Primary Study On Programmed Cell Death Of Pyropia Haitanensis Under High Temperature And Dehydration Stress

Pyropia haitanensis is widely cultivated in the southern China coast,which will naturally or artificially experience high temperature stress,dehydration stress and other adversity stress.In this study,we choose the Z-61 strain as materials,which is a high temperature resistant strain breeding by our lab.We use technologies include morphological observation,DNA Ladder,TUNEL and DAPI dyeing to detect programmed cell death of P.haitanensis induced by high temperature stress and dehydration stress.Genes related to the programmed cell death pathway were selected from the P.haitanensis transcriptome,their whole sequences were cloned by RACE and ordinary PCR amplification technology,further sequence analysis were employed using bio-information and q PCR.We preliminary discussed the programmed cell death regulatory mechanism under high temperature stress and dehydration stress,which will offer new thoughts for P.haitanensis resistance mechanism.The main results as follows:1.Under high temperature stress,we found that both Z-61 and WT strain had obvious DNA Ladder phenomenon.TUNEL and DAPI dyeing results further certified that both strains occurs programmed cell death under different time of high temperature.Meanwhile,we also investigated the cell morphology through ordinary optical microscope and found that these strains different in degree of programmed cell death.2.Through analyzing the DNA Ladder of Z-61 and WT strain under dehydration stress,we found that both had obviously DNA Ladder phenomenon which illustrates P.haitanensis will occur programmed cell death under dehydration stress.3.Combined RACE and ordinary PCR amplification technology was applied to clone six gene sequences related programmed cell death which named as Ph Cyt c,Ph Cyt c1,Ph Cap L,Ph Cap L1,Ph IAP,Ph RZF,respectively.Their sequences length are 607,1223,1586,2109,704 and 702 bp,which could encoding 164,205,443,681,231 and 156 amino acids,respectively.4.We also analyzed expression levels of the above genes responding to high temperature and dehydration stress using q PCR.We found that most genes of Z-61 were up-regulated under the two stressors.But genes of WT appeared opposite trends.So we conjectured that P.haitanensis Z-61 strain could effectively regulate programmed cell death pathway to responses stressful conditions.