Partial Mechanism of Photosynthetic Suppression in Soybean Varieties under Salt Stress
|Keywords||Salt Stress Soybean Photosynthesis Gas exchange Chlorophyll fluorescence Rubisco|
Salt is one of the most important abiotic factors limiting crop yield, and crop yield formation is closely related to photosynthesis, the study of salt stress on photosynthesis to clarify the internal mechanism of photosynthesis of the crop salt tolerance is particularly important . Of soybean cultivars Glycine max Melrose and wild soybean Glycine cyrtoloba, it ACC547 somatic cell hybrids S111-9 test material, the effect of salt stress on gas exchange parameters and chlorophyll fluorescence parameters, chlorophyll content and Rubisco activity. Under salt stress of Melrose photosynthesis has been compared to S111-9 a greater degree of inhibition. As the salt concentration increased, Melrose leaves the photosynthetic rate (P N ), stomatal conductance (g s ) down, but intercellular the CO 2 < / sub> concentration (C i ) in the 50 and 100 mM NaCl treatment was no significant difference compared with the control, 150mM NaCl treatment was significantly higher than that of the control, indicating inhibition of photosynthesis Melrose was mainly due to limit of nonstomatal. In contrast, with the NaCl concentration increased processing, S111-9 P N , g s is declining, C i also decreased , indicating that the inhibition of photosynthesis S111-9 is primarily due to the limitations of stomatal. Melrose and S111-9 PS Ⅱ maximum photochemical efficiency (F v / F m ) in 150mM NaCl treatment were statistically significant reduction, but reduction in Melrose Greater S111-9. Under salt stress, Melrose PS Ⅱ actual photochemical efficiency (the phi PS II ) than the S111-9 greater degree of decline, and photochemical quenching parameters the (q P ) also showed the same phi PS II the same trend than the S111-9 greater degree of reduction under salt stress the Melrose q P led Melrose Φ PS Ⅱ sub > greater degree of reduction. The CO 2 response curve analysis showed that under salt stress, Melrose Rubisco activity may be subject to a greater degree than the S111-9. Through quantitative analysis shows that the salt treatment reduced Melrose Rubisco initial activity and the total activity, and has no effect on the S111-9. Interestingly, no effect of salt stress on Rubisco activation of Melrose and S111-9. Melrose Rubisco activity decreased, thus negative feedback reduces the electron transfer activity, making Q P reduced, which may explain why the Melrose Φ PS Ⅱ than the S111-9 greater extent to reduce this problem. S111-9 of the photosynthetic apparatus under salt stress have a greater resistance to its chlorophyll content, PS Ⅱ photochemical efficiency and Rubisco activity was related to a smaller impact.