In this report, we demonstrate that sodium hydrosulfide （NariS）, a hydrogen sulfide （H2S） donor, promoted adventitious root formation mediated by auxin and nitric oxide （NO）. Application of the HzS donor to seed...In this report, we demonstrate that sodium hydrosulfide （NariS）, a hydrogen sulfide （H2S） donor, promoted adventitious root formation mediated by auxin and nitric oxide （NO）. Application of the HzS donor to seedling cuttings of sweet potato （Ipomoea batatas L.） promoted the number and length of adventitious roots in a dose-dependent manner. It was also verified that H2S or HS- rather than other sulfur-containing components derived from NariS could be attributed to the stimulation of adventitious root formation. A rapid increase in endogenous H2S, indole acetic acid （IAA） and NO were sequentially observed in shoot tips of sweet potato seedlings treated with HallS. Further investigation showed that H2S-mediated root formation was alleviated by N-1-naphthylphthalamic acid （NPA）, an IAA transport inhibitor, and 2-（4-carboxyphenyl）. 4,4,5,5-tetramethylimidazoline-1-oxyl-3-0xide （cPTIO）, an NO scavenger. Similar phenomena in H2S donor-dependent root organogenesis were observed in both excised willow （Salix matsudana var. tortuosa Vilm） shoots and soybean （Glycine max L.） seedlings. These results indicated that the process of H2S-induced adventitious root formation was likely mediated by IAA and NO, and that H2S acts upstream of IAA and NO signal transduction pathways.展开更多
The MtN3/saliva/SWEET-type genes, existing either alone or in a family group, are found in diverse organisms, from monocellular protozoa to higher eukaryotes, indicating their importance in cellular organisms. These g...The MtN3/saliva/SWEET-type genes, existing either alone or in a family group, are found in diverse organisms, from monocellular protozoa to higher eukaryotes, indicating their importance in cellular organisms. These genes encode polytopic membrane proteins that feature an MtN3/saliva domain, also known as a PQ loop repeat, The rice MtN3/saliva/SWEET gene family consists of 21 members and is among the largest families in sequenced organisms. Accumulating data suggest that these genes are involved in multiple physiological processes, including reproductive development, senescence, environmental adaptation, and host-pathogen interaction, in different species. In rice, some members of the family, including Xa13/Os8N3/OsSWEET11, which is essential for reproductive development, are used by the pathogenic bacterium Xanthomonas oryzae pv. oryzae to invade its host. Emerging data have also revealed that at least some MtN3/saliva/SWEET-type proteins may regulate different physiological processes by facilitating ion transport via interaction with ion transporters or as sugar transporters. The accumulating knowledge about MtN3/saliva/SWEET- type genes will help to elucidate the molecular bases of their function in different organisms.展开更多
Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) +...Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.展开更多
In this study, the proximate composition, mineral content and amino acid composition of starch processing residues from 10 cultivars of sweet potato and 10 cultivars of potato were determined, and the nutritional and ...In this study, the proximate composition, mineral content and amino acid composition of starch processing residues from 10 cultivars of sweet potato and 10 cultivars of potato were determined, and the nutritional and health-related values of these residues were investigated. The residual flours contained 20.63-31.48 g and 17.14-28.57 g rich dietary fiber per 100 g dry weight for sweet potato and potato, respectively, as well as mineral elements, including potassium, ferrum, zinc and copper. The highest limiting amino acid score （AAS） of the almost balanced amino acid composition were observed to be 71.07 and 57.96 for sweet potato and potato residues, respectively. A grey relational analysis showed that the nutritional values of Jishu 4 at 0.7519 and LT-5 at 0.7281 were the highest among the sweet potato and potato residues, respectively. The evaluation of the sweet potato/potato residues, the by-products of the starch industry, based on recommended daily intake （RDI） standards, indicated that the residues have potential nutritional and health-related food values.展开更多
Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY （low light-tolerant gen...Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY （low light-tolerant genotype） and 20078 （low light-sensitive genotype）, were used to study the effects of low light （photosynthetic photon flux density, PPFD was 75- 100 umol m-2 s-1, control 450-500 umol m-2 s-1） on photosynthesis during leaf development. The result indicated that under low light chlorophyll content, net photosynthetic rate （PN）, photosynthetic apparent quantum efficiency （Фi） and carboxylation efficiency （CE） of sweet pepper leaves increased gradually and decreased after reaching the maximum levels. The time to reach the peak values for all the above parameters was delayed, whereas the light compensation point （LCP） decreased gradually along with leaf expansion. The decrease in maximum quantum yield of PS II （Fv/Fm） was not observed at any stages of the leaf development under low light condition, but the actual PS II efficiency under irradiance （ФPS II） was lower accompanied by an increased non-photochemical quenching （NPQ） in young and/or old leaves compared with mature leaves. The antenna thermal dissipation （D） was a main way of heat dissipation when young leaves received excessive light energy, while the decline in photosynthetic function in senescence leaf was mostly owing to the decrease in carbon assimilation capacity, followed by a significantly increased allocation of excessive energy （Ex）. Compared with 20078, ShY could maintain higher PN, ФPS II and lower QA reduction state for a longer time during leaf development. Thus, in ShY photosynthetic efficiency and the activity of electron transport of PS II were not significantly affected due to low light stress.展开更多
Graft can induce inheritable variations in the progenies of the scion plants. Seedling of mungbean ( Vigna radiata (L.) Wilczek) was grafted onto the stem of sweet potato ( Ipomoea batatas (L.) Lam.). The growth...Graft can induce inheritable variations in the progenies of the scion plants. Seedling of mungbean ( Vigna radiata (L.) Wilczek) was grafted onto the stem of sweet potato ( Ipomoea batatas (L.) Lam.). The growth of the scion was maintained until the scion produced selfed seeds. We sowed the seeds for several generations under normal conditions. Distinct genetic variations appeared in the progenies. Similar variations did not appear in the generations of the scion sowed normally without graft. The variations seemed to be induced by the graft and they inherited steadily. For understanding the possible mechanism of the phenomenon (graft_induced inheritable variation), we analyzed the cytoplasmic and genomic DNA of the variations. The results showed that there was no restriction fragment length polymorphism (RFLP) in the cytoplasmic DNA between the original scion and the variation. However, significant difference between the scion and variation was recognized by random amplified polymorphic DNA (RAPD) analysis. In addition, there was no evidence that indicated the gene transformation from stock to scion. Our results suggest that the non_specific grafting has a pragmatic potential for plant breeding and crop improvement and, the genetic variation seems not to be caused simply by DNA transformation but most likely the stress induced mutation.展开更多
