Changes in photosynthesis, chloroplast ultrastructure, and antioxidant metabolism in leaves of sorghum under waterlogging stress

Abstract

Waterlogging limits plant growth and yield. We investigated the effects of waterlogging stress on leaf photosynthesis, chlorophyll fluorescence, antioxidant capacity, chloroplast ultrastructure, and yield of sorghum (Sorghum bicolor L.). Two sorghum cultivars, Jinuoliang01 (JN01, waterlogging-tolerant cultivar) and Jinza31 (JZ31, waterlogging-sensitive cultivar) were subjected to a 12-d waterlogging treatment; the plants of the two cultivars which were not subjected to waterlogging were used as control (CK), respectively. After waterlogging treatment, the yield of JZ31 and JN01 decreased by 72.3 and 52.9%, the net photosynthetic rate of JZ31 and JN01 decreased by 61.8 and 39.0%, respectively, compared with CK. The chlorophyll content was higher, PSII was more stable, and chloroplast structure remained more intact in JN01 than that in JZ31 under waterlogging. This was due to the higher peroxidase and catalase activities and nonphotochemical quenching in JN01 compared to JZ31. Therefore, greater antioxidant capacity and nonphotochemical quenching could alleviate damage to PSII and chloroplast ultrastructure to maintain higher net photosynthetic rate under waterlogging. This may be an important waterlogging-tolerance mechanism of sorghum.

Exogenous salicylic acid ameliorates waterlogging stress damages and improves photosynthetic efficiency and antioxidative defense system in waxy corn

“…3). A similar decline in PN, gs, and Ci was observed for sorghum by Zhang et al (2019a). Under waterlogging stress, the gs of waxy corn leaves significantly declined, causing a decrease in E and Ci.…”

“…Waterlogging stress is described as the saturation of soil with water around the crop roots, which is one of the major abiotic factors limiting plant growth, development, and crop yield (Ren et al 2017, Tian et al 2019, Panozzo et al 2019. Waterlogging stress has become a severe problem affecting crop growth and yield worldwide because of the increasing frequency of excessive rainfall, especially at the lack of soil drainage and irregular topography areas (Dar et al 2018, Zhang et al 2019a). An estimated 16% of the fertile areas of the globe annually undergo waterlogging stress (Xu et al 2016).…”

Mechanisms of Waterlogging Tolerance in Plants: Research Progress and Prospects

“…Genotypes withstanding the waterlogging stress displayed higher SOD, POD, and CAT activities ( Li et al, 2018 ). Similarly, induced SOD and CAT activities were observed in the Sorghum bicolor waterlogging-resistant lines JN01 and JZ31 ( Zhang R. et al, 2019 ). Waterlogging stress was given to barley-tolerant and -sensitive genotypes for 21 days to evaluate the antioxidant response ( Luan et al, 2018 ).…”

Reactive Oxygen Species and Antioxidant Defense in Plants under Abiotic Stress: Revisiting the Crucial Role of a Universal Defense Regulator

“…Flooding or waterlogging (WL)-induced hypoxic or anoxic conditions generate toxic compounds that impair plant metabolism resulting in ROS overgeneration and oxidative damages (Table 1) [119]. Zhang et al [120] also experimented with two Sorghum bicolor genotypes JN01 (WL-tolerant) and JN31 (WL-sensitive) and reported a remarkably higher accumulation of MDA in JN31 compared with JN01, at different duration (6, 9, and 12 d) of WL treatment. Anee et al [121] studied the WL-sensitive Sesamum indicum L. cv.…”