Kernel Protein Research Articles

Dual modification of the aggregation behavior and in vitro digestion of oxidized pine kernel protein via a combination of homogenization and succinylation

Protein oxidation affects the high-value utilization of nuts as oxidative attack causes protein aggregation, thereby challenging their technological functionality. Herein, a strategy using homogenization-assisted octenyl succinic anhydride (OSA) modification was proposed to tailor the structure, aggregation behavior, and digestive characteristics of oxidized pine kernel proteins. Results indicated that the ratio of α-helices to β-turns ranged from as low as 0.43 up to 0.67 after homogenization, suggesting greater molecular flexibility. With increasing protein oxidation, the acylation degree exhibited an inverted V-shaped trend, peaking at 67.22 %. OSA treatment reduced the aggregation rate and prolonged the lag time of proteins by stabilizing the α-helices and β-turns, increasing hydrogen bonding, and decreasing hydrophobicity. This increased the solubility of oxidized pine kernel proteins by ~30 % and improved their fluidity and thermal stability. A lower degree of succinylation was associated with higher free sulfhydryl content and surface hydrophobicity, which facilitated the thermal aggregation and the formation of elastomeric gels. Furthermore, the in vitro dynamic digestion and morphological observations of hydrolysis products indicated that cotreated proteins exhibited higher digestibility and formed small spherical particles ranging from 405.50 to 676.50 nm. These findings provide a promising approach to mitigate the adverse effects of oxidation on nut proteins.

A Genome-Wide Association Study Approach to Identify Novel Major-Effect Quantitative Trait Loci for End-Use Quality Traits in Soft Red Winter Wheat.

Wheat is used for making many food products due to its diverse quality profile among different wheat classes. Since laboratory analysis of these end-use quality traits is costly and time-consuming, genetic dissection of the traits is preferential. This study used a genome-wide association study (GWAS) of ten end-use quality traits, including kernel protein, flour protein, flour yield, softness equivalence, solvent's retention capacity, cookie diameter, and top-grain, in soft red winter wheat (SRWW) adapted to US southeast. The GWAS included 266 SRWW genotypes that were evaluated in two locations over two years (2020-2022). A total of 27,466 single nucleotide markers were used, and a total of 80 significant marker-trait associations were identified. There were 13 major-effect quantitative trait loci (QTLs) explaining >10% phenotypic variance, out of which, 12 were considered to be novel. Five of the major-effect QTLs were found to be stably expressed across multiple datasets, and four showed associations with multiple traits. Candidate genes were identified for eight of the major-effect QTLs, including genes associated with starch biosynthesis and nutritional homeostasis in plants. These findings increase genetic comprehension of these end-use quality traits and could potentially be used for improving the quality of SRWW.

Development of bread with partial substitute of wheat flour by apricot kernel flours and effects of apricot kernel proteins on bread quality

Development of bread with partial substitute of wheat flour by apricot kernel flours and effects of apricot kernel proteins on bread quality

Optimizing feature selection with gradient boosting machines in PLS regression for predicting moisture and protein in multi-country corn kernels via NIR spectroscopy

Differences in moisture and protein content impact both nutritional value and processing efficiency of corn kernels. Near-infrared (NIR) spectroscopy can be used to estimate kernel composition, but models trained on a few environments may underestimate error rates and bias. We assembled corn samples from diverse international environments and used NIR with chemometrics and partial least squares regression (PLSR) to determine moisture and protein. The potential of five feature selection methods to improve prediction accuracy was assessed by extracting sensitive wavelengths. Gradient boosting machines (GBMs), particularly CatBoost and LightGBM, were found to effectively select crucial wavelengths for moisture (1409, 1900, 1908, 1932, 1953, 2174 nm) and protein (887, 1212, 1705, 1891, 2097, 2456 nm). SHAP plots highlighted significant wavelength contributions to model prediction. These results illustrate GBMs' effectiveness in feature engineering for agricultural and food sector applications, including developing multi-country global calibration models for moisture and protein in corn kernels.

