The Influence Of Environmental Factors On Corn Root Potassium Ion Transmembrane Transfer

Potassium is one of the most abundant cations in plant cells and plays an important role in plant physiology.It has been proved that there are two ways of potassium ions' membrane-transport mainly,the high-affinity transport system composed of carrier proteins and the low-affinity transport system composed of channel proteins.The specific inhibitors of these two kinds of proteins have been founded.However,our early researches showed that when the two inhibitors were added at the same time,the plants on the absorption of potassium did not stop.It is still unclearly that how the plants take up potassium cations treated with inhibitors and the affection of environmental factors.Solution culture experiments were carried out to study the effects of potassium uptake on environmental factors by xianfeng 1 and xiyu 3.The main results were as follows:1.1mmol/L TEA have a better effect than 10mmol/L or 0.2mmol/L BaCl₂ in the K⁺ channel protein inhibition.2.The process of K⁺ transfer across cell membrane is by high-affinity transport system composed of carrier protein and the low-affinity transport system composed of channel protein.However,as elevated concentrations of K⁺,the former declined in the proportion and the latter increased.3.When the plant was treated with both of the two inhibitors,it could take up K⁺ through the non-selective ion channels.4.The absorption of K⁺ of maize was impacted of time and varieties.the uptake rate of xianfeng 1 and xiyu 3 achieve the maximum after two hours absorbing.With the extension of time.the uptake rate decreased significantly.The xianfeng 1 was higher than xiyu 3.It may be related to the hunger-induced feedback mechanism and the relevant mechanisms. 5.Under different temperatures,as the temperature rises,the uptake rate of xianfeng 1 and xiyu 3 showed that it rising at first then declined,at 25℃the rate achieve the maximum.as the temperature continues to rise,the rate declined,this may be related to the plant stomatal movement,as the temperature increases,leaf transpiration rate increase,the K⁺ in plant cells outflowed.In the case of adding inhibitors,the situation is different,the uptake rate of K⁺ is lower than without inhibitors,but with increasing temperature,the uptake rate of K⁺ showed an upward trend.Overall,whether or not to adding inhibitos,the uptake rate of xianfeng 1 were higher than xiyu 3.6.Different species showed different behavior under different pH.The results showed that the higher K⁺ uptake rate was in pH7.5,the low uptake rate was in pH4.5.When inhibitors were added,the uptake rate of K⁺ was at the same trend as without the inhibitors.But the higher uptake rate of xianfeng 1 was in pH6.5,after adding the inhibitors,the maximum uptake rate ccurred in pH7.5.In pH8.5 at a lower rate of absorption.7.In pH4.5,pH5.5,the absorption rate of potassium on two species of corn reduced the hydrogen ion concentration of the solution.In pH6.5,pH7.5 and pH8.5, the solution pH value is lower.