The Physiological Mechanism Of Silicon Efficient Uptake On Rice Root

Hydroponics experiments were performed to investigate the physiological mechanism of silicon efficient uptake on Rice root with four cultivars. This study was carried out on Science and Technology Park of henna Agricultural University from 2005 to 2007.We used the way that had cultured the rice indoor and outdoor,we selected four different efficiency to uptake silicon,which was high efficiency cultivars TN1 and white-japonica,and low efficiency cultivars juanyejing and Hitomebore.An experiment was made to use the basis prescription which was from International Rice Research Institute.With setting up different silicon concentration;we studied on the changes of the root morphology.And multiple ways metabolism pathway,for example, EMP and PPP,enzyme activities of them.In addition,this experiment studied that the effect of the metabolic inhibitors on the providing energy of ATP for the silicon uptake by pretreatment of the metabolic inhibitors,we analyzed the reasons of difference and the different mechanism,the mainly results as follow:1,Silicon-absorption kinetics of four rice varieties that the maximum absorption rate TN1,respectively,and the white-japonica were over juanyejing,Hitomebore than the 35.6 percent,28.8 percent and 43.5 percent,36.3 percent higher,showed that TN1 and the white-japonica were Silicon efficient absorption species,juanyejing,Hitomebore were low-efficiency silicon-absorbing species.2,Along with raising the level of silicon,shorter root,the numbers of root increased, the number of lateral root,reduced,the root diameter slightly increased,but the difference was not significant,biomass comparison,above-ground biomass increased, and the root decreased,Lateral root in the entire silicon-absorption played a leading role,the longer the roots,the more lateral roots was more conducive to the absorption of silicon.With the increasing concentration of silicon,IAA,ZR,GA₃ were upward trend,ABA was a declining trend,IAA / ABA,ZR / ABA in the ratio gradually increased,ABA/GA₃ ratio in the decline.3,The addition of inhibitors significantly reduce the root of the ATP,which DNP is the solution of phosphoric acid coupling agent,0.5 mMDNP inhibited six hours later, and the absorption of silicon was inhibited by 90%.After HgCl₂ dealed with the four rice varieties Silicon absorption decreased significantly,the efficient control between the two varieties between the two inefficient absorption was a significant difference between the level of white-japonica root had the highest ATP content,TN1,For,after four species of silicon-absorption difference was not obvious,but with control of the difference between a very significant level.Control over the four species were handled:TN1 was 92.5%,96.7%,Juanyejing,White-japonica 88.7%,91.3%in Hitomebore,the average rate was 92.3%in hibition.4,With the silicon level improving,that the PPP,EMP,TCA provided the energy for root to take up silicon together,and they mutual influenced,from the decreasing formation of the Si uptake,we could get the result that PPP and TCA were key pathways,but the PPP accounted for 42 percent.