Sufficient leaf transpiration and nonstructural carbohydrates are beneficial for high-temperature tolerance in three rice (Oryza sativa) cultivars and two nitrogen treatments

Abstract

To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.) cultivars and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates (NSC) in HT tolerance is related to E, a pot experiment supplied with two N levels (low N, 0.077 g urea kg–1 soil; sufficient N, 0.538 g urea kg–1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could be partly offset by a sufficient N supply. The most HT-tolerant cultivar, N22, had the highest E and stem NSC concentrations under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations. A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments were related to E, and possibly to NSC concentration.

Overexpression of OsSAP16 Regulates Photosynthesis and the Expression of a Broad Range of Stress Response Genes in Rice (Oryza sativa L.)

“…This would lead to higher rates of E in the mutants, despite lower rates of g s . In our previous study, higher transpiration rate is beneficial for high-temperature tolerance in rice [ 29 ].…”

Limitation of Unloading in the Developing Grains Is a Possible Cause Responsible for Low Stem Non-structural Carbohydrate Translocation and Poor Grain Yield Formation in Rice through Verification of Recombinant Inbred Lines

“…Because grain yield capacity sustains on carbohydrate partitioning, assimilate remobilization from stems and leaf sheaths becomes crucial in exigency, when challenging environments slacken current photosynthesis. NSC re-translocation associates with stress tolerance such as high or low irradiance ( Okawa et al, 2003 ), water deficiency stress ( Yang et al, 2001a ; Gupta et al, 2011 ), heat stress ( Tahir and Nakata, 2005 ; Morita and Nakano, 2011 ; Shi et al, 2013 ; Xiong et al, 2015 ) and low nitrogen availability ( Pan et al, 2011 ). These results illustrate the importance of stem NSC for yield stability and stress resistance in cereal crops.…”

Countermeasures for heat damage in rice grain quality under climate change

“…In this view, a canopy-temperature-based irrigation scheduling procedure (Wanjura & upchurch, 1997) may contribute to the reduction of heat damage in rice. In addition, it has been indicated that the use of nitrogen application with a heat-tolerant variety is a highly effective means of decreasing heat damage via lowering of the canopy temperature by enhancing evapotranspiration (Xiong et al, 2015). Also, it would be effective to use varieties which have a higher transpiration conductance and/or lower temperature of flowering rice panicle (Fukuoka et al, 2012;Maruyama et al, 2013) for diminishing heat damage.…”