Nitric Oxide Enhances Photosynthetic Nitrogen and Sulfur-Use Efficiency and Activity of Ascorbate-Glutathione Cycle to Reduce High Temperature Stress-Induced Oxidative Stress in Rice (Oryza sativa L.) Plants

Abstract

The effects of nitric oxide (NO) as 100 µM sodium nitroprusside (SNP, NO donor) on photosynthetic-nitrogen use efficiency (NUE), photosynthetic-sulfur use efficiency (SUE), photosynthesis, growth and agronomic traits of rice (Oryza sativa L.) cultivars, Taipie-309 (high photosynthetic-N and SUE) and Rasi (low photosynthetic-N and SUE) were investigated under high temperature stress (40 °C for 6 h). Plants exposed to high temperature stress caused significant reduction in photosynthetic activity, use efficiency of N and S, and increment in H2O2 and thiobarbituric acid reactive substance (TBARS) content. The drastic effects of high temperature stress were more pronounced in cultivar Rasi than Taipie-309. However, foliar spray of SNP decreased the high temperature induced H2O2 and TBARS content and increased accumulation of proline and activity of ascorbate–glutathione cycle that collectively improved tolerance to high temperature stress more effectively in Taipie-309. Exogenously applied SNP alleviated the high temperature induced decrease in photosynthesis through maintaining higher photosynthetic-NUE and photosynthetic-SUE, activity of ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco), and synthesis of reduced glutathione (GSH). The use of 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxy-3-oxide (cPTIO, NO scavenger) substantiated the study that in the absence of NO oxidative stress increased, while NO increased photosynthetic-NUE and photosynthetic-SUE, net photosynthesis and plant dry mass. Taken together, the present investigation reveals that NO increased heat stress tolerance and minimized high temperature stress adversaries more effectively in cultivar Taipie-309 than Rasi by enhancing photosynthetic-NUE and SUE and strengthening the antioxidant defense system.

Nitric Oxide and Abscisic Acid Mediate Heat Stress Tolerance through Regulation of Osmolytes and Antioxidants to Protect Photosynthesis and Growth in Wheat Plants

“…Heat stress adversely affects the photosynthesis and growth of plants [ 12 , 13 , 70 ] by affecting the thylakoid membrane, chloroplast protein complexes, photosystem II, and activity of Rubisco [ 13 , 100 ]. In order to protect plants from heat stress, the photosynthetic efficiency of plants should be improved.…”

“…In order to protect plants from heat stress, the photosynthetic efficiency of plants should be improved. Nitric oxide prevents chlorophyll loss and protects activity of PSII and photosynthesis under stress [ 12 , 101 , 102 ]. Treatment with SNP was found to maintain the Fv/Fm level while inhibiting F 0 rise, and increased chlorophyll and Rubisco by overexpressing NOA1 in rice [ 103 ].…”

“…Nitric oxide generation was confirmed by estimating the nitrite content by adopting the method of Zhou et al [ 78 ], with slight modifications. The details of the method are presented in Gautam et al [ 12 ]. The absorbance of the reaction mixture was read at 540 nm and NO content was estimated from a calibration curve plotted using sodium nitrite as standard.…”

“…Among the alterations, excessive temperature stress during the crop reproductive phase has a likely detrimental influence on agricultural productivity [ 6 , 7 ]. It has been shown that high temperatures adversely affected plant molecular, biochemical, and physiological characteristics [ 8 , 9 , 10 , 11 , 12 , 13 ]. Heat stress causes an oxidative burst, membrane lipid peroxidation, pigment bleaching, protein degradation, enzyme inactivation, and macromolecule damage in plants [ 2 , 14 , 15 , 16 ].…”

“…Over time, evidence developed that NO plays a vital function in a variety of plant physiological processes, including seed germination [ 33 , 34 ], senescence and maturation [ 35 ], and multiple abiotic stress responses [ 36 , 37 ]. Several researchers have focused on explaining the critical function of NO in modulating different plant hormone-mediated growth and stress responses [ 12 , 38 , 39 , 40 , 41 ]. NO might act as a secondary messenger for the other protective compound.…”