变温层积不同阶段刺五加种子萌发生理及代谢特点OA北大核心CSTPCD

To investigate the dormancy type and physiological and metabolic characteristics of Acanthopanax senticosus seeds during germination,the seeds from northeast China were treated with sand accumulation for 140 days under different temperature conditions(20 ℃,4 ℃,20 ℃/4 ℃)respectively.Five distinct stages were identified based on embryo phenotypic changes,and the dynamic changes in endogenous hormones,main nutrient substances and their hydrolases,antioxidant system,and metabolomics during these five stages were examined respectively.The results revealed that:(1)A.senticosus seeds exhibited good water absorption;while the constant temperature of 20 ℃ only promoted embryo elongation,but not germination.There was no increase in embryo rate at 4 ℃,and the embryo rate increased and the seeds germinated only when the temperature was maintained at 20 ℃ for 0-110 d and 4 ℃ for 110-140 d.(2)As the embryo growth rate increased,gibberellic acid content increased while abscisic acid content decreased.The levels of indoleacetic acid,indolebutyric acid,and naphthenic acetic acid all decreased.Fat content decreased while soluble sugar content increased.Fat content showed a significant negative correlation with lipohydrolase activity as well as a highly significant negative correlation with soluble sugar content.(3)A total of 92 differential metabolites were screened,and the carbon metabolism,energy metabolism,and antioxidant metabolism were the major differential metabolic pathways.Additionally,there were difference in sesquiterpene and triterpene biosynthesis,fatty acid biosynthesis and glyceride metabolism.In conclusion,seeds of A.senticosus were morphological and physiological dormancy,and variable temperature stratification was a necessary condition to break seed dormancy,and endogenous hormones might regulate seed dormancy and germination.Macromolecular nutrients such as fat were decomposed by hydrolases to provide material and energy for seed germination,which was also one of the necessary conditions for seed germination.This study provided theoretical guidance for identifying seed dormancy types and artificial propagation of A.senticosus.