Mature Grains Research Articles

Cadmium allocation to grains in durum wheat exposed to low Cd concentrations in hydroponics

This study aims to characterize the response of durum wheat to different concentrations of Cd found in agricultural soils. One French durum wheat cultivar (i.e. Sculptur) was exposed to low concentrations of Cd (5 nM or 100 nM) in hydroponics. After anthesis, the plants were fed with a solution enriched with the stable isotope 111Cd to trace the newly absorbed Cd. Plants were sampled at anthesis and grain maturity to assess how plant growth, Cd uptake and partitioning among organs, as well as Cd remobilization, differed between the two Cd exposure levels. Durum wheat did not show any visual symptoms of Cd toxicity, regardless of which Cd treatment was applied. However, post-anthesis durum wheat growth was 14% penalized at 100 nM due to the large transpiration-based accumulation of Cd in leaves at this stage. The allocation of Cd to the grains was not restricted but enhanced at 100 nM compared to 5 nM. Both the root-to-shoot Cd translocation and the fraction of aboveground Cd allocated to grains were higher in plants exposed to 100 nM. Cadmium was remobilized exclusively from roots and stems, and remobilized Cd contributed on average to 40–45% of the Cd accumulated in mature grains, regardless of which Cd treatment was applied. The relevance of these results to decreasing the concentration of Cd in durum wheat grains is discussed.

Overexpression of HvCslF6 in barley grain alters carbohydrate partitioning plus transfer tissue and endosperm development.

In cereal grain, sucrose is converted into storage carbohydrates: mainly starch, fructan, and mixed-linkage (1,3;1,4)-β-glucan (MLG). Previously, endosperm-specific overexpression of the HvCslF6 gene in hull-less barley was shown to result in high MLG and low starch content in mature grains. Morphological changes included inwardly elongated aleurone cells, irregular cell shapes of peripheral endosperm, and smaller starch granules of starchy endosperm. Here we explored the physiological basis for these defects by investigating how changes in carbohydrate composition of developing grain impact mature grain morphology. Augmented MLG coincided with increased levels of soluble carbohydrates in the cavity and endosperm at the storage phase. Transcript levels of genes relating to cell wall, starch, sucrose, and fructan metabolism were perturbed in all tissues. The cell walls of endosperm transfer cells (ETCs) in transgenic grain were thinner and showed reduced mannan labelling relative to the wild type. At the early storage phase, ruptures of the non-uniformly developed ETCs and disorganization of adjacent endosperm cells were observed. Soluble sugars accumulated in the developing grain cavity, suggesting a disturbance of carbohydrate flow from the cavity towards the endosperm, resulting in a shrunken mature grain phenotype. Our findings demonstrate the importance of regulating carbohydrate partitioning in maintenance of grain cellularization and filling processes.

Nutrient uptake, partitioning, and removal in two modern high-yielding Colombian rice genotypes

The objective of this research was to determine the difference on growth between a rice cultivar with Clearfield® technology (Only Rice 228) and a hybrid (Benja 1); to characterize nutrient uptake, distribution, accumulation and removal between these two commercial genotypes. Tests under shade house and field conditions were performed to estimate macro and micronutrient uptake patterns. Plants were sampled at nine growth stages (emergence, initiation of tillering, active tillering, initiation of panicle primordia, booting, flowering, milky, soft dough and mature grain) and divided into different organs for nutrient determination. The results showed that “Benja 1” plants (92 d) had a shorter cycle than “Only Rice 228” (OR 228) plants (118 d). “OR 228” exhibited a greater biomass production (16.575 kg ha−1 vs. 12.621 kg ha−1) in field. The nutrient acquisition was faster in the hybrid Benja 1 between tillering initiation and the milky grain stage in which the N, K, Ca, Mg, Mn, B, and Cu uptake was more evenly and highly distributed throughout these stages in both conditions. “Benja 1” showed a higher nutrient harvest index (HI). HI values above 50% (P (62%), N (61%), Cu (67%), S (55%), and Mg (52%)) were found in Benja 1 under field conditions. The results also highlight Si removal in both rice genotypes, in which Benja 1 stands out. These results provide information on the nutrient uptake and partitioning of modern rice genotypes, and give the knowledge to optimize fertilizer programs and timing recommendations for rice biomass and grain production in Colombia.

