Developmental pleiotropy of SDP1 from seedling to mature stages in B. napus.

Rapeseed, an important oil crop, relies on robust seedling emergence for optimal yields. Seedling emergence in the field is vulnerable to various factors, among which inadequate self-supply of energy is crucial to limiting seedling growth in early stage. SUGAR-DEPENDENT1 (SDP1) initiates triacylglycerol (TAG) degradation, yet its detailed function has not been determined in B. napus. Here, we focused on the effects of plant growth during whole growth stages and energy mobilization during seedling establishment by mutation in BnSDP1. Protein sequence alignment and haplotypic analysis revealed the conservation of SDP1 among species, with a favorable haplotype enhancing oil content. Investigation of agronomic traits indicated bnsdp1 had a minor impact on vegetative growth and no obvious developmental defects when compared with wild type (WT) across growth stages. The seed oil content was improved by 2.0-2.37% in bnsdp1 lines, with slight reductions in silique length and seed number per silique. Furthermore, bnsdp1 resulted in lower seedling emergence, characterized by a shrunken hypocotyl and poor photosynthetic capacity in the early stages. Additionally, impaired seedling growth, especially in yellow seedlings, was not fully rescued in medium supplemented with exogenous sucrose. The limited lipid turnover in bnsdp1 was accompanied by induced amino acid degradation and PPDK-dependent gluconeogenesis pathway. Analysis of the metabolites in cotyledons revealed active amino acid metabolism and suppressed lipid degradation, consistent with the RNA-seq results. Finally, we proposed strategies for applying BnSDP1 in molecular breeding. Our study provides theoretical guidance for understanding trade-off between oil accumulation and seedling energy mobilization in B. napus.

Apparent ileal amino acid digestibility, gut morphometrics, and gene expression of peptide and amino acid transporters in broiler chickens fed low-crude-protein diets supplemented with crystalline amino acids with soybean meal, canola meal, or corn DDGS as protein feedstuffs.

BACKGROUND: We investigated the impact of using canola meal (CM) or corn distillers dried grain soluble (cDDGS) in place of soybean meal (SBM) in low-crude-protein diets supplemented with amino acids (AA) on AA digestibility, gut morphometrics, and AA transporter genes in broiler chicken. On day 0, 540 Cobb 500 male broilers were allocated to six diets in 36-floor pens. The positive control (PC) was a corn-SBM diet with adequate crude protein (CP). The CP level of negative control (NC) was decreased by 45 and 40 g kg-1 relative to PC for grower and finisher phases, respectively. The subsequent two diets had the same CP levels as NC but with cDDGS added at 50 or 125 g kg-1. The last two diets had the same CP as NC but with CM added at 50 or 100 g kg-1. RESULTS: Dietary CP reduction in corn-SBM diets increased (P < 0.05) the digestibility of Lys (88.5%), Met (90.7%), Thr (77.4%), Cys (80.7%), and Gly (84.7%). Increasing levels of cDDGS linearly decreased (P < 0.05) the digestibility of Asp, Cys, Glu, and Ser, whereas increasing CM level linearly decreased (P < 0.05) the digestibility of Cys, Pro, and Ser. The CP reduction in corn-SBM diets produced downward expression of peptide transporter1 and decreased (P < 0.05) absolute pancreas and ileum weight and length of jejunum and ileum. CONCLUSIONS: Partial replacement of SBM with alternative protein feedstuffs (cDDGS or CM) in low-CP diets had minimal effects on AA digestibility and mRNA levels of peptides and AA transporters. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Novel sfericase protease improves amino acid digestibility of soybean meal and rapeseed meal in broiler chickens.

1. Two experiments were conducted to explore the effects of an exogenous sfericase protease on the apparent ileal nutrient digestibility of soybean meal (SBM) and rapeseed meal (RSM) in broiler chickens.2. In each experiment, a total of 256 sixteen-day-old male Cobb 500 broilers were fed one of four semi-purified experimental diets, comprising two different batches (A and B) of samples for either SBM (Exp. 1) or RSM (Exp. 2) without or with an exogenous sfericase (0 or 30,000 NFP/kg). Each experimental diet was fed to eight replicate pens of broiler chickens from 16 to 21 d of age (eight birds per cage), and ileal digesta were collected for measuring the digestibility coefficients.3. In Exp. 1, the amino acid digestibility was greater (P < 0.05) in SBM B compared with SBM A for Arg and Val, and a similar trend (P < 0.1) was observed for Tyr, Leu and Thr. Exogenous sfericase increased (P < 0.10) digestibility of most of amino acids except Gly, His and Trp. There was an interaction between SBM source and sfericase, whereby digestibility of P, N and Asp was increased by sfericase for SBM B but not for SBM A. In Exp. 2, there was no interaction (P > 0.05) between RSM source and sfericase for ileal nutrient digestibility. Digestibility was greater in RSM A compared to RSM B for all non-essential AA and most essential AA (except for Trp), while the reverse was noted for Ca and P (P < 0.05). Exogenous sfericase increased (P < 0.1) digestibility for all amino acids except Cys and Met.4. In conclusion, the current studies showed that both SBM and RSM batches influenced amino acid digestibility. Sfericase protease supplementation increased amino acid digestibility for both SBM and RSM. The digestibility effects were greater in the SBM batch with low digestibility for N and Asp which was in line with an increase in P digestibility.

