[Objective] This research aimed to study the FTIR spectra of corn germs and endosperms so as to provide a scientific way for identifying corn of different types. [Method] The corn germs and endosperms of three types w...[Objective] This research aimed to study the FTIR spectra of corn germs and endosperms so as to provide a scientific way for identifying corn of different types. [Method] The corn germs and endosperms of three types were studied by using Fourier transform infrared spectroscopy（FTIR） technology, combined with cluster analysis. [Result] The overall characteristics of original FTIR spectra were basically similar within the range of 700-1 800 cm^-1. The FTIR spectra were mainly composed by the absorption peaks of polysaccharides, proteins and lipids. Within the wavelength range of 700-1 800 cm^-1, there were only tiny differences in original FTIR spectra among the corn germs and endosperms of three different types. The spectra were then processed by using first derivative and second derivative. The second derivative spectra were used for hierarchical cluster analysis（HCA）. The results showed that with the wavelength range of 700-1 800 cm^-1, the second derivative spectra of the 52 samples could be better clustered according to the tree types and corn germ and corn endosperm. The clustering correct rate reached 96.1%.[Conclusion] FTIR technology, combined with cluster analysis, can be used to identify different types of corn germs and endosperms, and it is characterized by convenience and rapidness.展开更多
Recently, improving eating quality and processing properties has become one of the most important objectives in japonica rice breeding programs in Korea. This study was carried out to determine the agronomy and physic...Recently, improving eating quality and processing properties has become one of the most important objectives in japonica rice breeding programs in Korea. This study was carried out to determine the agronomy and physicochemical characteristics of the opaque endosperm rice "S-21-3-8" regenerated from seed-derived callus culture of a rice cultivar, "Ilpum". S3 generation of opaque endosperm mutants selected from pedigree breeding was used for analysis of agronomic and physicochemical traits. Genetic segregation was observed at the highest frequency among opaque endosperm mutants, being present in 85.7% (12/14 lines) of the entire opaque lines. However, the major agricultural characteristics and grain traits of "S-21-3-8" were similar to those of a donor cultivar, "Ilpum". "S-21-3-8" showed significantly lower (10.6%) amylose than those (17.7%) of "Ilpum" in brown rice, while the protein levels were similar to those of the donor plant. The grain hardness of "S-21-3-8" (1.67 kgf/mm2) was lower than that of "Ilpum" (1.97 kgf/mm2), resulting in a high flour-milling percentage. The loosely packed starch granules of "S-21-3-8" in the opaque endosperm were demonstrated by SEM analysis of cross-sectioned rice grains. The opaque endosperm mutants that were of somaclonal variations in the tissue culture will lead to improved eating quality and processing properties of rice.展开更多
Although it is known that in most angiosperms mitosis in early endosperm development is syncytial and synchronized, it is unclear how the synchronization is regulated. We showed previously that APC11, also named ZYGI,...Although it is known that in most angiosperms mitosis in early endosperm development is syncytial and synchronized, it is unclear how the synchronization is regulated. We showed previously that APC11, also named ZYGI, in Arabidopsis activates zygote division by interaction and degradation of cyclin B1. Here, we report that the mutation in APC11/ZYG1 led to unsynchronized mitosis and over-accumulation of cyclin B1-GUS in the endosperm. Mutations in two other APC subunits showed similar defects. Transgenic expression of stable cyclin B1 in the endosperm also caused unsynchronized mitosis. Further, downregulation of APC11 generated multi-nucleate somatic cells with unsynchronized mitotic division. Together, our results suggest that APC/C-mediated cyclin B1 degradation is critical for cell cycle synchronization.展开更多
Phosphorylation is one of the major posttranslational modifications to control plant growth and development.Opaque2(O2)represents a central hub for endosperm filling,which largely determines seed yield and nutrient st...Phosphorylation is one of the major posttranslational modifications to control plant growth and development.Opaque2(O2)represents a central hub for endosperm filling,which largely determines seed yield and nutrient storage in maize.However,it still remains unclear how O2 phosphorylation orchestrates endosperm filling and nutrient quality.Here,we systematically identified the phosphorylation sites of O2 during endosperm filling.A total of 18 phosphorylation sites were found in O2 and five sites were identified to apparently modulate its subcellular localization and transactivation capacity.In addition,a conserved protein kinase CK1 was confirmed to interact with and phosphorylate O2 at the residue Threonine(T)202 to promote O2-mediated transactivation and protein stability.Overexpression of CK1 resulted in increased kernel size,100-kernel weight and nutrient storage.Phosphorylation-mimic O2 seeds at T202 exhibited enhanced kernel dimension,test weight,vitreous endosperm area and nutrient accumulation,whereas the phosphorylation-deficient O2 seeds did not.Collectively,this study establishes a comprehensive phosphocode atlas of O2 during endosperm filling and highlights the importance of phosphorylation modification in O2 to precisely orchestrate maize yield and nutrient quality.展开更多
Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in eluc...Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in elucidating the physiology of endosperm filling in inferior grains,the role of the embryo remains underexplored and warrants comprehensive investigation.Two Wuyujing 3 mutants,DW024(relatively synchronous;syn-DW024)and DW179(significantly asynchronous;asyn-DW179),with different grain-filling patterns were used in this study.Samples of superior and inferior grains were collected at intervals from 5 to 60 d after fertilization and subsequently dissected into subsamples of the embryo and endosperm.Histochemical staining,biochemical analysis,and RNA sequencing(RNA-seq)were combined to systematically compare developmental and physiological traits between superior and inferior grains.Combining hierarchical clustering of mRNA datasets revealed three developmental phases of the endosperm and embryo:morphogenesis,endosperm filling/embryo enlargement,and maturation.In both syn-DW024 and asyn-DW179,the duration of the endosperm/embryo morphogenesis phase was identical in superior and inferior grains.The inferior grains of asyn-DW179 exhibited a 10-day prolongation in the endosperm filling phase and a 20-day extension in the embryo enlargement phase compared to the superior grains.The endosperm of inferior grains exhibited higher contents of sugars and free amino acids,along with slower accumulation of storage compounds,which was associated with the down-regulation of genes for starch synthesis and ABA signaling.In addition,transporters for nutrient exchanges between endosperm and embryo were down-regulated,suggesting a potential role of the embryo in adjusting the endosperm filling process.Collectively,our results reveal that the prolonged phases of endosperm filling and embryo enlargement may underlie the impaired development of inferior grains,offering a new perspective for breeding or cultivating rice with uniform grain quality.展开更多