Assessing potential of teosinte in diversification of maize germplasm for kernel protein

Assessing potential of teosinte in diversification of maize germplasm for kernel protein

Fabrication of 3D aligned porous nanocellulose-based aerogel for enrichment of the histidine-containing polypeptides

The high-throughput immobilized metal affinity chromatography (IMAC) material is urgently required to improve the efficiency of separation and purification of tagged peptides in related biomedical applications. Herein, the amino-thiourea-modified nanocellulose (S-TOCN) -polyvinyl alcohol (PVA) composite aerogel with aligned pores was prepared by a directional freeze-casting technique and then used to immobilize metal ions (M2+) for the selective separation and purification of histidine-containing peptides from protein hydrolysates. The obtained S-TOCN-PVA materials with an oriented porous structure exhibited excellent mechanical properties, good adsorption performance, and reusability under optimal conditions. The adsorption capacity of the S-TOCN-PVA aerogel for metal ions was as follows: Cu2+>Ni2+>Zn2+>Co2+, and the higher metal ion chelating amount of the S-TOCN-PVA composite aerogel for Cu2+ and Ni2+ reached 87.21 mg/g at pH=7 and 83.66 mg/g at pH=6 in the 2 h incubation period, respectively. The enrichment effects of Cu2+/S-TOCN-PVA and Ni2+/S-TOCN-PVA aerogels with the selectivity of His-containing peptides from apricot kernel protein hydrolysates were up to 3.99 folds and 4.81 folds, respectively, for one cycle. Furthermore, after 5cycles, the Ni2+/S-TOCN-PVA aerogels remained at 87.5% of their initial adsorption capacity (848 mg/g), and the concentration increased by 39.05-fold. Molecular docking simulations show that the oxygen of the carboxyl group (-C-O and -CO) and the hydrogen of the imidazole group on the His molecule are mainly bonded to the hydrogen of the amino groups and the oxygen of the carboxyl group (C-O-C) in the structure of M2+/S-TOCN-PVA aerogels. The fabricated metal ion-immobilized 3D-aligned porous nanocellulose-based aerogels are promising IMAC materials for efficient separation and purification of the histidine-containing polypeptides from complicated biological samples.

An Analysis of the Main Nutrient Components of the Fruits of Different Macadamia (Macadamia integrifolia) Cultivars in Rocky Desertification Areas and a Comprehensive Evaluation of the Mineral Element Contents

This study aims to understand the main nutrient composition and comprehensively evaluate the differences in the mineral element contents of fruits of different macadamia cultivars, as well as screen good cultivars that are suitable for use in rocky desert mountains. Nine macadamia nut cultivars were selected as test materials in rocky desert mountain orchards. The contents of crude fat, crude protein, and total soluble sugar in kernels and N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, and B in peels and kernels were determined, respectively. Then, the kernels’ mineral element contents were comprehensively evaluated based on principal component analysis. The results showed that the kernels were rich in crude fat, protein, and soluble sugar, with the crude fat content reaching 75% or greater, and the variation among cultivars was small. However, the variation in soluble sugar content was extensive. The content of mineral elements varied in different cultivars and parts of the fruit, with the average macronutrient content being K > N > Ca > P > Mg in the pericarp and N > K > P > Mg > Ca in the kernel, and the content of micronutrients in the pericarp and the kernel being Mn > Fe > Zn > Cu > B. By principal component analysis, the 10 mineral nutrient indexes were calculated as four principal components, with a cumulative contribution rate of 88.051%. Using the affiliation function value method and the calculation of the comprehensive evaluation value, the nine cultivars could be classified into three categories. The cultivar with the highest comprehensive evaluation value of the mineral element content was O.C. The one with the lowest value was H2, which indicated that O.C is a suitable variety for popularization in rocky desert mountainous areas. Stepwise regression analysis concluded that P, K, Fe, Mn, and Cu were the indicators significantly influencing the mineral element content of macadamia nuts and fruits in rocky desert mountains.