Evaluation of rapeseed cake as a protein substitute in the feed of edible crickets: A case study using Gryllus assimilis.

This paper aimed to investigate the optimization of Gryllus assimilis farming production by examining the effects of replacing soybean meal with rapeseed cake (25-100%) and supplementing it with rapeseed oil. The results reveal no adverse effects of soybean meal replacement on the feed conversion ratio and weight of the harvested crickets. However, incorporating larger quantities of rapeseed cake into the diet increased crude protein and decreased fat content. Moreover, the composition of fatty acids varied significantly, with increased levels of oleic acid and decreased levels of palmitic acid, while a high rapeseed cake content led to a decrease in the atherogenic and thrombogenic index values. The amino acid composition remained unaffected. In conclusion, the study demonstrates that rapeseed cake can serve as a viable substitute for soybean meal in the diet of Gryllus assimilis.

3D genome structural variations play important roles in regulating seed oil content of Brassica napus.

Dissecting the complex regulatory mechanism of seed oil content (SOC) is one of the main research goals in Brassica napus. Increasing evidence suggests that genome architecture is linked to multiple biological functions. However, the effect of genome architecture on SOC regulation remains unclear. Here, we used high-throughput chromatin conformation capture to characterize differences in the three-dimensional (3D) landscape of genome architecture of seeds from two B. napus lines, N53-2 (with high SOC) and Ken-C8 (with low SOC). Bioinformatics analysis demonstrated that differentially accessible regions and differentially expressed genes between N53-2 and Ken-C8 were preferentially enriched in regions with quantitative trait loci (QTLs)/associated genomic regions (AGRs) for SOC. A multi-omics analysis demonstrated that expression of SOC-related genes was tightly correlated with genome structural variations in QTLs/AGRs of B. napus. The candidate gene BnaA09g48250D, which showed structural variation in a QTL/AGR on chrA09, was identified by fine-mapping of a KN double-haploid population derived from hybridization of N53-2 and Ken-C8. Overexpression and knockout of BnaA09g48250D led to significant increases and decreases in SOC, respectively, in the transgenic lines. Taken together, our results reveal the 3D genome architecture of B. napus seeds and the roles of genome structural variations in SOC regulation, enriching our understanding of the molecular mechanisms of SOC regulation from the perspective of spatial chromatin structure.

Foliar application of iron-lysine to boost growth attributes, photosynthetic pigments and biochemical defense system in canola (Brassica napus L.) under cadmium stress.

In the current industrial scenario, cadmium (Cd) as a metal is of great importance but poses a major threat to the ecosystem. However, the role of micronutrient - amino chelates such as iron - lysine (Fe - lys) in reducing Cr toxicity in crop plants was recently introduced. In the current experiment, the exogenous applications of Fe - lys i.e., 0 and10 mg L - 1, were examined, using an in vivo approach that involved plant growth and biomass, photosynthetic pigments, oxidative stress indicators and antioxidant response, sugar and osmolytes under the soil contaminated with varying levels of Cd i.e., 0, 50 and 100 µM using two different varieties of canola i.e., Sarbaz and Pea - 09. Results revealed that the increasing levels of Cd in the soil decreased plant growth and growth-related attributes and photosynthetic apparatus and also the soluble protein and soluble sugar. In contrast, the addition of different levels of Cd in the soil significantly increased the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2), which induced oxidative damage in both varieties of canola i.e., Sarbaz and Pea - 09. However, canola plants increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and non-enzymatic compounds such as phenolic, flavonoid, proline, and anthocyanin, which scavenge the over-production of reactive oxygen species (ROS). Cd toxicity can be overcome by the supplementation of Fe - lys, which significantly increased plant growth and biomass, improved photosynthetic machinery and sugar contents, and increased the activities of different antioxidative enzymes, even in the plants grown under different levels of Cd in the soil. Research findings, therefore, suggested that the Fe - lys application can ameliorate Cd toxicity in canola and result in improved plant growth and composition under metal stress.

