8-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding AS-sphingo...8-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding AS-sphingolipid desaturases in Brassica rapa. In this study, four genes encoding AS-sphingolipid desaturases from B. rapa were isolated and characterised. Phylogenetic analyses indicated that these genes could be divided into two groups： BrD8A, BrD8C and BrD8D in group I, and BrD8B in group II. The two groups of genes diverged before the separation of Arabidopsis and Brassica. Though the four genes shared a high sequence similarity, and their coding desaturases all located in endoplasmic reticulum, they exhibited distinct expression patterns. Heterologous expression in Saccharomyces cerevisiae revealed that BrD8A/B/C/D were functionally diverse AS-sphingolipid desaturases that catalyse different ratios of the two products 8（Z）- and 8（E）-C18-phytosphingenine. The aluminium tolerance of transgenic yeasts expressing BrD8A/B/C/D was enhanced compared with that of control cells. Expression of BrD8A in Arabidopsis changed the ratio of 8（Z）：8（E）-C 18-phytosphingenine in transgenic plants. The information reported here provides new insights into the biochemical functional diversity and evolutionary relationship of AS-sphingolipid desaturase in plants and lays a foundation for further investigation of the mechanism of 8（Z）- and 8（E）-C18- phytosphingenine biosynthesis.展开更多
In this study,an adsorbent(LCB)with rich honeycomb structure was prepared from cork waste generated from furniture factories for efficient adsorption of excess phosphorus(P)from wastewater.This adsorbent was successfu...In this study,an adsorbent(LCB)with rich honeycomb structure was prepared from cork waste generated from furniture factories for efficient adsorption of excess phosphorus(P)from wastewater.This adsorbent was successfully prepared in only one step,in situ precipitation method,which greatly simplified the synthesis process.Kinetic studies showed that when the initial concentration(C0)of wastewater was 10 mg P L^(−1),the P in the water could be completely adsorbed within 20 min.The adsorption efficiency of phosphorus was significantly improved compared to previous studies.When the C0 of pollutant and the dosage of LCB were 20 mg P L^(−1) and 0.5 g L^(−1),respectively,the removal rate of P exceeded 99%in the pH range of 3-10,which indicates the wide applicability of LCB.In addition,the P adsorption capacity of LCB was 82.4%of its initial value after nine adsorption-desorption cycles,indicating that LCB has a high stability and can be widely used in different water environments.Therefore,LCB is a promising material for the treatment of P-containing wastewater.展开更多
基金supported by the National High-tech R&D Program(863 Program,No.2006AA10A113) of the Ministry of Science and Technology of Chinathe projects of Ministry of Agriculture of China for Transgenic Research (Nos.2009ZX08009-098B and 2008ZX08009-003)
文摘8-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding AS-sphingolipid desaturases in Brassica rapa. In this study, four genes encoding AS-sphingolipid desaturases from B. rapa were isolated and characterised. Phylogenetic analyses indicated that these genes could be divided into two groups： BrD8A, BrD8C and BrD8D in group I, and BrD8B in group II. The two groups of genes diverged before the separation of Arabidopsis and Brassica. Though the four genes shared a high sequence similarity, and their coding desaturases all located in endoplasmic reticulum, they exhibited distinct expression patterns. Heterologous expression in Saccharomyces cerevisiae revealed that BrD8A/B/C/D were functionally diverse AS-sphingolipid desaturases that catalyse different ratios of the two products 8（Z）- and 8（E）-C18-phytosphingenine. The aluminium tolerance of transgenic yeasts expressing BrD8A/B/C/D was enhanced compared with that of control cells. Expression of BrD8A in Arabidopsis changed the ratio of 8（Z）：8（E）-C 18-phytosphingenine in transgenic plants. The information reported here provides new insights into the biochemical functional diversity and evolutionary relationship of AS-sphingolipid desaturase in plants and lays a foundation for further investigation of the mechanism of 8（Z）- and 8（E）-C18- phytosphingenine biosynthesis.
基金National Key R&D Program of China(2019YFC1804400)Special Project for Social Development of Yunnan Province(202103AC100001)+2 种基金Double-First Class University Plan(C176220100042)Postgraduate Research and Innovation Foundation of Yunnan University(KC-23234662)Scientific Research Fund Project of Yunnan Provincial Department of Education(2023Y0210).
文摘In this study,an adsorbent(LCB)with rich honeycomb structure was prepared from cork waste generated from furniture factories for efficient adsorption of excess phosphorus(P)from wastewater.This adsorbent was successfully prepared in only one step,in situ precipitation method,which greatly simplified the synthesis process.Kinetic studies showed that when the initial concentration(C0)of wastewater was 10 mg P L^(−1),the P in the water could be completely adsorbed within 20 min.The adsorption efficiency of phosphorus was significantly improved compared to previous studies.When the C0 of pollutant and the dosage of LCB were 20 mg P L^(−1) and 0.5 g L^(−1),respectively,the removal rate of P exceeded 99%in the pH range of 3-10,which indicates the wide applicability of LCB.In addition,the P adsorption capacity of LCB was 82.4%of its initial value after nine adsorption-desorption cycles,indicating that LCB has a high stability and can be widely used in different water environments.Therefore,LCB is a promising material for the treatment of P-containing wastewater.
