Construction of Vectors to Express Foreign Protein within Potato Starch Grains

[Objective] The aim is to study the construction of vectors expressing foreign protein in potato starch grains specifically, and provide some reference for solving industrialized core problem of high cost and low expression level of foreign protein. [Method] By using molecular biological techniques of RT-PCR and nested PCR, plant expression vector for the foreign protein locating in the potato starch grains was constructed. [ Result] Coding sequence （ GC20 ） of potato starch grains that was located and expressed by GBSSI promoter was cloned. Plant expression vector was screened out through connection, transformation and enzyme digestion identification. [ Conclusion] This result laid a foundation for further screening the foreign protein on the potato starch grains.

Starch Digestibility and Physicochemical and Cooking Properties of Irradiated Rice Grains

This study evaluated the starch digestibility, physicochemical properties and cooking characteristics of polished rice（varieties IRGA417 and IAC202） subjected to the doses of 0（as the control）, 1, 2 and 5 k Gy of gamma radiation. The highest dose decreased the apparent amylose content, peak viscosity, water absorption and volume expansion. Irradiation increased the solid loss by 119% and 187% for IAC202 and IRGA417, respectively, when comparing the higher dose with the control. For IAC202, irradiation decreased the rapidly digestible starch and increased the slowly digestible starch（SDS） and resistant starch（RS）. IRGA417 showed an elevation of SDS and a reduction in RS. And 1 k Gy dose of gamma radiation generated the highest level of RS for both the two varieties and presented the smallest changes in other physicochemical and cooking properties.

Morphological Change of Starch Grain Based on Simulated Experiment and its Significance of Agricultural Archaeology——Taking Wheat as an Example

[Objective] The aim was to research and identify starch grain microfossil found in archaeological sites in China, and to find appropriate procedures for the starch grain analysis experiment.[Method] Wheat starch grain size distribution was analyzed, and some simulated experiments were carried out, like mortar grinding, ultrasonic treatment, hydrochloric acid and hydrogen peroxide immersion, drying treatment, and so on. [Result] The mean size of wheat starch grains had increased in the growth process. Mortar grinding would make wheat starch grains larger than untreated sample. Long time of ultrasonic treatment can also make the starch grain size larger. 10% HCl and 6% H2O2 would have little effects on morphological feature of wheat starch grains. Low temperature heating did not cause starch grains to be gelatinized. [Conclusion] These experiment results can improve the accuracy of starch grain microfossil identification in the archaeological site. Starch grain analysis may be a utility and effective analytical tool in studying the origin of agriculture and the dispersal of crops in China.

Effect of steam-flaking on chemical compositions,starch gelatinization,in vitro fermentability,and energetic values of maize,wheat and rice

Intact and steam-flaked grains of maize,wheat and rice（with whole hulls） were analyzed for chemical composition,starch gelatinization degree（SGD） and in vitro fermentation characteristics to investigate the influence of cereal type and steam-flaking（SF） processing on their nutritive values.The treatments were arranged in a 3×2 factorial design.Obvious differences（P〈0.001） in chemical composition and energetic values were observed among the different cereal types.SGD and gas production（GP） rate was significantly increased（P〈0.001） by SF processing.SF processing also increased（P〈0.01） the proportion of propionic acid and decreased the acetic：propionic acid ratio in vitro.Steam-flaking also increased organic matter digestibility and the energetic value of the cereal grains,especially rice.Based on these results,rice probably is more amendable to SF processing than maize and wheat.In conclusion,it is feasible to partially substitute maize grain with wheat or rice in ruminant diets,and steam-flaking can significantly improve the nutritional value of wheat and rice grains.

Methodological impact of starch determination on starch content and ileal digestibility of starch in grain legumes for growing pigs

