Selection and application of four QTLs for grain protein content in modern wheat cultivars

The grain protein content(GPC)is the key parameter for wheat grain nutritional quality.This study conducted a resampling GWAS analysis using 406 wheat accessions across eight environments,and identified four previously reported GPC QTLs.An analysis of 87 landraces and 259 modern cultivars revealed the loss of superior GPC haplotypes,especially in Chinese cultivars.These haplotypes were preferentially adopted in different agroecological zones and had broad effects on wheat yield and agronomic traits.Most GPC QTLs did not significantly reduce yield,suggesting that high GPC can be achieved without a yield penalty.The results of this study provide a reference for future GPC breeding in wheat using the four identified QTLs.

Effects of Sulfur Fertilizer Application Methods on Grain Protein Content During Filling Stage of Winter Wheat

[ Objective] The experiment aimed to provide a theoretical base of optimal cultivation management for the high yield and good quality and high efficiency of winter wheat. [ Method] The effects of two sulfur fertilizer application methods on dynamic changes of grain protein content and glutenin content of Yumai 49 and Yumai 66 during wheat grain filling stage were studied under the field conditions. [Result] Both the grain protein and glutenin content of two cultivars were increased by sulfur fertilizer, particularly, the effects on Yumai 49 were more significant.[ Conclusion] The grain content and glutenin content of different wheat cultivars could be increased by taking different sulfur fertilizer application methods.

Estimating Wheat Grain Protein Content Using Multi-Temporal Remote Sensing Data Based on Partial Least Squares Regression

Estimating wheat grain protein content by remote sensing is important for assessing wheat quality at maturity and making grains harvest and purchase policies. However, spatial variability of soil condition, temperature, and precipitation will affect grain protein contents and these factors usually cannot be monitored accurately by remote sensing data from single image. In this research, the relationships between wheat protein content at maturity and wheat agronomic parameters at different growing stages were analyzed and multi-temporal images of Landsat TM were used to estimate grain protein content by partial least squares regression. Experiment data were acquired in the suburb of Beijing during a 2-yr experiment in the period from 2003 to 2004. Determination coefficient, average deviation of self-modeling, and deviation of cross- validation were employed to assess the estimation accuracy of wheat grain protein content. Their values were 0.88, 1.30%, 3.81% and 0.72, 5.22%, 12.36% for 2003 and 2004, respectively. The research laid an agronomic foundation for GPC （grain protein content） estimation by multi-temporal remote sensing. The results showed that it is feasible to estimate GPC of wheat from multi-temporal remote sensing data in large area.

Amino acid permease 6 regulates grain protein content in maize

Grain protein content(GPC)is an indicator of cereal nutritional quality.Identification of genes involved in the regulation of GPC provides targets for molecular breeding for crop protein quality.We characterized a maize gene encoding the putative amino acid transporter ZmAAP6,a gene expressed mainly in immature seeds,especially in the basal endosperm transfer layer.Total protein and zein contents were decreased in ZmAAP6 null mutants and increased in ZmAAP6 overexpression(OE)lines,consistent with their changed in the size of protein bodies.Metabolic and transcriptomic analysis supported the regulatory role of ZmAAP6 in amino acid transportation.These results suggest that ZmAAP6 functions as a positive regulator of GPC in maize,shedding new light on the genetic basis of GPC regulation.

Modeling the effects of extreme high-temperature stress at anthesis and grain filling on grain protein in winter wheat