Fine mapping and candidate gene analysis of a major QTL for oil content in the seed of Brassica napus.

KEY MESSAGE: By integrating QTL fine mapping and transcriptomics, a candidate gene responsible for oil content in rapeseed was identified. The gene is anticipated to primarily function in photosynthesis and photosystem metabolism pathways. Brassica napus is one of the most important oil crops in the world, and enhancing seed oil content is an important goal in its genetic improvement. However, the underlying genetic basis for the important trait remains poorly understood in this crop. We previously identified a major locus, OILA5 responsible for seed oil content on chromosome A5 through genome-wide association study. To better understand the genetics of the QTL, we performed fine mapping of OILA5 with a double haploid population and a BC3F2 segregation population consisting of 6227 individuals. We narrowed down the QTL to an approximate 43 kb region with twelve annotated genes, flanked by markers ZDM389 and ZDM337. To unveil the potential candidate gene responsible for OILA5, we integrated fine mapping data with transcriptome profiling using high and low oil content near-isogenic lines. Among the candidate genes, BnaA05G0439400ZS was identified with high expression levels in both seed and silique tissues. This gene exhibited homology with AT3G09840 in Arabidopsis that was annotated as cell division cycle 48. We designed a site-specific marker based on resequencing data and confirmed its effectiveness in both natural and segregating populations. Our comprehensive results provide valuable genetic information not only enhancing our understanding of the genetic control of seed oil content but also novel germplasm for advancing high seed oil content breeding in B. napus and other oil crops.

Glycerol-3-Phosphate Acyltransferase GPAT9 Enhanced Seed Oil Accumulation and Eukaryotic Galactolipid Synthesis in Brassica napus.

Glycerol-3-phosphate acyltransferase GPAT9 catalyzes the first acylation of glycerol-3-phosphate (G3P), a committed step of glycerolipid synthesis in Arabidopsis. The role of GPAT9 in Brassica napus remains to be elucidated. Here, we identified four orthologs of GPAT9 and found that BnaGPAT9 encoded by BnaC01T0014600WE is a predominant isoform and promotes seed oil accumulation and eukaryotic galactolipid synthesis in Brassica napus. BnaGPAT9 is highly expressed in developing seeds and is localized in the endoplasmic reticulum (ER). Ectopic expression of BnaGPAT9 in E. coli and siliques of Brassica napus enhanced phosphatidic acid (PA) production. Overexpression of BnaGPAT9 enhanced seed oil accumulation resulting from increased 18:2-fatty acid. Lipid profiling in developing seeds showed that overexpression of BnaGPAT9 led to decreased phosphatidylcholine (PC) and a corresponding increase in phosphatidylethanolamine (PE), implying that BnaGPAT9 promotes PC flux to storage triacylglycerol (TAG). Furthermore, overexpression of BnaGPAT9 also enhanced eukaryotic galactolipids including monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), with increased 36:6-MGDG and 36:6-DGDG, and decreased 34:6-MGDG in developing seeds. Collectively, these results suggest that ER-localized BnaGPAT9 promotes PA production, thereby enhancing seed oil accumulation and eukaryotic galactolipid biosynthesis in Brassica napus.

Transcriptomic Analysis of the Reduction in Seed Oil Content through Increased Nitrogen Application Rate in Rapeseed (Brassica napus L.).

Nitrogen is essential for improving the seed oil yield of rapeseed (Brassica napus L.). However, the molecular mechanism by which increased nitrogen rates impact seed oil content is largely unknown. Therefore, a field experiment was conducted to determine how three nitrogen application rates (120, 240, and 360 kg ha-1) regulated seed oil content via transcriptomic analysis. The results showed that the seed yield and the protein and total N contents increased from N1 to N3, with average increases of 57.2%, 16.9%, and 79.5%, respectively. However, the seed oil content significantly decreased from N1 to N3, with an average decrease of 8.6%. These results were repeated over a number of years. The quantity of oil protein bodies observed under a transmission electron microscope was in accordance with the ultimate seed oil and protein contents. As the nitrogen application rate increased, a substantial number of genes involved in the photosynthesis, glycolysis, and phenylpropanoid biosynthesis pathways were up-regulated, as were TF families, such as AP2/ERF, MYB, and NAC. The newly identified genes were mainly involved in carbohydrate, lipid, and amino acid metabolism. Metabolic flux analysis showed that most of the genes involved in glycolysis and fatty acid biosynthesis had higher transcript levels in the early development stages. Our results provide new insights into the molecular regulation of rapeseed seed oil content through increased nitrogen application rates.

