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PubMed2004

Aminomethylphosphonic acid, a metabolite of glyphosate, causes injury in glyphosate-treated, glyphosate-resistant soybean.

Glyphosate-resistant (GR) soybean [Glycine max (L.) Merr.] was developed by stable integration of a foreign gene that codes insensitive enzyme 5-enolpyruvylshikimate-3-phosphate synthase, an enzyme in the shikimate pathway, the target pathway of glyphosate. Application of glyphosate to GR soybean results in injury under certain conditions. It was hypothesized that if GR soybean is completely resistant to the glyphosate, injury could be caused by a metabolite of glyphosate, aminomethylphosphonic acid (AMPA), a known phytotoxin. Glyphosate and AMPA effects on one- to two-trifoliolate leaf stage (16-18-days old) GR and non-GR soybean were examined in the greenhouse. In GR soybean, a single application of glyphosate-isopropylammonium (1.12-13.44 kg/ha) with 0.5% Tween 20 did not significantly reduce the chlorophyll content of the second trifoliolate leaf at 7 days after treatment (DAT) or the shoot dry weight at 14 DAT compared with Tween 20 alone. A single application of AMPA (0.12-8.0 kg/ha) with 0.5% Tween 20 reduced the chlorophyll content of the second trifoliolate leaf by 0-52% at 4 DAT and reduced shoot fresh weight by 0-42% at 14 DAT in both GR and non-GR soybeans compared with Tween 20 alone. AMPA at 0.12 and 0.50 kg/ha produced injury in GR and non-GR soybean, respectively, similar to that caused by glyphosate-isopropylammonium at 13.44 kg/ha in GR soybean. AMPA levels found in AMPA-treated soybean of both types and in glyphosate-treated GR soybean correlated similarly with phytotoxicity. These results suggest that soybean injury to GR soybean from glyphosate is due to AMPA formed from glyphosate degradation.

Dose-Response Relationship, Drug↗
PubMed1999

Long term outcome of soybean epidemic asthma after an allergen reduction intervention.

BACKGROUND: Asthma outbreaks due to the inhalation of soybean dust released from handling of soybean in the city harbour occurred in Barcelona, Spain from 1981 to 1987. The installation of bag filters in the responsible silo was followed by a substantial reduction of airborne soybean dust released into the atmosphere and the disappearance of asthma outbreaks. A study was undertaken to assess the relevant outcomes in asthma patients affected by soybean epidemic asthma eight years after this environmental intervention. METHODS: A repeat case-control study was performed in 1995 on a population of subjects with epidemic and non-epidemic asthma previously assessed in 1989. The same protocol was used in both surveys to collect data from patients via a questionnaire and respiratory function, skin and laboratory tests were performed under blinded conditions with regard to epidemic and non-epidemic status. Environmental soybean allergen in pollution filters was measured by means of a RAST inhibition technique. RESULTS: During 1995 and 1996 the 24 hour mean airborne levels of soybean allergen on a sample of 39 unloading days (range 31-269 U/m(3)) were systematically below the lowest level ever detected during an epidemic day (1500 U/m(3)). Measurable levels of serum IgE antibodies against soybean were still present in 55% of patients with epidemic asthma compared with 6.0% of those with non-epidemic asthma (p<0.05). These proportions were almost identical to those observed in 1989. The proportion of patients with soybean asthma with symptoms in 1989 who reported the absence of symptoms in 1995 was similar to the control subjects, so most of the relative risks (RRs) of improvement were near to 1. The only statistically significant differences between the two groups were a smaller proportion of patients with epidemic asthma showing improvement in terms of being woken up by attacks of coughing (RR improvement 0.47; 95% CI 0.22 to 0.99) and the need for treatment at the emergency room (RR improvement 0.63; 95% CI 0.41 to 0.96). CONCLUSIONS: Eight years after a large reduction in the levels of airborne soybean allergen half of the former soybean epidemic asthma patients were still sensitised to soybean. These results indicate an initial improvement in soybean epidemic asthma in the two years following the intervention with no further improvement in subsequent years.

Allergens↗
PubMed2003

Effect of the application of selenium on selenium content of soybean and its products.