Extreme high-temperature stress(HTS) associated with climate change poses potential threats to wheat grain yield and quality. Wheat grain protein concentration(GPC) is a determinant of wheat quality for human nutrition and is often neglected in attempts to assess climate change impacts on wheat production. Crop models are useful tools for quantification of temperature impacts on grain yield and quality.Current crop models either cannot simulate or can simulate only partially the effects of HTS on crop N dynamics and grain N accumulation. There is a paucity of observational data on crop N and grain quality collected under systematic HTS scenarios to develop algorithms for model improvement as well as evaluate crop models. Two-year phytotron experiments were conducted with two wheat cultivars under HTS at anthesis, grain filling, and both stages. HTS significantly reduced total aboveground N and increased the rate of grain N accumulation, while total aboveground N and the rate of grain N accumulation were more sensitive to HTS at anthesis than at grain filling. The observed relationships between total aboveground N, rate of grain N accumulation, and HTS were quantified and incorporated into the WheatGrow model. The new HTS routines improved simulation of the dynamics of total aboveground N, grain N accumulation, and GPC by the model. The improved model provided better estimates of total aboveground N, grain N accumulation, and GPC under HTS(the normalized root mean square error was reduced by 40%, 85%, and 80%, respectively) than the original WheatGrow model. The improvements in the model enhance its applicability to the assessment of climate change effects on wheat grain quality by reducing the uncertainties of simulating N dynamics and grain quality under HTS.

Predicting Grain Yield and Protein Content in Winter Wheat at Different N Supply Levels Using Canopy Reflectance Spectra

A field experiment using a split-plot randomized complete block design with three replications was carried out to determine relationships between spectral indices and wheat grain yield （GY）, to compare the performance of four vegetation indices （VIs） for GY prediction, and to study the feasibility of VI to estimate grain protein content （GPC） in winter wheat. Two typical winter wheat （Triticum aestivum L.） cultivars ＇Xuzhou 26＇ （high protein content） and ＇Huaimai 18＇ （low protein content） were used as the main plot treatments and four N rates, i.e., 0, 120, 210, and 300 kg N ha^-1, as the sub-plot treatments. Increasing soil N supply significantly increased GY and GPC （P ≤ 0.05）. For the two cultivars combined, significant and positive correlations were found between four VIs and GY, with the strongest relationship observed when using the green ratio vegetation index （GRVI） at mid-filling. Cumulative VI estimates improved yield predictions substantially, with the best interval being heading to maturity stage. Similar results were found between VI and grain protein yield. However, when using cumulative VI, GPC showed no significant improvement. The strong relationship between leaf N status and GPC （R2 =0.9144 for ＇Xuzhou 26＇ and R2 = 0.8285 for ＇Huaimai 18＇） indicated that canopy spectra could be used to predict GPC. The strong fit between estimated and observed GPC （R2 = 0.7939） indicated that remote sensing techniques were potentially useful predictors of grain protein content and quality in wheat.

Effect of delayed sowing on grain number, grain weight, and protein concentration of wheat grains at specific positions within spikes

Delays in sowing have significant effects on the grain yield,yield components,and grain protein concentrations of winter wheat.However,little is known about how delayed sowing affects these characteristics at different positions in the wheat spikes.In this study,the effects of sowing date were investigated in a winter wheat cultivar,Shannong 30,which was sown in 2019 and 2020 on October 8(normal sowing)and October 22(late sowing)under field conditions.Delayed sowing increased the partitioning of ^(13)C-assimilates to spikes,particularly to florets at the apical section of a spike and those occupying distal positions on the same spikelet.Consequently,the increase in grain number was the greatest for the apical sections,followed by the basal and central sections.No significant differences were observed between sowing dates in the superior grain number in the basal and central sections,while the number in apical sections was significantly different.The number of inferior grains in each section also increased substantially in response to delayed sowing.The average grain weights in all sections remained unchanged under delayed sowing because there were parallel increases in grain number and ^(13)C-assimilate partitioning to grains at specific positions in the spikes.Increases in grain number m^(–2) resulted in reduced grain protein concentrations as the limited nitrogen supply was diluted into more grains.Delayed sowing caused the greatest reduction in grain protein concentration in the basal sections,followed by the central and apical sections.No significant differences in the reduction of the grain protein concentration were observed between the inferior and superior grains under delayed sowing.In conclusion,a 2-week delay in sowing improved grain yield through increased grain number per spike,which originated principally from an increased grain number in the apical sections of spikes and in distal positions on the same spikelet.However,grain protein concentrations declined in each section because of the increased grain number and reduced N uptake.

