Elevated CO(2) concentration promotes photosynthesis of grape (Vitis vinifera L. cv. 'Pinot noir') plantlet in vitro by regulating RbcS and Rca revealed by proteomic and transcriptomic profiles.

BACKGROUND: Plant photosynthesis can be improved by elevated CO(2) concentration (eCO(2)). In vitro growth under CO(2) enriched environment can lead to greater biomass accumulation than the conventional in micropropagation. However, little is know about how eCO(2) promotes transformation of grape plantlets in vitro from heterotrophic to autotrophic. In addition, how photosynthesis-related genes and their proteins are expressed under eCO(2) and the mechanisms of how eCO(2) regulates RbcS, Rca and their proteins have not been reported. RESULTS: Grape (Vitis vinifera L. cv. 'Pinot Noir') plantlets in vitro were cultured with 2% sucrose designated as control (CK), with eCO(2) (1000 μmol·mol(- 1)) as C0, with both 2% sucrose and eCO(2) as Cs. Here, transcriptomic and proteomic profiles associated with photosynthesis and growth in leaves of V. vinifera at different CO(2) concentration were analyzed. A total of 1814 genes (465 up-regulated and 1349 down-regulated) and 172 proteins (80 up-regulated and 97 down-regulated) were significantly differentially expressed in eCO(2) compared to CK. Photosynthesis-antenna, photosynthesis and metabolism pathways were enriched based on GO and KEGG. Simultaneously, 9, 6 and 48 proteins were involved in the three pathways, respectively. The leaf area, plantlet height, qP, ΦPSII and ETR increased under eCO(2), whereas Fv/Fm and NPQ decreased. Changes of these physiological indexes are related to the function of DEPs. After combined analysis of proteomic and transcriptomic, the results make clear that eCO(2) have different effects on gene transcription and translation. RbcS was not correlated with its mRNA level, suggesting that the change in the amount of RbcS is regulated at their transcript levels by eCO(2). However, Rca was negatively correlated with its mRNA level, it is suggested that the change in the amount of its corresponding protein is regulated at their translation levels by eCO(2). CONCLUSIONS: Transcriptomic, proteomic and physiological analysis were used to evaluate eCO2 effects on photosynthesis. The eCO(2) triggered the RbcS and Rca up-regulated, thus promoting photosynthesis and then advancing transformation of grape plantlets from heterotrophic to autotrophic. This research will helpful to understand the influence of eCO(2) on plant growth and promote reveal the mechanism of plant transformation from heterotrophic to autotrophic.