SWEET(sugars will eventually be exported transporter)基因家族是一类新型的糖转运蛋白,可顺浓度梯度对糖分进行双向跨膜运输。SWEET在植物光合同化物韧皮部装载、蜜腺花蜜分泌、种子灌浆、花粉发育、病原菌互作、逆境调控等过程中...SWEET(sugars will eventually be exported transporter)基因家族是一类新型的糖转运蛋白,可顺浓度梯度对糖分进行双向跨膜运输。SWEET在植物光合同化物韧皮部装载、蜜腺花蜜分泌、种子灌浆、花粉发育、病原菌互作、逆境调控等过程中起着关键作用,近年来受到广泛关注。尽管SWEET广泛存在于植物中,但目前对其功能研究主要集中在水稻和拟南芥上。介绍了SWEET基因家族的发现、蛋白结构特征、生理功能及逆境调控的最新研究进展,有助于将来对SWEET基因家族进行更深入和全面的研究。展开更多
Sucrose is produced in mesophyll cells and transferred into phloem cells before it is delivered long- distance to sink tissues. However, little is known about how sucrose transport is regulated in plants. Here, we ide...Sucrose is produced in mesophyll cells and transferred into phloem cells before it is delivered long- distance to sink tissues. However, little is known about how sucrose transport is regulated in plants. Here, we identified a T-DNA insertional mutant of Oryza sativa DNA BINDING WITH ONE FINGER 11 （OsDOF11）, which is expressed in the vascular cells of photosynthetic organs and in various sink tissues. The osdofll mutant plants are semi-dwarf and have fewer tillers and smaller panicles as compared with wild-type （WT） plants. Although sucrose enhanced root elongation in young WT seedlings, this enhance- ment did not occur in osdof11 seedlings due to reduced sucrose uptake. Sugar transport rate analyses revealed that less sugar was transported in osdofll plants than in the WT. Expression of four Sucrose Transporter （SUT） genes-OsSUT1, OsSUT3, OsSUT4, and OsSUT5-as well as two Sugars Will Eventually be Exported Transporters （SWEET） genes, OsSWEETll and OsSWEET14, was altered in various organs of the mutant, including the leaves. Chromatin immunoprecipitation assays showed that OsDOFll directly binds the promoter regions of SUT1, OsSWEETll, and OsSWEET14, indicating that the expression of these transporters responsible for sucrose transport via apopiastic loading is coordinately controlled by OsDOFll. We also observed that osdofll mutant plants were less susceptible to infection byXanthomonas oryzae pathovar oryzae, suggesting that OsDOFll participates in sugar distribution during pathogenic in- vasion. Collectively, these results suggest that OsDOFll modulates sugar transport by regulating the expression of both SUT and SWEET genes in rice.展开更多
SWEET(sugars will be eventually exported transporters)是真核生物中普遍存在的一类多基因家族糖转运蛋白,在植物生理代谢、生长发育及植物-微生物互作过程中起重要调控作用。本研究利用RT-PCR、RACE技术,从珍稀药用铁皮石斛(Dendrob...SWEET(sugars will be eventually exported transporters)是真核生物中普遍存在的一类多基因家族糖转运蛋白,在植物生理代谢、生长发育及植物-微生物互作过程中起重要调控作用。本研究利用RT-PCR、RACE技术,从珍稀药用铁皮石斛(Dendrobium officinale Kimura et Migo)中分离到一个全新的SWEET基因,命名为DoSWEET1(Gen Bank注册号KT957550)。DoSWEET1基因cDNA全长1 150 bp,编码1条262个氨基酸组成的多肽,分子质量29.18 kD,等电点9.49。推定的DoSWEET1蛋白无信号肽,具有7个跨膜域,包含植物SWEET家族2个保守MtN3_slv结构域(11-94、130-212)。多序列比对表明,DoSWEET1与多种植物SWEET蛋白一致性较高(45%~54.6%)。进化树结果显示,DoSWEET1与水稻OsSWEET13、OsSWEET14和OsSWEET15亲缘关系最近,隶属于SWEET蛋白家族分子进化树的ClassⅡ分支。qPCR分析揭示,DoSWEET1在石斛3个器官中差异表达,该转录本在根中相对表达量最高,叶中次之,分别为茎中的9.88倍和2.85倍;在胶膜菌Tulasnella sp.侵染石斛共生萌发的3级种子中,该基因转录本剧烈上调为对照的1 359.06倍,说明其参与种子接菌共生萌发过程。DoSWEET1克隆和分子特征为进一步研究该基因在铁皮石斛糖转运及种子共生萌发过程中的调控作用奠定基础。展开更多
[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sod...[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sodium chloride with the concentration of 0 mmol/L and 100 mmol/L.After 20 days,Na+ content and Na+/K+ ratio in the roots,shoots and leave were determined by the flame photometer,while dry weight and fresh weight of roots,shoots and leave in different varieties were also studied.[Result]The growth of two sweet potato varieties was inhibited under salt stress,so the plant became shorter,leaf and root became fewer,dry weight of roots and leave decreased,but seedlings of Xu 25-2 were inhibited slightly.Furthermore,Na+ content and Na+/K+ ratio in roots,shoots and leaves of two sweet potato varieties increased.Na+ content of salt-tolerant Xu 25-2 was low in roots,shoots and leaves,while Na+ content of salt-sensitive Triumph 100 was high in shoots and leave of seedlings,but the change range of Xu 25-2 was less than that of Triumph 100.[Conclusion]The lower Na+ content and Na+/K+ ratio in leaves under salt stress were the most important characteristics for salt-tolerance of sweet potato varieties.展开更多
