Differential Molecular Responses of Rapeseed Cotyledons to Light and Dark Reveal Metabolic Adaptations toward Autotrophy Establishment

摘要: Photosynthesis competent autotrophy is established during the postgerminative stage of plant growth. Among multiple factors, light plays a decisive role in switch from heterotrophic to autotrophic Under dark conditions, rapeseed hypocotyl extends quickly with an apical hook, and cotyledon yellow folded, maintains high levels isocitrate lyase (ICL). By contrast, light, slowly, unfolds turns green, ICL content changes parallel greening. To reveal metabolic adaptations establishment rapeseed, we conducted comparative proteomic metabolomic analyses cotyledons seedlings grown under versus conditions. both increase proteases, fatty acid β-oxidation glyoxylate-cycle related proteins was accompanied by rapid degradation stored lipids accumulation amino acids. While condition partially retarded these conversions. Light significantly induced expression chlorophyll-binding photorespiration proteins, resulting reducing-sugars. However, some chlorophyllide conversion, Calvin-cycle also accumulated cotyledons, implying that transition heterotrophy programmed seed rather than light. Various anti-stress systems, e.g., redox salicylic acid, proline chaperones, were employed decrease oxidative stress, which mainly derived lipid oxidation or photorespiration, This study provides comprehensive understanding differential molecular responses will facilitate further on complex mechanism underlying autotrophy.