Details

Autor(en) / Beteiligte

• Rossi, Giulia S
• Elbassiouny, Alaa
• Jamison, Jerrica
• Welch, Jr, Kenneth C
• MacMillan, Heath

Titel

Heat exposure limits pentose phosphate pathway activity in bumblebees

Ist Teil von

• Conservation physiology, 2024-01, Vol.12 (1), p.coae031-coae031

Ort / Verlag

England: Oxford University Press

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Bumblebee populations across the globe are experiencing substantial declines due to climate change, with major consequences for pollination services in both natural and agricultural settings. Using an economically important species, , we explored the physiological mechanisms that may cause susceptibility to extreme heat events. We tested the hypothesis that heat exposure limits the activity of the pentose phosphate pathway (PPP)-a parallel pathway to glycolysis that can use nectar sugar to generate antioxidant potential and combat oxidative stress. Using isotopically labelled glucose, we tracked PPP activity in at rest, during exercise and during a post-exercise recovery period under two different temperature regimes (22°C and 32°C). We found that the PPP is routinely used by at moderate temperatures, but that its activity is markedly reduced when ATP demands are high, such as during periods of exercise and heat exposure. We also exposed to either 22°C or 32°C for 5 hours and assessed levels of oxidative damage (lipid peroxidation, protein carbonyls) and antioxidant potential [reduced (GSH) and oxidized (GSSG) glutathione concentrations]. Interestingly, bees exhibited little oxidative damage after the thermal exposure, but we found a lower GSH:GSSG ratio in 32°C-exposed bees, reflecting lower antioxidant potential. Overall, our study demonstrates that acute heat stress severely limits PPP activity and may constrain antioxidant potential in . The repeated attenuation of this pathway in a warming climate may have more severe physiological consequences for this species, with potential implications for pollination services across North America.