Studies on Single Cell Culture in vitro in Wheat——The variation of grain protein content and its fractions from regenerated plants

On the basis of previous studies dealing with the variation of major agronomic and yield characteristics of regenerated plants derived from single cell culture in vitro of common wheat (Triticum aestivum L.Cultivar NE 7742), the grain protein content and its fractions from regenerated plants with stable agronomic characteristics were studied from 1992 to 1995. The results showed that the variation of grain protein content and its fractions in somaclones from single cell culture in vitro were very significant and the range was very wide (11531770%). Several types of variation were found in the studies, especially the type with higher protein content than that of cultivar NE 7742 (non-culture parent). Among them, -2069% of lines the grain protein content was significantly higher than that of NE 7742 and combined with high yielding potential. The tendency of variation of the four protein fractions showed that the variation of albumin was not obvious and maintained the same level as NE774 increased in some somaclones and decreased in others. However, the percentages both globulin and glutenin tended to increase. The variation of total amount of structural protein and the ratio between globulin and glutenin tended to increase. The variation of total amount of structural protein and the ratio between globulin and albumm was mainly influenced by globulin under the condition of culture in vitro. The variation of total amount of storage protein and the ratio between gliadin and glutenin was mainly affected by glutenin. The results mentioned above demonstrated that the induction and screening of somaclonal variation could be an effective way in wheat improvement in combining high protein content with high yield.

Accumulation Characteristics of Protein and Non-Protein Components and Their Correlations with Protein Concentration in Rice Grains

Protein in rice grains is an important source of nutrition for rice consumers.This study mainly aimed to identify the critical factors that determine grain protein concentration in rice.Accumulation parameters,including mean accumulation rate(Rmean)and active accumulation duration(Dactive),for protein and non-protein components and their correlations with protein concentration in rice grains were investigated in field experiments conducted over two years with six rice cultivars.Results showed that grain protein concentration ranged from 9.6%to 11.9%across cultivars and years.Accumulation processes of protein and non-protein components were well fitted by the logistic equation for all six rice cultivars in both years,and the ratio of protein to non-protein for R_(mean) and D_(active) ranged from 0.08 to 0.12 and 1.01 to 1.33,respectively.Grain protein concentration was significantly correlated with protein to non-protein ratio for R_(mean).This study suggests that grain protein concentration is not solely determined by the accumulation of protein or non-protein component,but by the coordination of protein and non-protein accumulation.

SRG1,Encoding a Kinesin-4 Protein,Is an Important Factor for Determining Grain Shape in Rice

Grain shape is one of the important agronomic traits, which is closely related to the yield of rice.A new rice mutant, named small and round grain(srg1), was isolated from an indica cultivar Zhenong 34 by ethyl methane sulfonate(EMS) mutagenesis. The microscopic analysis showed that the cell length of spikelet in srg1 was decreased compared with that in wild type(WT), which caused the grain length short.Meanwhile, the grains of srg1 were wider than those of WT because of the increased cell layers in spikelet in the lateral direction. Therefore, the inhibition of cell expansion and increased cell proliferation collectively led to the small and round grain. By map-based cloning, the gene SRG1 was located on the short arm of chromosome 9, which encodes a kinesin-4 protein, represented by the gene LOC_Os09 g02650. A single nucleotide polymorphism, occurred in the 16 th exon of SRG1, led to premature translation stop in mutant. The cell cycle-related genes were up-regulated in srg1, which conferred that SRG1 controlled grain width through the cell proliferation. Since the role of SRG1 in regulating grain shape was not clarified well before, it is valuable to explore the mechanism of grain development. This study could, hence, provide a morphogenesis and molecular basis for elucidating the function of SRG1, as well as a new germplasm resource for the further study of grain development.

