Effects of high temperature on photosynthetic capacity in the leaves of creepers

Abstract

High temperature induces structural and physiological damage to plants. However, studies on the effects of constant high temperature on climbing plant species are limited. To estimate the response of photosynthetic capacity of two creeper species, Parthenocissus tricuspidata (Sieb. et Zucc.) and Parthenocissus quinquefolia (L.) Planch, to constant high-temperature treatment at noon, we measured photosynthetic pigments, gas exchange, and chlorophyll fluorescence parameters at 35, 40, and 45°C (25°C was the control treatment). High temperature significantly reduced photosynthetic pigment content, whereas carotenoid content showed the opposite trend. Net photosynthetic rate, stomatal conductance, transpiration rate, maximal quantum yield of PSII photochemistry, actual quantum yield of PSII photochemistry, and the coefficient of photochemical quenching all showed a decreasing trend, with increasing stress duration, whereas the non-regulated thermal energy loss and regulated thermal energy loss indexes increased. As temperature increased, intercellular CO 2 concentration initially decreased and then increased. Non-stomatal restriction factors were the main cause of the decrease in photosynthetic rate when temperature exceeded 40°C. These parameters recovered to pre-stress levels only in plants grown at 35°C upon stress relief. P. quinquefolia showed higher photosynthetic heat resistance and resilience than P. tricuspidata. Our results revealed photosynthetic adaptation and recovery mechanisms in two creepers grown under high-temperature stress. Molecular and genetic approaches should be considered to gain deeper insight into the mechanism underlying high temperature adaptation in these two creepers.

Hormonal Balance, Photosynthesis, and Redox Reactions in the Leaves of Caragana korshinskii Kom. under Water Deficit

“…Some researchers have shown that stomatal closure is the dominant factor that restricts photosynthesis [10]. However, other studies have shown that non-stomatal factors are the primary reasons for a reduction in the rate of photosynthesis [11,12].…”

Response of Dahlia Photosynthesis and Transpiration to High-Temperature Stress

“…High-temperature stress can destroy the integrity of the chloroplast and thylakoid membranes, resulting in a loss of cell membrane permeability, which affects the photosynthetic process, reduces photosynthetic efficiency [7], and inhibits plant growth. Chl fluorescence is the light signal emitted by the Chl molecule from the first singlet state back to the ground state after absorbing light energy [8], and the change in fluorescence can reflect the status of the photosynthetic apparatus and is often used as a reliable indicator of the structural activity of the photosynthetic system to evaluate the stress on plants [9]. High-temperature stress can damage the structure of the photosynthetic system; photosystem II (PSII) is considered the most temperature-sensitive component, and the ratio of variable to maximum fluorescence (Fv/Fm) can reflect the light energy conversion efficiency of the PSII reaction center [10].…”

Morphological and biochemical changes in shoot and root organs of common vetch (Vicia sativa L.) after exposure to drought stress

“…Many changes occur at the morphological, physiological, biochemical, and molecular levels in plants due to drought stress [3]. Similar to other stress factors, such as salinity, cold, heavy metals, etc., drought stress causes oxidative stress in plants, and then the stress causes the release of molecules called reactive oxygen species (ROS) (superoxide (O -2 ), singlet oxygen ( 1 O 2 ), hydroxyl radical (OH • ), and hydrogen peroxide (H 2 O 2 )) including certain metabolites in plant cells, which are very damaging to different cell compartments [4]. There is an enzymatic and non-enzymatic defense system against these molecules in cells.…”