Regulation Of Growth And Abiotic Stress Tolerance By Sphingolipid Metabolism In Brassica Napus L.

China is the second largest rapeseed oil producing countries,and the rapeseed oil production accounts for about 45% of the vegetable oil produced in China.However,the change of natural environment,such as drought,chilling injury,salinity and cold,have great impact on the growth of rapeseed and oil content.Improve the rapeseed of abiotic stress tolerance become one of the focus of rapeseed research.This research mainly focused on introstigation of sphingolipids' function during the process of growth and development,and the change of sphingolipids content and composition in rapeseed in response to abiotic stress.As an important component of cell membrane,sphingolipid also participates in the regulation of cell growth,cell division,apoptosis and abiotic stress response.In plants have been reported on the sphingolipids signaling pathway involved in regulating programmed cell death,ABA signaling pathway,pollen development and low temperature signal pathway,but specific regulatory mechanism is not detailed,especially the receptors,target proteins and regulatory factors in the signaling pathway of sphingolipids are unknown.In our study,we analyzed the content and composition of sphingolipids in different tissues of rapeseed by mass spectrometry,and found that the levels of Sph d18:0 and Sph d18:1 decreased significantly in leaves under dehydration and salt stress.This result was consistent with the higher gene expression levels of SphK.Through the transcriptome results,we found that the expression level of key genes in decreased significantly in leaves under dehydration and salt stress tolerance.The above data show that sphingolipids may be involved in regulation of rapeseed abiotic stress.Then we cloned two regulatory genes including sphingosine-1-phosphate(S1P)lyase(SPL1,SPL2)and two regulatory genes including sphingosine-1-phosphate(S1P)phosphatase(SPP1,SPP2),we build the vectors for over expression and CRISPR/Cas9 mutants and got the positive transgenic plants,for determining the phenotype identification and the composition and content of the sphingolipids,and studying the influence of the sphingolipids metabolism on the growth and the abiotic stress tolerance of the rapeseed.