Screening And Identification Of Lanthanum-Resistance Mutants Of Arabidopsis Thaliana

China is a country of large consumption of rare earth, rare earth which used in agriculture has become China's third largest consumer market. Rare earth elements(REEs) has been applied widely in agriculture ,especially application of REEs chemical fertilizer quicken the enrichment and accumulation of rare earth in the soil and environment.Because RE are heavy metal,the effects of REEs on the entironment and human body have aroused whole society attention. At the present time, study of REEs'effect on the entironment after accumulated in the soil has obtained a few fruit, but study of REEs'effect mechanism on the plant has no system.Arabidopsis is a mode plant. Its heredity resource has been exploited and utilized in the different field of biology. Higher plant Arabidopsis belongs to the cruciferous plants. Arabidopsis has a small size, short growth cycle, easy cultivation, seed quantity, simple structure and gene sequences have been fully sequenced genome, research and so easy to transform, so called Arabidopsis plant kingdom's "fly". As a model plant, Arabidopsis has a more important feature is very easy through the induction of a large number of mutants generated, artificial mutation produces mutants. There are many ways, of which there are the more commonly used radiation mutagenesis, insertional mutagenesis and Chemical mutagenesis, etc. Arabidopsis's many mutants have been used for the study of plant growth and metabolize pass. Screening mutants of Arabidopsis have been precondition of many important theory question solved. But utilization of Arabidopsis in REE used in agriculture is few, the study of screening REE-resistance mutants of Arabidopsis is absence at presence.This study have to screen La-resistance mutants of Arabidopsis based on the early study. The mutants will provide base material for gene mapping of La-resistance. The study of La-resistance mutants of Arabidopsis will clarify heredity effect of REE accumulate from the angle of gene , fill up the blank of REE study,perfect environment security evaluate system of REEs'application in agriculture.Through two-layer solid-medium of screening method experiment,roots could grow through the upper layer and penetrate the lower layer containing 50mg/kg La³⁺.Stem and leaf are under the non-intimidate ,and La absorbed by roots of the plant is transfer few to the upside,so seeding can endure even more higher concentration. In view of inoculating quantity in per vessel being finity, and seed germination being variance, and growth condition of root being very hard to control, the screening method using the root-bending assay is selected.Determination of screening pressure, through a series of comparative experiments of concentration gradient found Arabidopsis is restrained at La³⁺ from 7 mg/kg to 13 mg/kg, but still can grow, and it cannot at and up 14 mg/kg La³⁺. 14 mg/kg La³⁺ concertration of Col-0 Arabidopsis be entirely incapable of growing is selected for the best screening pressure at pH 5.5 and 1.0 % agar.By using different mutagenesis methods to filter access to the implantation progeny. Using the above selected screening concentration and screening method the EMS M₂ series are screened. 239 putative mutants are obtained, and cultured in nutritional soil, harvested disparting individual plant.Using the above selected screening concentration and screening method the obtained M₂ series (239 seeds) are screened again, and 58 suspected mutants are obtained, and cultured in nutritional soil, harvested disparting individual plant. Using the higher selected screening concentration, the obtained 58suspected mutants are screeded, Finally found code with KEMS-36 seedlings at higher concentrations (17 mg/kg La³⁺, 21 mg/kg La³⁺) conditions still can continue to grow and be more consistent root bending. We can be initially determined KEMS-36 Arabidopsis La-resistance mutants.