasses used in turfgrass settings, such as Kentucky bluegrass ( Poa pratensis L.), tall fescue ( Festuca arundinacea Schreb. ), and creeping bentgrass ( Agrostis stolonifera L.) (Wall et al, 2001; Lin and Wang, 2002; Qaderi et al, 2006; Yu et al, 2012a, 2012b; Burgess and Huang, 2014b, 2016).…”

“…), and creeping bentgrass ( Agrostis stolonifera L.) (Wall et al, 2001; Lin and Wang, 2002; Qaderi et al, 2006; Yu et al, 2012a, 2012b; Burgess and Huang, 2014b, 2016). The positive effects of elevated CO 2 concentrations have been mainly associated with regulation of leaf water relations, photosynthesis, carbohydrate metabolism, and protein metabolism (Ceulemans and Mousseau, 1994; Ainsworth et al, 2002; Kirkham, 2011; Yu et al, 2012a; Burgess and Huang, 2014b; Huang and Xu, 2015). Several studies have found that elevated CO 2 promoted tiller formation and growth in grass species under nonstress conditions (Baker et al 1990, 1992; Nicolas et al, 1993; Ziska et al, 1997); however, the effects of elevated CO 2 on tiller and stolon growth for grass species subjected to drought stress are not well documented.…”

Elevated and super‐elevated CO2 differ in their interactive effects with nitrogen availability on fruit yield and quality of cucumber

“…Elevated atmospheric CO 2 concentration (eCO 2 , commonly 500–800 µmol mol −1 ) can promote plant photosynthesis and productivity, and enhance plant tolerance to environmental stresses (e.g. heat or drought stress) . Hence, CO 2 enrichment is also an effective practice to increase yield that has been widely adopted in vegetable cultivation in greenhouses .…”

“…heat or drought stress). 3,4 Hence, CO 2 enrichment is also an effective practice to increase yield that has been widely adopted in vegetable cultivation in greenhouses. 1,5,6 The yield increase can result from increased plant productivity and/or greater carbon allocation to sinks (i.e.…”