Faster Removal of 2-Phosphoglycolate through Photorespiration Improves Abiotic Stress Tolerance of Arabidopsis

Abstract

Photorespiration metabolizes 2-phosphoglyolate (2-PG) to avoid inhibition of carbon assimilation and allocation. In addition to 2-PG removal, photorespiration has been shown to play a role in stress protection. Here, we studied the impact of faster 2-PG degradation through overexpression of 2-PG phosphatase (PGLP) on the abiotic stress-response of Arabidopsis thaliana (Arabidopsis). Two transgenic lines and the wild type were subjected to short-time high light and elevated temperature stress during gas exchange measurements. Furthermore, the same lines were exposed to long-term water shortage and elevated temperature stresses. Faster 2-PG degradation allowed maintenance of photosynthesis at combined light and temperatures stress and under water-limiting conditions. The PGLP-overexpressing lines also showed higher photosynthesis compared to the wild type if grown in high temperatures, which also led to increased starch accumulation and shifts in soluble sugar contents. However, only minor effects were detected on amino and organic acid levels. The wild type responded to elevated temperatures with elevated mRNA and protein levels of photorespiratory enzymes, while the transgenic lines displayed only minor changes. Collectively, these results strengthen our previous hypothesis that a faster photorespiratory metabolism improves tolerance against unfavorable environmental conditions, such as high light intensity and temperature as well as drought. In case of PGLP, the likely mechanism is alleviation of inhibitory feedback of 2-PG onto the Calvin–Benson cycle, facilitating carbon assimilation and accumulation of transitory starch.

Manipulating Amino Acid Metabolism to Improve Crop Nitrogen Use Efficiency for a Sustainable Agriculture

“…That said, the overexpression of PGLP1 in Arabidopsis did not significantly increase plant biomass and photosynthetic performances under current atmospheric conditions (21% O 2 ; Flugel et al, 2017). However, these transgenic lines showed a higher photosynthetic rate when compared to control lines without changing their water use efficiency under drought stress (Timm et al, 2019). As yet, we do not know whether overexpressing GDC subunits or SHMT1 confers an advantage under drought stress or low N inputs.…”

The effect of increasing temperature on crop photosynthesis: from enzymes to ecosystems

“…Temperature is a critical meteorological determinant of crop development and function. Temperature alters enzyme function within a leaf ( Bernacchi et al , 2001 ; Walker et al , 2013 ; Florian et al , 2014 ; Kumarathunge et al , 2019 ; Timm et al , 2019 ) and triggers changes in developmental growth stage that are tightly coupled with crop yield ( Ruiz-Vera et al , 2018 ; Zhu et al , 2018 ). Furthermore, the amount of water vapour in air at saturation increases exponentially with temperature, raising the vapour pressure deficit (VPD), and driving more potential water loss from plants ( Novick et al , 2016 ; Grossiord et al , 2020 ).…”

Modulation of Photorespiratory Enzymes by Oxidative and Photo-Oxidative Stress Induced by Menadione in Leaves of Pea (Pisum sativum)

“…The process of photorespiration is an essential component of abiotic stress responses and can help adapt to a multitude of environmental parameters [ 11 , 49 , 50 , 51 ]. Further, the benefits of photorespiration were proposed to be complemented by chloroplastic cyclic electron transport and mitochondrial alternative oxidase [ 21 ].…”