Arogenate dehydratase(ADT)catalyzes the final step in phenylalanine synthesis and is crucial for plant development and metabolism.Previously,we demonstrated that the ADT/prephenate dehydratase ZmADT2 is essential for ...Arogenate dehydratase(ADT)catalyzes the final step in phenylalanine synthesis and is crucial for plant development and metabolism.Previously,we demonstrated that the ADT/prephenate dehydratase ZmADT2 is essential for maize resistance to Ustilago maydis and for overall plant development.In this study,we explored the role of ZmADT2 in maize kernel development.The mmsu mutant,a dysfunctional ZmADT2 variant,exhibits delayed embryo and endosperm development,along with deficiencies in carbohydrate and protein storage.Transcriptome analysis revealed differential expression of many kernel compartment-specific genes between mmsu and wild-type(WT)kernels,with impaired nutrient accumulation and auxin signaling pathway in the mmsu endosperm.Compared to WT,ZmADT2 mutation led to reduced auxin levels and smaller endosperm cell size.Exogenous auxin rescued the small kernel phenotype of mmsu.Additionally,auxin distribution was reduced in the basal endosperm transfer layer(BETL),causing defects in its development and function,including reduced transfer cell elongation,cell wall ingrowth and nutrient uptake.These findings suggest that ZmADT2 mediated mediates an auxin signaling pathway that is essential for maize kernel development.展开更多
Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences product...Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences productivity.In this study,we revealed the role of smk23 in maize kernel development.The ethyl methanesulfonate mutant smk23 is characterized by substantially reduced kernel weight.Through map-based cloning,smk23 was found to be located on Chr5 and encode a putative B-type response regulator,Zm RR5.A change from G to A occurs in the coding sequence of Zm RR5,resulting in the early termination of smk23.In Arabidopsis,B-type response regulators are involved in cytokinin signaling.Histological analysis and in situ hybridization of the mutant revealed abnormal endosperm development,particularly in the basal endosperm transfer layer(BETL),a specialized tissue critical for nutrient transport from the maternal tissues to the developing kernel.Zm RR5 positively regulates key genes involved in BETL development and function,including MRP1 and TCRR1.Furthermore,RNA sequencing revealed that several genes closely linked to BETL development,including BETL2,MEG1,and MN1,were significantly downregulated in smk23.These genes are essential for nutrient transport,tissue development and signal transduction.In addition,haploid analysis of Zm RR5 revealed natural variations(Hap 2)that may contribute to the increased kernel yield.Disruption of Zm RR5 function in smk23 leads to defects in BETL development,impairing its ability to transport nutrients,and ultimately resulting in a smaller kernel size.This study provides new insights into the molecular mechanisms through which Zm RR5 regulates maize kernel development and offers potential strategies for improving grain yield.展开更多
Starch is a vital energy source for living organisms and is a key raw material and additive in the food and non-food industries.Starch has received continuous attention in multiple research fields.The endosperm of cer...Starch is a vital energy source for living organisms and is a key raw material and additive in the food and non-food industries.Starch has received continuous attention in multiple research fields.The endosperm of cereals(e.g.,rice,corn,wheat,and barley)is the most important site for the synthesis of storage starch.Around 2010,several excellent reviews summarized key progress in various fields of starch research,serving as important references for subsequent research.In the past 10 years,many achievements have been made in the study of starch synthesis and regulation in cereals.The present review provides an update on research progress in starch synthesis of cereal endosperms over the past decade,focusing on new enzymes and non-enzymatic proteins involved in starch synthesis,regulatory networks of starch synthesis,and the use of elite alleles of starch synthesis-related genes in cereal breeding programs.We also provide perspectives on future research directions that will further our understanding of cereal starch biosynthesis and regulation to support the rational design of ideal quality grain.展开更多
The 5' upstream region (—680—+40) containing the complete signal peptide coding sequence of the rice seed storage prolamin gene was amplified in vitro with polymerase chain reaction from the genome of Chinese su...The 5' upstream region (—680—+40) containing the complete signal peptide coding sequence of the rice seed storage prolamin gene was amplified in vitro with polymerase chain reaction from the genome of Chinese super rice cultivar Zhonghua 8. Physical map and DNA sequence analysis showed strong homology with the 5'-flanking region of rice prolamin gene reported by Kim in 1988. No changes in the signal peptide coding sequence and a long leader sequence with several small ORFs were found. Chimeric gene containing 5'-flanking region of the prolamin gene has been transcriptionally fused with the β-glucuronidase reporter gene. The fusion junction was confirmed by both physical map and DNA sequence analysis. The resultant chimeric gene was used to transform the tabacco explants by Ti binary system of Agrobacterium tumefaciens LBA4404. With dot and Southern blotting hybridization, three transgenic tobacco plants with the copies of chimeric GUS genes as many as 20 were obtained. Histochemical analysis revealed that the GUS activity in the endosperm tissues of tobacco seeds at the developmental stage was about 20 DAP. No GUS activity was found in leaves, stems, roots and flowers of the transgenic tobacco plants. Therefore, we concluded that the 5'-upstream cis-elements from—680 to—18 were enough to confer the endosperm-specific and temporal expression of rice prolamin gene.展开更多