Background： Grain legumes represent a valuable energy source in pig diets due to their high starch content. The present study was conducted to determine the content and apparent ileal digestibility（AID） of starch in different grain legume cultivars for pigs by means of both a polarimetric and enzymatic method for starch determination.Methods： Three experiments were conducted with six barrows each which were fitted with ileal T-cannulas. In total, 18 diets including six different cultivars of faba beans（Vicia faba L.） and peas（Pisum sativum L.）, five different cultivars of lupins（Lupinus luteus L., Lupinus angustifolius L.）, and one diet with a soybean meal（SBM） were fed.Results： The starch content of faba beans and peas was greater（P ＆lt; 0.05） when determined polarimetrically than enzymatically（438 vs. 345 g/kg dry matter（DM） in faba beans and 509 vs. 390 g/kg DM in peas, respectively）.Considerable lower starch contents were obtained in lupins and SBM, with 82 and 48 g/kg DM（analyzed polarimetrically） and ＆lt;1.1 and 3 g/kg DM（analyzed enzymatically）, respectively. Mean values for contents of neutral detergent fiber（NDF） and acid detergent fiber（ADF） in grain legumes ranged from 111 and 79 g/kg DM in peas to248 and 207 g/kg DM in lupins, respectively. Contents of condensed tannins in the colored flowered faba bean cultivars ranged from 2.1 to 7.4 g/kg DM. The AID of starch was greater（P ＆lt; 0.05） in pea than in faba bean cultivars,and using the polarimetric starch determination method resulted in greater（P ＆lt; 0.05） digestibility values than using enzymatic starch analysis（84 vs. 80% in faba beans and 86 vs. 83% in peas）. Moreover, AID of starch differed（P ＆lt; 0.05）within pea cultivars and starch digestibility in faba beans decreased linearly（P ＆lt; 0.05） as the content of condensed tannins increased. However, there was no relationship between contents of NDF and ADF and AID of starch in pea and faba bean cultivars.Conclusion： Both contents and AID of starch in grain legumes can vary as influenced by the analytical method used for starch determination. Generally, starch digestibility is greater when measured by polarimetric rather than enzymatic methods.

Anatomical Study on the Multi-Ovule Development and Abortion of Hanfu Apple

The terminal flower buds of 6-yr-old Hanfu apple were used to study the ovule development, ovular characteristics, cell death of abortive ovules, and dynamic change of starch grain quantity in the embryo sac with paraffin slices and terminal deoxynucleotidyl transferase-mediated fluorescein deoxyuridine triphosphate nick-end labeling （TUNEL） system. Four anatropous ovules in each ventricle could be observed before flowering. With the developing of floral organ, the bulk of normal ovules enlarged in each ventricle, the mature embryo sac differentiated into nucellus, and the egg cell developed into zygote by double fertilization. A large number of starch grains were observed during pollen tube growth and double fertilization, which guaranteed basic nutrient supply in the normal development of ovules. Moreover, abortion phenomenon of runtish ovules emerged at the stages of mature embryo sac, double fertilization and zygote development. The abortion characteristics included deformity of ovule development, degradation of nucellus tissue, separation between funiculus and ovule, abnormality of four-nucleate embryo sac, as well as development interruption of mature embryo sac. TUNEL analysis proved that ovule abortion was programmed cell death.

Identification and validation of novel loci associated with wheat quality through a genome-wide association study

Understanding the genetic basis of quality-related traits contributes to the improvement of grain protein concentration(GPC),grain starch concentration(GSC),and wet gluten concentration(WGC)in wheat.In this study,a genome-wide association study(GWAS)based on a mixed linear model(MLM)was performed on 236 wheat accessions,including 160 cultivars and 76 landraces,using a 55K single nucleotide polymorphism(SNP)array in multiple environments.A total of 12 stable QTL/SNPs that control different quality traits in this populations in at least two environments under stripe rust stress were identified.Among these 12,three,seven and two QTLs associated with GPC,GSC and WGC were characterized,respectively,and they were located on chromosomes(chr)1B,1D,2A,2B,2D,3B,3D,5D,and 7D with the phenotypic variation explained(PVE)ranging from 4.2 to 10.7%.Compared with the previously reported QTLs/genes,five QTLs(QGsc.sicau-1BL,QGsc.sicau-1DS,QGsc.sicau-2DL.1,QGsc.sicau-2DL.2,and QWgc.sicau-5DL)were potentially novel.KASP markers for the SNPs AX-108770574 and AX-108791420 on chr5D associated with wet gluten concentration were successfully developed.The phenotypes of the cultivars containing the A-allele in AX-108770574and the T-allele in AX-108791420 were extremely significantly(P<0.01)higher than those of the landraces containing the G-or C-allele with respect to the wet gluten concentration in each of the environments.The KASP markers developed and validated in this study could be utilized in molecular breeding aimed at improving the quality of wheat.

Plant food sources and stone tools' function at the site of Shunshanji based on starch grain analysis