Research Progress on the Effect of Nitrogen on Rapeseed between Seed Yield and Oil Content and Its Regulation Mechanism.

Rapeseed (Brassica napus L.) is one of the most important oil crops in China. Improving the oil production of rapeseed is an important way to ensure the safety of edible oil in China. Oil production is an important index that reflects the quality of rapeseed and is determined by the oil content and yield. Applying nitrogen is an important way to ensure a strong and stable yield. However, the seed oil content has been shown to be reduced in most rapeseed varieties after nitrogen application. Thus, it is critical to screen elite germplasm resources with stable or improved oil content under high levels of nitrogen, and to investigate the molecular mechanisms of the regulation by nitrogen of oil accumulation. However, few studies on these aspects have been published. In this review, we analyze the effect of nitrogen on the growth and development of rapeseed, including photosynthetic assimilation, substance distribution, and the synthesis of lipids and proteins. In this process, the expression levels of genes related to nitrogen absorption, assimilation, and transport changed after nitrogen application, which enhanced the ability of carbon and nitrogen assimilation and increased biomass, thus leading to a higher yield. After a crop enters the reproductive growth phase, photosynthates in the body are transported to the developing seed for protein and lipid synthesis. However, protein synthesis precedes lipid synthesis, and a large number of photosynthates are consumed during protein synthesis, which weakens lipid synthesis. Moreover, we suggest several research directions, especially for exploring genes involved in lipid and protein accumulation under nitrogen regulation. In this study, we summarize the effects of nitrogen at both the physiological and molecular levels, aiming to reveal the mechanisms of nitrogen regulation in oil accumulation and, thereby, provide a theoretical basis for breeding varieties with a high oil content.

NPs-Ca promotes Cd accumulation and enhances Cd tolerance of rapeseed shoots by affecting Cd transfer and Cd fixation in pectin.

The use of rapeseed (Brassica napus) as a hyperaccumulator plant has shown great promise for the remediation of cadmium (Cd) contaminated soils. Nanosized materials (NPs) have been shown to mitigate heavy metal toxicity in plants, but it is unknown how l-aspartate nano-calcium (NPs-Ca) affects Cd uptake, transport, and tolerance in rapeseed. A soil pot experiment was conducted with two treatments: a control treatment (CK) with 2.16 g CaCl2 and NPs-Ca treatment with 6.00 g NPs-Ca, to evaluate the effects and mechanisms of NPs-Ca on Cd tolerance in rapeseed. Compared to CaCl2, NPs-Ca promoted Cd transportation from roots to shoots by up-regulating the expression of Cd transport genes (ABCC12, HMA8, NRAM6, ZIP6, CAX4, PCR2, and HIP6). Therefore, NPs-Ca increased Cd accumulation in rapeseed shoots by 39.4%. Interestingly, NPs-Ca also enhanced Cd tolerance in the shoots, resulting in lower hydrogen peroxide (H2O2) accumulation and proline content, as well as higher antioxidant enzyme activities (POD, CAT). Moreover, NPs-Ca reduced the activity of pectin-degrading enzymes (polygalacturonase: PG, ß-galactosidase: ß-GAL), promoted the activity of pectin methyl esterase (PME), and changed transcription levels of related genes (PME, PMEI, PG, PGIP, and ß-GAL). NPs-Ca treatment also significantly increased the Cd content in cell walls by 59.8%, that is, more Cd was immobilized in cell walls, and less Cd entered organelles in shoots of NPs-Ca treatment due to increased pectin content and degree of pectin demethylation. Overall, NPs-Ca increased Cd accumulation in rapeseed shoots by promoting Cd transport from roots to shoots. And meantime, NPs-Ca enhanced Cd tolerance of shoots by inhibiting pectin degradation, promoting pectin demethylation and increasing Cd fixation in pectin. These findings suggest that NPs-Ca can improve the potential of rapeseed as a hyperaccumulator for the remediation of Cd-contaminated soil and the protection of the environment. Furthermore, the study provides a theoretical basis for the application of NPs-Ca in the phytoremediation of Cd-contaminated soils with hyperaccumulating plants.

Multi-omics strategies uncover the molecular mechanisms of nitrogen, phosphorus and potassium deficiency responses in Brassica napus.

