Tobacco Secretion Of Organic Acids On Soil Potassium Role And Related Gene Expression Research

Potassium is a large number of elements required for the growth and development of tobacco,due to the strong capacity of absorbed in K fixation in the north of soil,can not easily be absorbed by the tobacco plant,under the stess of lock of the potassium nutrition they tend to make the tobacco plant roots secrete acids,and improve use of.the potassium in the soil.This paper systematically analyzes the mechanism of root secretion of organic acids action on soil potassium element and provide a reference for screening the secretion of organic acids in tobacco varieties by activation of potassium in the rhizosphere soil by organic acid secretion、gene expression of organic acid secretion、effect of exogenous organic acids on Soil Potassium and the mechanism of organic acid activated potassium.The main results are as follows:1 Effect of organic acids on root exudates of different tobacco varietiesThe detection results of GC-MS in root exudates of 4 flue-cured tobacco varieties showed that:Different kinds of tobacco varieties have different kinds of organic acids in root exudates.Under the normal condition of potassium supply,the potassium accumulation of ND202 was the highest,which was 442.19mg,followed by NC89 and NC628,and the K326 was the lowest.Under the condition of potassium deficiency,the accumulation of potassium is from high to low order:NC628、ND202、NC89 and K326.The analysis showed that the potassium accumulation of ND202 and NC628 was higher than that of NC89 and K326,both of them are high accumulation of potassium varieties(high potassium varieties).Under the two potassium condition,high potassium varieties of root secretion of organic acid is higher than that of NC89 and K326.The difference significant under the conditions of potassium deficiency.Under the two potassium treatment,the content of rhizosphere soil slowly available potassium of K326 is the highest,followed by NC89,the lowest in ND 202;The root potassium content of ND 202 in rhizosphere soil under normal potassium treatments was the highest,while the highest in NC89 under potassium deficiency treatment,the values are 99.42mg/kg and 456.1 lmg/kg.The NC628 content was lowest,and the value was 218.72mg/kg and 88.40mg/kg.It was found that the contents of organic acid in root exudates of high potassium varieties were higher,but the content of the soil in the rhizosphere soil was lower.The contents of organic acid in root exudates of K326 and NC89 were lower,and the contents of the delayed effects of the soil in the rhizosphere soil were higher.The amount of organic acid in root system had an effect on the transformation of soil potassium form.The effect of organic acid on the soil potassium was higher than that of NC89 and K326.Under the condition of potassium deficiency,the root dry weight and root volume of the varieties were lower than those of normal potassium supply,and the root volume of NC89 and K326 was significantly smaller,NC628 and ND202 root volume became smaller,but this change were not significantly.4 varieties of root activity,ATP activity and cation exchange capacity are significantly reduced,It showed that the growth and development of root system and metabolic activity of the cultivars were hindered.2 Differences between different varieties of tobacco root exudates malic acid and citric acid content and related gene expressionThe analysis of root exudates of malic acid and citric acid content indicate that different varieties of tobacco varieties K326 roots secrete citric acid showed no significant difference between Y12,up to a significant difference with other varieties,were Honghuadajinyuan nearly 10 times.The amount of Malate secreted from roots have no significant difference between 90 and K326,were significant differences with other varieties,were nearly 20 times Y12,indicating that different varieties of tobacco root secretion of citric acid and malic acid content be quite different.Analysis with differential gene expressio of MATE and ALMT tobacco,under potassium stress all tobacco varieties MATE and ALMT relative gene expression levels were significantly increased,MATE gene expression of Luoning No.3 increased nearly six-fold,indicating that potassium deficiency can cause tobacco roots citrate malate channel proteins and channel proteins open,and cause the outflow of citric acid and malic acid,in order to withstand environmental stress.Under normal conditions,MATE gene expression in variety K326 was higher than Luoning No 3,ALMT gene expression higher than NC89,comparatively citric acid secretion in K326 was higher than Luoning No 3,the amount of malate acid secretion is higher than NC89,the difference discipline is similar,show that tobacco ALMT and MATE gene expression on root secretion of citric acid and malic acid content have a certain role.Under potassium stress condition,the same species of root length was significantly shorter,under the Potassium short the root length of Luoning No.3 and K326 short about 50%than normal,indicating that potassium play an important role on the growth and development of plant roots.Three varieties of root stress activity were higher than normal,in which root stress activity of Luoning No.3 and NC89 varied widely,root activity in K326 changed small,explanating that potassium stress treatment increased the antioxidant defense mechanisms in the body of tobacco plant.3 The effect of exogenous organic acids on tobacco physiology and soil potassium contentAnalyses the application of malic acid and citric acid potassium content,chlorophyll content,the tobacco leaf tobacco adversity enzyme activity,root activity,root in the influence of the enzyme activity and soil available potassium,The results showed that:the potassium content of organic acid treated tobacco leaf,chlorophyll content、root activity and soil available potassium content were higher than not applying organic acid treatment,Adversity of tobacco plant enzyme activity is lower than not applying organic acid treatment,the tobacco of organic acid can promote the growth of tobacco,increase soil available potassium content,increase the content of potassium.4 Study of the role of organic acids on soil available potassium releaseVarious of inorganic acid,organic acid and organic acid salt soil available k content in high with all the training time is controlled,after 1,3,7 and 18 days,Hydrochloric acid and citric acid,respectively,compared with the controls 49.13%、67.93%、81.54%、81.10%and 64.49%、78.68%、87.63%、87.03%.To deal with the soil after 18 days,malic acid,citric acid and hydrochloric acid were higher than control 1.19%.2.16%and 3.64%.Sodium citric acid and malic acid sodium were higher than control 0.74%and 0.71%,continuous use of inorganic acid activation soil has strong potassium release effect,the stronger the acid,potassium release ability stronger,inorganic acid organic acid and organic acid salt has the strong interpretation of potassium,difference between the organic acid salt of potassium release ability,release of soil potassium content is higher than that of complexation acidification.The same concentration of citrate,malate,and use of a different order,hydrochloric acid activation release there was no significant difference between soil potassium content,acidification and complexation against each soil potassium release is in order.When improving inorganic acid concentration,acidification,soil release potassium increased rapidly,and release a quantity to also increase more,explain to the release of potassium in the soil acidification is quick,can effectively improve the soil potassium content.