Comparisons of Protein Composition of Grains at Different Positions in Panicles between Erect and Curved Panicle Type Japonica Rice

Under field conditions, three erect panicle type japonica dee cultivars and three curved panicle type japonica rice cultivars were applied as experimental materials to investigate the differences of protein composition of grains at different positions in panicles between two different panicle types of japonica rice. Accord- ing to the results, the panicle type of japonica rice had no direct correlation with albumin content, globulin content, prolamin content and glutelin content in rice, variations of protein composition of grains at different positions in panicles. There were certain correlations between soluble protein contents at different grain posi- tions in the same panicle and the flowering order of glumous flowers in the panicle. Albumin content, prolamin content and glutelin content in grains on secondary rachis branches of two panicle types （erect and curved） of japonica rice cuhivars were higher than that on primary rachis branches, while globulin content exhibited an opposite trend. Globulin content, prolamin content and glutelin content in grains at different positions demonstrated a descending order of bottom 〉 middle 〉 top, while albumin content exhibited an opposite trend. The interactions between primary and secondary rachis branches and among top, middle and bottom rachis branches significantly affected soluble protein contents.

Variations in Carbohydrate and Protein Accumulation among Spikelets at Different Positions Within a Panicle During Rice Grain Filling

The accumulation dynamics of kernel components for spikelets at different positions within a rice panicle were investigated during grain filling to understand the physiological reasons for the variation of grain quality.Two rice cultivars,Yangdao 6 （indica） and Yangjing 9538 （japonica）,were field-grown,and the grain filling characters and contents of starch,soluble sugar,and protein of the spikelets at different positions were studied.There were significant differences in matter accumulation among spikelets at different positions during grain filling.The early-flowering spikelets presented dominance over the late-flowering spikelets in initial time and initial rate of accumulation.At the initial and mid filling stages,the contents and the rates of starch and amylose accumulation in spikelets decreased with the flowering sequence,but soluble sugar content （SSC） exhibited the opposite trend.The difference in SSC among the spikelets of Yangjing 9538 was greater than that of Yangdao 6,but amylose content in mature spikelets showed no obvious relationship to their flowering sequence.The crude protein content （CPC） of early-flowering spikelets decreased more rapidly than that of late-flowering ones at the initial filling stage,and CPC in the spikelets on the secondary branch was higher than that on the primary branch,but CPC in early-flowering ones was lower than that in late-flowering across the whole grain filling period.Grain water content （GWC） of early-flowering spikelets decreased more rapidly than that of late-flowering spikelets on the same branch at the initial and mid filling stages,especially for the top grain on each primary branch.The results suggested that poor grain filling of late-flowering spikelets may be attributed to their low biological activity rather than carbohydrate supply limitation.

Protein Quality of Amaranth Grains Cultivated in Ethiopia as Affected by Popping and Fermentation

The effect of popping and fermentation on protein quality of three different varieties of amaranth grains cultivated in Ethiopia was evaluated. Total lysine content of the grains was higher than that of commonly available cereals but close to that of legumes. Methionine and cysteine contents in the grains were also higher than that found in cereal and legume proteins. Percentage of total indispensable amino acids, excluding tryptophan, was 43% - 49%, which was higher than WHO reference pattern (31%). Popping resulted in 36% and 37% reduction in total lysine and cysteine contents, respectively, whereas fermentation reduced cysteine, lysine and methionine contents by 16%, 20% and 20%, respectively. From the free amino acids, histidine was the major indispensable amino acid but threonine was not detected. During popping, all free amino acids, except threonine, were reduced. On the other hand, fermentation significantly increased (p < 0.01) most amino acids except arginine, which was significantly decreased (p < 0.01), and tyrosine and glutamic acid, for which no change was observed. Popping decreased in vitro protein digestibility (IVPD) by 8.3% - 17.1% while fermentation increased IVPD by 4.8% - 7.5%. Substitution of amaranth for wheat and/or maize during complementary food formulation could contribute much to the daily requirements of indispensable amino acids of young children.

Genetic Analysis and Improvement Strategies of Protein Content in Rice Seeds

Enhancing the nutritional quality of food crops is a way to improve human nutrition and health. Grain protein content （ GPC ） is an important nutritional quality trait for rice and many other crops. Therefore, it will be very significant to increase GPC and improve rice quality. This paper mainly reviewed the genetic studies GPC in rice, mapping and cloning of QTLs and genes associated with GPC. However, little is known about the molecular mechanism and gene function related to GPC in rice. Thus, here we put forward the genetic strategy by gene pyramiding or molecular marker assisted selection to improve GPC and nutritional quality in rice. This review could provide important information for genetic improvement of grain nutritional quality of rice.