Anthocyanidin in plants, an important pigment, is of great interest to researchers, consumers, and commercial entities due to its physiological functions. Anthocyanin content and mRNA levels of anthocynin biosynthesis...Anthocyanidin in plants, an important pigment, is of great interest to researchers, consumers, and commercial entities due to its physiological functions. Anthocyanin content and mRNA levels of anthocynin biosynthesis genes were investigated in storage root of different purple-fleshed sweet potatoes (PFSP) genotypes to understand the regulation mechanism of anthocyanin under weak light conditions. Anthocyanin content, its amount of accumulation, and the expression of CHS, DFR, F3H, GT, and ANS genes in the PFSP storage root under weak light conditions were studied. The results demonstrated that the anthocyanin content of the treatments was decreased and was obviously lower than that of the control until 30 days after shading in Ayamurasaki, while it was lower than that of the control from the beginning of shading in Jishu 18. Their accumulation rates of both treatmeants were lower than its control before 10-20 d of shading in Jishu 18, while those of Ayamurasaki weren't in their treatments. This indicated that Jishul 8 is more sensitive to light as compared to Ayamuraska. Under the different weak light conditions, mRNA levels for ibCHS, ibF3H, ibDFR, and ibANS were obviously decreased, while the expression of ibGT was increased. These results indicated that anthocyanin content was regulated by light at the mRNA levels and the enzymatic level in sweet potato. Therefore, the development dynamic response to anthocyanin content varied in different genotypes of PFSP, and mRNA levels of anthocyanin biosynthesis were inhibited under the weak light condition.展开更多
基金Supported by the Great Project of the Natural Science Foundation from Anhui Provincial Education Department (ZD200910)the Natural Science Foundation of Anhui Province (070411009)the Innovation Funding to Undergraduate Students at HFUT (XS08072, 0637)
文摘In this report, we demonstrate that sodium hydrosulfide （NariS）, a hydrogen sulfide （H2S） donor, promoted adventitious root formation mediated by auxin and nitric oxide （NO）. Application of the HzS donor to seedling cuttings of sweet potato （Ipomoea batatas L.） promoted the number and length of adventitious roots in a dose-dependent manner. It was also verified that H2S or HS- rather than other sulfur-containing components derived from NariS could be attributed to the stimulation of adventitious root formation. A rapid increase in endogenous H2S, indole acetic acid （IAA） and NO were sequentially observed in shoot tips of sweet potato seedlings treated with HallS. Further investigation showed that H2S-mediated root formation was alleviated by N-1-naphthylphthalamic acid （NPA）, an IAA transport inhibitor, and 2-（4-carboxyphenyl）. 4,4,5,5-tetramethylimidazoline-1-oxyl-3-0xide （cPTIO）, an NO scavenger. Similar phenomena in H2S donor-dependent root organogenesis were observed in both excised willow （Salix matsudana var. tortuosa Vilm） shoots and soybean （Glycine max L.） seedlings. These results indicated that the process of H2S-induced adventitious root formation was likely mediated by IAA and NO, and that H2S acts upstream of IAA and NO signal transduction pathways.
基金This work was supported by grants from the National Program on the Development of Basic Research in China （2012CB114005）the National Program of High Technology Development of China （2012AA10A303） and the National Natural Science Foundation of China （31100875）No conflict of interest declared.