Toward a New Use for Carbon Isotope Discrimination in Wheat Breeding

A major obstacle in the effort to develop drought tolerant varieties of wheat (Triticum aestivum L.) is phenotyping. Traits known to contribute to improved drought tolerance, such as water-use behavior, reliance on stem reserve carbohydrates, and the ability to develop deep roots, require time and resource-intensive screening techniques. Plant breeding programs often have many thousands of experimental genotypes, which makes testing for each of these traits impractical. This work proposes that carbon isotope discrimination (∆) analysis of mature grains may serve as a relatively high-throughput approach to identify genotypes exhibiting traits associated with drought tolerance. Using ∆ as a proxy for stomatal conductance and photosynthetic capacity, assumptions can be made regarding fundamental plant physiological responses. When combined with knowledge of the terminal drought severity experienced in a particular environment, genotypes exhibiting conservative and rapid water use, deep roots, and reliance on stem reserve carbohydrates may be identified. Preliminary data in support of this idea are presented. Further verification of this use for grain ∆ will better equip wheat breeding programs to develop more drought tolerant varieties.

Protéomique de la couche à aleurone en grain mature de Triticum spelta et de trois espèces apparentées aux blés

Background : A proteomics approach was used to reveal major protein differences in the aleurone layer (AL) of mature grain between four wheat species: T. aestivum and T. spelta (6X), T. durum (4X), and T. monococum (2X). Materiel and methods: In each species, one representative cultivar was used for total AL protein extraction. Two-dimensional electrophoresis of AL proteins revealed 1380, 1355, 1120 and 973 Coomassie stained spots, respectively. Result: A total of 334 spots showed quantitative or qualitative (presence/absence) differences between the four cultivars. T. aestivum and T. spelta had 90.9% and 92.6% of their AL proteome respectively, identical to the other species. Only 25 spots were significantly different between the two hexaploid cultivars. AL proteins encoded by the A genome were mainly expressed in polyploid species. Percentages of proteins encoded by A genome was 85%, in tetraploid species and 70% in the hexaploid spelt. Eighty for proteins are identified by mass spectrometry and data mining and were classified in five bbiological processes and (12) functional categories. Conclusion: The major differences between species were particularly due to storage globulins (22, 11 and 1 of Glo-3, Glo-3B, Glo-3C, respectively), stress related proteins including antioxidant proteins like 1-Cys peroxiredoxin and manganese superoxide dismutase, defence proteins like xylanase, serpin3 and heat shock proteins.

Farmer Preferred Traits and Potential for Adoption of Hybrid Rice in Ghana

Hybrid rice (Oryza sativa L) cultivars exploit hybrid vigor to break the yield ceiling of their inbred counterpart thereby increasing productivity per unit area. Crop varieties released in developing countries are often poorly adopted as a result of their failure to meet farmer and consumer trait preferences. This study was therefore conducted to identify key farmer preferred traits, assess farmers' general rice agronomic practices and the potential for adoption of hybrid rice through formal and informal survey approaches. Farmer preferred traits include high yield, early maturity, and good grain quality, but few others, their preferences varied according to location. High cost of hybrid rice seeds was identified as a major challenge. There will be the need for reasonable pricing such that the return from growing hybrid seed is high enough for farmers to recognize the value of growing hybrids. Forty per cent (40%) of the responding farmers were found to employ seed wasting practices such as broadcasting and dibbling. Farmers gave mistrust and unreliable seed supply as the main reasons for their low patronage of the formal seed system. Only two per cent (2%) of the responding farmers purchase seeds from private seed companies. It will be necessary to revamp the formal seed system to encourage farmer patronage and private sector involvement for successful roll out of hybrid rice technology in Ghana. Considering the expected yield advantage (>50%) and the price farmers will like to pay (GH¢3.3; $0.8), the prospects of hybrid rice adoption could said to be low.

