| Drought hinder the plant growth and development as well as agricultural crop yields one of the main reasons for abiotic stress has long been a lot of research, while the plant itself is also in the process of evolution over many years, formed a very large response to drought stress mechanism.Plants facing drought stress, you can defend the stomatal cells by regulating, and then change the stomatal conductance and opening, so that a change in plant transpiration reduce the loss of watershed, in order to plant drought stress response, which is an important mechanism.Plasma membrane H+-ATPase activity is called life in higher plants dominate the enzyme, it is involved in a number of important physiological processes regulating stomatal aperture also subject to regulation of plasma membrane H+-ATPase, which pumps H+effect can cause stomatal opening so when drought stress, plasma membrane H+-ATPase activity in plant responses to drought stress is one of the important mechanisms.14-3-3proteins in eukaryotic cells are a class of highly conserved regulatory protein can H+-ATPase C-terminal membrane binding and phosphorylation H, in order to enhance its activity, but the plasma membrane H+-ATPase by the multi-level phosphorylation factors regulating species.Nitrogen is the largest mineral elements of plant demand, the lack of nitrogen not only make the plants grow slowly, lower production, but also to make crops grain protein content decreased, the quality drops.Nitrate (NO3-) is one of the main plant nitrogen uptake, electrochemical gradient generated plasma membrane H+-ATPase can provide a driving force and energy absorption of various nutrients, for plants to absorb nitrate transporter Research indicates that the mechanism of nitrogen NO3-absorption requires energy plasma membrane H+-ATPase and the release of H+produced by the hydrolysis of ATP, so whether it is high or low affinity NO3-affinity transporter for transport of both NO3-is an active transport process requires energy supply.Soybean is one of the country’s main cash crop, and the drought severely restrict its production, research on soybean response to drought stress involved in some physiological and biochemical characteristics of the ground a lot of changes, and examine the underground parts of the plant response to drought stress little research.In this thesis, the Japanese Tamba black beans (RB) and Yunnan local black beans (SB) as experimental material, analyze its physiological and biochemical characteristics under hydroponic conditions on polyethylene glycol (PEG-6000) simulated drought stress response, PEG simulated test H Effect of drought stress on their nitrate uptake and membrane "-ATPase activity from Soybean root plasma membrane H+-ATPase activity as the starting point, and then nitrate absorption studies to increase our understanding of the black Soybean response to drought stress and understanding, mainly achieved the following results:1.Under hydroponic conditions simulated drought by polyethylene glycol (PEG-6000) and stress treatments RB SB, analyze physiological characteristics of soybean leaves, roots of soybean14-3-3protein expression (SGF14) and root plasma membrane H+-ATPase, and interaction and correlation of the activity and nitrate (NO3-) of absorption. The results show that2%,5%,10%PEG (PEG-6000) and2d5h after stress treatment, SB leaf transpiration rate and stomatal conductance were greater than the decrease in RB, described SB drought tolerance stronger than RB. In the short stress (5h) period, RB and SB nitrate absorption volume increases the concentration of PEG stress increases, SB uptake of nitrate uptake was significantly higher than that of RB under the same treatment conditions. In5%PEG increased stress to1,2,3and4d, the nitrate uptake compared with RB and SB are still no significant increase in stress control, but under the same stress conditions, RB nitrate absorption significantly exceed the amount of absorption of the SB. RB and SB apical plasma membrane H+-ATPase activity and hydrogen pump activity with increasing PEG stress time showed a significant decreasing trend, but under the same conditions of stress treatments RB apical plasma membrane H+-ATPase activity and hydrogen pump activity was significantly higher than SB. These results suggest that PEG simulated drought stress significantly enhanced absorption of RB and SB apical plasma membrane nitrate but decreased the activity of H+-ATPase pump activity and hydrogen.2.Vanadate (VA) is a plasma membrane H+-ATPase inhibitor, and MgC12is the plasma membrane H+-ATPase activator, it can enhance the plasma membrane H+-ATPase of phosphorylation promote14-3-3protein phosphorylation of the plasma membrane H+-ATPase binding to improve the plasma membrane H+-ATPase activity. To further understand the next PEG simulated drought, drought tolerance of weak inhibitor vanadate applied RB, SB drought strong activators applied magnesium chloride, after analysis of two soybean plasma membrane H T-ATPase activity changes, physiological changes in biochemical characteristics and nitrate absorption situation. The results showed that, compared with the applied PEG alone mixed imposed VA, RB ’s water loss rate has been significantly reduced in the treatment and2d5h under circumstances decreased by approximately34%and24%,-while the transpiration rate and stomatal conductance phase are significantly higher than the case applied only to the PEG. RB nitrate uptake when compared to PEG treatment only when2d5h and have a significantly decreased, decreased by approximately43%and46%. Plasma membrane H+-ATPase activity and hydrogen pump activity compared to the PEG treatment have been significantly reduced. These results illustrate the inhibitor VA RB drought conditions played a role in improving and alleviate drought stress reduced the RB absorption of nitrate. After applying MgC12, water loss rate when compared to SB PEG treatment alone, in the2d5h and have a significantly elevated, were increased by approximately12.5%and25.2%. Stomatal conductance and transpiration rate compared to PEG treatment alone has been significantly improved. SB absorption of nitrate treatment when compared to PEG2d5h and has significantly improved, were increased by approximately11%and12%. SB’s root plasma membrane H+-ATPase activity, phosphorylation levels and activity of the hydrogen pumps applied after mixing MgC12, has been significantly improved when compared PEG treatment alone. This suggests applying activator MgC12for SB plasma membrane H+-ATPase activity occurred in the role of increased aridity, and improved absorption of nitrate SB.3.Recent studies suggest that H2O2can inhibit the plasma membrane H -ATPase phosphorylation and binding to14-3-3proteins, thereby reducing the H-ATPase activity and reduced stomatal aperture, and ascorbic acid (ASA) is a commonly used H2O2scavenger. Under drought stress can increase the accumulation of H2O2in plants, so in PEG simulated drought, drought tolerance of strong SB applied ASA, for drought tolerance weak RB applied exogenous H2O2, learn more about the two beans membrane H+-ATPase activity changes and drought conditions and nitrate uptake contact. The results showed that after mixing applied ASA compared with PEG applied alone, SB’s water loss rate has significantly increased, and2d5h case under treatment were increased by approximately1.97times and1.9times, transpiration rate and stomatal conductance PEG compared to only impose conditions have also improved significantly. SB nitrate uptake when compared to PEG treatment only when2d5h and has significantly improved, were increased by approximately1.52times and1,23times. SB’s root plasma membrane H+-ATPase activity, phosphorylation levels and hydrogen pump activity, compared to the PEG treatment has also been significantly increased. This shows that the ASA applied for SB plasma membrane H+-ATPase activity plays a regulatory role, exacerbated by the drought SB, increased uptake of nitrate. After applying exogenous H2O2RB applied compared to PEG alone, the loss rate has significantly decreased, and2d5h case under treatment were reduced by approximately36%and30%, transpiration rate and stomatal conductance compared to only impose PEG situation has also decreased significantly. After applying H2O2, RB nitrate uptake appeared decline, RB root plasma membrane H+-ATPase activity, phosphorylation levels and hydrogen pump activity after applying H2O2, PEG treatment than when alone, there were significantly decreased. This shows that exogenous RB imposed on the plasma membrane H H2O2+-ATPase activity of regulation, RB improved drought tolerance, drought mitigation RB also reduces the absorption of nitrate. |
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