BACKGROUND: Nitrogen (N), phosphorus (P) and potassium (K) are critical macronutrients in crops, such that deficiency in any of N, P or K has substantial effects on crop growth. However, the specific commonalities of plant responses to different macronutrient deficiencies remain largely unknown. METHODS: Here, we assessed the phenotypic and physiological performances along with whole transcriptome and metabolomic profiles of rapeseed seedlings exposed to N, P and K deficiency stresses. RESULTS: Quantities of reactive oxygen species were significantly increased by all macronutrient deficiencies. N and K deficiencies resulted in more severe root development responses than P deficiency, as well as greater chlorophyll content reduction in leaves (associated with disrupted chloroplast structure). Transcriptome and metabolome analyses validated the macronutrient-specific responses, with more pronounced effects of N and P deficiencies on mRNAs, microRNAs (miRNAs), circular RNAs (circRNAs) and metabolites relative to K deficiency. Tissue-specific responses also occurred, with greater effects of macronutrient deficiencies on roots compared with shoots. We further uncovered a set of common responders with simultaneous roles in all three macronutrient deficiencies, including 112 mRNAs and 10 miRNAs involved in hormonal signaling, ion transport and oxidative stress in the root, and 33 mRNAs and 6 miRNAs with roles in abiotic stress response and photosynthesis in the shoot. 27 and seven common miRNA-mRNA pairs with role in miRNA-mediated regulation of oxidoreduction processes and ion transmembrane transport were identified in all three macronutrient deficiencies. No circRNA was responsive to three macronutrient deficiency stresses, but two common circRNAs were identified for two macronutrient deficiencies. Combined analysis of circRNAs, miRNAs and mRNAs suggested that two circRNAs act as decoys for miR156 and participate in oxidoreduction processes and transmembrane transport in both N- and P-deprived roots. Simultaneously, dramatic alterations of metabolites also occurred. Associations of RNAs with metabolites were observed, and suggested potential positive regulatory roles for tricarboxylic acids, azoles, carbohydrates, sterols and auxins, and negative regulatory roles for aromatic and aspartate amino acids, glucosamine-containing compounds, cinnamic acid, and nicotianamine in plant adaptation to macronutrient deficiency. CONCLUSIONS: Our findings revealed strategies to rescue rapeseed from macronutrient deficiency stress, including reducing the expression of non-essential genes and activating or enhancing the expression of anti-stress genes, aided by plant hormones, ion transporters and stress responders. The common responders to different macronutrient deficiencies identified could be targeted to enhance nutrient use efficiency in rapeseed.

A novel type of Brassica napus with higher stearic acid in seeds developed through genome editing of BnaSAD2 family.

KEY MESSAGE: Modifications of multiple copies of the BnaSAD2 gene family with genomic editing technology result in higher stearic acid content in the seed of polyploidy rapeseed. Solid fats from vegetable oils are widely used in food processing industry. Accumulating data showed that stearic acid is more favorite as the major composite among the saturate fatty acids in solid fats in considerations of its effects on human health. Rapeseed is the third largest oil crop worldwide, and has potential to be manipulated to produce higher saturated fatty acids as raw materials of solid fats. Toward that end, we identified four SAD2 gene family members in B. napus genome and established spatiotemporal expression pattern of the BnaSAD2 members. Genomic editing technology was applied to mutate all the copies of BnaSAD2 in this allopolyploid species and mutants at multiple alleles were generated and characterized to understand the effect of each BnaSAD2 member on blocking desaturation of stearic acid. Mutations occurred at BnaSAD2.A3 resulted in more dramatic changes of fatty acid profile than ones on BnaSAD2.C3, BnaSAD2.A5 and BnaSAD2.C4. The content of stearic acid in mutant seeds with single locus increased dramatically with a range of 3.1-8.2%. Furthermore, combination of different mutated alleles of BnaSAD2 resulted in more dramatic changes in fatty acid profiles and the double mutant at BnaSAD2.A3 and BnaSAD2.C3 showed the most dramatic phenotypic changes compared with its single mutants and other double mutants, leading to 11.1% of stearic acid in the seeds. Our results demonstrated that the members of BnaSAD2 have differentiated in their efficacy as a Δ9-Stearoyl-ACP-Desaturase and provided valuable rapeseed germplasm for breeding high stearic rapeseed oil.

Comparing dehulled hemp meal and canola meal as a protein supplement for lactating dairy cows.