Growing tall and dwarf rice cultivars in mixture for better weed management and higher yield

Growing two or more cultivars of same crop species in mixture reduces intra-specific competition for natural resources and increases competitive ability of crops against weeds and thus enhances crop yield. The objective of this study was to evaluate the potentiality of growing rice cultivars in mixtures for minimizing weed pressure and increasing rice yield. The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during Aman season (July-December) 2017. Two transplant Aman rice cultivars viz. Binadhan-13 (tall, late- maturing and fine grain aromatic cultivar) and BRRI dhan49 (semi-dwarf, mid-maturing and coarse grain cultivar) were grown following two spatial arrangements viz., alternate row and alternate hill, and nine different cultivar mixture (Binadhan-13:BRRI dhan49) row ratios viz., 1:0, 1:2, 2:1, 2:3, 3:2, 2:4, 4:2,1:1 and 0:1. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Results confirmed the positive influence of spatial arrangement and cultivar mixture ratio on rice productivity. Both the cultivars showed better growth and higher yield when grown in mixture irrespective of ratios compared to their sole culture performances. But cultivar mixture ratio showed no advantages over sole culture in suppressing weeds. Based on the total yield Binadhan-13 and BRRI dhan49 inter-planted in 1:1 row ratio following alternate hill performed the best resulting in 50% and 12% yield advantages over sole culture of Binadhan-13 and BRRI dhan49, respectively. Therefore, growing tall and dwarf rice cultivars in mixture can be adopted as a tool for increasing rice productivity.
 J. Bangladesh Agril. Univ. 17(2): 133–141, June 2019

Suppression of phospholipase D genes improves chalky grain production by high temperature during the grain-filling stage in rice.

High temperature (HT) during the grain developing stage causes deleterious effects on rice quality resulting in mature grains with a chalky appearance. Phospholipase D (PLD) plays an important role in plants, including responses to environmental stresses. OsPLDα1, α3 and β2-knockdown (KD) plants showed decreased production of chalky grains at HT. HT ripening increased H2O2 accumulated in the developing grains. However, the increase was canceled by the knockdown of OsPLDβ2. Expression levels of OsCATA which is one of three rice catalase genes, in developing grains of OsPLDβ2-KD plants at 10 DAF were increased compared with that in vector-controls in HT growth conditions. Overexpression of OsCATA markedly suppressed the production of chalky grains in HT growth conditions. These results suggested that OsPLDβ2 functions as a negative regulator of the induction of OsCATA and is involved in the production of chalky grains in HT growth conditions.

Molecular Advances on Phytases in Barley and Wheat.

Phytases are pro-nutritional enzymes that hydrolyze phytate and make associated nutrients, such as phosphorous, iron, and zinc, bioavailable. Single-stomached animals and humans depend on phytase supplied through the diet or the action of phytase on the food before ingestion. As a result, phytases—or lack thereof—have a profound impact on agricultural ecosystems, resource management, animal health, and public health. Wheat, barley and their Triticeae relatives make exceptionally good natural sources of phytase. This review highlights advances in the understanding of the molecular basis of the phytase activity in wheat and barley, which has taken place over the past decade. It is shown how the phytase activity in the mature grains of wheat and barley can be ascribed to the PAPhy_a gene, which exists as a single gene in barley and in two or three homeologous copies in tetra- and hexaploid wheat, respectively. It is discussed how understanding the function and regulation of PAPhy_a may support the development of improved wheat and barley with even higher phytase activity.

