Biochemical acclimation, stomatal limitation and precipitation patterns underlie decreases in photosynthetic stimulation of soybean (Glycine max) at elevated [CO2] and temperatures under fully open air field conditions

Abstract

Rosenthala, David M.; Ruiz-Vera, Ursula M.; Siebers, Matthew H.; Gray, Sharon B.; Bernacchi, Carl J.; and Ort, Donald R., "Biochemical acclimation, stomatal limitation and precipitationpatterns underlie decreases in photosynthetic stimulation of soybean(Glycine max) at elevated [CO 2 Contents lists available at ScienceDirect Plant Science j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / p l a n t s c i (1) the acclimation of two biochemical parameters that frequently limit photosynthesis (A), the maximum carboxylation capacity of Rubisco (V c,max ) and the maximum potential linear electron flux through photosystem II (J max ), (2) the associated responses of leaf structural and chemical properties related to A, as well as (3) the stomatal limitation (l) imposed on A, for soybean over two growing seasons in a conventionally managed agricultural field in Illinois, USA. Acclimation to elevated [CO 2 ] was consistent over two growing seasons with respect to V c,max and J max . However, elevated temperature significantly decreased J max contributing to lower photosynthetic stimulation by elevated CO 2 . Large seasonal differences in precipitation altered soil moisture availability modulating the complex effects of elevated temperature and CO 2 on biochemical and structural properties related to A. Elevated temperature also reduced the benefit of elevated [CO 2 ] by eliminating decreases in stomatal limitation at elevated [CO 2 ]. These results highlight the critical importance of considering multiple environmental factors (i.e. temperature, moisture, [CO 2 ]) when trying to predict plant productivity in the context of climate change.

Variable Mesophyll Conductance among Soybean Cultivars Sets a Tradeoff between Photosynthesis and Water-Use-Efficiency

“…S2). The mean C i * here falls between the value of G* from tobacco (Nicotiana tabacum; Bernacchi et al, 2002) commonly used for soybean (Bernacchi et al, 2005;Rosenthal et al, 2014;Köhler et al, 2017) and a value calculated from soybean Rubisco kinetic properties (Gallé et al, 2013), and it further matches exactly the C i * estimated for soybean with similar methodology (Walker and Ort, 2015). Thus, the mean C i * value was used as a proxy for G* in all calculations.…”

Heat waves imposed during early pod development in soybean (Glycine max) cause significant yield loss despite a rapid recovery from oxidative stress

“…Furthermore, soybean has an extended flowering period producing flowers for 20-30 days (Smith et al, 1988;Castro et al, 2009), which implies a potential for yield recovery following a heat wave by increased pod set. Photosynthetic and respiratory acclimation can also occur in response to high temperatures (Rosenthal et al, 2014). This acclimation can include but is not limited to: decreased daytime respiration, increased electron transport capacity, and the synthesis of a more heat stable rubisco activase (Sage & Kubien, 2007;Way & Yamori, 2014).…”

Elevated CO2 and temperature increase soil C losses from a soybean–maize ecosystem

“…Gray, in prep). In 2009, soybeans in heated plots appeared to use deeper soil water (Rosenthal et al, 2014), possibly indicating a shift of roots toward deeper soil that would have reduced the amount of root-respired C reaching the surface, thus contributing to the reduction in R aut from soybeans we observed that year.…”

“…The heating system operated continuously between June 2009 and September 2011 except during planting when all equipment was removed to allow field tillage, during harvest when power cables were removed to allow harvester traffic, and during a 2-week period in January 2010 when the equipment was rebuilt to repair damage from rodents. Further details on the heating treatment are reported in studies by Ruiz-Vera et al (2013 and Rosenthal et al (2014).…”