Effects of replacing canola meal with dehulled hemp meal in the diet of lactating dairy cows on the dry matter intake (DMI), milk production, milk fatty acid profile, blood metabolites, total-tract nutrient digestibility, and transfer of cannabinoids were determined in 12 lactating, nonpregnant Holstein cows. These cows were used in a 3 × 3 Latin square design with three 3-wk experimental periods consisting of 2 wk of adaptation and 1 wk of sampling. Cows received basal partial mixed rations supplemented with either 15% dry matter (DM) canola meal (CM15), 15% DM dehulled hemp meal (HM15), or 7.5% DM dehulled hemp meal and 7.5% DM canola meal (CM7.5HM7.5). Diets were formulated to be isoenergetic and isonitrogenous, but the HM15 and CM7.5HM7.5 diets contained, on average 1.2 percentage units more crude protein (CP) that the CM15 diet. The CP of the dehulled hemp meal contained less soluble protein than that of canola meal. Hence, the intake of soluble protein did not differ among diets. Canola meal contained less crude fat than hemp seed meal (3.46% vs. 8.25% DM). The lipid fraction of canola meal fat contained more oleic acid (C18:1 cis-9; 47.3 vs. 14.9 g/100 g of fatty acids, FA) and vaccenic acid (18:1 cis-11; 13.7 vs. 1.2 g/100 g of FA) and less linoleic acid (C18:2n-6; 21.9 vs. 55.7 g/100 g of FA) and α linolenic acid (C18:3n-3; 3.2 vs. 8.9 g/100 g of FA) than the lipid fraction of hemp seed meal. The hemp seed meal contained 4.9 µg/g cannabidiol, 5.1 µg/g cannabidiolic acid, and 0.1 µg/g tertahydroxycannabinolic acid A. Treatments did not differ in DMI, yields of milk, milk protein and milk fat, total-tract neutral detergent fiber digestibility, and blood plasma concentrations of ß-hydroxybutyrate and nonesterified FA. Apparent total-tract DM digestibility was lowest in the HM15 treatment, whereas the CP digestibility and the concentrations of urea in blood, urine, and milk were lowest in the CM15 treatment. Cannabinoids were not detected in urine, milk, and blood plasma. Replacing canola meal with hemp seed meal increased milk fat contents of polyunsaturated fatty acids (PUFA), which were 3.42, 3.90, and 4.25 g/100 g of FA for the CM15, CM7.5HM7.5, and HM15 treatments, respectively. Especially, the milk fat contents of 18:2n-6 (1.99 vs. 1.56 g/100 g FA) and 18:3n-3 (0.31 vs. 0.43 g/100 g FA) were increased by hemp meal feeding. Especially, the milk fat contents of 18:2n-6 (1.99 vs. 1.56 g/100 g FA) and 18:3n-3 (0.31 vs. 0.43 g/100 g FA) were increased by hemp meal feeding. Our data show that hemp seed meal is a suitable and safe replacement for canola meal as a feed for lactating dairy cows and that this replacement increases CP digestibility and urea in urine, milk, and blood plasma, as well the PUFA content of milk fat.

Seed-specific expression of the class 2 Phytoglobin (Pgb2) increases seed oil in Brassica napus.

To examine the function of phytoglobin 2 (Pgb2) on seed oil level in the oil-producing crop Brassica napus L., we generated transgenic plants in which BnPgb2 was over-expressed in the seeds using the cruciferin1 promoter. Over-expression of BnPgb2 elevated the amount of oil, which showed a positive relationship with the level of BnPgb2, without altering the oil nutritional value, as evidenced by the lack of major changes in composition of fatty acids (FA), and key agronomic traits. Two key transcription factors, LEAFY COTYLEDON1 (LEC1) and WRINKLED1 (WRI1), known to promote the synthesis of fatty acids (FA) and potentiate oil accumulation, were induced in BnPgb2 over-expressing seeds. The concomitant induction of several enzymes of sucrose metabolism, SUCROSE SYNTHASE1 (SUS) 1 and 3, FRUCTOSE BISPHOSPHATE ALDOLASE (FPA), and PHOSPHOGLYCERATE KINASE (PGK), and starch synthesis, ADP-GLUCOSE PHOSPHORYLASE (AGPase) suggests that BnPgb2 favors sugar mobilization for FA production. The two plastid FA biosynthetic enzymes SUBUNIT A OF ACETYL-CoA CARBOXYLASE (ACCA2), and MALONYL-CoA:ACP TRANSACYLASE (MCAT) were also up-regulated by the over-expression of BnPgb2. The requirement of BnPgb2 for oil deposition was further evidenced in natural germplasm by the higher levels of BnPgb2 in seeds of high-oil genotypes relative to their low-oil counterparts.

Effects of faba bean, blue lupin and rapeseed meal supplementation on amino acid metabolism of dairy cows fed grass silage-based diets.

