Response of Photosynthesis to High Growth Temperature Was Not Related to Leaf Anatomy Plasticity in Rice (Oryza sativa L.)

Abstract

Photosynthesis is highly sensitive to high temperature stress, and with the rising global temperature, it is meaningful to investigate the response of photosynthesis to growth temperature and its relationship with leaf anatomy plasticity. We planted 21 cultivars including eight indica cultivars, eight japonica cultivars, and five javanica cultivars in pot experiments under high growth temperature (HT, 38/28°C, day/night) and control treatment (CK, 30/28°C, day/night). Photosynthetic rate (A), stomatal conductance (g s ), transpiration rate (E), stomatal density (SD), vein density (VD), minor vein area (SVA), and major vein area (LVA) were measured after 30 treatment days. Results showed HT significantly increased A, g s , and E, while significantly decreased SD and LVA. There was no significant difference in A among the three subspecies both under CK and HT, while the javanica subspecies had higher g s , E, SVA, and LVA under HT, and the indica cultivars had higher VD and SD both under CK and HT. The javanica subspecies had higher relative value (HT/CK) of A, g s , and E, while difference was not observed in the relative value of SD, VD, and LVA among the three subspecies. The relative value of A was positively related to that of g s , while the latter was not correlated with the relative value of SD, VD, SVA, and LVA. Overall, the results suggested the increase of A and g s at HT was not attributed to leaf anatomy plasticity in respect of stomata and vein under HT. HIGHLIGHTS 1. High growth temperature (HT) significantly affected rice leaf photosynthetic rate (A), stomatal conductance (g s ), transpiration rate (E), stomatal density (SD), and major vein area (LVA). 2. The javanica subspecies had higher g s , E, and LVA under HT, and possessed higher heat resistance than indica and japonica subspecies. 3. Across different cultivars, the response of A and g s to HT were not related to leaf anatomy plasticity such as stomatal and vein anatomy.

Coping with inclement weather conditions due to high temperature and water deficit in rice: An insight from genetic and biochemical perspectives

“…This eventually leads to abscission, thereby affecting plant growth and productivity (Guo, Liu, et al, 2016; Gururani et al, 2015). Photosynthesis is one of the biological processes, which is significantly affected by HTS in rice plants (Yang et al, 2020). The optimum growth temperature for photosynthesis in rice plants is approximately 30°C and significantly decrease when temperature increases, resulting in the inhibitions of various redox and metabolic reactions taking place in PSII, PSI, cytochrome complex, and RuBisCo, that leads to decrease in photosynthetic rate (Yang et al, 2020; Yin et al, 2010).…”

“…Photosynthesis is one of the biological processes, which is significantly affected by HTS in rice plants (Yang et al, 2020). The optimum growth temperature for photosynthesis in rice plants is approximately 30°C and significantly decrease when temperature increases, resulting in the inhibitions of various redox and metabolic reactions taking place in PSII, PSI, cytochrome complex, and RuBisCo, that leads to decrease in photosynthetic rate (Yang et al, 2020; Yin et al, 2010). Studies performed by Yin et al (2010) showed that rice seedlings exposed to temperature higher than 35°C resulted in significant reduction of CO 2 assimilation under light and dark conditions, but was more sensitive under light.…”

“…The signals generated from hormonal crosstalk in response to HTS are translated into physiological and morphological adaptations including changes in the biomass of the above and below plant parts, stomatal movement, transport of water, and grain filling rate (Skalák et al, 2016; Dobrá et al, 2015). Plants also exhibit short‐term avoidance mechanisms such as stomatal closure and transpirational cooling in response to HTS (Yang et al, 2020). However, Yang et al (2020) observed that though HTS increase photosynthetic rate (A) and stomatal conductance ( g s ), these were not attributed to stomatal density, vein density and vein area in japonica , indica , and javanica rice.…”

“…Plants also exhibit short‐term avoidance mechanisms such as stomatal closure and transpirational cooling in response to HTS (Yang et al, 2020). However, Yang et al (2020) observed that though HTS increase photosynthetic rate (A) and stomatal conductance ( g s ), these were not attributed to stomatal density, vein density and vein area in japonica , indica , and javanica rice.…”

Climatic constraints to yield and yield components of temperate japonica rice

“…As the subspecies adapt to different thermal regimes, the response of rice yield to temperatures varies with the subspecies. Indica and tropical japonica have higher heat resistance compared to temperate japonica (Shah et al., 2014; Yang et al., 2020). Despite the higher heat‐resistance of indica and tropical japonica , rice plants grown in the tropics and subtropics are frequently injured by high temperatures, most severe damage occurring during the booting and flowering stages, followed by the grain‐filling stage (Counce et al., 2005; Mohammed & Tarpley, 2009, 2010; Satake & Yoshida, 1978).…”