Nutrient Use Efficiency and Grain Quality of Malt Barley (Hordeum vulgare L.) Varieties in Response to Nitrogen Fertilizer in, Southeastern Ethiopia

The expansion of brewing industries in Ethiopia has been inducing a growing demand for the supply of malt with optimum kernel protein content. However, the supply has been constrained by the unavailability of sufficient volumes of acceptable quality of malting barley grain to meet the ever-increasing demand. In this regard, field experiments were conducted in the southeastern Ethiopian highlands to evaluate the combined effects of six fertilizer levels (0, 11.5, 23, 34.5, 46, and 57.5) N kg ha<sup>-1 </sup>and three malt barley varieties (Fanaka, Ibon and Holker) on the yield, quality and nutrient use efficiency of malting barley. The experiment was laid out in a randomized complete block design with three replications. Application of 11.5, 23, 34.5, 46 and 57.5 N kg ha<sup>-1</sup> increased the grain yields by 1010.3, 1065.9, 1288.1, 1421.3, and 1777.6 kg ha<sup>-1</sup> and economic benefits by 31 ETB, 30.4 ETB, 32.9 ETB, 33.16 ETB and 33.38 ETB respectively, for each increment of on N fertilizer, when compared to the control treatment. The production of malting barley with improved yield, optimum kernel protein concentrations and enhanced economic benefit was attained through 57.5 and 46 N kg ha<sup>-1</sup> as first and second option respectively in the study area. Thus, to improve the likelihood of acceptance of malting barley by malting industries, growers are recommended to select low-protein containing varieties and decide application of N fertilization based on soil test results.

Biological properties of LMW-peptide fractions from apricot kernel protein: Nutritional, antibacterial and ACE-inhibitory activities

In this study, angiotensin-converting enzyme (ACE) inhibitory, antioxidant and antibacterial activities, and nutritional quality of low molecular weights (LMWs) peptide fractions (PFs) from apricot-kernel (Prunus armeniaca cv. Tabarzeh) with PFs <3, 3–10, 10–30 and 30–100 kDa were investigated. The ratio of essential to total (E/T) amino acids (∼34.5 %) and PER value (1.8–1.9) indicated the high nutritional and digestibility of peptide fractions. Antioxidant indices were affected by enzymatic hydrolysis, molecular weight (Mw) and concentration of peptides. In general, the highest inhibition of DPPH− (89.2 %), ABTS+ (93.1 %), TEAC (2.52 mM), OH• (78.1 %), NO• (70.4 %), total antioxidant activity (2.01), reducing power (1.27), ACE inhibitory (75.1 %), chelation of Fe2+ (90.2 %) and Cu2+ (40.2 %) metal-ions were related to low Mw fractions (PF-3 and PF-10). The hydrolysates and primary protein showed enhanced antibacterial effects against Escherichia coli and Bacillus cereus with diameter of inhibition zones of 17 and 14 mm, respectively. Overall, apricot-kernel peptides can be considered as a nutrient source, natural antioxidant and preservative with ACE-inhibitory effect in dietary supplements and food formulations.

Effects of Drying Methods on the Physicochemical and Functional Properties of Cinnamomum camphora Seed Kernel Protein Isolate.

Cinnamomum camphora seed kernel protein isolate (CPI) has attracted increasing attention due to its sustainability and potential applications. This study aimed to investigate the effects of freeze-drying (FD), vacuum-drying (VD), and spray-drying (SD) on the physicochemical and functional properties of CPI. The morphology observation results showed that the SD-CPI, SD-CPI, and VD-CPI were spherical, lamellar, and massive, respectively. Compared to FD and SD, VD had more impact on the color, surface hydrophobicity, intermolecular disulfide bonds, intrinsic fluorescence, and thermal stability of CPI. Fourier transform infrared spectroscopy (FTIR) analyses showed that among three CPI samples, VD-CPI had the highest content of β-sheet but the lowest contents of α-helix and β-turn. At different pH values, the solubility, emulsification, and foaming properties of VD-CPI were inferior to those of FD-CPI and SD-CPI. These results provide useful information on the changes in the physicochemical and functional properties of CPI subjected to different drying methods, and offer theoretical guidance for the production and use of CPI in the food industry.