The early development of the endosperm is crucial for balancing the allocation of maternal nutrients to offspring.This process is believed to be evolutionarily associated with genomic imprinting,resulting in parentall...The early development of the endosperm is crucial for balancing the allocation of maternal nutrients to offspring.This process is believed to be evolutionarily associated with genomic imprinting,resulting in parentally biased allelic gene expression.Beyond Fertilization Independent Seed(FIS)genes,the number of imprinted genes involved in early endosperm development and seed size determination remains limited.This study introduces early endosperm-expressed HAIKU(IKU)downstream Candidate F-box 1(ICF1)and ICF2 as maternally expressed imprinted genes(MEGs)in Arabidopsis thaliana.Although these genes are also demethylated by DEMETER(DME)in the central cell,their activation differs from the direct DME-mediated activation seen in classical MEGs such as the FIS genes.Instead,ICF maternal alleles carry pre-established hypomethylation in their promoters,priming them for activation by the WRKY10 transcription factor in the endosperm.On the contrary,paternal alleles are predominantly suppressed by CG methylation.Furthermore,we find that ICF genes partially contribute to the small seed size observed in iku mutants.Our discovery reveals a two-step regulatory mechanism that highlights the important role of conventional transcription factors in the activation of imprinted genes,which was previously not fully recognized.Therefore,the mechanism provides a new dimension to understand the transcriptional regulation of imprinting in plant reproduction and development.展开更多
Amylose content(AC)is a crucial determinant of the eating and cooking quality(ECQ)of rice,with low AC varieties exhibiting a softer texture and greater stickiness-attributes that enhance palatability and are desirable...Amylose content(AC)is a crucial determinant of the eating and cooking quality(ECQ)of rice,with low AC varieties exhibiting a softer texture and greater stickiness-attributes that enhance palatability and are desirable in specific culinary contexts.To harness these traits,significant efforts have been made to manipulate AC to improve rice ECQ.Our research utilized the MutMap+approach to identify LAC6/TL1,a gene that is an allele of Du13,responsible for low AC.LAC6 encodes a C2H2 zinc finger protein,which specifically increases the splicing efficiency of the Wxb allele without affecting the Wxa allele.Functional studies of LAC6 revealed that its proper integration could rectify the undesirable AC phenotype,whereas mutations within this gene led to reduced AC and were associated with shorter grain length and decreased thousand-grain weight.Despite these drawbacks,such mutations positively impact rice palatability,presenting a trade-off between grain size and eating quality.To address the challenges posed by the reduced grain weight associated with LAC6 mutations,we developed a specific molecular marker for LAC6,which has been effectively used in breeding programs to select lac6/tl1/du13 homozygous individuals with larger grain size.Our findings demonstrate that the“small grain”trait associated with lac6/tl1/du13 can be effectively mitigated through combined phenotype-based and marker-assisted selection.This study highlights the potential of lac6/tl1/du13 as a valuable gene for breeding novel,high-quality soft rice varieties through targeted breeding strategies.展开更多
Ultrastructural features of nucleus degradation during programmed cell death (PCD) of starchy endosperm cells in rice ( Oryza sativa L.) were observed using transmission electron microscopy. Several distinct morpho...Ultrastructural features of nucleus degradation during programmed cell death (PCD) of starchy endosperm cells in rice ( Oryza sativa L.) were observed using transmission electron microscopy. Several distinct morphological features of PCD have been found in the developing starchy endosperm cells, e.g. nucleus deformation, chromatin condensation, nuclear envelope disruption, and nuclear matrix leakage. DNA ladder displayed a smear of large DNA fragments from nucleus and evident bands of small DNA fragments (140-180 bp) from both nucleus and cytoplasm. In contrast with the rapid nucleus degradation, cell organelles in cytoplasm, such as rough endoplasmic reticulum, amyloplast, and mitochondrion, maintained their metabolic functions for a longer time. Seed reserves were continually synthesized and accumulated in the starchy endosperm cells despite the nucleus degradation during the PCD process. These results suggest that starchy endosperm cells remain active during reserve material synthesis and accumulation in the PCD process. The specific relationships between nucleus and cytoplasm in the developing endosperm cells and the morphological changes of nucleus in the endosperm PCD process were also discussed.展开更多
A statistical method for mapping quantitative trait loci （QTLs） underlying endosperm traits is proposed. The method is based on a genetic model containing both the direct effects and maternal effects of an endosperm...A statistical method for mapping quantitative trait loci （QTLs） underlying endosperm traits is proposed. The method is based on a genetic model containing both the direct effects and maternal effects of an endosperm QTL and on an experimental design termed two-stage hierarchical design, in which the trait information is obtained from F3 endosperms and molecular marker information is obtained from F2 plants and F3 embryos （plants）. Results of computer simulations indicate that the method can efficiently map endosperm QTLs and precisely estimate both the direct and maternal effects of endosperm QTLs when the sample size is sufficiently large.展开更多
This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has bee...This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has been made by Chinese in nearly every branches of tissue culture, including in vitro organogenesis, shoot tip culture, anther culture, ovary culture, endosperm culture, protoplast culture as well as mass cell culture. On the basis of reviewing the articles written by Chinese on plant tissue culture, the internationally recognized contributions are specially mentioned. The applications of plant tissue culture to agriculture and industry in China are also introduced.展开更多
This study provided visual evidence of a nitrogen effect on starch granules(SGs) in wheat endosperm. Winter wheat(Titicum aestivum L.) cultivar Xumai 30 was cultured under no nitrogen(control) and 240 kg ha-1of nitrog...This study provided visual evidence of a nitrogen effect on starch granules(SGs) in wheat endosperm. Winter wheat(Titicum aestivum L.) cultivar Xumai 30 was cultured under no nitrogen(control) and 240 kg ha-1of nitrogen applied at the booting stage. The number, morphology, and size of Aand B-type SGs in subaleurone of dorsal endosperm(SDE), center of dorsal endosperm(CDE), modified aleurone(MA), subaleurone of ventral endosperm(SVE), and center of ventral endosperm(CVE) were observed under light and electron microscopes.(1) The distribution of SGs in SDE was similar to that in SVE, the distributions of SGs in CDE and CVE were similar, but the distribution of SGs in MA was different from those in the other four endosperm regions. The number of SGs in the five endosperm regions was in the order SDE > CDE > SVE > CVE > MA.(2) Nitrogen increased the number of Aand B-type SGs in SDE and SVE. Nitrogen also increased the number of B-type SGs but decreased the number of A-type SGs in CDE and CVE. Nitrogen decreased the numbers of A-type and B-type SGs in MA. The results suggest that increased N fertilizer application mainly increased the numbers of small SGs and decreased the numbers of large SGs, but that the results varied in different regions of the wheat endosperm.展开更多
