a: embryos before PDT; b: embryos after 7 days of PDT; c: embryos after 14 days of PDT
Partial desiccation treatment (PDT) stimulates germination and enhances the conversion of conifer somatic embryos. To better understand the mechanisms underlying the responses of somatic embryos to PDT, the team of Prof. Junhui Wang used proteomic and physiological analyses to investigate these responses during PDT in Picea asperata. Comparative proteomic analysis revealed that, during PDT, stress-related proteins were mainly involved in osmosis, endogenous hormones, anti-oxidative proteins, molecular chaperones, and defense-related proteins. Compared with those in cotyledonary embryos before PDT, these stress-related proteins remained at high levels on days 7 (D7) and 14 (D14) of PDT. The proteins that differentially-accumulated in the somatic embryos on D7 were mapped to stress and/or stimuli. They may also be involved in the glyoxylate cycle and the chitin metabolic process. The most significant difference in the differentially-accumulated proteins occurred in the metabolic pathways of photosynthesis on D14. Furthermore, in accordance with the changes in stress-related proteins, analyses of changes in water content, abscisic acid, indoleacetic acid and H2O2 levels in the embryos indicated that PDT is involved in water deficit tolerance and affects endogenous hormones. These results provide insight into the mechanisms responsible for the transition from morphologically mature to physiologically mature somatic embryos during the PDT process in P. asperata.
The article “Proteomic analysis of stress-related proteins and metabolic pathways in Piceaasperata somatic embryos during partial desiccation” has been published on Plant Biotechnology Journal (doi: 10.1111/pbi.12588). Danlong Jing and Jianwei Zhang contributed equally to this work. This work was supported by a grant from the China Twelfth Five-Year Plan for Science & Technology Support (2012BAD01B01).