Grain Quality and Yield Response of Malt Barley Varieties to Nitrogen Fertilizer Rates in the West Arsi, Oromia Reginal State of Ethiopia

Grain yield and yield components of malt barley (&amp;lt;i&amp;gt;Hordeum vulgare&amp;lt;/i&amp;gt; L.) were investigated concerning varieties and nitrogen application rates. A field experiment was conducted to evaluate (i) the optimal fertilizer level for maximum yield and quality of malt barley varieties (ii) to determine the impacts of nitrogen fertilizer rate, vaieties and growing season on yield and yield components of malt barley. Three malt barley varieties (Ibon, Bekoji 1, and EH1847) and four fertilizer rates (RNP kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;, 150% RNP kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;, 200% RNP kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; and RNPS kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) were studied over two growing season (2019 and 2020) in a factorial arrangement of randomized complete block design (RCBD) and replicated three times. The main effects of&amp;lt;sup&amp;gt;-&amp;lt;/sup&amp;gt; variety and fertilizer rate were significantly (P&amp;lt;0.01) variation, on grain yield, biomass yield, hectolitre weight and thousand kernel weight, while plant height, spike length and grain protein content showed significant (P&amp;lt;0.05) variations. The interaction effect of variety and fertilizer rate on the number of grains per spike indicated significant (P&amp;lt;0.001) variation. The use of a 200% RNP kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; fertilizer rate resulted in a higher (4152.9 kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) grain yield. The highest (33.1) number of grain per spike was produced from the combination of 150% RNP kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; fertilizer rate with Bekoji 1 malt barley variety, Like wise higher (48.6) thousand kernel weight was produced from RNPS. The results of this study indicated that, the importance of using appropriate malt barley variety and fertilizer rate to increase the yield of malt barley with acceptable grain quality in the study area. Hence application of 150% RNP and 200% RNP kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; gave a grain yield of (3582.81 kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) and (4152.9 kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;, and economic benefit of 5.99 (ETB) and 3.65 (ETB) respectively. Among malt barley varieties highest (4110.4) and (3538.3) kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; grain yield was recorded from EH1847 and Bekoji 1 verities respectively. The production of malt barley with higher yield, optimal kernel protein concentration and higher economic benefit was obtained via EH1847 malt barley varieties along with 150% RNP and 200% kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; fertilizer rate in the study area and similar agro ecologies.

Growth and yield of groundnut (Arachis hypogaea) under varying levels of gypsum and zinc application in Iran

A field study was carried out during spring season of 2021 and 2022 at Astaneh-ye Ashrafiyeh, Guilan, (Islamic Azad University, Lahijan, Iran) northern Iran to study the effect of natural gypsum (NG) and zinc (Zn) foliar application on peanut (Arachis hypogaea L.) yield and quality. NG was applied at 4 levels [0 (NG0); 10 (NG10); 20 (NG20); and 30 (NG30) g/m2] and Zn nano-chelates were applied at 3 levels [0 (Zn0); 1 (Zn1); and 2 (Zn2) g/L)] as foliar application. The results showed that the interaction of NG × Zn was significant for leaf chlorophyll, kernel and pod number per plant, kernel protein, oil content and and kernel yield during both the years. The interaction of NG × Zn was also significant on the P, S and Fe of kernels. Leaf K and Fe contents were significantly influenced only by NG. The comparison between mean revealed that the highest kernel yield (5839 kg/ha), kernel number (93.5 kernels/plant), pod number (66.3 pods/plant) and kernel S (0.384%) were recorded from the plots applied with NG20 + Zn2. The highest leaf chlorophyll (3.83 mg/kg FW) and oil content (46.09%) were related to the treatment NG20 + Zn1. The plots applied with NG10 + Zn2 exhibited the highest kernel protein (17.92%). Based on the results, it can be stated that the NG and Zn as soil application and foliar spray respectively, improved peanut yield and qualitative traits hence can be recommended for similar climatic conditions.

Insecticidal Effects of Transgenic Maize Bt-Cry1Ab, Bt-Vip3Aa, and Bt-Cry1Ab+Vip3Aa against the Oriental Armyworm, Mythimna separata (Walker) in Southwest China.

