Lipidomics Under Salt Stress In Oryza.Sativa L

Sphingolipids and phospholipids in plant whole lipids are important components of plant cell membrane,and glycerides are important components of plant light and membrane.Cell membrane is the first barrier for plants to resist adverse factors under the stress of adversity.Therefore,through long-term evolution,plants can autonomously change the content and components of cell membrane lipids with the changes of the external environment to improve the survival ability of plants in adversity.GIPC(glucophosphatidylinositol ceramide)is the most abundant spongolipids in plants and plays an important role in the process of stress resistance.Ipcs synthase is a key enzyme in the biosynthesis of GIPCS.Under salt stress,plants can increase the synthesis of IPC by up-regulating the expression of ipcs.Related studies have shown that GIPC located on the plasma membrane can combine with Na+ to open Ca2+ channel,and this salt sensitive mechanism may mean that plasma membrane lipides are involved in the adaptation of different environmental salt levels,which can be used to improve the salinity resistance of crops.In this study,we take "the 93-11" conventional indica and "rice" 86 sea salt resistance indica two rice varieties as materials,by comparing the ipcs gene under different growth conditions in the two kinds of rice gene expression level in order to further speculated that the ipcs family type,by extracting rice whole qualitative differences in content and composition change and study its under salt stress response mechanism,so as to increase rice production of resilience and provide theoretical basis.The results are as follows:1.Under normal growth conditions,compared with 93-11,haitao 86 has narrower and slender leaves.Although haitao 86 grows slightly faster in 3weeks than 93-11,the same number of leaves weigh less than 93-11.Its stem and "sea rice86" comparison is also relatively stout.In the two rice seedlings treated with 100mmol/LNaCl for 3 weeks,"sea rice 86" had a stronger salt-resistant phenotype than "93-11".2.The contents of water content,malondialdehyde,soluble sugar and proline in two kinds of rice seedlings of3 weeks were determined by 100mmol/LNaCl after sampling at different time points.It was found that the water content of the two kinds of rice was basically the same before and after treatment.The content of malondialdehyde and soluble sugar increased and then decreased with the treatment time,and the content of proline increased with the treatment time.3.Two kinds of rice seedlings with a size of 3 weeks were treated with 100mmol/LNaCl,and the gene expression was determined after sampling at different time points.It was found that the gene expressions of Os IPCS01g(Os IPCS1)and Os IPCS05g(Os IPCS3)in "93-11" conventional rice varied greatly.There was a significant increase in stress and then a decrease,but the level of expression after the decrease was still higher than that of the control group.The expression of Os IPCS05g(Os IPCS2)gene increased slowly with the extension of treatment time.No downward trend in 0-9 hours.However,there was no significant change in the gene expression of Os IPCS in sea rice 86 salt tolerant rice.It is speculated that "93-11" has more sensitive molecular response mechanism than "sea rice 86" in response to salt stress.4.After treatment with 100mmol/LNaCl for 3 weeks for 4 hours,a total of 24 kinds of lipid difference metabolites of the two kinds of rice seedlings were detected by mass spectrometry,which can be divided into three categories,including phospholipids,sphingolipids and glycerides.Among them,phospholipids include membrane phospholipids and hemolysis phospholipids.In terms of identification types,TAG has the most identification types and LPS the least.The average content of MGDG is the highest.Phyto Cer t18:1/h24:0),glucosylphosphatidylinositol ceramide(GIPC t18:0/h22:1),Glu Cer t18:1(Glu Cer t18:1),are the first three metabolites with the most significant differences among the four groups of 86-0,86-100,9311-0 and 9311-100.It is worth emphasizing that these three metabolites belong to sphingolipids,so it is speculated that sphingolipids play an important role in the response mechanism of plants to salt stress.