Activities of several key enzymes of C-4 photosynthesis pathway and stable carbon isotope discrimination were investigated in flag leaves of a super high-yield hybrid rice (Oryza sativa L.) cv. Peiai 64S/E32 and a tra...Activities of several key enzymes of C-4 photosynthesis pathway and stable carbon isotope discrimination were investigated in flag leaves of a super high-yield hybrid rice (Oryza sativa L.) cv. Peiai 64S/E32 and a traditional hybrid rice cv. Shanyou 63 at different developing stages. Results show that the activity of PEP carboxylase (PEPCase) increased with age of flag leave; the activity of NADP-malate dehydrogenase (NADP-MDH) increased and reached to a peak value at grain filling stage (68-75 d after transplanting), then fell down; the activity of NADP-MDH in cv. Peiai 64S/E32 was much higher than that in cv. Shanyou 63. Before ripening stage (95 d after transplanting), NADP-malic enzyme activity rose gradually. The level of stable carbon isotope discrimination (Delta(13)C) in flag leaves and grains at different developing stages were similar and exhibited a comparative high value at ripening stage. The average Delta(13)C in leaf of cv. Peiai 64S/E32 during different developing stages was 0.43parts per thousand more than that in cv. Shanyou 63.展开更多
The activities of RuBPC and C4 photosynthetic enzymes in ear and flag leaf blade were examined in wheat. The results showed that photosynthesis of ear was less sensitive to soil drought than that of flag leaf, and dec...The activities of RuBPC and C4 photosynthetic enzymes in ear and flag leaf blade were examined in wheat. The results showed that photosynthesis of ear was less sensitive to soil drought than that of flag leaf, and decrease of CO2 assimilation in flag leaf blade with water stress was more than that in ear. Compared with flag leaf, ear organs (awn, glume and lemma) had higher C4 enzyme activities and lower RuBPC activity. Under moderate water-stress, the increase of C4 enzyme activities was induced, and the increase was higher in ear than in flag leaf. Under severe water-stress, relatively higher C4 enzyme activities were still maintained in ear, rather than that in flag leaf. It suggests that high activities of C4 enzymes in ear may contribute to its high tolerance of photosynthesis to water-stress.展开更多
Studies for many years have indicated that the seed yield of (Glycine max L. Merr.) soybean can be increased by increasing photosynthetic efficiency. The yield of cultivars with high photosynthetic efficiency (HPE) in...Studies for many years have indicated that the seed yield of (Glycine max L. Merr.) soybean can be increased by increasing photosynthetic efficiency. The yield of cultivars with high photosynthetic efficiency (HPE) increased by 30% - 40% in comparison with the cultivars with normal photosynthetic efficiency, indicating that the breeding of soybean by increasing RPE may have a bright prospect. HPE breeding can be used as the temporal monitoring in the breeding process to avoid the divergency of the predetermined goal, although HPE breeding does not shorten the breeding time. It was observed that limited C-4 pathway exists in soybean leaf and pod, suggesting that by increasing the genetic expression of some C-4 enzymes in C-3 crops through traditional or genetic engineering techniques, new breakthroughs in increasing the photosynthetic efficiency of C-3 plant may be practicable in the future.展开更多
AgCl/ZnO/g-C_(3)N_(4), a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochlor...AgCl/ZnO/g-C_(3)N_(4), a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochloride(TC-HCl) from pharmaceutical wastewater under visible light. The morphological, structural, electrical, and optical features of the novel photocatalyst were characterized using scanning electron microscopy(SEM), UV-visible light absorption spectrum(UV–Vis DRS), X-ray diffractometer(XRD), Fourier transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), and transient photocurrent techniques. All analyses confirmed that the formation of heterojunctions between AgCl/ZnO and g-C_(3)N_(4)significantly increase electron-hole transfer and separation compared to pure ZnO and g-C_(3)N_(4). Thus, AgCl/ZnO/g-C_(3)N_(4)could exhibit superior photocatalytic activity during TC-HCl assays(over 90% removal) under visible light irradiation. The composite could maintain its photocatalytic stability even after four consecutive reaction cycles. Hydrogen peroxide(H_(2)O_(2)) and superoxide radical(·O_(2)) contributed more than holes(h+) and hydroxyl radicals(·OH) to the degradation process as showed by trapping experiments. Liquid chromatograph-mass spectrometer(LC-MS) was used for the representation of the TC-HCl potential degradation pathway. The applicability and the treatment potential of AgCl/ZnO/gC_(3)N_(4)against actual pharmaceutical wastewater showed that the composite can achieve removal efficiencies of 81.7%, 71.4% and 69.0% for TC-HCl, chemical oxygen demand(COD) and total organic carbon(TOC) respectively. AgCl/ZnO/g-C_(3)N_(4)can be a prospective key photocatalyst in the field of degradation of persistent, hardly-degradable pollutants, from industrial wastewater and not only.展开更多
文摘Activities of several key enzymes of C-4 photosynthesis pathway and stable carbon isotope discrimination were investigated in flag leaves of a super high-yield hybrid rice (Oryza sativa L.) cv. Peiai 64S/E32 and a traditional hybrid rice cv. Shanyou 63 at different developing stages. Results show that the activity of PEP carboxylase (PEPCase) increased with age of flag leave; the activity of NADP-malate dehydrogenase (NADP-MDH) increased and reached to a peak value at grain filling stage (68-75 d after transplanting), then fell down; the activity of NADP-MDH in cv. Peiai 64S/E32 was much higher than that in cv. Shanyou 63. Before ripening stage (95 d after transplanting), NADP-malic enzyme activity rose gradually. The level of stable carbon isotope discrimination (Delta(13)C) in flag leaves and grains at different developing stages were similar and exhibited a comparative high value at ripening stage. The average Delta(13)C in leaf of cv. Peiai 64S/E32 during different developing stages was 0.43parts per thousand more than that in cv. Shanyou 63.