The objective of the current study is to investigate the effects of different stages of shading after anthesis on grain weight and quality of maize at cytology level. The shading experiments were conducted in the fiel...The objective of the current study is to investigate the effects of different stages of shading after anthesis on grain weight and quality of maize at cytology level. The shading experiments were conducted in the field from 2005 to 2006, with a common maize cultivar （TY2） as the experimental material. Plants were given stress using horizontal shading net and the light intensity was reduced by 55%. Field-grown maize plants were shaded at 1-14 d （S1）, 15-28 d （$2）, and 29-42 d （$3） after pollination, respectively. Control plants （SO） were grown under natural light. Grain weight, quality, endosperm cell proliferation, cob sugar content, and grain pedicel vascular bundle cross section area were measured. The ultrastructural changes of endosperm ceils and endosperm transfer cells were observed after pollination. The result indicated that the grain weight, starch content, endosperm cell number, and volume were declined after shading. On the contrary, the proportion of embryo and endosperm, protein content, and fat content in grain increased. Shading treatments significantly delayed the development of the starch granules and remarkably reduced the endosperm filling status. Among the three treatments, the number of the grain endosperm was the least under shading stress at 1-14 d after pollination. However, the volume of starch granules and the substantiation of endosperm under shading treatment at 15-28 d after pollination were the worst. Compared with the control （natural sunlight without shading）, the soluble sugar of maize cob increased significantly, while there was no obvious change in vascular structure of small cluster stalk. The number of protein body in maize endosperm was influenced markedly by low light at different stages after pollination. Low light decreased the volume of the grain endosperm transfer and the cell wall extensions of the basal transfer ceils became thinner and shorter under shading treatment than those of the control. Furthermore, the degree of connection and the capacity of the nutrient transport were decreased and the mitochondrion number of the transfer cell was reduced after shading. The change in grain quality after shading was observed due to increase in the proportion of embryo and endosperm. The morphology and functions in endosperm transfer cell and the shortage of energy restricted the nutrient transport greatly with shading at different stages, suggesting that an impeded flux may be one of the important reasons for the reduction of maize grain weight of maize grain at later growth stage under low light condition.展开更多
The translucent endosperm trait in a japonica rice variety ＇Kantou 194＇ is controlled by a Wx-mq gene which is allelic to Wx locus by genetic analysis and allelic test. The amylose content analysis showed that an in...The translucent endosperm trait in a japonica rice variety ＇Kantou 194＇ is controlled by a Wx-mq gene which is allelic to Wx locus by genetic analysis and allelic test. The amylose content analysis showed that an intermediate amylose content between those of glutinous and non-glutinous rice existed in endosperm of homozygous Wx-mq genotype. The slight changes of amylose content in different varieties and F1 grains with an identical Wx-mq genotype might be influenced by dissimilar genetic background. To identify the Wx-mq genotype simply and rapidly, a cleaved amplified polymorphic sequence （CAPS） marker was designed. The result from the molecular detection indicated that it could be used for marker-assisted selection for low amylose content varieties in rice breeding.展开更多
Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of co...Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.展开更多
Physicochemical properties of endosperm starches in milled rice determine its cooking and eating quality.Amylose is synthesized by granule-bound starch synthase I(GBSSI),whilst amylopectin is synthesized by the synerg...Physicochemical properties of endosperm starches in milled rice determine its cooking and eating quality.Amylose is synthesized by granule-bound starch synthase I(GBSSI),whilst amylopectin is synthesized by the synergistic activities of starch synthases(SSs),branching enzymes(BEs)and debranching enzymes(DBEs).However,the complexes formed by starch biosynthetic enzymes are not well characterized.Gene expression profiles and protein complexes were determined in white-core(GM645)and waxy(GM077)mutants derived from a high amylose indica rice Guangluai 4(GLA4).In GM645,genes including AGPS1,GBSSI,SSIIa,BEI,BEIIa,BEIIb,PUL,ISA1 and SP were significantly downregulated during seed development.In GM077,the expression levels of AGPL2,AGPS1,AGPS2b,SSIIIa,BEI,PUL and ISA1 were significantly upregulated.Co-immunoprecipitation assays revealed interactions of SSs-BEs,SSs-PUL and BEs-PUL in developing seeds.However,weak SSI-SSIIa interaction was detected in GM077,whilst SSI-PUL interaction was absent.Weak interaction signals for SSI-SSIIa,SSIIa-BEI,SSIIa-BEIIb,BEI-BEIIb and SSI-BEI were also observed in GM645.These results suggest that the protein-protein interactions for starch biosynthesis are modified in mutants,which provides insight into the mechanisms of starch biosynthesis,particularly in indica rice.展开更多
基金Supported by National Natural Science Foundation of China(30960179)Natural Science Foundation of Yunnan Province(2007A048M)~~
文摘[Objective] This research aimed to study the FTIR spectra of corn germs and endosperms so as to provide a scientific way for identifying corn of different types. [Method] The corn germs and endosperms of three types were studied by using Fourier transform infrared spectroscopy（FTIR） technology, combined with cluster analysis. [Result] The overall characteristics of original FTIR spectra were basically similar within the range of 700-1 800 cm^-1. The FTIR spectra were mainly composed by the absorption peaks of polysaccharides, proteins and lipids. Within the wavelength range of 700-1 800 cm^-1, there were only tiny differences in original FTIR spectra among the corn germs and endosperms of three different types. The spectra were then processed by using first derivative and second derivative. The second derivative spectra were used for hierarchical cluster analysis（HCA）. The results showed that with the wavelength range of 700-1 800 cm^-1, the second derivative spectra of the 52 samples could be better clustered according to the tree types and corn germ and corn endosperm. The clustering correct rate reached 96.1%.[Conclusion] FTIR technology, combined with cluster analysis, can be used to identify different types of corn germs and endosperms, and it is characterized by convenience and rapidness.