Differentiation of maize breeding samples by β-carotene content

Plant carotenoids are important micronutrients in the diet of humans and animals, since they act as precursors for the synthesis of vitamin A in animal cells. The most effective precursor to the vitamin A biosynthesis is β-carotene. Increasing the β-carotene content in maize grain as an important feed and food crop is an urgent task for plant selection. The purpose of this work was to differentiate maize breeding samples from the Dnipro breeding program by the β-carotene content in mature grain. Maize grain of 18 inbreds harvested in 2015 and 5 inbreds harvested in 2016 was researched. Determination of β-carotene content in matured dry grain was carried out after petroleum ether extraction and ultra performance liquid chromatography (UPLC) in the mobile phase of methanol/acetonitrile. The β-carotene content in the grain of genotypes from the Dnipro breeding program was on average 1.020 mg/kg for inbreds grown in 2015, and 0.672 mg/kg for inbreds grown in 2016. These values correspond to the β-carotene content in the grain of the majority of genotypes from world breeding programs selected by methods of classical selection. The inbred DKV3262 with white grain had the smallest content of β-carotene (0.076 mg/kg), while the yellow-coloured line DKD9066 had the highest one (2.146 mg/kg). The variation in the grain β-carotene content in different years of maize cultivation was noted. Inbreds of flint and semident maize showed the general tendency to increase the β-carotene content in grain compared with dent ones. The distribution of the studied inbreds on germplasm types showed the significant variation of β-carotene content in grain and the incidence of relatively high values in all germplasms analyzed. Inbreds containing more than 1.5 mg of β-carotene per 1 kg of grain, DK239, DK206A, DK212, DKD9066 and DKE-1, are emphasized as promising for the selection to increase the content of valuable micronutrients.

Growth and Yield of Rice (Oryza sativa L.) Under Raised- and Sunken-Bed System as Affected by Saline Irrigation in Baros, Bantul, Yogyakarta

It is expected that by utilizing marginal land (e.g. saline field) is able to increase rice production under saline condition. One of integrated approaches that can be applied is a raised- and sunken-bed system. This experiment aimed to investigate the growth and yield of rice under raised- and sunken-bed system as affected by saline irrigation. The field experiment was conducted at Baros Helmet, Bantul District, Yogyakarta from October 2016 to February 2017. The experiment was arranged in a multi-location (oversite) design, consisted of saline irrigation (S1) and nonsaline irrigation (S0) in a raised-bed (A1) and sunken-bed (A0) planting system. The observations were done on leaf area index, chlorophyll a, chlorophyll b, total chlorophyll, photosynthesis rate, total dry weight, root length, leaf Na+ and K+ concentration, proline concentration, maturity and dry grain yield (DGY). The results showed that saline irrigation negatively affected leaf area index, photosynthetic rate and root length of rice grown at sunken-bed. However, leaf Na+ concentration and leaf proline concentrations of rice grown at sunken-bed were higher. The leaf K+ concentration decreased with increasing Na+ concentration. Although saline irrigation could accelerate harvesting age of rice grown at sunken-bed, the dry grain yield of rice grown at sunken-bed did not significantly different with that of rice grown at raised-bed.

Grain legume production and their potential for sustainable agriculture in Botswana between 2008 and 2015: a review

