The Effect Of Lanthanum On Root Exudation Of Rice

This experiment used rice as material,solution incubate as methed is carried out and the effect of the RE Lanthanum on membrance permeability of rice and changes of organic ingredient such as amino acid,organic acid and inorganic ingredient such as K,Ca2,Hand P in root exudation have been studied. The aim is to investigate the effect of lanthanum on membrance permeability and content in root exudation,then provide the reference data for the safe application of RRE in agriculture.The result in this experiment have indicated that the effect of lanthanum on membrance permeability of rice is different in different lanthanum concentration. In low concentration,the effect of La3' is to stabilize the membrance permeability of root. For example,When La3 in 10 and 50 ug/ml,in 6-54 hour's treatment,the ratio of electrolyte exosmosis of root membrance is lower than the conteol. This fact showed that in low concentration,La3 can stabilize the membrance and decrease the ratio of electrolyte exosmosis of root. Under this concertration,organic ingredients(such as amino acid and organic acid)and inorganic ingredients(such as K,H+,Ca2+andP) in root exudation are lower than the control.Under higher concentration of La3+ and the longer time condition,the ratio of electrolyte exosmosis is increased. When La3 in 100-400ug/ml,in short time treatment such as 6h,the stability of membrance is enhanced. But in long time treatment (t>6h),the ratio of electrolyte exosmosis is larged and higher than the control. When La3 in high concentration,in spite of in short time treatment,the ratio of electrolyte exosmosis is also increased. This probabily indicated high concentration La3 can destroyed the membrance ofroot. Under this concertration,organic ingredients (such as amino acid and organic acid) and inorganic ingredients(such as K+,H+,Ca2 andP) of root exudation are higher than the control.According to results,we can see that the ratio of root electrolyte exosmosis is affected by the concentration of La3 and the time of stress. When in given La3 concentration,the longer treatment time,the larger the ratio of electrolyte exosmosis is. When the time is fixed,the higher concentration of La3',the larger the ratio of electrolyte exosmosis,the severer destroy to root membrance. The rule of P and K+ in root exudation changed is similar to the ratio of electrolyte exosmosis. Correlative analyse indicated that their correlative constant are 0.963 and 0.915 and they haxe reached very significant level.In this experiment,the effect of La3+ on amino acid in root exudation have been studied. In the common eighteen amino acids,except tryptophan,the left are all examined. The quantity of alkaline amino acid increased is higher than acidic amino acid. There are five organic acids have been examined in this experiment:oxalic acid,malic acid,citric acid,succinic acid and lactic acid. The rule of gross organic acid and single acid changed is similar to amino acid. The quantity of oxalic acid is higher,while the quantity of succinic acid is lower than the other organic acid when La3+ in all concentration in experiment. Oxalic acid is a sensitive material or not as an indicator in root exudation for Lanthanum stressing the rice,complicated research is needed.