文摘Recently, improving eating quality and processing properties has become one of the most important objectives in japonica rice breeding programs in Korea. This study was carried out to determine the agronomy and physicochemical characteristics of the opaque endosperm rice "S-21-3-8" regenerated from seed-derived callus culture of a rice cultivar, "Ilpum". S3 generation of opaque endosperm mutants selected from pedigree breeding was used for analysis of agronomic and physicochemical traits. Genetic segregation was observed at the highest frequency among opaque endosperm mutants, being present in 85.7% (12/14 lines) of the entire opaque lines. However, the major agricultural characteristics and grain traits of "S-21-3-8" were similar to those of a donor cultivar, "Ilpum". "S-21-3-8" showed significantly lower (10.6%) amylose than those (17.7%) of "Ilpum" in brown rice, while the protein levels were similar to those of the donor plant. The grain hardness of "S-21-3-8" (1.67 kgf/mm2) was lower than that of "Ilpum" (1.97 kgf/mm2), resulting in a high flour-milling percentage. The loosely packed starch granules of "S-21-3-8" in the opaque endosperm were demonstrated by SEM analysis of cross-sectioned rice grains. The opaque endosperm mutants that were of somaclonal variations in the tissue culture will lead to improved eating quality and processing properties of rice.
基金supported by“Mechanistic dissection of plant embryo and seed development“project(2014CB943401)from The National Basic Research Program,the Ministry of Science and Technology of China
文摘Although it is known that in most angiosperms mitosis in early endosperm development is syncytial and synchronized, it is unclear how the synchronization is regulated. We showed previously that APC11, also named ZYGI, in Arabidopsis activates zygote division by interaction and degradation of cyclin B1. Here, we report that the mutation in APC11/ZYG1 led to unsynchronized mitosis and over-accumulation of cyclin B1-GUS in the endosperm. Mutations in two other APC subunits showed similar defects. Transgenic expression of stable cyclin B1 in the endosperm also caused unsynchronized mitosis. Further, downregulation of APC11 generated multi-nucleate somatic cells with unsynchronized mitotic division. Together, our results suggest that APC/C-mediated cyclin B1 degradation is critical for cell cycle synchronization.
基金supported by Biological Breeding-National Science and Technology Major Project(2023ZD04069)Young Scientist Project(2023YFD1200008)+2 种基金the National Natural Science Foundation of China(32472122)Sichuan Provincial General Project(24NSFSC1704)the Open Project Program and Biological Breeding Program of State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China(SKL-ZY202211).
文摘Phosphorylation is one of the major posttranslational modifications to control plant growth and development.Opaque2(O2)represents a central hub for endosperm filling,which largely determines seed yield and nutrient storage in maize.However,it still remains unclear how O2 phosphorylation orchestrates endosperm filling and nutrient quality.Here,we systematically identified the phosphorylation sites of O2 during endosperm filling.A total of 18 phosphorylation sites were found in O2 and five sites were identified to apparently modulate its subcellular localization and transactivation capacity.In addition,a conserved protein kinase CK1 was confirmed to interact with and phosphorylate O2 at the residue Threonine(T)202 to promote O2-mediated transactivation and protein stability.Overexpression of CK1 resulted in increased kernel size,100-kernel weight and nutrient storage.Phosphorylation-mimic O2 seeds at T202 exhibited enhanced kernel dimension,test weight,vitreous endosperm area and nutrient accumulation,whereas the phosphorylation-deficient O2 seeds did not.Collectively,this study establishes a comprehensive phosphocode atlas of O2 during endosperm filling and highlights the importance of phosphorylation modification in O2 to precisely orchestrate maize yield and nutrient quality.
基金supported by the National Key Research and Development Program of China(2022YFD2300700)the National Natural Science Foundation of China(32201894)+1 种基金Hainan Provincial Natural Science Foundation of China(323QN193)Rothamsted Research receives strategic funding from the Biotechnological and Biological Sciences Research Council of the UK.Matthew J.Paul acknowledges funding from the Delivering Sustainable Wheat(BB/X011003/1)Strategic Program.
文摘Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in elucidating the physiology of endosperm filling in inferior grains,the role of the embryo remains underexplored and warrants comprehensive investigation.Two Wuyujing 3 mutants,DW024(relatively synchronous;syn-DW024)and DW179(significantly asynchronous;asyn-DW179),with different grain-filling patterns were used in this study.Samples of superior and inferior grains were collected at intervals from 5 to 60 d after fertilization and subsequently dissected into subsamples of the embryo and endosperm.Histochemical staining,biochemical analysis,and RNA sequencing(RNA-seq)were combined to systematically compare developmental and physiological traits between superior and inferior grains.Combining hierarchical clustering of mRNA datasets revealed three developmental phases of the endosperm and embryo:morphogenesis,endosperm filling/embryo enlargement,and maturation.In both syn-DW024 and asyn-DW179,the duration of the endosperm/embryo morphogenesis phase was identical in superior and inferior grains.The inferior grains of asyn-DW179 exhibited a 10-day prolongation in the endosperm filling phase and a 20-day extension in the embryo enlargement phase compared to the superior grains.The endosperm of inferior grains exhibited higher contents of sugars and free amino acids,along with slower accumulation of storage compounds,which was associated with the down-regulation of genes for starch synthesis and ABA signaling.In addition,transporters for nutrient exchanges between endosperm and embryo were down-regulated,suggesting a potential role of the embryo in adjusting the endosperm filling process.Collectively,our results reveal that the prolonged phases of endosperm filling and embryo enlargement may underlie the impaired development of inferior grains,offering a new perspective for breeding or cultivating rice with uniform grain quality.