Information about the amino acid (AA) supply of locally produced protein supplements to dairy cow metabolism is needed to design sustainable diets for milk production. In this dairy cow experiment, grass silage and cereal-based diets supplemented with isonitrogenous amounts of rapeseed meal (RSM), faba beans (FB) and blue lupin seeds (BL) were compared with a control diet (CON) without protein supplementation. The diets were arranged as a 4 × 4 Latin Square using periods of 21 days, and four rumen-cannulated Nordic Red dairy cows were used in the experiment. The intake of all AAs increased in response to protein supplementation and was for many individual AAs higher when RSM rather than the grain legumes FB and BL were fed. The total AA flow at the omasal canal was 3 026, 3 371, 3 373 and 3 045 g/day for cows fed CON, RSM, FB and BL, respectively, but only RSM resulted in higher milk protein output. This may be explained by the higher provision of essential AA for milk protein synthesis when RSM was fed. The cows fed FB showed some positive features such as a tendency for greater omasal flow of branched-chain AA compared with BL. Overall, low plasma methionine and/or glucose concentrations in all treatments suggest that their supply was possibly limiting further production responses under the dietary conditions of the current study. It seems that the benefits of grain legume supplementation are limited when high-quality grass silage and cereal-based diets are used as the basal diet, but higher responses in amino acid supply and subsequent production responses can be expected when RSM is used.

Effect of heat treatment on protein quality of rapeseed protein isolate compared with non-heated rapeseed isolate, soy and whey protein isolates, and rice and pea protein concentrates.

BACKGROUND: Rapeseed protein isolate is used in the food industry, and heating is often used during rapeseed processing. However, the digestible indispensable amino acid score (DIAAS) for heat-treated rapeseed protein isolate is unknown. The present study aimed to test the hypothesis that heating rapeseed protein isolate improves protein quality resulting in DIAAS that is greater than for pea and rice protein concentrates, and comparable to that of soy and whey protein isolates. RESULTS: Standardized ileal digestibility (SID) of amino acids (AA), except leucine and methionine, was not different between heat-treated rapeseed protein isolate and soy protein isolate, but SID of most AA was greater (P < 0.001) for heat-treated rapeseed protein isolate than for brown rice protein concentrate, pea protein concentrate, rapeseed protein isolate and soy protein isolate, but not whey protein isolate. Non-heated rapeseed protein isolate had a reduced (P < 0.001) DIAAS for 6-month-old to 3-year-old children compared with soy protein isolate, but this was greater (P < 0.001) than for pea and brown rice protein concentrates. The DIAAS for heat-treated rapeseed protein isolate was greater (P < 0.001) than for non-heated rapeseed protein isolate for all age groups. Heat-treated rapeseed protein isolate and whey protein isolate had a DIAAS > 100 for individuals older than 3 years. CONCLUSION: Rapeseed protein isolate had a DIAAS comparable to soy protein isolate, but heat-treated rapeseed protein isolate and whey protein isolate had DIAAS ≥ 100, qualifying these proteins as 'excellent'. Rice and pea protein concentrates had DIAAS < 75. © 2023 Society of Chemical Industry.

Characterization of novel loci controlling seed oil content in Brassica napus by marker metabolite-based multi-omics analysis.

BACKGROUND: Seed oil content is an important agronomic trait of Brassica napus (B. napus), and metabolites are considered as the bridge between genotype and phenotype for physical traits. RESULTS: Using a widely targeted metabolomics analysis in a natural population of 388 B. napus inbred lines, we quantify 2172 metabolites in mature seeds by liquid chromatography mass spectrometry, in which 131 marker metabolites are identified to be correlated with seed oil content. These metabolites are then selected for further metabolite genome-wide association study and metabolite transcriptome-wide association study. Combined with weighted correlation network analysis, we construct a triple relationship network, which includes 21,000 edges and 4384 nodes among metabolites, metabolite quantitative trait loci, genes, and co-expression modules. We validate the function of BnaA03.TT4, BnaC02.TT4, and BnaC05.UK, three candidate genes predicted by multi-omics analysis, which show significant impacts on seed oil content through regulating flavonoid metabolism in B. napus. CONCLUSIONS: This study demonstrates the advantage of utilizing marker metabolites integrated with multi-omics analysis to dissect the genetic basis of agronomic traits in crops.

Effects of forage and grain legume-based silages supplemented with faba bean meal or rapeseed expeller on lactational performance, nitrogen utilization, and plasma amino acids in dairy cows.

