No abstract

Epimedium brevicornu Maxim is a traditional Chinese medicinal plant with important value for curing several diseases, including liver cancer. Seed germination, field seedling emergence, and morphological and physiological traits were measured in developing seeds of E. brevicornu, which were collected at 7, 14, 21, 28, and 35 days after flowering. The results showed that with the fruit pericarp changing from lime green to dark red, the seed volume increased. Furthermore, the dry mass of seeds gradually increased from 0.011 g at 7 d to 0.275 g at 35 d, which was a significantly positive correlation with seed vigour (r = 0.980). The soluble protein content initially increased and then decreased to 11.09 mg/g and presented a maximum at 28 d; however, the soluble sugar content gradually declined to a minimum of 30.45 mg/g at 35 d, which was also significantly negatively correlated with seed vigour (r = −0.915). Furthermore, the unsaturated fatty acids (oleic acid and linoleic acid) increase with seed development. Abscisic acid (ABA) reached a maximum value of 18.45 ng/g at 28 d, and gibberellin (GA3), 3-Indoleacetic acid (IAA) and zeatin-riboside (ZR) initially increased and then decreased. These results suggest that the vigour of E. brevicornu seeds is closely associated with their stage of development, with the highest vigour observed at 28~35 d after flowering.

Purpose: Epimedium brevicornu Maxim. is a perennial persistent C3 plant of the genus Epimedium Linn. in the family Berberaceae that exhibits severe physiological and morphological seed dormancy. We placed mature E.brevicornu seeds under nine stratification treatment conditions and explored the mechanisms of influence by combining seed embryo growth status assessment with related metabolic pathways and gene co-expression analysis. Results: We identified 3.9 °C as the optimum cold-stratification temperature of E.brevicornu seeds via a chilling unit (CU) model. The best treatment was variable-temperature stratification (10/20 °C, 12/12 h) for 120 d followed by low-temperature stratification (4 °C) for 90 d. A total of 63801 differentially expressed genes were annotated to 2587 transcription factors (TFs) in 17 clusters in two comparisons. Genes specifically highly expressed in the dormancy release treatment group were significantly enriched in embryo development ending in seed dormancy and fatty acid degradation, indicating the importance of these two processes. Coexpression analysis implied that the TF GRF had the most reciprocal relationships with genes, and multiple interactions centered on zf-HD and YABBY as well as on MYB, GRF, and TCP were observed. Conclusion: In this study, analyses of plant hormone signal pathways and fatty acid degradation pathways revealed changes in key genes during the dor- mancy release of E.brevicornu seeds, providing evidence for the filtering of E.brevicornu seed dormancy-related genes.