Low Gossypol Research Articles

Ultrasonic-aided extraction and degossypolization of cottonseed meal protein: Optimization and characterization of functional traits and molecular structure

Cottonseed meal (CM) is a useful protein resource, but the presence of gossypol (a toxic compound) limits it utilization in industry. To reduce the gossypol content, the use of ultrasonication in extracting protein from CM was explored. Following single-factor experiments, operative limits of independent variables affecting removal ratio of total-gossypol (RRTG) and extractability of CM protein (CMP) were achieved as temperature (35–55 °C), sonication power (250–350 W), time (12–24 min), and NaOH concentration (2–6 g/L). Box-Behnken’s Design centered on a 3–level-4–factor was employed to optimize ultrasonication conditions on the yield and RRTG of CMP. The predictive models were statistically adequate (p < 0.0001) to reflect the experimental results of the responses as verified by insignificant lack-of-fit (p ≥ 0.1333) and high coefficient of determination (R2 ≥ 0.976) values. The optimized sonication conditions for two responses were 53 °C, 320 W, 21 min, and 4.6 g-NaOH/L. Under optimized conditions, the observed removal ratio of free- and total-gossypol and yield values were 93.21 %, 87.56 %, and 58.23 %, which substantially increased by 15.64 %, 12.88 %, and 29.56 %, respectively over control (alkaline extraction). Furthermore, sonicated isolate showed an increase in solubility and emulsion property relative to control, buttressed by particle sizing and zeta potential outcomes. Sodium dodecyl sulfide polyacrylamide gel electrophoresis (SDS-PAGE), Fourier Transform Infrared (FTIR) spectroscopy, atomic force microscopy (AFM), and amino acid data showed notable changes in molecular weight, functional groups, surface topography, and hydrophobic amino acid content of CMP, respectively (i.e., after sonication), suggesting partial unfolding in CMP conformation. Accordingly, CMP isolates (especially the sonicated protein) could be considered edible because of the observed low gossypol content (< 0.045 %) and thus can be utilized as natural additives in food formulations.

Nutritional composition, antioxidant activity and gossypol level of Nazilli glandless cottonseed, cottonseed kernel and their cold-pressed meal

BackgroundThe study was conducted to determine the nutrient composition and gossypol levels of glandless cottonseed (GCS), glandless cottonseed kernel (GCSK) glandless cottonseed meal (GCSM) and cottonseed kernel meal (GCSKM) obtained by cold pressing of cotton seeds and kernels (Glandless Nazilli variety) as a raw material of compound feed industry.ResultFeed and dry matter (DM)-based nutrient analyses showed significant differences (p < 0.05) in DM, OM (organic matter), CP (crude protein), EE (ether extract), ash and NFE (nitrogen-free extract) contents between GCS and GCSK. The DM-based K, P, S, Mg, Ca, Na, Fe, Cu, Zn and Al contents were significantly different (p < 0.05) between GCS and GCSK. The concentrations of nonessential heavy metals (Cd, Pb, Ni and Al) in GCS, GCSK, GCSM and GCSKM samples were below the permissible limits. The linoleic acid (C18:2; ω6) was the main component (55.55%) among the 20 fatty acids identified in GCS oil. The level of unsaturated fatty acids (70.78%) was higher than that of saturated fatty acids (29.22%). Total phenolics concentrations of GCS, GCSK, GCSM and GCSKM samples were 7.87, 2.18, 5.86 and 1.91 mg gallic acid equivalents (GAE)/g, respectively. Free and total gossypol levels of GCS and GCSK were 294 and 440, and 521 and 706 mg/kg, respectively.ConclusionThe results revealed that nutritional properties of Nazilli GCS with low gossypol and high linoleic acid content were relatively higher compared to the other meals investigated. The antioxidant activity of phenolic compounds, albeit at low levels in Nazilli GCS and GCSM, may contribute to animal health and production efficiency when used in animal rations.

Comparative Transcriptome Analysis Reveals Genes Associated with the Gossypol Synthesis and Gland Morphogenesis in Gossypium hirsutum.