The upper-middle Huai River valley(HRV) is located in the transition zone in the middle of eastern China. Previous studies have shown that the past populations in the upper HRV obtained plant food through gathering and cultivation of both rice and millet during the middle Neolithic. However, for the middle HRV it is not very clear what methods were used by humans to obtain plant food in that time. In this paper, starch grain analysis was carried out on 17 stone tools and 29 cauldron pottery sherds unearthed at Shunshanji(8.5–7.0 kyr BP), which is known as the earliest Neolithic site in the middle HRV excavated so far. Here, ancient starches from Coix lacryma-jobi, Triticeae, Oryza sativa, Trichosanthes kirilowii and one unidentified specie were recovered. This study contributes to the limited knowledge of food strategies as observed in the middle HRV. It demonstrates that both gathering and cultivation of rice took place during the middle-Neolithic. Among the identified species, Coix lacryma-jobi appears to have been the main plant food at Shunshanji. Moreover, it is clear that Oryza sativa was not consumed as much as other plant species according to the occurrence frequency of different starch grains. Starch grains were also found on the used surfaces of grinding stone implements as well as pestles, which means that these stone tools were used for food processing. In addition, axes from Shunshanji may also have been used for food processing as well as wood working because starches were also found on the edge of axes. Information about subsistence strategies and tool use at Shunshanji will also be helpful to understanding the utilization of plants and agricultural development in the middle HRV during the early-middle Neolithic period.

Starch grain analysis reveals Late Neolithic plant utilization in the middle reaches of the Ganjiang River

Plant utilization is poorly known in South China as compared to North China.Fanchengdui, Zhuweicheng, Shinianshan, and Yinjiaping, which date back to 5-4 ka BP, are typical Neolithic sites located at the middle reaches of the Ganjiang River in Jiangxi Province.Due to the lack of systematic plant archaeological work, only rice straw and husk residues have been found in some archaeological sites in Jiangxi Province.Thirteen stone tools excavated from these sites were examined in this study.The results showed that among the plants utilized are Coix spp., Oryza spp., Vigna spp., plants from the tribe Triticeae, roots from some plants of Zingiberaceae, and other species of roots and tubers.More than 457 grains were retrieved from the 13 stone tools.The fact that Coix spp.were found in all stone tools suggests that these species were a major food source during the Neolithic era.In addition, 28 starch grains of Oryza spp.were found in 8 stone tools.The analysis also revealed that not only seeds of Gramineae but also those of Leguminosae, Zingiberaceae and other species of roots and tubers are among the plants utilized in the four Fanchengdui culture sites.These results indicate that ancient plant utilization was rather diverse, and this study elucidates the prehistoric agricultural systems of South China.

GRAIN INCOMPLETE FILLING 2 regulates grain filling and starch synthesis during rice caryopsis development

Rice grain filling determines grain weight, final yield and grain quality. Here, a rice defective grain filling mutant, gif2, was identified. Grains ofgif2 showed a slower filling rate and a significant lower final grain weight and yield compared to wild-type. The starch content in gilt2 was noticeably decreased and its physicochemical properties were also altered. Moreover, gif2 endosperm cells showed obvious defects in compound granule formation. Posi- tional cloning identified GIF2 to encode an ADP-glucose pyrophosphorylase （AGP） large subunit, AGPL2; consequently, AGP enzyme activity in gif2 endosperms was remarkably decreased. GIF2 is mainly expressed in developing grains and the coded protein localizes in the cytosol. Yeast two hybrid assay showed that GIF2 interacted with AGP small subunits OsAGPS% OsAGPS2a and OsAGPS2b. Transcript levels for granule-bound starch synthase, starch synthase, starch branching enzyme and starch debranching enzyme were distinctly elevated in gif2 grains. In addition, the level of nucleotide diversity of the GIF2 locus was extremely low in both cultivated and wild rice. All of these results suggest that GIF2 plays important roles in the regulation of grain filling and starch biosynthesis during caryopsis development, and that it has been preserved during selection throughout domestication of modern rice.

Early millet use in West Liaohe area during early-middle Holocene

It is generally recognized that millet agriculture originated in northern China. However, the domestication process of foxtail millet(Setaria italica) and broomcorn millet(Panicum miliaceum) is still poorly understood. Based on statistical and morphological analyses of ancient millet starch grains, a tangible hypothesis has been proposed for the long-term domestication of green foxtail millet(S. viridis). However, the hypothesis requires validation by evidence from more regions and more archaeological finds. The West Liaohe region is one of the earliest regions of millet cultivation. Here, we report ancient starch grains recovered from 12 stone grinding tools from eight sites of the Xiaohexi culture(before 8.5 ka BP), Xinglongwa culture(8.2–7.4 ka BP), Zhaobaogou culture(7.0–6.4 ka BP), and Hongshan culture(6.5–5.0 ka BP) in the West Liaohe region of China. Our results indicate that the proportion of millet starch grains with wrinkled surfaces and rough edges, which are diagnostic of wild millet grasses, decreased from 13.0% to 3.4% from the Xiaohexi culture to the Hongshan culture. Millet starch grains measuring >16.8 ?m, a size class recorded only in domesticated foxtail millet, increased from 55.0% to 62.1%. These millet data imply that the process of millet domestication in the West Liaohe region began in the Xiaohexi period and continued up to the Hongshan period.