文摘The MtN3/saliva/SWEET-type genes, existing either alone or in a family group, are found in diverse organisms, from monocellular protozoa to higher eukaryotes, indicating their importance in cellular organisms. These genes encode polytopic membrane proteins that feature an MtN3/saliva domain, also known as a PQ loop repeat, The rice MtN3/saliva/SWEET gene family consists of 21 members and is among the largest families in sequenced organisms. Accumulating data suggest that these genes are involved in multiple physiological processes, including reproductive development, senescence, environmental adaptation, and host-pathogen interaction, in different species. In rice, some members of the family, including Xa13/Os8N3/OsSWEET11, which is essential for reproductive development, are used by the pathogenic bacterium Xanthomonas oryzae pv. oryzae to invade its host. Emerging data have also revealed that at least some MtN3/saliva/SWEET-type proteins may regulate different physiological processes by facilitating ion transport via interaction with ion transporters or as sugar transporters. The accumulating knowledge about MtN3/saliva/SWEET- type genes will help to elucidate the molecular bases of their function in different organisms.
文摘Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.
基金supported by the National Key Research and Development Program of China(2017YFD0400401)the Public Welfare Industry(Agriculture) Research Project,China(201503001-2)the earmarked foud for the China Agriculture Research System(CARS-10-B21)
文摘In this study, the proximate composition, mineral content and amino acid composition of starch processing residues from 10 cultivars of sweet potato and 10 cultivars of potato were determined, and the nutritional and health-related values of these residues were investigated. The residual flours contained 20.63-31.48 g and 17.14-28.57 g rich dietary fiber per 100 g dry weight for sweet potato and potato, respectively, as well as mineral elements, including potassium, ferrum, zinc and copper. The highest limiting amino acid score （AAS） of the almost balanced amino acid composition were observed to be 71.07 and 57.96 for sweet potato and potato residues, respectively. A grey relational analysis showed that the nutritional values of Jishu 4 at 0.7519 and LT-5 at 0.7281 were the highest among the sweet potato and potato residues, respectively. The evaluation of the sweet potato/potato residues, the by-products of the starch industry, based on recommended daily intake （RDI） standards, indicated that the residues have potential nutritional and health-related food values.
基金supported by the National Science and Technology Support Program, China (2011BAZ01732-2)the Earmarked Fund for Modern Agro-Industry Technology Research System in China (CARS-25-A-07)
文摘Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY （low light-tolerant genotype） and 20078 （low light-sensitive genotype）, were used to study the effects of low light （photosynthetic photon flux density, PPFD was 75- 100 umol m-2 s-1, control 450-500 umol m-2 s-1） on photosynthesis during leaf development. The result indicated that under low light chlorophyll content, net photosynthetic rate （PN）, photosynthetic apparent quantum efficiency （Фi） and carboxylation efficiency （CE） of sweet pepper leaves increased gradually and decreased after reaching the maximum levels. The time to reach the peak values for all the above parameters was delayed, whereas the light compensation point （LCP） decreased gradually along with leaf expansion. The decrease in maximum quantum yield of PS II （Fv/Fm） was not observed at any stages of the leaf development under low light condition, but the actual PS II efficiency under irradiance （ФPS II） was lower accompanied by an increased non-photochemical quenching （NPQ） in young and/or old leaves compared with mature leaves. The antenna thermal dissipation （D） was a main way of heat dissipation when young leaves received excessive light energy, while the decline in photosynthetic function in senescence leaf was mostly owing to the decrease in carbon assimilation capacity, followed by a significantly increased allocation of excessive energy （Ex）. Compared with 20078, ShY could maintain higher PN, ФPS II and lower QA reduction state for a longer time during leaf development. Thus, in ShY photosynthetic efficiency and the activity of electron transport of PS II were not significantly affected due to low light stress.
