光合作用同化物分配供给是果实和种子发育的主要限制因子,增加蔗糖分配转运到果实和种子是增产优质的潜在策略。SWEET(sugar will eventually be exported transporter)是近年来被鉴定较多的一类糖转运蛋白,该蛋白质通过从源叶运输营养...光合作用同化物分配供给是果实和种子发育的主要限制因子,增加蔗糖分配转运到果实和种子是增产优质的潜在策略。SWEET(sugar will eventually be exported transporter)是近年来被鉴定较多的一类糖转运蛋白,该蛋白质通过从源叶运输营养物质调控库组织发育,参与植物生长发育以及生物和非生物胁迫反应。SWEET蛋白定位于膜结构,属于MtN3家族,通常包含7个跨膜结构域,其中包含2个MtN3/saliva结构域。随着染色体加倍、片段复制和串联复制等,SWEET基因在物种中得到扩张。SWEET4和SWEET39基因是作物驯化改良过程中选择的关键基因;SWEET9蛋白是蜜腺特异性糖转运蛋白,参与植物蜜腺的进化;SWEET16和SWEET17蛋白参与植物根系生长发育;SWEET11和SWEET15蛋白参与植物种子胚乳填充。本文系统综述了SWEET蛋白的结构、数量、分类、亚细胞定位、成员扩张与进化,分析了SWEET蛋白在叶、茎、根系发育,花药发育,花蜜分泌,种子填充和果实发育等植物生长发育中的功能作用,强调了SWEET蛋白在作物改良中的应用,说明增强源库强度对作物产量提高的可持续性具有重要意义。展开更多
AIM: To investigate the effects of proteins purified from sweet potato storage roots on human colorectal cancer cell lines. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst 33...AIM: To investigate the effects of proteins purified from sweet potato storage roots on human colorectal cancer cell lines. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst 33258 nuclear staining and Boyden transwell chamber methods were used to determine whether purified sweet potato protein (SPP) from fresh sweet potato roots affected proliferation, migration and invasion, respectively, of human colorectal cancer SW480 cells in vitro . The inhibitory effects of SPP on growth of human colorectal cancer HCT-8 cells intraperitoneally xenografted in nude mice and spontaneous lung metastasis of murine Lewis lung carcinoma 3LL cells subcutaneously transplanted in C57 BL/6 mice were also investigated in vivo . RESULTS: SPP inhibited the proliferation of SW480 cells in a dose-dependent manner, with an IC 50 value of 38.732 μmol/L (r2 = 0.980, P = 0.003) in the MTT assay. Hoechst 33258 nuclear staining further revealed inhibition of cell viability and induction of apoptosis by SPP. The transwell assay disclosed significant reduction in migrated cells/field by 8 μmol/L SPP (8.4 ± 2.6 vs 23.3 ± 5.4, P = 0.031) and invaded cells/field through the ECMatrix by 0.8 μmol/L SPP, compared with the control (25.2 ± 5.2 vs 34.8 ± 6.1, P = 0.038). Both intraperitoneal (ip) and intragastric (ig) administration of SPP led to significant suppression of growth of intraperitoneally inoculated HCT-8 cells in nude mice to 58.0% ± 5.9% (P = 0.037) and 43.5% ± 7.1% (P = 0.004) of the controls, respectively, after 9 d treatment. Bloody ascites additionally disappeared after ip injection of trypsin inhibitor. Notably, ig and ip administration of SPP induced a significant decrease in spontaneous pulmonary metastatic nodule formation in C57 BL/6 mice (21.0 ± 12.3 and 27.3 ± 12.7 nodules/lung vs 42.5 ± 4.5 nodules/lung in controls, respectively, P < 0.05) after 25 d treatment. Moreover, the average weight of primary tumor nodules in the hind leg of mice decreased from 8.2 ± 1.3 g/mice in the control to 6.1 ± 1.4 g/mice in the ip group (P = 0.035). CONCLUSION: SPP exerts significant antiproliferative and antimetastatic effects on human colorectal cancer cell lines, both in vitro and in vivo .展开更多
Some indices concerning the metabolism of substance and energy in sweet potato leaves underwater stress were studied. The results showed an obvious increase in soluble protein content. Compared withcontrol, Chl a, Chl...Some indices concerning the metabolism of substance and energy in sweet potato leaves underwater stress were studied. The results showed an obvious increase in soluble protein content. Compared withcontrol, Chl a, Chl b, total Chl contents and the ratio of Chl a to Chl b all decreased to some extent. ATPcontent increased in some varieties and decreased in others, but the stronger the drought resistance of the vari-ety, the higher the ATP content. The correlation coefficient(r)of the soluble protein content, ratio of Chl a toChl b and ATP content as a percentage of the drought-resistant sweet potato control variety are 0. 8968,- 0. 8509 and 0. 8200, respectively, P<0.01. So these indices can be used to evaluate the drought resistance ofdifferent sweet potato varieties.展开更多
