Drought stress strengthens the link between chlorophyll fluorescence parameters and photosynthetic traits

Abstract

Chlorophyll fluorescence (ChlF) has been used to understand photosynthesis and its response to climate change, particularly with satellite-based data. However, it remains unclear how the ChlF ratio and photosynthesis are linked at the leaf level under drought stress. Here, we examined the link between ChlF ratio and photosynthesis at the leaf level by measuring photosynthetic traits, such as net CO2 assimilation rate (An), the maximum carboxylation rate of Rubisco (Vcmax), the maximum rate of electron transport (Jmax), stomatal conductance (gs) and total chlorophyll content (Chlt). The ChlF ratio of the leaf level such as maximum quantum efficiency of PSII (Fv/Fm) is based on fluorescence kinetics. ChlF intensity ratio (LD685/LD740) based on spectrum analysis was obtained. We found that a combination of the stomatal limitation, non-stomatal limitation, and Chlt regulated leaf photosynthesis under drought stress, while Jmax and Chlt governed the ChlF ratio. A significant link between the ChlF ratio and An was found under drought stress while no significant correlation in the control, which indicated that drought stress strengthens the link between the ChlF ratio and photosynthetic traits. These results suggest that the ChlF ratio can be a powerful tool to track photosynthetic traits of terrestrial ecosystems under drought stress.

Chlorophyll Fluorescence and Drought Tolerance in a Mapping Population of Durum Wheat

“…The content of chlorophyll is a functional physiological trait used to estimate the effect of drought stress (Zhuang et al, 2020). Under both rainfed and irrigated conditions (Tab.…”

“…1). The reduction of F v /F m was found to be associated with chlorophyll concentration, thus affecting the processes of photosynthetic electron transport and photo-phosphorylation (Fracheboud & Leipner, 2003;Zhuang et al, 2020). In non-stressed plants, the optimal level of F v /F m is approximately 0.834, which is considered essential for the plant's photosynthetic performance (Björkman & Demmig, 1987).…”

Imaging of Chlorophyll a Fluorescence in Natural Compound-Induced Stress Detection

“…CF could be affected by a wide number of both biotic and abiotic factors (e.g., drought, heat, flooding, temperature variation, parasitization, etc.) ( Dong et al, 2020 ; Duarte et al, 2020 ; Zhou et al, 2020 ; Zhuang et al, 2020 ), which makes the evaluation of the mode of action of natural molecules quite impossible because of the overlapping of stressing conditions, which makes impossible to attribute the observed effects to the molecule assayed. Therefore, it is strongly suggested to perform experiments in completely controlled conditions using phytotrons and cropping plants hydroponically or on inert substrates enriched with nutrients and carbon sources ( Graña et al, 2013b , 2016 ; Araniti et al, 2017c ).…”

Effect of precipitation change on the photosynthetic performance of Phragmites australis under elevated temperature conditions

“…On the other hand, with the increasing of temperature (T 4 ), precipitation decreased by 30% caused a remarkable reduction of G s , C i and T r , suggesting that higher temperature exacerbates the detrimental effect of water shortage, which is in accordance with the studies on Xanthoceras sorbifolium Bunge ( Du et al, 2021 ), Solanum lycopersicum ( Raja et al, 2020 ), and Stipa bungeana ( Song et al, 2016b ). Furthermore, drought and heat stress also cause damage to the photosynthetic apparatus as confirmed by reduced V cmax and J max , as the decline in these two parameters are ascribed to a reduced number of active Rubisco molecules and a decrease of photosynthetic energy during the process of CO 2 assimilation ( Olorunwa, Shi & Barickman, 2021 ; Zhuang et al, 2020 ).…”