Two experiments were conducted to study the effect of the application of selenium on the selenium content of soybean and its products in two counties with selenium-deficient soil. Selenium-enriched soybean was produced by the application of sodium selenite and Se-enriched fertilizer. The selenium contents of soybeans, soybean protein and okra were determined by hydride-generation atomic fluorescence spectrometry. The results showed that the selenium contents of soybean, soybean protein, and okra were significantly increased by the application of sodium selenite and selenium-enriched fertilizer. Foliar application of selenium provided a higher efficiency for increasing the selenium content of soybean than soil application. Significant differences were found in that soybean cultivars exhibited different accumulation of selenium. There was no remarkable difference in soybean yield, soybean protein, and lipid between selenium and control. The selenium-enriched protein derived from selenium-enriched soybean could be used as a functional ingredient and soybean okra as a selenium-enriched feed for animals for increasing selenium intake.

China↗
PubMed1995

The effect of roasting temperature applied to whole soybeans on site of digestion by steers: I. Organic matter, energy, fiber, and fatty acid digestion.

A 4 x 5 Youden square design was used to determine the effects of form of oil and roasting temperature of soybeans on site and extent of OM, fiber, energy, lipid, and fatty acid digestion and the degree of ruminal biohydrogenation of C18 unsaturated fatty acids. Four steers (373 kg +/- 30.7) with ruminal, duodenal, and ileal cannulas were fed each of five diets during five periods. Diets contained (percentage of DM) corn silage (50%), alfalfa hay (24%), and a corn-urea concentrate (6%). Cornstarch grits (4%) and whole full-fat soybeans (16% of diet DM), raw or roasted to an exit temperature of 141 degrees, 149 degrees, or 157 degrees C in a commercial roaster, constituted the remainder of the RAW, 141, 149, and 157 treatments. Soybean oil equivalent to the quantity in the whole soybeans (3.4% of diet DM) and corn starch grits (16.6% of diet DM) constituted the basal treatment. Diets provided 6.0% ether extract (EE) and 4.6 Mcal of GE/kg of DM. Flows of nutrients were determined by reference to Cr2O3 as an external marker. Ruminal pH, molar proportions of acetate and butyrate, and total ruminal VFA (mM) were not affected by treatment. Ruminal digestibilities of OM, GE, EE, NDF, and ADF were not different among treatments (average 49.5, 41.7, -3.6, 47.4, and 50.1%, respectively). Small intestinal disappearances of OM, GE, and EE were not different among treatments (average 18.4, 24.8, and 61.6% of intake, respectively). Overall, C18:0, C18:1, C18:2, and C18:3 acids averaged 4.4, 25.3, 60.6, and 8.5% of total C18 fatty acids in the diet, respectively; digesta at the duodenum contained 79.0, 16.5, 4.4, and .2%, respectively. The unsaturated C18 fatty acids of soybean oil from whole soybeans, regardless of roasting temperature, were hydrogenated to a similar degree as free soybean oil in the basal diet (average 78.0%). Small intestinal digestibility of total fatty acids was greater (P = .04) for roasted than for raw soybeans (70.9 vs 60.4%). Total tract digestibilities of total C18 fatty acids and total fatty acids were greater (P = .01) for roasted soybeans than for raw soybeans (88.0 vs 82.4 and 86.3 vs 81.0%, respectively). Total tract apparent digestibility of energy was lower (P = .07) for the basal diet than for soybean-containing diets (69.2 vs 70.0%, respectively). Diets containing whole soybeans, regardless of roasting temperature, or free SB oil had similar effects on ruminal characteristics and nutrient digestion.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Effects of extruded soybeans and forage source on fermentation by rumen microorganisms in continuous culture.

Continuous culture fermenters were used to evaluate effects of extrusion of whole soybeans and changes in forage composition of diets on microbial fermentation. Treatments were arranged in a 2 x 4 factorial design with soybeans (raw or extruded) and dietary treatment (ratio of alfalfa hay to corn silage; 82:18, 61:39, 43:57, and 27:73 of dietary forage) as main effects. Soybeans constituted 9.6, 14.4, 19.2, and 23.9% of DM for each of the respective dietary treatments. True digestion of DM, ADF, and NDF was unaffected by processing of soybeans or dietary treatment, but true digestion of OM decreased as concentration of corn silage and soybeans increased. Total VFA concentration was unaffected by source of soybeans or dietary treatments; however, molar concentration of butyrate decreased in fermenters supplied with diets containing extruded soybeans. Degradation of CP was not influenced by soybean source but decreased as the concentration of corn silage and soybeans increased. Bacterial N output decreased, and dietary N flow from the fermenters increased, as concentration of corn silage and soybeans increased. Changes in the ratio of alfalfa hay to corn silage and alteration of dietary soybean concentration affected true OM digestion and dietary CP degradation, but extrusion of whole soybeans had little effect on fermentation.

