Effects of High Temperature Stress on the Physiological and Biochemical Characteristics of Paeonia ostii

Abstract

In order to explore the effects of high temperature stress on the physiological characteristics of Paeonia ostii, the Paeonia ostii were subjected to 25 °C, 35 °C, 38 °C, and 40 °C for 7 days. Meanwhile, the physiological indicators of oxidative stress (hydrogen peroxide, H2O2; malondialdehyde, MDA; relative electrical conductivity, REC), antioxidant enzyme activity (superoxide dismutase, SOD; ascorbate peroxidase, APX; catalase, CAT; peroxidase, POD), photosynthetic pigment content (chlorophyll a, Chla; chlorophyll b, Chlb), photosynthetic characteristics (net photosynthetic rate, Pn; intercellular CO2 concentration, Ci; stomatal conductance, Gs; transpiration rate, Tr), and osmoregulatory substances content (soluble protein, SP; soluble sugar, SS) were determined. The results showed that, with the increase in temperature and stress time, the H2O2 content, MDA content, REC value, CAT activity, and APX activity increased, while Chla content, Chlb content, SS content, and SP content decreased. With the extension of stress time, the SOD activity, POD activity, and Tr value of each high temperature stress group first increased and then decreased; Ci first decreased, then increased, and then decreased; meanwhile, Pn and Gs showed an overall downward trend. PLS-DA (partial least squares discriminant analysis) was used to analyze the changes in physiological and biochemical indexes of peony leaves under 40 °C stress for different days. SOD was found to be the biggest factor affecting the changes in physiological and biochemical indexes of peony leaves treated with different days of stress.

Influence of High-Temperature and Intense Light on the Enzymatic Antioxidant System in Ginger (Zingiber officinale Roscoe) Plantlets

“…On the second day, SOD activity decreased. This is consistent with Erman’s findings that SOD activity under high temperature stress showed a trend of increasing and then decreasing [ 44 ]. This is because, as the stress temperature increases and the duration of stress prolongs, plants continue to increase the production of antioxidant enzymes within their own bodies.…”

Quantifying High-Temperature-Induced Injury in Nanfeng Tangerine Plants: Insights from Photosynthetic and Biochemical Mechanisms

“…This study showed that under high-temperature treatment, the activities of the SOD, POD, and CAT enzymes in NT leaves showed an initial increase followed by a decrease, and that the decrease in the antioxidant enzyme activity in leaves increased with the prolongation of the high-temperature treatment time. Hong et al [33] found that high-temperature stress significantly reduces the activates of SOD, POD and CAT. There are also studies indicating that the antioxidant protection system (APX, SOD, CAT) and other enzyme activities in plant leaves show an upward trend under high-temperature stress [54].…”

“…Additionally, 0.5 g of healthy and mature NT leaves was weighed and ground evenly with 2 mL of 100 g L −1 TCA solution. The resulting mixture was then centrifuged at a speed of 4000 r min −1 for a duration of 20 min at a temperature of 4 • C. The supernatant obtained from this process was employed for the determination of the MDA content using the thiobarbituric acid (TBA) colorimetric method [33].…”

Construction and Identification of Cold Tolerance in Different Broccoli Cultivars at the Seedling Stage

“…V is the total volume of the reaction system (5 × 10 −4 L), ε is the molar absorptivity of MDA (1.55 × 10 5 L), V is the volume of added sample (0.1 mL), D is the optical diameter of the 96-well plate (0.6 cm), V is the volume of added extract (1 mL), W is the sample mass, and F is the dilution factor [15].…”