The objective of this experiment was to investigate the effect of forage type [red clover (51%)-grass silage, i.e., RCG; vs. faba bean (66%)-grass silage, i.e., FBG] and concentrate type (faba bean, FB; vs. rapeseed expeller, RE) on lactational performance, milk composition and nitrogen (N) utilization in lactating dairy cows. Eight lactating multiparous Nordic Red cows were used in a replicated 4 × 4 Latin Square experiment, with 21-d periods, in a 2 × 2 factorial arrangement of treatments. The experimental treatments were as follows: (1) RCG with RE, (2) RCG with FB, (3) FBG with RE, and (4) FBG with FB. Inclusion rates of RE and FB were isonitrogenous. Crude protein contents of the experimental diets were 16.3, 15.9, 18.1, and 17.9% of dry matter, respectively. All diets included oats and barley and were fed ad libitum as total mixed rations with forage-to-concentrate ratio of 55:45. Dry matter intake and milk yield were recorded daily, and spot samples of urine, feces, and blood were collected at the end of each experimental period. Dry matter intake did not differ across diets, averaging 26.7 kg/d. Milk yield averaged 35.6 kg/d and was 1.1 kg/d greater for RCG versus FBG, and milk urea N concentration was lower for RCG compared with FBG. Milk yield was 2.2 kg/d and milk protein yield 66 g/d lower for FB versus RE. Nitrogen intake, urinary N, and urinary urea N excretions were lower, and milk N excretion tended to be lower for RCG compared with FBG. The proportion of the dietary N excreted as fecal N was larger in cows fed RCG than for those fed FBG, and the opposite was true for urinary N. We detected an interaction for milk N as percentage of N intake: it increased with RE compared with FB for RCG-based diet, but only a marginal increase was observed for FBG-based diet. Plasma concentration of His and Lys were lower for RCG than for FBG, whereas His tended to be greater and Lys lower for FB compared with RE. Further, plasma Met concentration was around 26% lower for FB than for RE. Of milk fatty acids, saturated fatty acids were decreased by RCG and increased by FB compared with FBG and RE, respectively, whereas monounsaturated fatty acids were increased by RCG versus FBG, and were lower for FB than for RE. In particular, 18:1n-9 concentration was lower for FB compared with RE. Polyunsaturated fatty acids, such as 18:2n-6 and 18:3n-3, were greater for RCG than for FBG, and 18:2n-6 was greater and 18:3n-3 was lower for FB versus RE. In addition, cis-9,trans-11 conjugated linoleic acid was lower for FB compared with RE. Faba bean whole-crop silage and faba bean meal have potential to be used as a part of dairy cow rations, but further research is needed to improve their N efficiency. Red clover-grass silage from a mixed sward, without inorganic N fertilizer input, combined with RE, resulted in the greatest N efficiency in the conditions of this experiment.

Processed fava bean as a substitute for rapeseed meal with or without rumen-protected methionine supplement in grass silage-based dairy cow diets.

Fava bean offers a sustainable home-grown protein source for dairy cows, but fava bean protein is extensively degraded in the rumen and has low Met concentration. We studied the effects of protein supplementation and source on milk production, rumen fermentation, N use, and mammary AA utilization. The treatments were unsupplemented control diet, and isonitrogenously given rapeseed meal (RSM), processed (dehulled, flaked, and heated) fava bean without (TFB) or with rumen-protected (RP) Met (TFB+). All diets consisted of 50% grass silage and 50% cereal-based concentrate including studied protein supplement. The control diet had 15% of crude protein and protein-supplemented diets 18%. Rumen-protected Met in TFB+ corresponded to 15 g/d of Met absorbed in the small intestine. Experimental design was a replicated 4 × 4 Latin square with 3-wk periods. The experiment was conducted using 12 multiparous mid-lactation Nordic Red cows, of which 4 were rumen cannulated. Protein supplementation increased dry matter intake (DMI), and milk (31.9 vs. 30.7 kg/d) and milk component yields. Substituting RSM with TFB or TFB+ decreased DMI and AA intake but increased starch intake. There were no differences in milk yield or composition between RSM diet and TFB diets. Rumen-protected Met did not affect DMI, or milk or milk component yields but increased milk protein concentration in comparison to TFB. There were no differences in rumen fermentation except for increased ammonium-N concentration with the protein-supplemented diets. Nitrogen-use efficiency for milk production was lower for the supplemented diets versus control diet but tended to be greater for TFB and TFB+ versus RSM. Protein supplementation increased plasma essential AA concentration but there were no differences between TFB diets and RSM. Rumen-protected Met clearly increased plasma Met concentration (30.8 vs. 18.2 µmol/L) but did not affect other AA. Absence of differences between RSM and TFB in milk production together with limited effects of RP Met suggest that TFB is a potential alternative protein source for dairy cattle.