The oriental armyworm, Mythimna separata (Walker), an important migratory pest of maize and wheat, is posing a severe threat to maize production in Asian countries. As source areas of spring-summer emigratory populations, the control of M. separata in southwestern China is of great significance for East Asian maize production. To assess the toxicity of Bt maize against the pest, bioassays of Bt-(Cry1Ab+Vip3Aa) maize (event DBN3601T), Bt-Cry1Ab maize (event DBN9936), and Bt-Vip3Aa maize (event DBN9501) were conducted in Yunnan province of southwest China. There were significant differences in insecticidal activity between the three Bt maize events, and DBN3601T presented the highest insecticidal role. The results also indicated that the insecticidal effect of various Bt maize tissues took an order in leaf > kernel > silk, which is highly consistent with the expression amounts of Bt insecticidal protein in leaf (69.69 ± 1.18 μg/g), kernel (11.69 ± 0.75 μg/g), and silk (7.32 ± 0.31 μg/g). In field trials, all larval population densities, plant damage rates, and leaf damage levels of DBN3601T maize were significantly lower than the conventional maize. This research indicated that the DBN3601T event had a high control efficiency against M. separata and could be deployed in southwest China for the management of M. separata.

Nitrogen application in pod zone improves yield and quality of two peanut cultivars by modulating nitrogen accumulation and metabolism

Cultivated peanut (Arachis hypogaea L.) represents one of the most important oil and cash crops world-widely. Unlike many other legumes, peanuts absorb nitrogen through their underground pods. Despite this unique feature, the relationship between yield and nitrogen uptake within the pod zone remains poorly understood. In our pot experiment, we divided the underground peanut part into two zones—pod and root—and investigated the physiological and agronomic traits of two peanut cultivars, SH11 (large seeds, LS) and HY23 (small seeds, SS), at 10 (S1), 20 (S2), and 30 (S3) days after gynophores penetrated the soil, with nitrogen application in the pod zone. Results indicated that nitrogen application increased pod yield, kernel protein content, and nitrogen accumulation in plants. For both LS and SS peanut cultivars, optimal nitrogen content was 60 kg·hm− 2, leading to maximum yield. LS cultivar exhibited higher yield and nitrogen accumulation increases than SS cultivar. Nitrogen application up-regulated the expression of nitrogen metabolism-related genes in the pod, including nitrate reductase (NR), nitrite reductase (NIR), glutamine synthetase (GS), glutamate synthase (NADH-GOGAT), ATP binding cassette (ABC), and nitrate transporter (NRT2). Additionally, nitrogen application increased enzyme activity in the pod, including NR, GS, and GOGAT, consistent with gene expression levels. These nitrogen metabolism traits exhibited higher up-regulations in the large-seeded cultivar than in the small-seeded one and showed a significant correlation with yield in the large-seeded cultivar at S2 and S3. Our findings offer a scientific basis for the judicious application and efficient utilization of nitrogen fertilization in peanuts, laying the groundwork for further elucidating the molecular mechanisms of peanut nitrogen utilization.

Source-sink coordinated peanut cultivar increases yield and kernel protein content through enhancing photosynthetic characteristics and regulating carbon and nitrogen metabolisms

The grain yield of crops is determined by the synergistic interaction between source activity and sink capacity. However, source-sink interactions are far from being fully understood of peanut. Therefore, a 2-year field study (2018–2019) was conducted to compare differences in photosynthetic characteristics, carbon and nitrogen metabolism, and yield and quality of different source–sink peanut varieties. Four representative source–sink types were examined: JH5 (source–sink coordination type), SH9 (sufficient source–large sink type), ZH24 (sufficient source–few sink type), and HY36 (large source–few sink type). The results showed that the photosynthetic potential of HY36 was higher than that of the other varieties after flowering because of a large source (leaves), whereas the chlorophyll content and net photosynthetic rate of HY36 were significantly lower than those of JH5 and ZH24. Proportions of dry matter transferred to pods were significantly different among four source–sink peanut varieties. From 50 days after flowering, the dry matter distribution ratio of pods exceeded that of stems and leaves in JH5, significantly earlier than other varieties, which prolong the duration of pod-filling period, followed by SH9 and ZH24. The activities of nitrate reductase, glutamine synthetase, glutamate dehydrogenase, and glutamate synthase in JH5 were the highest among the varieties, and thus, the highest protein content was also in JH5. The activities of sucrose synthase and sucrose phosphate synthase in ZH24 were significantly higher than those in HY36. The highest oil content was also in ZH24. Among pod sink characteristics and yield, SH9 had the longest flowering period and the highest gynophore formation rate but the lowest pod-bearing rate, and the effective proportion and pod fullness were also lower than those of other varieties. The highest pod rate was in ZH24. The effective proportion and pod fullness of JH5 were higher than those of the other varieties, and its yield was also the highest, followed by SH9 and ZH24, with the lowest yield in HY36. The obtained results indicate that the source–sink coordinated variety had high Pn and chlorophyll content in the late growth stage, a long functional period of leaves, and a high proportion of assimilates transported to pods, thus promoting effective proportions and pod fullness to improve peanut yield and protein content, suggesting that different cultivation and management measures should select for different peanut varieties to best coordinate the relationship between the source and sink.