Gossypium hirsutum is an important source of natural textile fibers. Gossypol, which is a sesquiterpenoid compound mainly existing in the cotton pigment glands, can facilitate resistance to the stress from diseases and pests. The level of gossypol in the cotton is positively correlated to the quantity of pigment glands. However, the underlying regulatory mechanisms of gossypol synthesis and gland morphogenesis are still poorly understood, especially from a transcriptional perspective. The transcripts of young leaves and ovules at 30 DPA of the glanded plants and glandless plants were studied by RNA-Seq and 865 million clean reads were obtained. A total of 34,426 differentially expressed genes (DEGs) were identified through comparative transcriptome analysis. Genes related to gossypol synthesis or gland morphogenesis displayed significant differential expression between the two cultivars. Functional annotation revealed that the candidate genes related to catalytic activity, the biosynthesis of secondary metabolites, and biomolecular decomposition processes. Our work herein unveiled several potential candidate genes related to gossypol synthesis or gland morphogenesis and may provide useful clues for a breeding program of cotton cultivars with low cottonseed gossypol contents.

Development of the engineered “glanded plant and glandless seed” cotton

After fiber, cottonseed is the second most important by-product of cotton production. However, high concentrations of toxic free gossypol deposited in the glands of the cottonseed greatly hamper its effective usage as food or feed. Here, we developed a cotton line with edible cottonseed by specifically silencing the endogenous expression of GoPGF in the seeds, which led to a glandless phenotype with an ultra-low gossypol content in the seeds and nearly normal gossypol in other parts of the plants. This engineered cotton maintains normal resistance to insect pests, but the gossypol content in the seeds dropped by 98%, and thus, it can be consumed directly as food. The trait of a low gossypol content in the cottonseeds was stable and heritable, while the protein, oil content, and fiber yield or quality were nearly unchanged compared to the transgenic receptor W0. In addition, comparative transcriptome analysis showed that down-regulated genes in the ovules of the glandless cotton were enriched in terpenoid biosynthesis, indicating the underlying relationship between gland formation and gossypol biosynthesis. These results pave the way for the comprehensive utilization of cotton as a fiber, oil, and feed crop in the future.

Assessment of Conventional and Low Gossypol Cottonseed Meal as Alternative Protein Sources in Low-Fishmeal Diets of Hybrid Grouper (Epinephelus fuscoguttatus♀× Epinephelus lanceolatus♂): Growth, Feed Utilization, Gut Histology, and Immunity.

Simple SummaryThe rapid and sustained growth rate of global aquaculture has forced the aquaculture industry to explore alternative and more sustainable feed ingredients. Plant protein ingredients are promising substitutions for fish meal in the aquaculture industry. The current study aimed to investigate the potential influence of replacing poultry by-product meal protein with conventional cottonseed meal protein (CCMP) or low-gossypol cottonseed meal protein (LGCMP) on growth, feed utilization, gut micromorphology, and immunity of hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) juveniles fed low fish-meal (18.53%, dry matter) diets. Results demonstrated that, without any reduction in fish performance, 80% dietary PBMP could be replaced by CCMP, while this replacement level was 40% for LGCMP. Survival remained unaffected in all dietary treatments, and no fish mortality was observed during the growth trial. These results suggest that cottonseed meal could be a suitable alternative protein source for hybrid grouper farming.A 9-week growth trial was carried out to assess the influence of replacing poultry by-product meal protein with conventional cottonseed meal protein (CCMP) or low gossypol cottonseed meal protein (LGCMP) on growth, feed utilization, gut micromorphology, and immunity of hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) juveniles fed low-fish meal (18.53%, dry matter) diets. Eleven experimental diets were prepared. The control diet (PBMP) contained 46.15% poultry by-product meal protein. Both conventional cottonseed meal protein (CCMP) and low-gossypol cottonseed meal protein (LGCMP) were used in replacement ratios of 20, 40, 60, 80, and 100% of poultry by-product meal protein (PBMP) from the control diet, forming ten experimental diets (CCMP20, CCMP40, CCMP60, CCMP80, CCMP100, LGCMP20, LGCMP40, LGCMP60, LGCMP80, and LGCMP100). Results demonstrated that weight-gain percentage (WG%) was not different between different sources of cottonseed meal (CCMP and LGCMP). However, values of WG% significantly differed among different replacement levels, with CCMP80 and LGCMP40 having significantly higher values compared to other treatments. Fish fed CCMP80 and LGCMP40 exhibited higher protein efficiency ratios (PERs) than fish fed other experimental diets. The regression analysis from a second-order or third-order polynomial model based on WG% showed that the optimal PBMP replacement levels by CCMP and LGCMP are 74% and 33%, respectively. The whole-body lipid contents remarkably decreased as dietary CCMP or LGCMP inclusion levels increased. The relative mRNA expression of insulin-like growth factor-1(IGF-1) in liver was higher in fish fed CCMP80 and LGCMP40 diets compared to fish fed other diets. Generally, in low-FM diets of hybrid grouper, CCMP and LGCMP could replace 74% and 33% of PBMP, respectively.

