The leaf-air temperature difference reflects the variation in water status and photosynthesis of sorghum under waterlogged conditions

Abstract

Waterlogging stress is one of the most important abiotic stresses limiting sorghum growth and development. Consequently, the responses of sorghum to waterlogging must be monitored and studied. This study investigated changes in the leaf water status, xylem exudation rate, leaf anatomical structure, leaf temperature and photosynthetic performance. Waterlogging-tolerant (Jinuoliang 01, abbreviated JN01) and waterlogging-sensitive (Jinza 31, abbreviated JZ31) sorghum cultivars were planted in pots. The experiment was carried out using a split block design with three replications. Waterlogging stress was imposed at the sorghum five-leaf stage. The leaf free water content (FWC) and relative water content (RWC) decreased under the waterlogged condition. The leaf thickness was thinner under the waterlogged condition, and the main changes occurred in the upper epidermal and mesophyll cells. Gas exchange parameters and the xylem exudation rate were also restrained by waterlogging; however, greater responses of these parameters were observed in JZ31. JZ31 had a higher leaf-air temperature difference (ΔT) than JN01. We found that changes in ΔT were always consistent with changes in the RWC and the gas exchange parameters. ΔT was significantly associated with the leaf RWC, photosynthetic rate (Pn) and transpiration rate (Tr). The results suggest that ΔT may be an indicator reflecting the water status in leaves and can be used to evaluate the tolerance of sorghum to waterlogging.

The OsERF115/AP2EREBP110 Transcription Factor Is Involved in the Multiple Stress Tolerance to Heat and Drought in Rice Plants

“…The water content of leaf is one of the major physiological indicators that reflects their ability to withstand adversity in stressful environments [78,79]. Heat and drought stress cause decreased water uptake and increased transpiration of plants, significantly impeding efficient water utilization and moisture retention of leaf [7,80].…”

“…Heat and drought stress cause decreased water uptake and increased transpiration of plants, significantly impeding efficient water utilization and moisture retention of leaf [7,80]. It has been demonstrated that the leaf-air temperature difference of soybean plants measured through high-resolution thermal IR images under various moisture stresses correlated with the leaf water content [79]. We phenotyped plant temperature by FLIR thermography, and the results indicate that leaf temperature of OsERF115/AP2EREBP110-OE plants was lower than WT plants under the heat-drought combined stress conditions (Figure 5).…”

Optimizing Sensor-Based Irrigation Management in a Soilless Vertical Farm for Growing Microgreens

“…Such difference could be due to the low energy input in the controlled environment growth room, the crop being grown in a hydroponic setup, minimal heat waste from the light source (LED lights) and constant air circulation in the growth room. In previous studies, CTD values of 7.5, 10, and 12 • C have been reported for sorghum (Zhang et al, 2019), alfalfa (Moran et al, 1994) and soybean (Hou et al, 2019), respectively.…”

Ecoengineering Solutions for the Impairment of Spreading and Growth of Invasive Spartina patens in Mediterranean Salt Marshes

“…However, no changes were observed in the carotenoid pool, occurring a decrease in photochemical quenching and an increase in non-photochemical quenching (NPQ), leading to a decrease in the lumen pH, attributed to protonation of the light-harvesting complexes (LHC) proteins associated with the PSII (Cousins et al, 2002). This, in turn, can explain the increase in leaf temperature observed in the waterlogged plants (Zhang et al, 2019). Moreover, it was possible to observe that waterlogged plants had their trapped and transported energy fluxes reduced, but no increase in the energy dissipation.…”