Global sensitivity analysis of wheat grain yield and quality and the related process variables from the DSSAT-CERES model based on the extended Fourier Amplitude Sensitivity Test method

A crop growth model,integrating genotype,environment,and management factor,was developed to serve as an analytical tool to study the influence of these factors on crop growth,production,and agricultural planning.A major challenge of model application is the optimization and calibration of a considerable number of parameters.Sensitivity analysis(SA) has become an effective method to identify the importance of various parameters.In this study,the extended Fourier Amplitude Sensitivity Test(EFAST) approach was used to evaluate the sensitivity of the DSSAT-CERES model output responses of interest to 39 crop genotype parameters and six soil parameters.The outputs for the SA included grain yield and quality(take grain protein content(GPC) as an indicator) at maturity stage,as well as leaf area index,aboveground biomass,and aboveground nitrogen accumulation at the critical process variables.The key results showed that:(1) the influence of parameter bounds on the sensitivity results was slight and less than the impacts from the significance of the parameters themselves;(2) the sensitivity parameters of grain yield and GPC were different,and the sensitivity of the interactions between parameters to GPC was greater than those between the parameters to grain yield;and(3) the sensitivity analyses of some process variables,including leaf area index,aboveground biomass,and aboveground nitrogen accumulation,should be performed differently.Finally,some parameters,which improve the model’s structure and the accuracy of the process simulation,should not be ignored when maturity output as an objective variable is studied.

Effects of Late Nitrogen Application on Nitrogen Translocation and Protein Fractions of Wheat Genotypes Differing in Protein Content

In order to investigate the effeits of late nitrogen application on nitrogen translocation and protein fractions, three genotypes differing in protein content were studied in pot experiments at low and high fertility regimes with late foliar nitrogen application. At high fertility, late nitrogen application increased N translocation and improved N translocation efficiency greatly, however, cultivar differences were found at low fertility and late nitrogen application increased both leaf and chaff N translocation, and increased culm N translocation only at high fertility. Relative contributions of vegetative components to N translocation efficiency were altered by late nitrogen application. Albumin and gliadin contents at maturity were decreased by late nitrogen application for all cultivars used, and cultivar variations for globulins were also observed. Xin Kehan No. 9, the high yielding, low grain protein content cultivar remained no change for glutenin content to late nitrogen application, Dongnong 7742, the high yielding, high grain protein content, decreased slightly, and Roblin, high grain protein but low yielding cultivar decreased only at hihg fertility. Residual protein contents were significantly increased by late nitrogen application for all cultivars. It was concluded that nitrogen applied at later stage could be used efficiently noly at high fertility, and most of the N translocated were used for the synthesis of residual proteins.

Identification of QTL Affecting Protein and Amino Acid Contents in Rice

The phenotypes of protein and amino acid contents were measured in an F9 recombinant inbred line population derived from a cross between Zhenshan 97B and Delong 208. A total of 48 and 64 QTLs were identified in 2004 and 2005, respectively. The contribution of each QTL to the phenotypic variation ranged from 4.0% to 43.7%. Most QTLs co-localized, forming 29 QTL clusters on the chromosomes with three major ones detected in both years, which were mapped on chromosomes 1, 7 and 9, respectively. The two QTL clusters for amino acid content, qAa1 and qAa7, influenced almost all the traits with the allele from Zhenshan 97B, and the third QTL cluster for amino acid content, qAa9, increased the lysine content with the allele from Delong 208. A wide coincidence was found between the QTL detected under this study and the loci involved in amino acid metabolism pathways in nitrogen assimilation and transport, or protein biosynthesis. The results would facilitate the identification of candidate genes and could be used in marker-assisted selection for the favorable allele in rice quality improvement.