基金This work was supported by the State Key Basic Research and Development Plan(G1998010100)the State Natural Science Fund(30270780)the State"Tenth Five Year"Project(2001BA507A-09)of China
文摘The activities of RuBPC and C4 photosynthetic enzymes in ear and flag leaf blade were examined in wheat. The results showed that photosynthesis of ear was less sensitive to soil drought than that of flag leaf, and decrease of CO2 assimilation in flag leaf blade with water stress was more than that in ear. Compared with flag leaf, ear organs (awn, glume and lemma) had higher C4 enzyme activities and lower RuBPC activity. Under moderate water-stress, the increase of C4 enzyme activities was induced, and the increase was higher in ear than in flag leaf. Under severe water-stress, relatively higher C4 enzyme activities were still maintained in ear, rather than that in flag leaf. It suggests that high activities of C4 enzymes in ear may contribute to its high tolerance of photosynthesis to water-stress.
文摘Studies for many years have indicated that the seed yield of (Glycine max L. Merr.) soybean can be increased by increasing photosynthetic efficiency. The yield of cultivars with high photosynthetic efficiency (HPE) increased by 30% - 40% in comparison with the cultivars with normal photosynthetic efficiency, indicating that the breeding of soybean by increasing RPE may have a bright prospect. HPE breeding can be used as the temporal monitoring in the breeding process to avoid the divergency of the predetermined goal, although HPE breeding does not shorten the breeding time. It was observed that limited C-4 pathway exists in soybean leaf and pod, suggesting that by increasing the genetic expression of some C-4 enzymes in C-3 crops through traditional or genetic engineering techniques, new breakthroughs in increasing the photosynthetic efficiency of C-3 plant may be practicable in the future.
基金supported by National Natural Science Foundation of China (No. 41771295)。
文摘AgCl/ZnO/g-C_(3)N_(4), a visible light activated ternary composite catalyst, was prepared by combining calcination, hydrothermal reaction and in-situ deposition processes to treat/photocatalyse tetracycline hydrochloride(TC-HCl) from pharmaceutical wastewater under visible light. The morphological, structural, electrical, and optical features of the novel photocatalyst were characterized using scanning electron microscopy(SEM), UV-visible light absorption spectrum(UV–Vis DRS), X-ray diffractometer(XRD), Fourier transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), and transient photocurrent techniques. All analyses confirmed that the formation of heterojunctions between AgCl/ZnO and g-C_(3)N_(4)significantly increase electron-hole transfer and separation compared to pure ZnO and g-C_(3)N_(4). Thus, AgCl/ZnO/g-C_(3)N_(4)could exhibit superior photocatalytic activity during TC-HCl assays(over 90% removal) under visible light irradiation. The composite could maintain its photocatalytic stability even after four consecutive reaction cycles. Hydrogen peroxide(H_(2)O_(2)) and superoxide radical(·O_(2)) contributed more than holes(h+) and hydroxyl radicals(·OH) to the degradation process as showed by trapping experiments. Liquid chromatograph-mass spectrometer(LC-MS) was used for the representation of the TC-HCl potential degradation pathway. The applicability and the treatment potential of AgCl/ZnO/gC_(3)N_(4)against actual pharmaceutical wastewater showed that the composite can achieve removal efficiencies of 81.7%, 71.4% and 69.0% for TC-HCl, chemical oxygen demand(COD) and total organic carbon(TOC) respectively. AgCl/ZnO/g-C_(3)N_(4)can be a prospective key photocatalyst in the field of degradation of persistent, hardly-degradable pollutants, from industrial wastewater and not only.
