Brassica napus L.(B.napus)is an important oil crop worldwide and it rapidly accumulates oil at late stage of seed maturation.However,little is known about the cellular mechanism of oil accumulation and seed color chan...Brassica napus L.(B.napus)is an important oil crop worldwide and it rapidly accumulates oil at late stage of seed maturation.However,little is known about the cellular mechanism of oil accumulation and seed color changes during the late stage of rapeseed development.Here,we analyzed the ultrastructure of seed coat,aleurone and cotyledon in embryos of B.napus from 25 to 70 days after flowering(DAF).The pigments,which were deposited on the cell wall of palisade cells in seed coat,determined dark black color of rapeseed.The chloroplasts degenerated into non-photosynthetic plastids which caused the green cotyledon to turn into yellow.The chloroplasts in aleurone and cotyledon cells respectively degenerated into remnants without inner and outer envelope membranes and ecoplasts with intact inner and outer envelope membranes.From 40 to 70 DAF,there were degraded chloroplasts without thylakoid,oil bodies contacting with plastids or protein bodies,big starch deposits of chloroplasts degrading into small particles then disappearing,and small endoplasmic reticulum(ER)in aleurone and cotyledon cells.Additionally,there were decreases of chlorophyll content and dramatic increases of oil content in rapeseed.These results suggested that the rapid oil accumulation was independent on the NADPH synthesized by photosynthesis of chloroplasts and probably utilized other sources of reductant,such as the oxidative pentose phosphate pathway during the late stage of rapeseed development.The triacylglycerol assembly presumably utilizes the enzymes in the plastid,cytosol or oil body of cotyledon and aleurone cells.展开更多
基金Project supported by the State Environmental Protection Administration of China (No.2001-1-2)State Environmental Protection Administration of Guangdong (No.2001-08)Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control,and the National Natural Science Foundation of China(Nos.30170147 and 30270282)
文摘从到全球环境的污染的中国的副热带的区域的坚持的有机污染物(流行音乐) 的贡献被付了大注意；然而，很少在中国的这些区域以内在农业生态系统对流行音乐的国家被知道。这研究首先揭示了污染的国家和多不的芳族烃的分发(哼) 在在副热带的区域的农业土壤。115 表土(0 20 厘米) 在这些区域的胃被取样。集中和类型哼坚定的使用气体色层法被连接到质谱法(GCMS ) 。总数哼集中从 22.1 ～ 1 256.9 ng g ? 1，与 318.2 ±的一个平均数 148.2 ng g ? 1。措辞笼统地，水流哼集中比大多数哼低层次从不同国家和区域在很多调查报导了。哼异构体比率显示了那焦性没食子酸 lysin 的起源例如与车辆尾巴气体和工业排出物有关的石块燃料燃烧，是主导的来源在中国的南部的副热带的区域哼。尽管哼集中与减少的污染，人口，和交通密度减少了，在很大程度上哼作文在整个副热带的土壤是类似的与萘，菲， fluoranthene，和是主导的 benzo (b) fluoranthene。
基金the National Natural Science Foundations of China(41877528,41471432 and 31500977)。
文摘Brassica napus L.(B.napus)is an important oil crop worldwide and it rapidly accumulates oil at late stage of seed maturation.However,little is known about the cellular mechanism of oil accumulation and seed color changes during the late stage of rapeseed development.Here,we analyzed the ultrastructure of seed coat,aleurone and cotyledon in embryos of B.napus from 25 to 70 days after flowering(DAF).The pigments,which were deposited on the cell wall of palisade cells in seed coat,determined dark black color of rapeseed.The chloroplasts degenerated into non-photosynthetic plastids which caused the green cotyledon to turn into yellow.The chloroplasts in aleurone and cotyledon cells respectively degenerated into remnants without inner and outer envelope membranes and ecoplasts with intact inner and outer envelope membranes.From 40 to 70 DAF,there were degraded chloroplasts without thylakoid,oil bodies contacting with plastids or protein bodies,big starch deposits of chloroplasts degrading into small particles then disappearing,and small endoplasmic reticulum(ER)in aleurone and cotyledon cells.Additionally,there were decreases of chlorophyll content and dramatic increases of oil content in rapeseed.These results suggested that the rapid oil accumulation was independent on the NADPH synthesized by photosynthesis of chloroplasts and probably utilized other sources of reductant,such as the oxidative pentose phosphate pathway during the late stage of rapeseed development.The triacylglycerol assembly presumably utilizes the enzymes in the plastid,cytosol or oil body of cotyledon and aleurone cells.