Genome-wide identification and characterization of terpene synthase genes in Gossypium hirsutum

Terpenoids are widely distributed in plants and play important roles in the regulation of plant growth and development and in the interactions between plants and both the environment and other organisms. However, terpene synthase (TPS) genes have not been systematically investigated in the tetraploid Gossypium hirsutum. In this study, whole genome identification and characterization of the TPS family from G. hirsutum were carried out. Eighty-five TPS genes, including 47 previously unidentified genes, were identified in the G. hirsutum genome and classified into 5 subfamilies according to protein sequence similarities, as follows: 43 GhTPS-a, 29 GhTPS-b, 4 GhTPS-c, 7 GhTPS-e/f, and 2 GhTPS-g members. These 85 TPS genes were mapped onto 19 chromosomes of the G. hirsutum genome. Segmental duplications and tandem duplications contributed greatly to the expansion of TPS genes in G. hirsutum and were followed by intense purifying selection during evolution. Indentification of cis-acting regulatory elements suggest that the expression of TPS genes is regulated by a variety of hormones. RNA sequencing (RNA-seq) expression profile analysis revealed that the TPS genes had distinct spatiotemporal expression patterns, and several genes were highly and preferentially expressed in the leaves of cotton with gossypol glands (glanded cotton) versus a glandless strain. Virus-induced gene silencing (VIGS) of three TPS genes yielded plants characterized by fewer, smaller, and lighter gossypol glands, which indicated that these three genes were responsible for gland activity. Taken together, our results provide a solid basis for further elucidation of the biological functions of TPS genes in relation to gland activity and gossypol biosynthesis to develop cotton cultivars with low cottonseed gossypol contents.

Root Illumination Promotes Seedling Growth and Inhibits Gossypol Biosynthesis in Upland Cotton.

Gossypol, a terpenoid compound mainly synthesized in the cotton roots, acts as a phytoalexin in protecting the plants from biotic stress. Roots are critical for both the secondary metabolism and the growth of the plant. Light plays an important role in plant growth and material metabolism, however, the effect of root illumination (RI) on the cotton seedling growth and gossypol metabolism remains unclear. In the present study, the cotton genetic standard line TM-1 and four pairs of near-isogenic lines (NILs) were used as materials to study the impact of RI on cotton seedlings. Results showed that, compared with the cotton seedlings cultivated without RI, the photosynthetic rate, leaf area, and dry weight of roots and leaves were significantly increased, while the gossypol content in leaves and roots was significantly reduced in seedlings cultivated with RI. GO and KEGG enrichment analysis of the differentially expressed genes (DEGs) with and without RI both indicated that photosynthesis and terpenoid biosynthesis-related GO terms and pathways were significantly enriched, the expression profile confirmed that RI positively regulated the photosynthesis system and negatively affected the gossypol biosynthesis pathway in roots. This study revealed the effects of RI on seedlings’ growth and gossypol biosynthesis in upland cotton, and provided important insights for the engineering of cotton with low gossypol accumulation.

