Photosynthetic machinery and antioxidant status of wheat genotypes under drought stress followed by rewatering

Abstract

Land plants shorten their vegetation period during water deficiency. Under water stress, wheat plants undergo several changes at the morphophysiological level. We tried to elucidate the role of the morphophysiological parameters and the photosynthetic machinery in response to drought followed by rewatering. Therefore, some morphophysiological traits of two bread wheat genotypes (drought-tolerant Gobustan, drought-sensitive Tale 38) were studied. The H2O2 content increased under drought in both genotypes but recovered in the Gobustan genotype after rewatering. The isozymes of peroxidase manifested dynamic changes under drought. The electron transport rate and the maximum photochemical quantum efficiency of PSII showed similar responses to drought with subsequent rewatering in both genotypes. However, the amount of the photosynthetic pigments changed drastically resulting in structural changes of thylakoid membranes. In Gobustan, the thylakoid membrane structure almost completely recovered after rewatering. Thus, the drought-tolerant genotype shows a more dynamic response of photosynthetic machinery and antioxidant capacity.

Photosynthesis of winter wheat effectively reflected multiple physiological responses under short‐term drought–rewatering conditions

“…40 The dynamic interaction among ROS, the antioxidant system and thylakoid membranes under drought stress was found to be very important for the regulation of wheat photosynthesis under drought stress. 14 In this study, the activities of SOD and POD in winter wheat leaves increased during drought, and the contents of Pro and SS also increased significantly. This showed that the physiological mechanisms of crop resistance positively responded to weaken the adverse effects of drought on the photosynthetic environment.…”

“…The RWC data were not measured in this study. However, other studies have shown that the RWC of wheat within the moisture range 30–60% FC was approximately 70–100% by examining two varieties with different degrees of drought tolerance 14 . The lowest soil moisture in this study was 45% FC, so it was hypothesized that the RWC should be some distance away from 70%.…”

“…However, other studies have shown that the RWC of wheat within the moisture range 30-60% FC was approximately 70-100% by examining two varieties with different degrees of drought tolerance. 14 The lowest soil moisture in this study was 45% FC, so it was hypothesized that the RWC should be some distance away from 70%. This means that the stomata of the leaves in this study should not be completely closed, but in fact the Gs of some treatments was already very small.…”

“…The drought tolerance and sensitivity of ryegrass varieties can be distinguished by fluorescence parameters, such as OJIP, DF and MR 12 . It is apparent that the phenotype of photosynthesis is critical for understanding which physiological parameters limit crop productivity 14 . Under unbalanced water deficit conditions, the photosynthetic rate of soybean is significantly positively correlated with stomatal conductance, transpiration rate, chlorophyll content, ChlF parameters, rubisco activity and protein content 15 .…”

Role of Thylakoid Protein Phosphorylation in Energy-Dependent Quenching of Chlorophyll Fluorescence in Rice Plants

“…Plants harmonize light harvesting, electron transport, and protein synthesis by adjusting the thylakoid membrane proteome in response to changes in the light environment [ 19 , 20 ]. The PsbS protein of PSII, responsible for qE, is also involved in the reorganization of the thylakoid membrane [ 21 , 22 , 23 , 24 , 25 , 26 ].…”