文摘Graft can induce inheritable variations in the progenies of the scion plants. Seedling of mungbean ( Vigna radiata (L.) Wilczek) was grafted onto the stem of sweet potato ( Ipomoea batatas (L.) Lam.). The growth of the scion was maintained until the scion produced selfed seeds. We sowed the seeds for several generations under normal conditions. Distinct genetic variations appeared in the progenies. Similar variations did not appear in the generations of the scion sowed normally without graft. The variations seemed to be induced by the graft and they inherited steadily. For understanding the possible mechanism of the phenomenon (graft_induced inheritable variation), we analyzed the cytoplasmic and genomic DNA of the variations. The results showed that there was no restriction fragment length polymorphism (RFLP) in the cytoplasmic DNA between the original scion and the variation. However, significant difference between the scion and variation was recognized by random amplified polymorphic DNA (RAPD) analysis. In addition, there was no evidence that indicated the gene transformation from stock to scion. Our results suggest that the non_specific grafting has a pragmatic potential for plant breeding and crop improvement and, the genetic variation seems not to be caused simply by DNA transformation but most likely the stress induced mutation.
文摘SWEET(sugars will eventually be exported transporter)基因家族是一类新型的糖转运蛋白,可顺浓度梯度对糖分进行双向跨膜运输。SWEET在植物光合同化物韧皮部装载、蜜腺花蜜分泌、种子灌浆、花粉发育、病原菌互作、逆境调控等过程中起着关键作用,近年来受到广泛关注。尽管SWEET广泛存在于植物中,但目前对其功能研究主要集中在水稻和拟南芥上。介绍了SWEET基因家族的发现、蛋白结构特征、生理功能及逆境调控的最新研究进展,有助于将来对SWEET基因家族进行更深入和全面的研究。
文摘Sucrose is produced in mesophyll cells and transferred into phloem cells before it is delivered long- distance to sink tissues. However, little is known about how sucrose transport is regulated in plants. Here, we identified a T-DNA insertional mutant of Oryza sativa DNA BINDING WITH ONE FINGER 11 （OsDOF11）, which is expressed in the vascular cells of photosynthetic organs and in various sink tissues. The osdofll mutant plants are semi-dwarf and have fewer tillers and smaller panicles as compared with wild-type （WT） plants. Although sucrose enhanced root elongation in young WT seedlings, this enhance- ment did not occur in osdof11 seedlings due to reduced sucrose uptake. Sugar transport rate analyses revealed that less sugar was transported in osdofll plants than in the WT. Expression of four Sucrose Transporter （SUT） genes-OsSUT1, OsSUT3, OsSUT4, and OsSUT5-as well as two Sugars Will Eventually be Exported Transporters （SWEET） genes, OsSWEETll and OsSWEET14, was altered in various organs of the mutant, including the leaves. Chromatin immunoprecipitation assays showed that OsDOFll directly binds the promoter regions of SUT1, OsSWEETll, and OsSWEET14, indicating that the expression of these transporters responsible for sucrose transport via apopiastic loading is coordinately controlled by OsDOFll. We also observed that osdofll mutant plants were less susceptible to infection byXanthomonas oryzae pathovar oryzae, suggesting that OsDOFll participates in sugar distribution during pathogenic in- vasion. Collectively, these results suggest that OsDOFll modulates sugar transport by regulating the expression of both SUT and SWEET genes in rice.