Optimization of extraction parameters to improve cottonseed milk yield and reduce gossypol levels using response surface methodology (RSM)

The consumption of plant-based milk products is a healthy alternative to dairy-based milk for lactose intolerant people. This study aimed to optimize the extraction condition for cottonseed (Gossypium spp.) milk using enzymatic assisted aqueous extraction technique (EAAE) and access the gossypol-protein interaction by electrophoresis. The influence of enzymatic treatment parameters included protease enzyme concentration, incubation temperature, pH, and hydrolysis time on extraction yield, protein, and gossypol content were optimized by response surface methodology (RSM). The optimized extraction conditions were enzyme concentration 0.50%, temperature 30°C, pH 7.0, and hydrolysis time 165.31 min with the desirability value 0.825. The optimized EAAE cottonseed milk had a significant increase in extraction yield by 11.11% and protein content by 21.35%, while the gossypol content decreased by 37.14% with conventional extracted cottonseed milk (CECM). The optimized cottonseed milk met the permissible intake level of gossypol content as set by the USFDA and FAO/WHO. Novelty Impact Statement A novel technique for extraction of cottonseed milk from cottonseed using protease enzyme and its optimized extraction condition resulted in a breakdown of the gossypol–protein complex molecules. The cottonseed milk may be suitable for lactose intolerant people and those in search of novel health-promoting beverages keeping in view the high protein content, lactose-free, and low gossypol level.

Influence of enzymes and extraction conditions on high yield of cottonseed milk

Aim: This research aimed to optimize suitable hydrolytic enzymes for maximizing cottonseed milk extracts for high cottonseed milk yield, protein content and low gossypol level. Methodology: Known amount of cottonseed was soaked for 90 min at 32°C and blended (cottonseed:water@1:6). Different aliquots of the blended cottonseed slurry were treated with 1% of enzymes viz., protease, cellulase and α-amylase enzyme at pH 7.0 followed by incubation at 40 and 52°C for 2.30 hr for the extraction of cottonseed milk. The enzyme activity of extracted milk was subsequently inactivated by pasteurization (90°C, 5 min). Further analysis of physico-chemical characteristics was also carried. The control sample included milk extraction from non-enzyme treated cottonseed milk extract (30±2°C). Results: Among different treatments, cottonseed milk extraction using protease enzyme at 40°C incubation showed the highest milk yield (86.71%) with the lowest sedimentation (3.72%). Further incubation 40°C and 52°C showed the highest protein content of 2.10 and 2.27 g 100 ml-1 and gossypol reduction of 40.36 and 35.22%, respectively, in the cottonseed milk extract. Meanwhile, cellulase and α-amylase enzymes treated samples at both incubation temperatures showed poor physico-chemical characteristics as compared to control. Interpretation: Protease enzyme seems to be the most suitable for optimum or higher extraction of cottonseed milk.

Physiological, ultrastructural, biochemical, and molecular responses of glandless cotton to hexavalent chromium (Cr6+) exposure

Glandless cotton can be grown to obtain cotton seeds free of toxic gossypol for use as both food and feed. However, they are not grown normally due to their lesser productivity and higher susceptibility to biotic stress. Great attention has been paid to biotic stresses rather than abiotic stresses on glandless cotton. Chromium (Cr) is a common pollutant of soil and considered a serious threat to plants due to its adverse effects on different functions. Although numerous studies are available on the toxicity of Cr6+ in various plants. However, its adverse effects and mechanism of toxicity in glandless cotton can seldom be found in the literature. This study examined the Cr6+ effect on glandless cotton in comparison to glanded cotton. Four pairs of glanded and glandless cotton near-isogenic lines (NILs) were exposed to different doses (0, 10, 50, and 100 μM/L) of Cr6+ for seven days, and biochemical, physiological, molecular, and ultrastructure changes were observed, which were significantly affected by Cr6+ at high concentrations in all NILs. The effect of Cr6+ on ionic contents shows the same trend in glanded and glandless NILs except for manganese (Mn2+) that show inhibition in glandless (ZMS-12w and Coker-312w) and enhance in the glanded NIL (ZMS-17). The gene expression of superoxide dismutase (SOD) and peroxidase (POD) revealed similar trends as enzyme activities in glandless NILs. The principal component analysis (PCA) and Agglomerative hierarchical clustering (AHC) results of all NILs from morpho-physiological traits, cluster ZMS-16, and ZMS-17 into Cr6+ sensitive group. While the glandless NILs have the potential to cope with the Cr toxicity by increasing the antioxidant enzyme activity and their gene expression. This study also revealed that Cr6+ tolerance in cotton is genotypic and has an independent mechanism in the root that not related to low gossypol.