Pulse crops are an integral component of arable agriculture in Botswana, particularly in subsistence farming. The benefits of these crops include provision of nutrition for both human beings and livestock, as well as environmental sustainability needs. Although they have a far reaching socio-economic impact, these benefits have not been adequately characterized for inclusion in endeavors of conservation agriculture in the country. Furthermore, data on pulses are often lumped together without identifying important pulse crops grown in Botswana. The objective of this paper was to review production of pulses and their potential as components in cropping systems and conservation agriculture in Botswana. The data used in this study were obtained from reports of Ministry of Agriculture and Food Security (MOA), Statistics Botswana, FAOSTAT and other literature sources. With the ongoing changes in climate and predicted increase in incidences of drought, pulses are among crops most relevant to sustainable agriculture. They are among the most versatile because of their variability in cropping duration from early to late maturity. Their consumption ranges from fresh forms to physiologically mature grain. Pulses play an important role in climate change mitigation through their ability to fix nitrogen, thus reducing dependency on organic and synthetic fertilizers. They use less water from relatively shallow soil and allow for stratified soil water use for companion crops in intercropping or conserve soil water for subsequent crops in rotations. Thus pulses improve both water and nutrient use efficiencies when included in cropping systems. Their production also has a low footprint in both carbon and water. Currently, pulses are among the few highly priced crops in Botswana markets and together with the possibility of replacement of imported grain, investments in their production can generate income and improve livelihood of both farmers and consumers in Botswana. Crop production management technology involves judicious use of integrated nutrient, pest and disease management; appropriate integrated management packages that include pulses can be promoted to ensure sustainable crop production under the adverse impacts of climate change.

Unpacking a crop diversity hotspot: farmer practice and preferences in Northern Malawi

ABSTRACT Crop diversity is a key principle of sustainable food production systems. Yet, inter and intra specific diversification is declining in many regions of the world. In Northern Malawi, a participatory action research project (Soils Food and Healthy Communities) has conducted agroecological co-learning with farmers for over a decade, providing an opportunity to explore farmer management, crop choice and variety selection practices. Farmers who participate receive seed for 0.10 ha of on-farm testing for one growing season and then decide whether to continue to grow the crop. Cropping system diversity, management practices and traits associated with crops grown and lost were assessed through interviews with 198 farm households (757 fields). We found an average of 1.3 species per field and 4.0 crops per farm. This is almost twice the level of diversity in other reports from Malawi smallholder farms. Farmers cited a wide range of preferred groundnut variety traits, as well as concerns (namely, high labour requirements). Both modern and local maize varieties are being grown and those retained were often associated with early maturity or preferred grain quality traits such as storability. Overall, farmers at this Northern Malawi agroecology education site are growing diverse crop mixtures that include traditional as well as modern varieties of maize and groundnut.

“Wild barley serves as a source for biofortification of barley grains”

The continuing growth of the human population creates an inevitable necessity for higher crop yields, which are mandatory for the supply with adequate amounts of food. However, increasing grain yield may lead to a reduction of grain quality, such as a decline in protein and mineral nutrient concentrations causing the so-called hidden hunger. To assess the interdependence between quantity and quality and to evaluate the biofortification potential of wild barley, we conducted field studies, examining the interplay between plant development, yield, and nutrient concentrations, using HEB-YIELD, a subset of the wild barley nested association mapping population HEB-25. A huge variation of nutrient concentration in grains was obtained, since we identified lines with a more than 50% higher grain protein, iron, and zinc concentration in comparison to the recurrent parent ‘Barke’. We observed a negative relationship between grain yield and nutritional value in barley, indicated by predominantly negative correlations between yield and nutrient concentrations. Analyzing the genetic control of nutrient concentration in mature grains indicated that numerous genomic regions determine the final nutritional value of grains and wild alleles were frequently associated with higher nutrient concentrations. The targeted introgression of wild barley alleles may enable biofortification in future barley breeding.

Metabolomic approach to study the impact of flour type and fermentation process on volatile profile of bakery products