基金funded by the National Natural Science Foundation of China(32071921)Key R&D Program of Shandong Province,China(2021LZGC022)Taishan Scholars Project(ts201712024).
文摘Arogenate dehydratase(ADT)catalyzes the final step in phenylalanine synthesis and is crucial for plant development and metabolism.Previously,we demonstrated that the ADT/prephenate dehydratase ZmADT2 is essential for maize resistance to Ustilago maydis and for overall plant development.In this study,we explored the role of ZmADT2 in maize kernel development.The mmsu mutant,a dysfunctional ZmADT2 variant,exhibits delayed embryo and endosperm development,along with deficiencies in carbohydrate and protein storage.Transcriptome analysis revealed differential expression of many kernel compartment-specific genes between mmsu and wild-type(WT)kernels,with impaired nutrient accumulation and auxin signaling pathway in the mmsu endosperm.Compared to WT,ZmADT2 mutation led to reduced auxin levels and smaller endosperm cell size.Exogenous auxin rescued the small kernel phenotype of mmsu.Additionally,auxin distribution was reduced in the basal endosperm transfer layer(BETL),causing defects in its development and function,including reduced transfer cell elongation,cell wall ingrowth and nutrient uptake.These findings suggest that ZmADT2 mediated mediates an auxin signaling pathway that is essential for maize kernel development.
基金supported by National Key Research and Development Program of China(2023YFD1200500,2022YFD1201700)the National Natural Science Foundation of China(32071921)+1 种基金Key Research and Development Program of Shandong Province,China(2021LZGC022)the Taishan Scholars Project。
文摘Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences productivity.In this study,we revealed the role of smk23 in maize kernel development.The ethyl methanesulfonate mutant smk23 is characterized by substantially reduced kernel weight.Through map-based cloning,smk23 was found to be located on Chr5 and encode a putative B-type response regulator,Zm RR5.A change from G to A occurs in the coding sequence of Zm RR5,resulting in the early termination of smk23.In Arabidopsis,B-type response regulators are involved in cytokinin signaling.Histological analysis and in situ hybridization of the mutant revealed abnormal endosperm development,particularly in the basal endosperm transfer layer(BETL),a specialized tissue critical for nutrient transport from the maternal tissues to the developing kernel.Zm RR5 positively regulates key genes involved in BETL development and function,including MRP1 and TCRR1.Furthermore,RNA sequencing revealed that several genes closely linked to BETL development,including BETL2,MEG1,and MN1,were significantly downregulated in smk23.These genes are essential for nutrient transport,tissue development and signal transduction.In addition,haploid analysis of Zm RR5 revealed natural variations(Hap 2)that may contribute to the increased kernel yield.Disruption of Zm RR5 function in smk23 leads to defects in BETL development,impairing its ability to transport nutrients,and ultimately resulting in a smaller kernel size.This study provides new insights into the molecular mechanisms through which Zm RR5 regulates maize kernel development and offers potential strategies for improving grain yield.
基金supported by grants from the National Natural Science Foundation of China(grant numbers 31825019,32072032,and 31901517)the PAPD Programs from Jiangsu Province Government.
文摘Starch is a vital energy source for living organisms and is a key raw material and additive in the food and non-food industries.Starch has received continuous attention in multiple research fields.The endosperm of cereals(e.g.,rice,corn,wheat,and barley)is the most important site for the synthesis of storage starch.Around 2010,several excellent reviews summarized key progress in various fields of starch research,serving as important references for subsequent research.In the past 10 years,many achievements have been made in the study of starch synthesis and regulation in cereals.The present review provides an update on research progress in starch synthesis of cereal endosperms over the past decade,focusing on new enzymes and non-enzymatic proteins involved in starch synthesis,regulatory networks of starch synthesis,and the use of elite alleles of starch synthesis-related genes in cereal breeding programs.We also provide perspectives on future research directions that will further our understanding of cereal starch biosynthesis and regulation to support the rational design of ideal quality grain.
基金Project supported by Rockefeller Foundation for International Program on Rice Biotechnology.
文摘The 5' upstream region (—680—+40) containing the complete signal peptide coding sequence of the rice seed storage prolamin gene was amplified in vitro with polymerase chain reaction from the genome of Chinese super rice cultivar Zhonghua 8. Physical map and DNA sequence analysis showed strong homology with the 5'-flanking region of rice prolamin gene reported by Kim in 1988. No changes in the signal peptide coding sequence and a long leader sequence with several small ORFs were found. Chimeric gene containing 5'-flanking region of the prolamin gene has been transcriptionally fused with the β-glucuronidase reporter gene. The fusion junction was confirmed by both physical map and DNA sequence analysis. The resultant chimeric gene was used to transform the tabacco explants by Ti binary system of Agrobacterium tumefaciens LBA4404. With dot and Southern blotting hybridization, three transgenic tobacco plants with the copies of chimeric GUS genes as many as 20 were obtained. Histochemical analysis revealed that the GUS activity in the endosperm tissues of tobacco seeds at the developmental stage was about 20 DAP. No GUS activity was found in leaves, stems, roots and flowers of the transgenic tobacco plants. Therefore, we concluded that the 5'-upstream cis-elements from—680 to—18 were enough to confer the endosperm-specific and temporal expression of rice prolamin gene.