Low Gossypol Containing Cottonseed: Not only a Fibre but also a Food Crop

We achieved self-sufficiency in food grains but are still deficient in pulses and oilseeds production. Cottonseed is a good source of quality oil and is rich in protein. But the presence of gossypol in the seed makes it toxic for human consumption. Therefore, low gossypol cultivars were developed either through genetic modification or screening and conventional breeding techniques. Texas A&M University patented the genetically modified ultra-low gossypol (< 450 mg kg−1) cultivar—TAM66274. Our breeders developed cultivars with gossypol content as low as 1100 mg kg−1 using conventional breeding techniques. Cottonseed meal, after oil extraction, can be used as a protein supplement similar to soybean. Cotton breeders need to screen the available germplasm and cultivars for low gossypol as well as high oil and fibre productivity. Thus, developing low and ultra-low gossypol cultivars will be a boon to our country.

THE ENANTIOMERATION OF GINNING PERCENTAGE AT ADVANCED GENERATION OF COTTON HYBRIDS DEVELOPED BY METHODS OF ECOLOGIC- LONG GEOGRAPHICAL HYBRIDIZATION

Despite the greater achievements in the cotton breeding, in this article the issue of developing of initial materials was presented which hasn’t been almost studied yet for the breeding of the varieties with high (+)-gossypol traits through some breeding aspects including determination of the accessions with low total gossypol or nontoxic (+)- gossypol enantiomer among the world cotton germpool accessions, and involving them to breeding process. It has been emphasized that the researches on this concern are the prior tasks corresponding to the requirements of today and the future also the efficiency of of these varieties with positive traits in national economy, livestock husbandry and food industry. As research results it was noted that, there was possibility to select sustainable cotton progenies with high complex of agronomic valuable traits and high lint percentage among the F8-F9 developed by the method of ecologico- geographical long hybridization. Furthermore, it was concluded that the results of hybridization of the USA accessions with a high level of (+)-gossypol in seeds and local varieties were successful for both as developing of breeding material with high level of nontoxic (+)-gossypol in seeds and high lint percentage. KEYWORDS: cotton progenies, ecologico-geographical long hybridization, gossypol enantiomers, lint percentage.

Gossypol in cottonseed increases the fitness cost of resistance to Bt cotton in pink bollworm

Fitness costs of resistance to Bacillus thuringiensis (Bt) toxins can delay or counter the evolution of insect resistance to transgenic Bt crops. Here we tested the hypothesis that the plant defensive compound gossypol in cottonseed increases costs associated with resistance to Bt toxin Cry1Ac in pink bollworm (Pectinophora gossypiella), a cosmopolitan pest that feeds primarily on cottonseed. Previous work showed pink bollworm resistance to Cry1Ac produced by Bt cotton is associated with mutations disrupting a gene encoding a cadherin protein that binds Cry1Ac in susceptible larvae. We used larvae from two strains of pink bollworm, each harboring an intermediate frequency of a different cadherin allele linked with resistance. We tested larvae from both strains on two types of non-Bt cotton that differed nine-fold in the gossypol concentration in their seeds: a transgenic cultivar engineered for low gossypol production and its untransformed parental cultivar. After 10 days of larval feeding on bolls, the resistance allele frequency was significantly lower in larvae from the conventional cotton than transgenic cotton. These results imply the higher gossypol concentration in the conventional cottonseed increased the fitness cost affecting survival. Using a population genetics model, we estimated this increase in survival cost was at least 32%. We also detected a recessive fitness cost reducing larval weight in both strains of pink bollworm that did not differ between the two cotton cultivars. Designing insecticidal crops and refuge plants that exploit the vulnerability of resistant insects to plant defensive compounds could improve resistance management.