The influence of phytase, pre-pellet cracked maize and dietary crude protein level on broiler performance via response surface methodology

Background:The reduction of crude protein levels in diets for broiler chickens may generate economic,environmental and flock welfare and health benefits;however,performance is usually compromised.Whole grain feeding and phytase may improve the utilization of reduced crude protein diets.Results:The effects of pre-pellet cracked maize(0,15%and 30%)and phytase(0,750 and 1500 FTU/kg)in isoenergetic maize-soy diets with three levels of crude protein(22%,19.5%and 17%)were evaluated via a BoxBehnken response surface design.Each of 13 dietary treatments were offered to 6 replicate cages(6 birds/cage)of male Ross 308 broiler chicks from 7 to 28 d post-hatch.Model prediction and response surface plots were generated from experimental data via polynomial regression in R and only significant coefficients were included and discussed in the predicted models.Weight gain,feed intake and FCR were all influenced by pre-pellet cracked maize,phytase and crude protein level,where crude protein level had the greatest influence.Consequently,the reduction from 22%to 17%dietary crude protein in non-supplemented diets reduced weight gain,feed intake,relative gizzard weight,relative gizzard content and relative pancreas weight but improved FCR.However,the inclusion of 30%cracked maize to 17%crude protein diets restored gizzard weight and 1500 FTU phytase inclusion to 17%crude protein diets increased relative gizzard contents and pancreas weights.Cracked maize and phytase inclusion in tandem to 17%crude protein diets increased weight gain,feed intake and FCR;however,this FCR was still more efficient than broilers offered the non-supplemented 22%crude protein diet.Broilers offered the prepellet cracked maize and phytase inclusions reduced AME in 22%crude protein diets but improved AME by 2.92 MJ(14.16 versus 11.24 MJ;P<0.001)in diets containing 17%crude protein.Ileal N digestibility was greater in broilers offered diets with 17%crude protein than those offered the 22%crude protein diet;irrespective of phytase and pre-pellet cracked maize.Conclusion:Pre-pellet cracked maize and phytase inclusions will improve the performance of broilers offered reduced crude protein diets.

Influence of Amino Acid Supplementations in Juvenile Yellow Perch Fed Plant Protein Combinations

Distillers dried grains with solubles (DDGS) in combination with soy protein concentrate (SPC) with and without an essential amino acid (EAA) complex were assessed as protein alternatives in juvenile Yellow Perch Perca flavescens diets. Diets contained 5% FM, 40% SPC, and 20% or 40% DDGS each with or without EAA. No mortalities or health assessment differences were observed during the trial and all fish readily accepted the experimental diets. Diets supplemented with EAA produced greater weight gain, improved feed conversion, and apparent protein digestibility. Performance was consistently improved for fish fed diets containing amino acid supplements. Based on these results, Yellow Perch are able to utilize high levels of the plant proteins, accompanied with EAAs, as a FM replacer.

Multiscale molecular dynamics simulations of membrane remodeling by Bin/Amphiphysin/Rvs family proteins

Membrane curvature is no longer thought of as a passive property of the membrane; rather, it is considered as an ac- tive, regulated state that serves various purposes in the cell such as between cells and organelle definition. While transport is usually mediated by tiny membrane bubbles known as vesicles or membrane tubules, such communication requires complex interplay between the lipid bilayers and cytosolic proteins such as members of the Bin/Amphiphysin/Rvs （BAR） superfam- ily of proteins. With rapid developments in novel experimental techniques, membrane remodeling has become a rapidly emerging new field in recent years. Molecular dynamics （MD） simulations are important tools for obtaining atomistic information regarding the structural and dynamic aspects of biological systems and for understanding the physics-related aspects. The availability of more sophisticated experimental data poses challenges to the theoretical community for devel- oping novel theoretical and computational techniques that can be used to better interpret the experimental results to obtain further functional insights. In this review, we summarize the general mechanisms underlying membrane remodeling con- trolled or mediated by proteins. While studies combining experiments and molecular dynamics simulations recall existing mechanistic models, concurrently, they extend the role of different BAR domain proteins during membrane remodeling pro- cesses. We review these recent findings, focusing on how multiscale molecular dynamics simulations aid in understanding the physical basis of BAR domain proteins, as a representative of membrane-remodeling proteins.