基金supported by the National Natural Science Foundation of China(31570322)。
文摘The early development of the endosperm is crucial for balancing the allocation of maternal nutrients to offspring.This process is believed to be evolutionarily associated with genomic imprinting,resulting in parentally biased allelic gene expression.Beyond Fertilization Independent Seed(FIS)genes,the number of imprinted genes involved in early endosperm development and seed size determination remains limited.This study introduces early endosperm-expressed HAIKU(IKU)downstream Candidate F-box 1(ICF1)and ICF2 as maternally expressed imprinted genes(MEGs)in Arabidopsis thaliana.Although these genes are also demethylated by DEMETER(DME)in the central cell,their activation differs from the direct DME-mediated activation seen in classical MEGs such as the FIS genes.Instead,ICF maternal alleles carry pre-established hypomethylation in their promoters,priming them for activation by the WRKY10 transcription factor in the endosperm.On the contrary,paternal alleles are predominantly suppressed by CG methylation.Furthermore,we find that ICF genes partially contribute to the small seed size observed in iku mutants.Our discovery reveals a two-step regulatory mechanism that highlights the important role of conventional transcription factors in the activation of imprinted genes,which was previously not fully recognized.Therefore,the mechanism provides a new dimension to understand the transcriptional regulation of imprinting in plant reproduction and development.
基金supported by the National Key Research and Development Program of China(2023YFD1200901)the National Natural Science Foundation of China(32230074 and 32161143004)+3 种基金the Research Programs from Jiangsu Government(JBGS[2021]001,BZ2021017,and Qing Lan Project)the Foreign Expert Project(G2023014064L)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_3239)the Yangzhou University High-end Talent Program.
文摘Amylose content(AC)is a crucial determinant of the eating and cooking quality(ECQ)of rice,with low AC varieties exhibiting a softer texture and greater stickiness-attributes that enhance palatability and are desirable in specific culinary contexts.To harness these traits,significant efforts have been made to manipulate AC to improve rice ECQ.Our research utilized the MutMap+approach to identify LAC6/TL1,a gene that is an allele of Du13,responsible for low AC.LAC6 encodes a C2H2 zinc finger protein,which specifically increases the splicing efficiency of the Wxb allele without affecting the Wxa allele.Functional studies of LAC6 revealed that its proper integration could rectify the undesirable AC phenotype,whereas mutations within this gene led to reduced AC and were associated with shorter grain length and decreased thousand-grain weight.Despite these drawbacks,such mutations positively impact rice palatability,presenting a trade-off between grain size and eating quality.To address the challenges posed by the reduced grain weight associated with LAC6 mutations,we developed a specific molecular marker for LAC6,which has been effectively used in breeding programs to select lac6/tl1/du13 homozygous individuals with larger grain size.Our findings demonstrate that the“small grain”trait associated with lac6/tl1/du13 can be effectively mitigated through combined phenotype-based and marker-assisted selection.This study highlights the potential of lac6/tl1/du13 as a valuable gene for breeding novel,high-quality soft rice varieties through targeted breeding strategies.
文摘Ultrastructural features of nucleus degradation during programmed cell death (PCD) of starchy endosperm cells in rice ( Oryza sativa L.) were observed using transmission electron microscopy. Several distinct morphological features of PCD have been found in the developing starchy endosperm cells, e.g. nucleus deformation, chromatin condensation, nuclear envelope disruption, and nuclear matrix leakage. DNA ladder displayed a smear of large DNA fragments from nucleus and evident bands of small DNA fragments (140-180 bp) from both nucleus and cytoplasm. In contrast with the rapid nucleus degradation, cell organelles in cytoplasm, such as rough endoplasmic reticulum, amyloplast, and mitochondrion, maintained their metabolic functions for a longer time. Seed reserves were continually synthesized and accumulated in the starchy endosperm cells despite the nucleus degradation during the PCD process. These results suggest that starchy endosperm cells remain active during reserve material synthesis and accumulation in the PCD process. The specific relationships between nucleus and cytoplasm in the developing endosperm cells and the morphological changes of nucleus in the endosperm PCD process were also discussed.
基金This work was supported by the Key Sci-Tech Project of Fujian Province (No. 2004NZ01-2) the Natural Science Foundation of Fujian Province of China (No. 2006J0300).
文摘A statistical method for mapping quantitative trait loci （QTLs） underlying endosperm traits is proposed. The method is based on a genetic model containing both the direct effects and maternal effects of an endosperm QTL and on an experimental design termed two-stage hierarchical design, in which the trait information is obtained from F3 endosperms and molecular marker information is obtained from F2 plants and F3 embryos （plants）. Results of computer simulations indicate that the method can efficiently map endosperm QTLs and precisely estimate both the direct and maternal effects of endosperm QTLs when the sample size is sufficiently large.
文摘This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has been made by Chinese in nearly every branches of tissue culture, including in vitro organogenesis, shoot tip culture, anther culture, ovary culture, endosperm culture, protoplast culture as well as mass cell culture. On the basis of reviewing the articles written by Chinese on plant tissue culture, the internationally recognized contributions are specially mentioned. The applications of plant tissue culture to agriculture and industry in China are also introduced.