Cottonseed protein concentrate (CPC) suppresses immune function in different intestinal segments of hybrid grouper ♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatu via TLR-2/MyD88 signaling pathways

Cottonseed protein concentrate (CPC) has similar amino acid composition compared with fish meal, and has the characteristics of low gossypol and low toxicity. The present study was conducted to investigate the growth performance, antioxidant capacity and different intestinal segments immune responses of hybrid grouper to replacement dietary fish meal ofCPC. Six iso-nitrogenous (50% crude protein) and iso-lipidic (10% crude lipid) diets were formulated: a reference diet (FM) containing 60% fishmeal and five experimental diets (12%, 24%, 36%, 48 and 60%) in which fishmeal protein was substituted at different levels by CPC to feed fish (initial body weight: 11 ± 0.23 g) for 8 weeks. Thena challenge test with injection of Vibrio parahaemolyticus was conducted for 7 days until the fish stabilized. The results showed that specific growth rate (SGR) was the highest with 24% replacement level and feed conversion ratio (FCR)was significantly increased when the replacement level reached 48% (P < 0.05). The content of malonaldehyde (MDA) in the serum was significantly increased when the replacement level reached 36% (P < 0.05). The plica height in the proximal, mid and distal intestine were significantly decreased with the replacement level up to 48% (P < 0.05). Hepatic fat deposition wasaggravatedwhen the replacement level reached 36% (P < 0.05). The expression of IL-6, TNF-α, and IL-1β mRNAs were significantly up-regulated (P < 0.05). The hepcidin mRNA expression was significantly down-regulated (P < 0.05). In proximal intestine (PI) and mid intestine (MI), IFN-γ mRNA expression was significantly up-regulated (P < 0.05). These results suggested that the CPC decreased hybrid grouper growth performance and inflammation function, and different inflammation function responses in PI,MI, and distal intestine (DI) were mediated partly by the TLR-2/MyD88 signaling pathway. According to the analysis of specific growth rate, the dietary optimum replacement level and maximum replacement level were estimated to be 17% and 34%, respectively.

Biodegradation of Gossypol by Mixed Fungal Cultures in Minimal Medium

The fungal cultures, namely – Pleurotus sajor-caju MTCC 1806, Saccharomyces cerevisiae MTCC 6933 and Candida tropicalis MTCC 1406 and their combinations, C. tropicalis + S. cerevisiae, P. sajor-caju + S. cerevisiae and C. tropicalis + P. sajor-caju were grown in minimal medium containing 100 ppm of gossypol as the sole carbon and energy source. The culture supernatants of C. tropicalis + S. cerevisiae and P. sajor-caju + S. cerevisiae had low residual gossypol levels of 29 and 25 ppm, respectively. In the present study, we attempted to isolate gossypol-degrading enzyme and biodegraded gossypol from the culture supernatants of C. tropicalis + S. cerevisiae and P. sajor-caju + S. cerevisiae. The specific activity of laccase in the purified enzyme extracts of the C. tropicalis + S. cerevisiae and P. sajor-caju + S. cerevisiae treated samples was 425 and 224 U/mg, respectively. In SDS-PAGE, the gossypol-degrading enzyme was revealed as 3 bands of molecular weights ranging from 45 to 66 kDa. The characterization of biodegraded gossypol by FTIR analysis showed a reduction in aldehydes (C-H) stretches in samples treated with fungi. Mass spectrometry analysis revealed that the monoisotopic mass of the biodegraded gossypol was 474 g/mol.

Evaluation of genetically-improved (glandless) and genetically-modified low-gossypol cottonseed meal as alternative protein sources in the diet of juvenile southern flounder Paralichthys lethostigma reared in a recirculating aquaculture system

