Starch is the major component in rice grain that determines not just the cooking and eating quality of rice but also the nutritive value of a particular rice variety.It also plays a key role in determining the consume...Starch is the major component in rice grain that determines not just the cooking and eating quality of rice but also the nutritive value of a particular rice variety.It also plays a key role in determining the consumer acceptance of a variety,its trade and market value.Thus,it is essential to assess the available genetic variation for starch composition in the rice germplasm and its effective utilization in varietal improvement programmes.In assessing the nutritional value of rice,resistant starch has received a lot of attention lately.It plays vital roles in reducing glycaemic index and post prandial glucose.The study evaluated a set of 192 rice genotypes of diverse origins for starch composition and viscosity parameters and observed significant variation for these traits.Genome-wide association studies(GWAS)using the multi-locus models BLINK and FarmCPU in GAPIT software resulted in the identification of 45 significant Marker Trait Associations(MTAs)distributed in 11 of the 12 chromosomes except chromosome 8.A total of 15 annotated genes in the 250 kb LD region flanking the significant SNPs were identified as putative candidates through insilico analysis.Some of the important genes underlying the MTAs found were GBSS1,OsACS,SSG6,RSR1 and OsPUL which are known to be associated with starch synthesis in rice.These significant MTAs could be deployed in manipulating the starch composition and developing tailored rice varieties for various consumer needs.展开更多
A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potentia...A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato（Ipomoea batatas（L.） Lam.）. Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization（DP） of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.展开更多
Cellulosic fibres from coffee(CF)and rice(RF)husks have been obtained applying chemical treatments and characterized as to their microstructure and thermal behaviour.These materials have been incorporated into glycero...Cellulosic fibres from coffee(CF)and rice(RF)husks have been obtained applying chemical treatments and characterized as to their microstructure and thermal behaviour.These materials have been incorporated into glycerol plasticised thermoplastic starch(TPS)films obtained by melt blending and compression moulding at 1 wt%,5 wt%and 10 wt%.Microstructure,thermal behaviour and optical,tensile and barrier properties of the composites were analysed.Both kinds of micro-fibres improve the film stiffness while reduced the film stretchability.However,CF better maintained the film ductility at 1 and 5 wt%.A network of fine oriented fibres was observed on the surface of the films,while internal fibres exhibited a good adherence to the polymer network.The water vapour permeability of TPS films was not reduced in composites,although oxygen permeability was lowered by about 17%.Film transparency decreased by fibre addition in the UVVIS range.Thermal stability of composites was slightly higher than net TPS films.展开更多
基金the Indian Council of Agricultural Research(ICAR)for funding and supporting the work under the CRP-Biofortification project.
文摘Starch is the major component in rice grain that determines not just the cooking and eating quality of rice but also the nutritive value of a particular rice variety.It also plays a key role in determining the consumer acceptance of a variety,its trade and market value.Thus,it is essential to assess the available genetic variation for starch composition in the rice germplasm and its effective utilization in varietal improvement programmes.In assessing the nutritional value of rice,resistant starch has received a lot of attention lately.It plays vital roles in reducing glycaemic index and post prandial glucose.The study evaluated a set of 192 rice genotypes of diverse origins for starch composition and viscosity parameters and observed significant variation for these traits.Genome-wide association studies(GWAS)using the multi-locus models BLINK and FarmCPU in GAPIT software resulted in the identification of 45 significant Marker Trait Associations(MTAs)distributed in 11 of the 12 chromosomes except chromosome 8.A total of 15 annotated genes in the 250 kb LD region flanking the significant SNPs were identified as putative candidates through insilico analysis.Some of the important genes underlying the MTAs found were GBSS1,OsACS,SSG6,RSR1 and OsPUL which are known to be associated with starch synthesis in rice.These significant MTAs could be deployed in manipulating the starch composition and developing tailored rice varieties for various consumer needs.
基金supported by the National Natural Science Foundation of China(31371680)the Beijing Food Crops Innovation Consortium Programthe China Agriculture Research System(CARS-11)
文摘A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato（Ipomoea batatas（L.） Lam.）. Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization（DP） of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.
文摘Cellulosic fibres from coffee(CF)and rice(RF)husks have been obtained applying chemical treatments and characterized as to their microstructure and thermal behaviour.These materials have been incorporated into glycerol plasticised thermoplastic starch(TPS)films obtained by melt blending and compression moulding at 1 wt%,5 wt%and 10 wt%.Microstructure,thermal behaviour and optical,tensile and barrier properties of the composites were analysed.Both kinds of micro-fibres improve the film stiffness while reduced the film stretchability.However,CF better maintained the film ductility at 1 and 5 wt%.A network of fine oriented fibres was observed on the surface of the films,while internal fibres exhibited a good adherence to the polymer network.The water vapour permeability of TPS films was not reduced in composites,although oxygen permeability was lowered by about 17%.Film transparency decreased by fibre addition in the UVVIS range.Thermal stability of composites was slightly higher than net TPS films.