文摘SWEET(sugars will be eventually exported transporters)是真核生物中普遍存在的一类多基因家族糖转运蛋白,在植物生理代谢、生长发育及植物-微生物互作过程中起重要调控作用。本研究利用RT-PCR、RACE技术,从珍稀药用铁皮石斛(Dendrobium officinale Kimura et Migo)中分离到一个全新的SWEET基因,命名为DoSWEET1(Gen Bank注册号KT957550)。DoSWEET1基因cDNA全长1 150 bp,编码1条262个氨基酸组成的多肽,分子质量29.18 kD,等电点9.49。推定的DoSWEET1蛋白无信号肽,具有7个跨膜域,包含植物SWEET家族2个保守MtN3_slv结构域(11-94、130-212)。多序列比对表明,DoSWEET1与多种植物SWEET蛋白一致性较高(45%~54.6%)。进化树结果显示,DoSWEET1与水稻OsSWEET13、OsSWEET14和OsSWEET15亲缘关系最近,隶属于SWEET蛋白家族分子进化树的ClassⅡ分支。qPCR分析揭示,DoSWEET1在石斛3个器官中差异表达,该转录本在根中相对表达量最高,叶中次之,分别为茎中的9.88倍和2.85倍;在胶膜菌Tulasnella sp.侵染石斛共生萌发的3级种子中,该基因转录本剧烈上调为对照的1 359.06倍,说明其参与种子接菌共生萌发过程。DoSWEET1克隆和分子特征为进一步研究该基因在铁皮石斛糖转运及种子共生萌发过程中的调控作用奠定基础。
基金Supported by the National Natural Science Foundation(30670177)Scientific Research Foundation for the Outstanding Young Scientist of Shangdong Province(006BS06002)National Ministry of Education Doctoral Fund(20050445003)~~
文摘[Objective] This study aimed to investigate the salt-tolerance mechanism of sweet potato.[Method]Two sweet potato varieties of Xu 25-2(salt-tolerant cultivar)and Triumph 100(salt-sensitive cultivar)were treated by sodium chloride with the concentration of 0 mmol/L and 100 mmol/L.After 20 days,Na+ content and Na+/K+ ratio in the roots,shoots and leave were determined by the flame photometer,while dry weight and fresh weight of roots,shoots and leave in different varieties were also studied.[Result]The growth of two sweet potato varieties was inhibited under salt stress,so the plant became shorter,leaf and root became fewer,dry weight of roots and leave decreased,but seedlings of Xu 25-2 were inhibited slightly.Furthermore,Na+ content and Na+/K+ ratio in roots,shoots and leaves of two sweet potato varieties increased.Na+ content of salt-tolerant Xu 25-2 was low in roots,shoots and leaves,while Na+ content of salt-sensitive Triumph 100 was high in shoots and leave of seedlings,but the change range of Xu 25-2 was less than that of Triumph 100.[Conclusion]The lower Na+ content and Na+/K+ ratio in leaves under salt stress were the most important characteristics for salt-tolerance of sweet potato varieties.
基金support by the NationalHigh-Tech R&D Program of China (863 Program,2006AA100107)the National Key Technologies R&DProgram of China (2006BAD01A06-2)+2 种基金the NationalSpecial Scientific Research Project for Public Industryof China (nyhyzx07-012-03)the Project of 948 from Ministry of Agriculture of China (2006-G21-02)the National System of Sweet Potato Industrial Tech-nology of China (nycytx-16-B-3)
文摘Anthocyanidin in plants, an important pigment, is of great interest to researchers, consumers, and commercial entities due to its physiological functions. Anthocyanin content and mRNA levels of anthocynin biosynthesis genes were investigated in storage root of different purple-fleshed sweet potatoes (PFSP) genotypes to understand the regulation mechanism of anthocyanin under weak light conditions. Anthocyanin content, its amount of accumulation, and the expression of CHS, DFR, F3H, GT, and ANS genes in the PFSP storage root under weak light conditions were studied. The results demonstrated that the anthocyanin content of the treatments was decreased and was obviously lower than that of the control until 30 days after shading in Ayamurasaki, while it was lower than that of the control from the beginning of shading in Jishu 18. Their accumulation rates of both treatmeants were lower than its control before 10-20 d of shading in Jishu 18, while those of Ayamurasaki weren't in their treatments. This indicated that Jishul 8 is more sensitive to light as compared to Ayamuraska. Under the different weak light conditions, mRNA levels for ibCHS, ibF3H, ibDFR, and ibANS were obviously decreased, while the expression of ibGT was increased. These results indicated that anthocyanin content was regulated by light at the mRNA levels and the enzymatic level in sweet potato. Therefore, the development dynamic response to anthocyanin content varied in different genotypes of PFSP, and mRNA levels of anthocyanin biosynthesis were inhibited under the weak light condition.