Metabolomic approaches applied to fermented foods are at the state of the science and represent a robust and reliable approach to identify, quantify and characterise the biochemical profiles of raw materials and transformed products. The outcomes so far obtained are cornerstones to understand mainly nutritional and sensorial inherent features. Formulations of new bakery products with increased nutritional values is trending the market, but sensorial attributes still need to be improved to reach a wider audience. The present work describes the application of gas chromatography–mass spectrometry (GC–MS) and electronic nose analyses, to investigate over the volatilome of different bakery products, obtained from mature and immature grains (KAMUT® khorasan and durum wheat) and transformed by a sourdough made of Lactobacillus spp. and Saccharomyces cerevisiae.From the recipient results has emerged that the sensors used can distinguish the KAMUT® khorasan doughs fermented industrially at the fully ripe stage, the same doughs at the milky stage and KAMUT® khorasan sourdough at the fully ripe stage. Electronic nose allowed discriminating between different types of flours and GC–MS indicated the volatilome of sourdough KAMUT® khorasan case as the most promising. Thus, the combination of different independent variables in the bread process to improve the sensorial quality of the product, when is backed by metabolomics, represents an effective approach to study, characterise and exploit the sensorial quality of breads.

Corn Mineral Nutrition Responses to NPSFe Biofertilizer and NPKZn Briquettes

Alternative fertilizers have been increasingly developed during recent years in order to improve crop nutrition. The efficacy of these fertilizers on corn (Zea mays L.) production has not been well examined. Alternative fertilizers of organically enhanced NPSFe biofertilizer (NPSFe) manufactured from sterilized organic additives extracted from municipal wastewater biosolids and NPKZn briquettes (briquettes) produced by compacting commercially available solid fertilizers into a super-granule between 1-3 grams were evaluated for nutrient concentrations in plant biomass and grain of corn compared to commonly used N fertilizers ammonium sulfate and urea at Jackson and Grand Junction, TN during 2011-2013. NPSFe, the briquettes, ammonium sulfate, and urea and four N application rates of 0, 85, 128/170, and 170/255 kg ha-1 were assigned to the main and sub plots, respectively, in a split plot randomized complete block design with four replicates. Aboveground plant biomass at the silking growth stage (R1) and physiological maturity stage (R6) and grain at harvest were analyzed for N, P, K, S, Fe, and Zn concentrations. NPSFe resulted in similar or lower plant N concentrations relative to the conventional fertilizers ammonium sulfate and urea. The briquettes performed equally or better in terms of plant N concentrations compared to ammonium sulfate and urea. In excessive spring precipitation, the briquettes had higher biomass N concentrations at R1. NPSFe tended to have lower P concentrations in plant biomass at R1 and R6. The briquettes had similar or higher plant P levels relative to ammonium sulfate and urea. Both NPSFe and ammonium sulfate increased S concentrations in plant biomass compared to the briquettes and urea. In conclusion, the briquettes do not consistently improve corn N, P, K, and Zn nutrition compared to the conventional fertilizers ammonium sulfate and urea. NPSFe sometimes seems to reduce corn N and P nutrition but increase Zn nutrition relative to ammonium sulfate and urea.

Spatial and temporal distribution of cell wall polysaccharides during grain development of Brachypodium distachyon

Brachypodium distachyon (Brachypodium) is now well considered as being a suitable plant model for studying temperate cereal crops. Its cell walls are phylogenetically intermediate between rice and poaceae, with a greater proximity to these latter. By microscopic and biochemical approaches, this work gives an overview of the temporal and spatial distribution of cell wall polysaccharides in the grain of Brachypodium from the end of the cellularization step to the maturation of grain. Variation in arabinoxylan chemical structure and distribution were demonstrated according to development and different grain tissues. In particular, the kinetic of arabinoxylan feruloylation was shown occuring later in the aleurone layers compared to storage endosperm. Mixed linked β-glucan was detected in whole the tissues of Brachypodium grain even at late stage of development. Cellulose was found in both the storage endosperm and the outer layers. Homogalacturonan and rhamnogalacturonan I epitopes were differentially distributed within the grain tissues. LM5 galactan epitope was restricted to the aleurone layers contrary to LM6 arabinan epitope which was detected in the whole endosperm. A massive deposition of highly methylated homogalacturonans in vesicular bodies was observed underneath the cell wall of the testa t2 layer at early stage of development. At maturity, low-methylated homogalacturonans totally fulfilled the lumen of the t2 cell layer, suggesting pectin remodeling during grain development. Xyloglucans were only detected in the cuticle above the testa early in the development of the grain while feruloylated arabinoxylans were preferentially deposited into the cell wall of t1 layer. Indeed, the circumscribed distribution of some of the cell wall polysaccharides raises questions about their role in grain development and physiology.

