A Preliminary Study On The Function Of LRR - RLKs Family Of LL1 Gene In Pollen Tube Sensation Of Arabidopsis Thaliana

The quality of food depends largely on the quality of agricultural raw materials, and the crop varieties are the most critical factor in determining the crop quality. Crossbreeding was the major method to improve the quality of agricultural products, but a phenomenon called cross barrier shows the low rate of fertility always occurs in the hybrid F1generation. In the double fertilization process, the angiosprem evolve a precise regulatory pathway to control the growth of the pollen tube toward the embryo sac, enter the micropyle and release the sperms to complete double fertilization. While cross barrier often occurs in the process of fertilization, especially during pollen tube receiving signals which guide the growing pollen tubes.As a model plant, Arabidopsis thaliana is an ideal plant for the study of pollen tube signal-oriented process. But in Arabidopsis, there are few research results on pollen tube guidance. As receptor-like protein kinases, LRR-RLKs are likely to participate in this process and play an important role.Based on the microarray data of pollen, a member of the LRR-RLKs gene family, LL1, is isolated and analyzed. The homozygous T-DNA insertion mutant of LL1is obtained from TAIR stock center, and genotyping confirmed the T-DNA insertion in LL1. RT-PCR analysis further confirms that the111mutant is homozygous. Aniline blue staining shows that111is defective in pollen tube guidance. Statistical analysis indicates the defect ratio is just a bit higher than the wild type. This indicates redundancy exists in this process, which means other receptor-like kinase may also be involved. LL1-GFP fusion construct expressed in protoplast shows LL1is located in the plasma menbrane. Southern blot result shows that there is more than oneT-DNA insert in111background.Through the above preliminary analysis on LL1, the conclusion is that as a member of the family of LRR-RLKs, LL1is likely involved in the process of pollen tube guidance. However, because of the presence of the multiple copies of T-DNA insertion and existence other redundant proteins, the mutant phenotype is not obvious, and further research is needed.