基金supported by the National Natural Science Foundation (31171482)Jiangsu Natural Science Foundation (BK2011445)Jiangsu Graduate Innovation Project (CXLX12-0910)
文摘This study provided visual evidence of a nitrogen effect on starch granules(SGs) in wheat endosperm. Winter wheat(Titicum aestivum L.) cultivar Xumai 30 was cultured under no nitrogen(control) and 240 kg ha-1of nitrogen applied at the booting stage. The number, morphology, and size of Aand B-type SGs in subaleurone of dorsal endosperm(SDE), center of dorsal endosperm(CDE), modified aleurone(MA), subaleurone of ventral endosperm(SVE), and center of ventral endosperm(CVE) were observed under light and electron microscopes.(1) The distribution of SGs in SDE was similar to that in SVE, the distributions of SGs in CDE and CVE were similar, but the distribution of SGs in MA was different from those in the other four endosperm regions. The number of SGs in the five endosperm regions was in the order SDE > CDE > SVE > CVE > MA.(2) Nitrogen increased the number of Aand B-type SGs in SDE and SVE. Nitrogen also increased the number of B-type SGs but decreased the number of A-type SGs in CDE and CVE. Nitrogen decreased the numbers of A-type and B-type SGs in MA. The results suggest that increased N fertilizer application mainly increased the numbers of small SGs and decreased the numbers of large SGs, but that the results varied in different regions of the wheat endosperm.
基金supported by the National Basic Research Program of China (973 Program,2006CB101700)the National Natural Science Foundation of China (30871476)the Opening Foundation of State Key Laboratory of Crop Biology, and the Shandong Agricultural University (2009KF07)
文摘The objective of the current study is to investigate the effects of different stages of shading after anthesis on grain weight and quality of maize at cytology level. The shading experiments were conducted in the field from 2005 to 2006, with a common maize cultivar （TY2） as the experimental material. Plants were given stress using horizontal shading net and the light intensity was reduced by 55%. Field-grown maize plants were shaded at 1-14 d （S1）, 15-28 d （$2）, and 29-42 d （$3） after pollination, respectively. Control plants （SO） were grown under natural light. Grain weight, quality, endosperm cell proliferation, cob sugar content, and grain pedicel vascular bundle cross section area were measured. The ultrastructural changes of endosperm ceils and endosperm transfer cells were observed after pollination. The result indicated that the grain weight, starch content, endosperm cell number, and volume were declined after shading. On the contrary, the proportion of embryo and endosperm, protein content, and fat content in grain increased. Shading treatments significantly delayed the development of the starch granules and remarkably reduced the endosperm filling status. Among the three treatments, the number of the grain endosperm was the least under shading stress at 1-14 d after pollination. However, the volume of starch granules and the substantiation of endosperm under shading treatment at 15-28 d after pollination were the worst. Compared with the control （natural sunlight without shading）, the soluble sugar of maize cob increased significantly, while there was no obvious change in vascular structure of small cluster stalk. The number of protein body in maize endosperm was influenced markedly by low light at different stages after pollination. Low light decreased the volume of the grain endosperm transfer and the cell wall extensions of the basal transfer ceils became thinner and shorter under shading treatment than those of the control. Furthermore, the degree of connection and the capacity of the nutrient transport were decreased and the mitochondrion number of the transfer cell was reduced after shading. The change in grain quality after shading was observed due to increase in the proportion of embryo and endosperm. The morphology and functions in endosperm transfer cell and the shortage of energy restricted the nutrient transport greatly with shading at different stages, suggesting that an impeded flux may be one of the important reasons for the reduction of maize grain weight of maize grain at later growth stage under low light condition.
基金supported by the National High Technology Research and Development Program of China(Grant No.2006AA100101)National Science and Technology Support Program of China(Grant No. 2006BAD01A01-5)+1 种基金Special Program for Rice Scientific Research,Ministry of Agriculture,China(Grant No. nyhyzx 07-001-006)Super Rice Breeding and Demonstration Program,Ministry of Agriculture,China and Jiangsu Agricultural Scientific Self-innovation Fund,China(Grant No.CX[07]603)
文摘The translucent endosperm trait in a japonica rice variety ＇Kantou 194＇ is controlled by a Wx-mq gene which is allelic to Wx locus by genetic analysis and allelic test. The amylose content analysis showed that an intermediate amylose content between those of glutinous and non-glutinous rice existed in endosperm of homozygous Wx-mq genotype. The slight changes of amylose content in different varieties and F1 grains with an identical Wx-mq genotype might be influenced by dissimilar genetic background. To identify the Wx-mq genotype simply and rapidly, a cleaved amplified polymorphic sequence （CAPS） marker was designed. The result from the molecular detection indicated that it could be used for marker-assisted selection for low amylose content varieties in rice breeding.
基金supported by the National 863 Program of China (2011AA10A101)the Chinese High-Yielding Transgenic Program (2011ZX08001-004)a project of the State Key Laboratory of Rice Biology,China(ZZKT201101)
文摘Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.
基金National Key Research and Development Program of China(Grant No.2016YFD0400104)the Natural Science Foundation of China(Grant Nos.31800640 and 31871531).
文摘Physicochemical properties of endosperm starches in milled rice determine its cooking and eating quality.Amylose is synthesized by granule-bound starch synthase I(GBSSI),whilst amylopectin is synthesized by the synergistic activities of starch synthases(SSs),branching enzymes(BEs)and debranching enzymes(DBEs).However,the complexes formed by starch biosynthetic enzymes are not well characterized.Gene expression profiles and protein complexes were determined in white-core(GM645)and waxy(GM077)mutants derived from a high amylose indica rice Guangluai 4(GLA4).In GM645,genes including AGPS1,GBSSI,SSIIa,BEI,BEIIa,BEIIb,PUL,ISA1 and SP were significantly downregulated during seed development.In GM077,the expression levels of AGPL2,AGPS1,AGPS2b,SSIIIa,BEI,PUL and ISA1 were significantly upregulated.Co-immunoprecipitation assays revealed interactions of SSs-BEs,SSs-PUL and BEs-PUL in developing seeds.However,weak SSI-SSIIa interaction was detected in GM077,whilst SSI-PUL interaction was absent.Weak interaction signals for SSI-SSIIa,SSIIa-BEI,SSIIa-BEIIb,BEI-BEIIb and SSI-BEI were also observed in GM645.These results suggest that the protein-protein interactions for starch biosynthesis are modified in mutants,which provides insight into the mechanisms of starch biosynthesis,particularly in indica rice.