Protein Disulfide Isomerase (PDI1-1) differential expression and modification in Mexican malting barley cultivars.

Barley malting quality depends on seed characteristics achieved during grain development and germination. One important parameter is protein accumulation in the mature seed, which may vary between cultivars. Here we conducted a protein pattern analysis in the range of pI 4–7 of mature grains from five Mexican barley cultivars, commonly used for malt and beer production. Reproducibly distinct protein spots, separated by 2D SDS PAGE, were identified by mass spectrometry and considered as potential markers for cultivars with distinct seed protein accumulation. The expression patterns of glutamate decarboxylase (GAD) and protein disulfide isomerase (PDI1-1) were followed at transcript level during grain development for three independent growth cycles to establish whether differences between cultivars were reproducible. Quantitative determination of PDI1-1 protein levels by ELISA confirmed a reproducibly, distinctive accumulation and post-translational modifications between cultivars, which were independent of plant growth regimes. According to its impact on differential storage protein accumulation, we propose the PDI1-1 protein as potential biomarker for Mexican malting barley cultivars.

Enhancing grain size in durum wheat using RNAi to knockdown GW2 genes.

Knocking down GW2 enhances grain size by regulating genes encoding the synthesis of cytokinin, gibberellin, starch and cell wall. Raising crop yield is a priority task in the light of the continuing growth of the world's population and the inexorable loss of arable land to urbanization. Here, the RNAi approach was taken to reduce the abundance of Grain Weight 2 (GW2) transcript in the durum wheat cultivar Svevo. The effect of the knockdown was to increase the grains' starch content by 10-40%, their width by 4-13% and their surface area by 3-5%. Transcriptomic profiling, based on a quantitative real-time PCR platform, revealed that the transcript abundance of genes encoding both cytokinin dehydrogenase 1 and the large subunit of ADP-glucose pyrophosphorylase was markedly increased in the transgenic lines, whereas that of the genes encoding cytokinin dehydrogenase 2 and gibberellin 3-oxidase was reduced. A proteomic analysis of the non-storage fraction extracted from mature grains detected that eleven proteins were differentially represented in the transgenic compared to wild-type grain: some of these were involved, or at least potentially involved, in cell wall development, suggesting a role of GW2 in the regulation of cell division in the wheat grain.

Rice Grain Quality Benchmarking Through Profiling of Volatiles and Metabolites in Grains Using Gas Chromatography Mass Spectrometry.

Gas chromatograph coupled with mass spectrometer is widely used to profile volatiles and metabolites from the homogenized rice flour obtained from mature grains. Rice grains consist of central endosperm which stores majorly starch and, in addition, accumulate various storage proteins as storage reserves. The outer nutritious aleurone layer stores lipids, sugar alcohols, volatiles, antioxidants, vitamins, and various micronutrients. Once paddy sample is dehulled, milled, and ground cryogenically, the brown rice flour is subjected to extraction of primary metabolites and volatiles using an appropriate extraction method. In metabolite profiling of the liquid extract obtained from the rice sample, mixture is initially subjected to methoxyamination then silylation before being subjected to untargeted metabolite profiling. Peaks obtained are processed for noise reduction and specific signal selection. Volatile compounds are initially extracted using a solid phase adsorbent prior to analysis. All these compounds, metabolites, and volatiles are detected in the mass selective detector by fragmentation at 70eV ionization energy and the resultant mass spectrum compared with a built-in library of compounds. Data mined from the gas chromatography mass spectrometry analysis are then subjected to post-processing statistical analysis.