Effect Of Rare Earth Element Lanthanum On Drought Resistance And CDNA-AFLP Analysis Of Upland Cotton Seedling Under Drought Stress

Cotton is a water consuming crop,the drought is an important factor that affects the yield of cotton in our country.Under drought condition,the balance between the scavenging activity of free radical scavenging activity and the accumulation of excessive reactive oxygen species,which is harmful to the growth of crops.Previous studies have indicated that the rare earth element lanthanum can improve plant stress resistance,including the ability to significantly enhance the plant antioxidant capacity.But so far,the anti oxidative mechanism of Lanthanum on drought resistance has not been reported.In this study,the different concentration of lanthanum chloride solution pre treated cotton seedlings,then were treated with drought stress,through the determination of seedling leaves of superoxide ions,soluble protein,free proline and MDA content and pod,SOD,CAT activity.And the cDNA-AFLP technology was used to screen the genes of lanthanum chloride to alleviate drought stress,and to provide reference for the suppression of the drought resistance of the cotton growth.The main results are as follows:(1)By drought treatment of cotton seedlings(3d)found that the color of cotton leaves than in the control group became yellow,in lanthanum chloride pre treated several groups of cotton leaf color than drought group to green,which 200 mg·L-1 processing group leaf color is close to that of the control group,indicating that lanthanum chloride concentration of the pre culture under the arid environment of cotton seedling chloroplasts to better protective effect.(2)Drought stress will make cotton seedling leaves of superoxide anion,MDA,free proline,soluble protein content significantly increased,SOD,pod,CAT activity significantly increased,and the lanthanum chloride solution,pre incubation of cotton leaves,physiological indexes was lower than that of the untreated closer to the normal value,which with 200 mg·L-1 concentration of processing on relieving of cotton seedlings subjected to drought stress effect is the best.(3)The experiment by 64 primer combinations for cDNA AFLP amplification,received a total of 2164 clear bands,from isolated 32 differentially expressed fragments,cloning,sequencing and sequence analysis of the expression differences of 21 TDFS.The results showed that the 17 TDFs,11 were up-regulated and 6 were down-regulated under drought stress;And 4 specific expression of TDFs was found between the treatment group and the dry group.Through and the known functional genes in NCBI homology alignment to predict the function of these differentially expressed TDFS,results show that these fragments function including signal transduction,transcriptional regulation,stress response,cell metabolism and stress aspects,explanation of cotton through various types of gene association with mutual harm the plants caused by drought resistance.