Cottonseed meal (CSM) proteins from genetically-improved (glandless) low-gossypol seed (GI-CSM, 52.1% crude protein, CP), genetically-modified low-gossypol seed (GMO-CSM, 56.0% CP) and from an untreated regular (glanded) seed (R-CSM 49.9% CP) were evaluated to replace fish meal (FM) protein (59.5% CP) in juvenile southern flounder Paralichthys lethostigma diets. Eight isonitrogenous (45% CP) and isolipidic (16% crude lipid, CL) diets were formulated. A control diet (0% CSM) contained 40% fishmeal (FM) and other practical protein sources. Six diets replaced 50, 75 and 100% FM protein with GI-CSM or GMO-CSM protein. One diet replaced 100% FM protein by R-CSM protein. Fifteen fish (mean = 1.81 g) were stocked in each of twenty-four 75-L tanks (N = 3 per treatment) and were fed the treatment diets for eight weeks. Final percent weight gain was not significantly (P > 0.05) different in fish fed the GI- and GMO- and R-CSM protein diets (898–1405%) compared with the control diet (0% CSM) (1242%), but percent weight gain was greater (P < 0.05) in fish fed the 50% GI-CSM diet (1405%) versus the 100% GI-CSM diet (898%). Feed conversion ratio was excellent for all treatments (FCR = 0.70–1.00), with no treatment differences (P < 0.05). Protein efficiency ratios (PER) were also not significantly different among the treatments (2.26–3.24), although the lowest value was for 100% R-CSM diets. After 8 weeks of feeding, survival of fish ranged from 80 to 91%, with no treatment differences. Apparent protein digestibility of diets was significantly higher for the fish fed 75% and 100% GI-CSM and 100% GMO-CSM protein diets (83.5, 83.5 and 86.5%, respectively) compared with the control diet (79.4%). After 8 weeks, no significant (P > 0.05) interactive effects between CSM sources and FM replacement levels on final weight, FCR and PER were observed. Arginine levels in the diets increased as CSM was increased, consistent with the high arginine concentrations found in CSM. Liver gossypol was only detectable in fish fed the 100% R-CSM diet (37 μg/g). Replacing up to 75% FM protein by GI- or GMO-CSM protein did not affect on whole body omega-3 PUFAs, or liver gossypol. The results suggest that up to 75% of fish meal protein may be replaced by GI- or GMO-CSM protein in the diet of juvenile flounder without adverse effects on growth performance and body composition. Statement of relevanceCottonseed meal (CSM) is a potentially cost-effective alternative plant protein source for use in aquafeeds. The results suggest that a 75% of fishmeal protein could be replaced by genetically-improved and genetically modified (GMO) low gossypol based cottonseed flour protein in the diet of southern flounder. These ultra-low gossypol cottonseed flour proteins could be inexpensive protein sources for the commercial culture of southern flounder and other finfish species.

Gossypol ameliorates liver fibrosis in diabetic rats induced by high-fat diet and streptozocin

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) inhibitors have been shown to treat type 2 diabetes (T2D). Since gossypol is an 11β-HSD1 inhibitor, the objective of the present study was to treat T2D and T2D-related liver fibrosis in rat model using low-dose gossypol. T2D was induced by feeding with high fat diet plus injection of streptozocin (30mg/kg). Diabetic rats were treated with either vehicle control or racemic gossypol with a dose of 15mg/kg/day for 4weeks followed by 15mg/kg/week for additional 8weeks. Blood glucose, cholesterol, LDL, and triglycerides were measured. Messenger mRNA levels of glucocorticoid receptor (Nr3c1), phosphoenolpyruvate carboxykinase (Pck1), glucose-6-phosphatase (G6pc), collagen I (Col1a1), collagen III (Col3a1), fibronectin (Fn1), tissue inhibitor of metalloproteinase 1 (Timp1), and 2 (Timp2) were measured. T2D rats had higher serum glucose, cholesterol, LDL, and triglyceride levels compared to control. Liver Nr3c1, Col1a1, Col3a1, Fn1, Timp1, and Timp2 were increased in T2D rats. T2D liver showed significant fibrosis with the increases of α-smooth muscle actin and fibronectin. After gossypol treatment, serum glucose level was lowered by 64%. Liver fibrosis was significantly ameliorated. Nr3c1, Col1a1, Col3a1, Fn1, Timp1, Timp2, Pck1 as well as G6pc levels were significantly reduced. In conclusion, low dose gossypol is effective for the treatment of T2D and T2D-related fibrosis.