Ca and Mg stimulate protein synthesis in maize kernel through the action of endogenous hormones and defense enzymes

Soil calcium (Ca) and magnesium (Mg) mineral states in rain-fed arid regions of Northwest China are inefficient, and their levels of substitution and water-soluble states are far below the lowest threshold required for maize growth, resulting in frequent physiological diseases, restricting synthesis of kernel protein (CRP). Our study set up different levels of foliar spraying of Ca and Mg fertilizers before maize pollination to examine the response characteristics of physiological and biochemical indicators in kernel, and the driving process of CRP synthesis. The main findings were: (1) Ca and Mg significantly increased the levels of CRP and endogenous hormones, and the activities of defense enzymes and CRP synthesis enzymes, which decreased significantly and stabilized at the maturity stage of maize. (2) The synthesis and accumulation of CRP were synergistically regulated by endogenous hormones, defense enzymes, and CRP synthase enzymes, with the degree of regulation varying with the level of Ca and Mg supplementation. Indole-3-acetic acid (IAA), gibberellin (GA), zeatin riboside (ZR), catalase (CAT), malondialdehyde (MDA), and glutamate dehydrogenase (GDH) were the primary physiological driving indicators of CRP synthesis, with CRP having a significant synergistic relationship with CAT and a remarkable trade-off with other driving indicators. (3) The dominant driving pathway of CRP synthesis was “Ca, Mg-IAA or GA or ZR-CAT-GDH-CRP”. Ca and Mg positively affected IAA and GA levels, and IAA and GA positively regulated CAT activity. However, CAT negatively regulated GDH levels, causing GDH to negatively influence the synthesis and accumulation of CRP and its components. The findings provide theoretical support for further study of inter-root endogenous hormones and soil microbe-driven processes in the regulation of maize quality by Ca and Mg.

Rotational strip peanut/cotton intercropping improves agricultural production through modulating plant growth, root exudates, and soil microbial communities

Legume-based intercropping is widely used by smallholder farmers; however, there is scarce information governing the long-term effects of interspecific interactions on the crop growth performance. Here, we present data of 5 years field experimentation on a rotational strip peanut/cotton intercropping system to uncover its beneficial effects on crop production and decipher the underlying mechanisms. Treatments included monoculture of peanut (MP), monoculture of cotton (MC), peanut/cotton intercropping (IC), and peanut/cotton intercropping with solid root barrier (SC). Averaged for 5 years, intercropping did not alter the peanut pods yield whereas the seed cotton yield was significantly increased by 52.63% compared with monoculture. Moreover, the net economic return of IC was significantly increased by 59.49%. Physiological data indicated that the leaf net photosynthetic rate, total biomass, and the accumulation of total nitrogen in peanut pods and cotton buds were significantly increased in IC compared with MP and MC. Meanwhile, the contents of total protein and oleic acid in peanut kernels were also increased by intercropping. Metabolomics evidence showed that differential metabolites from “Tryptophan” and “Carbon” pathways were significantly enriched in peanut and cotton strips of IC. Additionally, IC significantly altered the rhizosphere soil bacterial abundance composition and diversity, and the metabolic functional features of “carbohydrate” and “amino acid” were significantly enriched. Strikingly, the beneficial effects of intercropping were partially counteracted by SC as indicated by the reduction of crop production and net return. Our results demonstrated that rotational strip peanut/cotton intercropping increases production, net economic returns, and peanut quality parameters via the interspecific interactions by enhancing plant growth, regulating root exudates, and modulating soil microbial communities.