Australian Sweet Lupin (ASL) has a nutritional profile ideally suited for human consumption with high protein and fibre, but low starch and fat content. The nutritional and protein profile of germinated ASL may be bet...Australian Sweet Lupin (ASL) has a nutritional profile ideally suited for human consumption with high protein and fibre, but low starch and fat content. The nutritional and protein profile of germinated ASL may be better than ungerminated ASL and these improvements would provide further benefits in its use as an ingredient in food applications. In this study the nutritional components such as protein, crude fibre, fat and protein profile of germinated ASL flour following germination at 25℃ and 90% - 95% relative humidity for 9 days were determined. The changes in the pattern of ASL protein during germination were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Germination significantly increased crude fibre contents by 450% (db), total protein contents by 38% (db) and decreased the fat content by 70% (db) at day 9 of germination. Electrophoretic analysis of the protein fractions revealed that during germination up to 9 days, some of the high molecular weight proteins disappeared. Germination represents a means to further improve the nutritional profile of the germinated ASL flour with an increased fibre and protein, but lower fat content.展开更多
Despite being a healthy low glycaemic index food, the production and consumption of sweet potatoes are decreasing globally. The global production trends indicated a decline from 130.47 million tonnes (MT) in 2004 to 1...Despite being a healthy low glycaemic index food, the production and consumption of sweet potatoes are decreasing globally. The global production trends indicated a decline from 130.47 million tonnes (MT) in 2004 to 107.64 MT in 2009, while the production in China, having the largest share towards world production of sweet potatoes, witnessed a decrease from 105.84 MT in 2004 to 81.21 MT in 2009. There is an interest in increasing consumption of healthy low glycaeimic index foods, especially in the context of a projected alarming rise in the diabetic population in the developing world by 2025. The objective of this study was to enhance the utilization of sweet potato as a low glycaemic food, mainly through its use in the development of high protein pasta. Among three protein sources, whey protein concentrate (WPC), defatted soy flour (DSF), and fish powder (FP), WPC gave high quality pasta with strong starch-protein network formation, as evidenced from scanning electron microscopic studies and low in vitro starch digestibility. Protein nutritional quality was also high for WPC-fortified sweet potato pasta, with very high scores for lysine and leucine as well as high essential amino acid index and calculated protein efficiency ratio. Fractionation of starch showed that the WPC-fortified sweet potato pasta had the lowest rapidly digested starch (RDS) and the highest resistant starch (RS) content, indicating its potential as a low glycaemic food.展开更多
Sweet potato is one of the first natural GMOs, genetically modified 8000 years ago by Agrobacterium rhizogenes as reported recently by Kyndt et al. A section of 10 kbp long DNA (Transferred- DNA or T-DNA) of the Ri (R...Sweet potato is one of the first natural GMOs, genetically modified 8000 years ago by Agrobacterium rhizogenes as reported recently by Kyndt et al. A section of 10 kbp long DNA (Transferred- DNA or T-DNA) of the Ri (Root-inducing) plasmid was transferred to the plant genome by A. rhizo-genes and has been maintained in all 291 hexaploid sweet potato cultivars of the world. The maintenance in the sweet potato genome and expression of two T-DNA genes for tryptophan-2-monooxygenease (iaaM) and for indole-3-acetamide hydrolase (iaaH) are likely to be physiologically significant since these enzymes convert tryptophan to indole-3-acetic acid, a major plant growth hormone auxin. Sweet potato (Ipomoea batatas (L.) Lam) is ranked the third most important root crop after potato and cassava, and the seventh in global food crop production with more than 126 million metric tons. Although sweet potato originated in Central or South America, China currently produces over 86% of world production with 109 million metric tons. In the United States, North Carolina is the leading producer with 38.5% of the 2007 sweet potato production, followed by California, Mississippi, and Louisiana with 23%, 19%, and 15.9%, respectively. Leaf curl virus diseases have been reported in sweet potato throughout the world. One of the causal agents is Sweet potato leaf curl virus (SPLCV) belonging to the genus Begomovirus (family Geminiviridae). Although SPLCV does not cause symptoms on Beauregard, one of the most predominant sweet potato cultivars in the US, it can reduce the yield up to 26%. Serological detection of SPLCV is not currently available due to the difficulties in obtaining purified virions that can be used as antigen for antiserum production. In attempts to obtain the coat protein (CP) of SPLCV for antibody production, primers were designed to amplify the CP gene. This gene was cloned into the expression vector pMAL-c2E as a fusion protein with maltose-binding protein, and transformed into Escherichia coli strain XL1-Blue. After gene induction, a fusion protein of 72 kDa was purified by amylose affinity chromatography. The yield of the purified fusion protein was approximately 200 μg/liter of bacterial culture. Digestion with enterokinase cleaved the fusion protein into a 42.5 kDa maltosebinding protein and a 29.4 kDa protein. The latter protein was identified by mass spectrometry analysis as the coat protein of SPLCV based on the fact that the mass spectrometry elucidated the sequences corresponding to 37% of amino acid positions of the SPLCV coat protein.展开更多
为探究蛋白质和淀粉对魔芋凝胶的影响,研究不同质量分数红薯淀粉(sweet potato starch,SPS)和大豆分离蛋白(soy protein isolate,SPI)对魔芋凝胶的质地、色泽、感官、水分分布、流变学特性和微观结构的影响。单因素试验结果表明,SPS质...为探究蛋白质和淀粉对魔芋凝胶的影响,研究不同质量分数红薯淀粉(sweet potato starch,SPS)和大豆分离蛋白(soy protein isolate,SPI)对魔芋凝胶的质地、色泽、感官、水分分布、流变学特性和微观结构的影响。单因素试验结果表明,SPS质量分数从0%增加到2.5%对魔芋凝胶质构特性有显著影响(P<0.05),硬度和弹性分别上升86.43%和27.69%,凝胶强度和持水性显著上升(P<0.05);添加2%以下的SPI显著提高凝胶的L*值和b*值(P<0.05),硬度和弹性分别上升13.41%和15.38%,凝胶强度和持水性显著上升(P<0.05),但胶黏性降低54.19%。流变学分析结果表明,随着SPS和SPI质量分数增加,凝胶G’和G”值逐渐上升,表明凝胶结构更加牢固。低场核磁共振结果表明,二者的添加显著增加了凝胶体系中结合水含量(P<0.05),自由水和弛豫时间没有显著变化。综合评分实验结果表明,优化配比后的复合凝胶质构特性进一步提高。扫描电子显微镜结果表明,优化配比后的复合凝胶形成更为致密、结构连续的稳定结构。研究表明添加2.5%SPS和1.0%SPI为复合凝胶的最佳配比。总体来说,本研究结果为魔芋凝胶在方便即食食品的应用提供良好的实验参考和理论基础。展开更多
文摘光合作用同化物分配供给是果实和种子发育的主要限制因子,增加蔗糖分配转运到果实和种子是增产优质的潜在策略。SWEET(sugar will eventually be exported transporter)是近年来被鉴定较多的一类糖转运蛋白,该蛋白质通过从源叶运输营养物质调控库组织发育,参与植物生长发育以及生物和非生物胁迫反应。SWEET蛋白定位于膜结构,属于MtN3家族,通常包含7个跨膜结构域,其中包含2个MtN3/saliva结构域。随着染色体加倍、片段复制和串联复制等,SWEET基因在物种中得到扩张。SWEET4和SWEET39基因是作物驯化改良过程中选择的关键基因;SWEET9蛋白是蜜腺特异性糖转运蛋白,参与植物蜜腺的进化;SWEET16和SWEET17蛋白参与植物根系生长发育;SWEET11和SWEET15蛋白参与植物种子胚乳填充。本文系统综述了SWEET蛋白的结构、数量、分类、亚细胞定位、成员扩张与进化,分析了SWEET蛋白在叶、茎、根系发育,花药发育,花蜜分泌,种子填充和果实发育等植物生长发育中的功能作用,强调了SWEET蛋白在作物改良中的应用,说明增强源库强度对作物产量提高的可持续性具有重要意义。
基金Supported by The Earmarked Fund for China Agriculture Research System, No. CARS-11-B-19"Technique of Processing and Utilization for Plant Proteins" from China-Argentina Science and Technology Cooperation Program, No. 2010DFA32690+1 种基金Grant from the Capital Medical University, No. 2009ZR03 and No. 2012ZR17the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions
