Study On Priming Of Rice Resistance Against Insects And Stresses By Seed Pretreatment

Rice is one of the main grain crops in China and most Asian Countries,and its yield is one of the important factors that affect the foot security in our country.Biotic and abiotic stress can severely affect the yield of rice.The main biotic stress is producing by feeding damage of herbivore insects such as brown planthoppers and rice stem borer.And the abiotic stress mainly includes drought,low temperature,soil salinization and so on.The brown planthopper(Nilaparvata lugens Stal)is the main pest of rice,and BPH is a specialist feeding on rice causing several damage of rice production every year.Therefore,increased rice resistance to BPH is an important way to ensure the yield of rice.With the global climate war:ming and the reduction of freshwater resources,many areas of China are experiencing drought.Rice is sensitive to water,drought directly leads to a significant reduction in rice yield.Therefore,improve the tolerance of rice to drought is helpful to ensure rice yield and reduce the loss of rice yield.Although China has vast territory,the actual available cultivated land is still lack.Due to the destruction of forest vegetation and unreasonable farming system,part of the arable land is salinized.In addition,the salinization is still serious in coastal cities.So that improve the tolerance of rice to salt can make more effective use of saline alkali land,and then increase the arable land area,thereby improve the r:ice yield.Some studies provide that if we add some reagents into water during presoaking,it can induce the Priming in rice,and then the rice will stay in a waiting state,in the face of biotic or abiotic stress it can response rapidly and improve the resistance to the biotic and abiotic stresses.In this study,we used the Bacillus amyloliquefaciens strain HB19459,HB19461,G2;VdAL protein(Verticillium dahlia activator)solution;Nano silica solution and sodium silicate solution on rice seed,and then studied the resistance of the pretreated rice to the biotic and abiotic stress.Among them,for the biotic stress we studied the resistance to the BPH,and for the abiotic stress we studied the resistance to the drought and salt.and we also studied the molecular mechanism.The purpose of this study is to explore the effect of seed treatment on resistance of biotic and abiotic stress,provide reference for future research and to be applied in agricultural production.The main result is listed as follows:1.Rice seed pretreatment with nano silicon and pre-inoculation with strains HB 19459,HB 19461 of B.amyloliquefaciens can enhance resistance to brown planthopper.Seed pretreated with HB 19459 can reduce the honeydew product by BPH feeding.The qRT-PCR showed that seed pretreated with HB19461 could induce the OsPAL gene into priming while feeding by BPH,thereby improving the defense response of rice to BPH.2.Rice seed pre-inoculation with strains G2 and HB 19461 of B.amyloliquefaciens enhanced drought tolerance of rice.G2 can lead to a rapid response of OsbZIP23,OsbZIP23 plays an important role in the ABA pathway,indicating that G2 can induce ABA pathway to rapid response to drought stress.In addition,HB 19461 can induce the OsSIK1 response to drought tolerance more quickly,showed that HB 19461 can improve the drought tolerance with OsSIKl.3.Rice seed pre-inoculation with strain G2 of B.amyloliquefaciens enhanced the tolerance to salt through enhance response of OsYP1 that is an important gene in the H+-pyrophosphatase pathway,indicating that G2 pre-inoculation can leads to primed state of the H+-pyrophosphatase pathway,and then improve the salt tolerance of rice.