Enzymatic Defense Response of Apple Aphid Aphis pomi to Increased Temperature

Abstract

Climate change, and in particular the increase in temperature we are currently observing, can affect herbivorous insects. Aphids, as poikilothermic organisms, are directly exposed to temperature increases that influence their metabolism. Heat stress causes disturbances between the generations and the neutralization of reactive oxygen species (ROS). The aim of this work is focused on explaining how the aphid, using the example of Aphis pomi, responds to abiotic stress caused by temperature increase. The experiment was carried out under controlled conditions at three temperatures: 20, 25, and 28 °C. In the first stage, changes in the activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO), and peroxidase (POD)) were determined in aphid tissues, at each temperature. In the second stage, microcalorimetry monitored changes in heat emitted by aphids, at each temperature. Our results showed that A. pomi defense responses varied depending on temperature and were highest at 28 °C. The flexible activity of enzymes and increase in the metabolic rate played the role of adaptive mechanisms and ran more effectively at higher temperatures. The A. pomi thus protected itself against ROS excessive induction and the aphids were able to respond quickly to environmental stress.

Effects of Temperature on Lifespan of Drosophila melanogaster from Different Genetic Backgrounds: Links between Metabolic Rate and Longevity

“…Similarly, aphids have shorter lifespans at higher temperatures [22,23]. More recent data showed that an increase in temperature to 28 • C increased metabolism in Aphis pomi five-fold, measured as heat energy flow, which caused shortened aphid longevity [24]. The effect of temperature on insect metabolism has been investigated in many species.…”

Mild Abiotic Stress Affects Development and Stimulates Hormesis of Hemp Aphid Phorodon cannabis

“…However, further temperature increase caused a decrease in hemp aphid longevity by 6.4 d at 28 °C and by 3.1 d at 30 °C. A similar effect at 28 °C was observed in the apple aphid, Aphis pomi (De Geer), with an associated peak in the activity of enzymes indicating stress in aphids [ 24 ]. In our study, the temperature increase above 25 °C significantly shortened the pre-reproduction period, by 0.4 and 0.6 day at 28 and 30 °C, respectively, and the reproduction period also decreased significantly, by 5.6 and 7.5 days.…”

“…Again, the activity of one of the enzymes (β-glucosidase) increased significantly only 24 h after the beginning of feeding on graminicide-treated plants, whereas the significant increase in GST activity lasted over the whole period of the experiment. This reaction differed from the enzymatic defense response of apple aphid, A. pomi , but the measurements in the study on apple aphid concerned the temperature increase, and not the herbicide [ 24 ]. However, there was a similarity in β-glucosidase activity fluctuations in the response of pea aphid, A. pisum , feeding on a low dose of selenate-treated pea plants, and GST activity changes to a high dose of selenate [ 70 ].…”

“…Studies of the aphid enzymes followed the methods described by Dampc et al [ 24 ]. The experiments were carried out in a growth chamber with photoperiod, temperature and humidity regimes described in Section 2.1 .…”

“…Numerous abiotic factors, such as temperature above the thermal optimum [ 24 ], treatment with pesticides or adverse response of the host plant [ 25 , 26 ] may lead to imbalance between the production of reactive oxygen species (ROS) and antioxidant processes in both plants and aphids [ 27 , 28 ]. The sudden increase in ROS levels is toxic to cells and leads to the destruction of proteins, lipids, and DNA [ 29 , 30 ].…”