文摘AIM: To investigate the effects of proteins purified from sweet potato storage roots on human colorectal cancer cell lines. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst 33258 nuclear staining and Boyden transwell chamber methods were used to determine whether purified sweet potato protein (SPP) from fresh sweet potato roots affected proliferation, migration and invasion, respectively, of human colorectal cancer SW480 cells in vitro . The inhibitory effects of SPP on growth of human colorectal cancer HCT-8 cells intraperitoneally xenografted in nude mice and spontaneous lung metastasis of murine Lewis lung carcinoma 3LL cells subcutaneously transplanted in C57 BL/6 mice were also investigated in vivo . RESULTS: SPP inhibited the proliferation of SW480 cells in a dose-dependent manner, with an IC 50 value of 38.732 μmol/L (r2 = 0.980, P = 0.003) in the MTT assay. Hoechst 33258 nuclear staining further revealed inhibition of cell viability and induction of apoptosis by SPP. The transwell assay disclosed significant reduction in migrated cells/field by 8 μmol/L SPP (8.4 ± 2.6 vs 23.3 ± 5.4, P = 0.031) and invaded cells/field through the ECMatrix by 0.8 μmol/L SPP, compared with the control (25.2 ± 5.2 vs 34.8 ± 6.1, P = 0.038). Both intraperitoneal (ip) and intragastric (ig) administration of SPP led to significant suppression of growth of intraperitoneally inoculated HCT-8 cells in nude mice to 58.0% ± 5.9% (P = 0.037) and 43.5% ± 7.1% (P = 0.004) of the controls, respectively, after 9 d treatment. Bloody ascites additionally disappeared after ip injection of trypsin inhibitor. Notably, ig and ip administration of SPP induced a significant decrease in spontaneous pulmonary metastatic nodule formation in C57 BL/6 mice (21.0 ± 12.3 and 27.3 ± 12.7 nodules/lung vs 42.5 ± 4.5 nodules/lung in controls, respectively, P < 0.05) after 25 d treatment. Moreover, the average weight of primary tumor nodules in the hind leg of mice decreased from 8.2 ± 1.3 g/mice in the control to 6.1 ± 1.4 g/mice in the ip group (P = 0.035). CONCLUSION: SPP exerts significant antiproliferative and antimetastatic effects on human colorectal cancer cell lines, both in vitro and in vivo .
文摘Some indices concerning the metabolism of substance and energy in sweet potato leaves underwater stress were studied. The results showed an obvious increase in soluble protein content. Compared withcontrol, Chl a, Chl b, total Chl contents and the ratio of Chl a to Chl b all decreased to some extent. ATPcontent increased in some varieties and decreased in others, but the stronger the drought resistance of the vari-ety, the higher the ATP content. The correlation coefficient(r)of the soluble protein content, ratio of Chl a toChl b and ATP content as a percentage of the drought-resistant sweet potato control variety are 0. 8968,- 0. 8509 and 0. 8200, respectively, P<0.01. So these indices can be used to evaluate the drought resistance ofdifferent sweet potato varieties.
文摘Australian Sweet Lupin (ASL) has a nutritional profile ideally suited for human consumption with high protein and fibre, but low starch and fat content. The nutritional and protein profile of germinated ASL may be better than ungerminated ASL and these improvements would provide further benefits in its use as an ingredient in food applications. In this study the nutritional components such as protein, crude fibre, fat and protein profile of germinated ASL flour following germination at 25℃ and 90% - 95% relative humidity for 9 days were determined. The changes in the pattern of ASL protein during germination were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Germination significantly increased crude fibre contents by 450% (db), total protein contents by 38% (db) and decreased the fat content by 70% (db) at day 9 of germination. Electrophoretic analysis of the protein fractions revealed that during germination up to 9 days, some of the high molecular weight proteins disappeared. Germination represents a means to further improve the nutritional profile of the germinated ASL flour with an increased fibre and protein, but lower fat content.