Utilization of decorticated, low gossypol cotton seed meal in WL layer diets

Utilization of decorticated, low gossypol cotton seed meal in WL layer diets

The TMEn, Proximate Analysis, Amino Acid Content and Amino Acid Digestibility of Glandless and Commercial Cottonseed Meal for Broilers

Cotton seed meal (CSM) is an alternative ingredient in poultry diets but its use is limited due to the presence of gossypol and the potential effects of gossypol on digestibility of nutrients. Glandless cottonseed is available and contains very low gossypol but there has been a limited amount of poultry nutritional studies completed with glandless cottonseed meal (GCSM). The TMEn, proximate analysis, amino acid content and amino acid (AA) digestibility of a glandless (GCSM) and a commercial (CCSM) cottonseed meal were determined with broilers. Thirty 42-day old Cobb 500 male broilers were precision-fed 30g of CCSM, GCSM and glucose and excreta collected during a 48 h period. Glucose was fed to serve as a control (no nitrogen or AA content). The chemical composition, gossypol content, True metabolizable energy (TMEn) and digestibility coefficients for AA were calculated for both meals. The crude protein and fat content of GCSM was higher than the CCSM (54 and 51%, 6 and 2%, respectively). Both meals were similar in calcium, total phosphorus and phytic acid contents. The CCSM had a higher content of total and free gossypol (1.52 and 0.161%, respectively) when compared to GCSM (0.02 and .003%, respectively). The TMEn for the GCSM provided approximately one thousand kcal more per energy/ kg than the CCSM. The essential AA content (g/kg; 90% DM) was determined for both cottonseed meals and was generally higher for GCSM compared to CCSM but both types of CSM contained higher levels of key essential AA than reported values for AA in the literature. The most extreme differences were for methionine and cystine; % methionine content was approximately 2 fold higher than values in the literature and the % cystine was 74 to 93% higher. The true digestibility coefficients for essential AA ranged from the low of 73.9% for isoleucine to 91.8% for arginine, for CCSM; the amino acid digestibility coefficients for GCSM were all higher than 90% for the essential AAs.

Transcriptional responses underlying the hormetic and detrimental effects of the plant secondary metabolite gossypol on the generalist herbivore Helicoverpa armigera

BackgroundHormesis is a biphasic biological response characterized by the stimulatory effect at relatively low amounts of chemical compounds which are otherwise detrimental at higher concentrations. A hormetic response in larval growth rates has been observed in cotton-feeding insects in response to increasing concentrations of gossypol, a toxic metabolite found in the pigment glands of some plants in the family Malvaceae. We investigated the developmental effect of gossypol in the cotton bollworm, Helicoverpa armigera, an important heliothine pest species, by exposing larvae to different doses of this metabolite in their diet. In addition, we sought to determine the underlying transcriptional responses to different gossypol doses.ResultsLarval weight gain, pupal weight and larval development time were measured in feeding experiments and a hormetic response was seen for the first two characters. On the basis of net larval weight gain responses to gossypol, three concentrations (0%, 0.016% and 0.16%) were selected for transcript profiling in the gut and the rest of the body in a two-color double reference design microarray experiment. Hormesis could be observed at the transcript level, since at the low gossypol dose, genes involved in energy acquisition such as β-fructofuranosidases were up-regulated in the gut, and genes involved in cell adhesion were down-regulated in the body. Genes with products predicted to be integral to the membrane or associated with the proteasome core complex were significantly affected by the detrimental dose treatment in the body. Oxidoreductase activity-related genes were observed to be significantly altered in both tissues at the highest gossypol dose.ConclusionsThis study represents the first transcriptional profiling approach investigating the effects of different concentrations of gossypol in a lepidopteran species. H. armigera's transcriptional response to gossypol feeding is tissue- and dose-dependent and involves diverse detoxifying mechanisms not only to alleviate direct effects of gossypol but also indirect damage such as pH disturbance and oxygen radical formation. Genes discovered through this transcriptional approach may be additional candidates for understanding gossypol detoxification and coping with gossypol-induced stress. In a generalist herbivore that has evolved transcriptionally-regulated responses to a variety of different plant compounds, hormesis may be due to a lower induction threshold of growth-promoting, stress-coping responses and a higher induction threshold of detoxification pathways that are costly and cause collateral damage to the cell.