NanoLC-MS/MS protein analysis on laser-microdissected wheat endosperm tissues: A comparison between aleurone, sub-aleurone and inner endosperm

Wheat kernel proteins are not homogeneously distributed throughout the endosperm. The goal of this study was to investigate the relative differences in protein composition between the aleurone, sub-aleurone and inner endosperm. Using laser microdissection followed by nanoLC-MS/MS, an innovative method combining high spatial specificity and analytical selectivity in sample-limited situations, 780 proteins were detected and classified by function. A higher proportion of gluten proteins was detected in the sub-aleurone than inner endosperm. Composition-wise, gluten from the sub-aleurone is relatively more enriched in ω-gliadins but impoverished in LMW-GS and γ-gliadins. While a basic set of albumins and globulins was detected in all three microdissected endosperm tissues, specific proteins, like puroindoline B, displayed a gradient. This study provides indications that both histological origin and relative positioning of the tissues drive the protein distribution. Knowledge of this protein distribution offers significant opportunities for the wheat manufacturing industry. Data available via ProteomeXchange, identifier PXD038743.

Antioxidant activity of palm kernel meal protein hydrolysate and characterization of its peptide profile

Palm kernel meal (PKM) is a major by-product of the palm oil industry, and its high protein content is a potential source of value-added functional food or feed. In this study, the total protein from PKM was isolated and hydrolyzed with alcalase enzyme (pH 7.5, 55oC) to obtain palm kernel protein hydrolysate. The results showed that PKM protein hydrolysate after 60 min of hydrolysis exhibited strong radical scavenging activity with IC50 values of 5.73±0.23 and 7.84±0.90 μg/mL as determined by 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), respectively. Furthermore, PKM protein hydrolysate was not toxic to mouse L929 fibroblast cells while protecting cells from H2O2-induced oxidative damage. Analysis of its peptide profile by liquid chromatography-mass spectrometry (LC-MS/MS) revealed nine peptide sequences with hydrophobic and negatively-charged amino acids with molecular weights ranging from 1,085.13 to 1,292.32 Da. Taken together, alcalase hydrolysate of PKM was found to have potent antioxidant and cytoprotective properties justifying further study for potential development as a functional food/feed.

Marker–Trait Association for Protein Content among Maize Wild Accessions and Coix Using SSR Markers

Teosinte is the closest wild ancestor of maize and is used as a valuable resource for taxonomical, evolutionary and genetic architectural studies of maize. Teosinte is also a repository of numerous diverse alleles for complex traits, including nutritional value and stress adaptation. Accessions including teosintes, maize inbred lines and coix were investigated for kernel protein and its association with DNA markers. The proposed investigation assumed that wild accessions had different genic/allelic content and consequently expression profile than modern maize because of the domestication syndrome and bottleneck effects. Total protein content in hard stony fruit case teosinte accessions were assessed from kernels with and without seed coats, while protein content from coix and maize lines was evaluated from kernels only. The accessions were also subjected to molecular profiling using 84 SSR markers, and obtained genotypic data were used for population structure and association analysis. The results emphasize that teosintes have higher protein content (18.5% to 26.29%), followed by coix (18.26%), and the least among maize lines (9% to 11%). Among teosintes, without-seed-coat samples had 3–6% higher protein content than with-seed-coat samples. When compared to other teosinte species, Z. mays subsp. mexicana accessions showed higher protein content, ranging from 18.62% to 26.29%. All evaluated accessions were divided into four subpopulations with K = 4, and seven significant (p &lt; 0.01) marker–trait associations were seen with umc1294, umc1171, phi091, umc2182 and bnlg292 markers, which are distributed across chromosomes 4, 5, 7, 8 and 9, respectively. We have observed that the wild relatives carry protein content-enhancing alleles and can be used as productive donor parents in pre-breeding efforts to increase the protein content of maize.