文摘Despite being a healthy low glycaemic index food, the production and consumption of sweet potatoes are decreasing globally. The global production trends indicated a decline from 130.47 million tonnes (MT) in 2004 to 107.64 MT in 2009, while the production in China, having the largest share towards world production of sweet potatoes, witnessed a decrease from 105.84 MT in 2004 to 81.21 MT in 2009. There is an interest in increasing consumption of healthy low glycaeimic index foods, especially in the context of a projected alarming rise in the diabetic population in the developing world by 2025. The objective of this study was to enhance the utilization of sweet potato as a low glycaemic food, mainly through its use in the development of high protein pasta. Among three protein sources, whey protein concentrate (WPC), defatted soy flour (DSF), and fish powder (FP), WPC gave high quality pasta with strong starch-protein network formation, as evidenced from scanning electron microscopic studies and low in vitro starch digestibility. Protein nutritional quality was also high for WPC-fortified sweet potato pasta, with very high scores for lysine and leucine as well as high essential amino acid index and calculated protein efficiency ratio. Fractionation of starch showed that the WPC-fortified sweet potato pasta had the lowest rapidly digested starch (RDS) and the highest resistant starch (RS) content, indicating its potential as a low glycaemic food.
文摘Sweet potato is one of the first natural GMOs, genetically modified 8000 years ago by Agrobacterium rhizogenes as reported recently by Kyndt et al. A section of 10 kbp long DNA (Transferred- DNA or T-DNA) of the Ri (Root-inducing) plasmid was transferred to the plant genome by A. rhizo-genes and has been maintained in all 291 hexaploid sweet potato cultivars of the world. The maintenance in the sweet potato genome and expression of two T-DNA genes for tryptophan-2-monooxygenease (iaaM) and for indole-3-acetamide hydrolase (iaaH) are likely to be physiologically significant since these enzymes convert tryptophan to indole-3-acetic acid, a major plant growth hormone auxin. Sweet potato (Ipomoea batatas (L.) Lam) is ranked the third most important root crop after potato and cassava, and the seventh in global food crop production with more than 126 million metric tons. Although sweet potato originated in Central or South America, China currently produces over 86% of world production with 109 million metric tons. In the United States, North Carolina is the leading producer with 38.5% of the 2007 sweet potato production, followed by California, Mississippi, and Louisiana with 23%, 19%, and 15.9%, respectively. Leaf curl virus diseases have been reported in sweet potato throughout the world. One of the causal agents is Sweet potato leaf curl virus (SPLCV) belonging to the genus Begomovirus (family Geminiviridae). Although SPLCV does not cause symptoms on Beauregard, one of the most predominant sweet potato cultivars in the US, it can reduce the yield up to 26%. Serological detection of SPLCV is not currently available due to the difficulties in obtaining purified virions that can be used as antigen for antiserum production. In attempts to obtain the coat protein (CP) of SPLCV for antibody production, primers were designed to amplify the CP gene. This gene was cloned into the expression vector pMAL-c2E as a fusion protein with maltose-binding protein, and transformed into Escherichia coli strain XL1-Blue. After gene induction, a fusion protein of 72 kDa was purified by amylose affinity chromatography. The yield of the purified fusion protein was approximately 200 μg/liter of bacterial culture. Digestion with enterokinase cleaved the fusion protein into a 42.5 kDa maltosebinding protein and a 29.4 kDa protein. The latter protein was identified by mass spectrometry analysis as the coat protein of SPLCV based on the fact that the mass spectrometry elucidated the sequences corresponding to 37% of amino acid positions of the SPLCV coat protein.
文摘为探究蛋白质和淀粉对魔芋凝胶的影响,研究不同质量分数红薯淀粉(sweet potato starch,SPS)和大豆分离蛋白(soy protein isolate,SPI)对魔芋凝胶的质地、色泽、感官、水分分布、流变学特性和微观结构的影响。单因素试验结果表明,SPS质量分数从0%增加到2.5%对魔芋凝胶质构特性有显著影响(P<0.05),硬度和弹性分别上升86.43%和27.69%,凝胶强度和持水性显著上升(P<0.05);添加2%以下的SPI显著提高凝胶的L*值和b*值(P<0.05),硬度和弹性分别上升13.41%和15.38%,凝胶强度和持水性显著上升(P<0.05),但胶黏性降低54.19%。流变学分析结果表明,随着SPS和SPI质量分数增加,凝胶G’和G”值逐渐上升,表明凝胶结构更加牢固。低场核磁共振结果表明,二者的添加显著增加了凝胶体系中结合水含量(P<0.05),自由水和弛豫时间没有显著变化。综合评分实验结果表明,优化配比后的复合凝胶质构特性进一步提高。扫描电子显微镜结果表明,优化配比后的复合凝胶形成更为致密、结构连续的稳定结构。研究表明添加2.5%SPS和1.0%SPI为复合凝胶的最佳配比。总体来说,本研究结果为魔芋凝胶在方便即食食品的应用提供良好的实验参考和理论基础。
