Photosynthetic capacity and temperature responses of photosynthesis of rubber trees (Hevea brasiliensis Müll. Arg.) acclimate to changes in ambient temperatures

Abstract

The aim of this study was to assess the temperature response of photosynthesis in rubber trees (Hevea brasiliensis Müll. Arg.) to provide data for process-based growth modeling, and to test whether photosynthetic capacity and temperature response of photosynthesis acclimates to changes in ambient temperature. Net CO 2 assimilation rate (A) was measured in rubber saplings grown in a nursery or in growth chambers at 18 and 28°C. The temperature response of A was measured from 9 to 45°C and the data were fitted to an empirical model. Photosynthetic capacity (maximal carboxylation rate, V cmax , and maximal light driven electron flux, J max ) of plants acclimated to 18 and 28°C were estimated by fitting a biochemical photosynthesis model to the CO 2 response curves (A-C i curves) at six temperatures: 15, 22, 28, 32, 36 and 40°C. The optimal temperature for A (T opt ) was much lower in plants grown at 18°C compared to 28°C and nursery. Net CO 2 assimilation rate at optimal temperature (A opt ), V cmax and J max at a reference temperature of 25°C (V cmax25 and J max25 ) as well as activation energy of V cmax and J max (E aV and E aJ ) decreased in individuals acclimated to 18°C. The optimal temperature for V cmax and J max could not be clearly defined from our response curves, as they always were above 36°C and not far from 40°C. The ratio J max25 /V cmax25 was larger in plants acclimated to 18°C. Less nitrogen was present and photosynthetic nitrogen use efficiency (V cmax25 /N a ) was smaller in leaves acclimated to 18°C. These results indicate that rubber saplings acclimated their photosynthetic characteristics in response to growth temperature, and that higher temperatures resulted in an enhanced photosynthetic capacity in the leaves, as well as larger activation energy for photosynthesis.

Effects of temperature on growth and photosynthesis in the seedling stage of the sheath blight-resistant rice genotype 32R

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Changes in the potential distribution of humid tropical forests on a warmer planet

“…The temperature sensitivities of both photosynthesis and respiration can change, and there are ecophysiological arguments that plants can acclimate to a warming of a few degrees [59,60]. However, there are very few empirical data on the degree to which tropical trees respond and are able to acclimate to increased temperatures and drought [61][62][63]. Several contemporary dynamic vegetation models may be overly sensitive to temperature and not allowing for acclimation effects [31].…”

Determination of photosynthetic parameters Vcmax and Jmax for a C3 plant (spring hulless barley) at two altitudes on the Tibetan Plateau

“…The differences might be closely related to the highly diverse environmental conditions in which plants grown. CO 2 and temperature are considered two of the primary environmental factors that determine, directly or indirectly, the photosynthetic capacity (Bunce, 2008;Stojanovic, 2008;Kositsup et al, 2009;Possell and Hewitt, 2009). Changes in CO 2 and temperature affect the photosynthetic capacity at the levels of leaf biochemistry, stomata and CO 2 diffusion as well as photosynthetic component activities and CO 2 partial pressure at the carboxylation sites.…”