Animal Feed↗
PubMed1997

Performance and profiles of milk fatty acids of cows fed full fat, heat-treated soybeans using various processing methods.

Twenty-four multiparous Holstein cows (48 d in lactation) were used in an 8-wk trial employing a completely randomized block design to determine the effect of heat treatment of full fat soybeans on the fatty acid composition of milk fat. Treatments consisted of a total mixed ration supplemented with 1) ground raw, 2) extruded, 3) micronized, or 4) roasted soybeans included at 17.5% of the dry matter of the total mixed ration. Dietary treatment had no effect on body weight, yields of milk or solids-corrected milk, fat percentage, or yield of milk fat or protein. Cows fed ground raw soybeans had a higher dry matter intake and a higher percentage of protein in milk than those fed heat-treated soybeans. The concentrations of saturated fatty acids from C8:0 to C16:0 were lower, and cis-delta-9-C18:1 tended to be higher, in the milk fat of cows fed heat-treated soybeans than in the milk fat of cows fed ground raw soybeans. The concentration of trans-delta-11-C18:1 was lowest for cows fed ground raw soybeans, intermediate for cows fed micronized and roasted soybeans, and highest for cows fed extruded soybeans. Cows fed extruded soybeans had lower concentrations of C18:2 and C18:3 than did cows fed micronized or roasted soybeans; cows fed ground raw soybeans had intermediate concentrations of C18:2 and C18:3.

Animal Feed↗
PubMed1997

Dietary soybeans extruded at different temperatures: milk composition and in situ fatty acid reactions.

Twenty-four multiparous Holstein cows, 4 of which were ruminally fistulated, were assigned to one of four diets containing full-fat soybeans, either raw or extruded at 120, 130, or 140 degrees C. Our hypothesis was that the extrusion of full-fat soybeans, as well as the extrusion temperature, would affect the bypass of fatty acids in the rumen and, thus, would modify the fatty acid profile of milk fat. Total mixed diets containing 23.7% soybeans (percentage of DM) were fed for 8 wk. Milk yield was lower, and the proportion of milk CP was higher, for cows fed raw soybeans than for cows fed extruded soybeans. Compared with raw soybeans, extruded soybeans increased the concentration of delta-11-trans-C18:1 from 2.72 to 11.41% in milk fat but had no effect on yield or percentage of milk fat. Polyunsaturated fatty acids of raw soybeans disappeared more rapidly than did those of extruded soybeans from bags incubated in the rumen of fistulated cows. However, more delta-11-trans-C18:1 and C18:0 appeared in bags containing extruded soybeans than in bags containing raw soybeans. Extrusion of full-fat soybeans influenced the metabolism of fatty acids in the rumen and the fatty acid profile of milk fat, but the temperature of extrusion had only minor effects on these parameters.

Animal Feed↗
PubMed2003

Anti-nutritional effects of a moderate dose of soybean agglutinin in the rat.

This study was conducted to investigate the effects of a moderate dose of purified soybean agglutinin on performance and nitrogen digestibility in rats as well as to determine its effects on the protein, DNA and RNA content of the small intestine and pancreas. Twenty-four Sprague-Dawley rats were randomly allotted into one of four groups for a 10-day nitrogen balance experiment. The four groups of rats were fed 7 g of a casein-cornstarch based diet or a similar diet supplemented with 0.1, 0.2 or 0.4 mg/g purified soybean agglutinin. All experimental diets were adjusted to an identical nutrient level. Dose of soybean agglutinin had no significant effect on rat performance. Incorporation of soybean agglutinin in the diet reduced apparent protein digestibility and the utilization of dietary protein by increasing nitrogen loss from the faeces and urine. Fresh pancreatic weight increased in rats fed soybean agglutinin at a level of 0.4 mg/g in the diet compared to the control, but the dry pancreatic weight and the protein content of the pancreas did not differ among the four groups. However the DNA and RNA content of the pancreas had a tendency to increase with a higher level of soybean agglutinin. The weight of the jejunum and its protein, DNA and RNA content were not significantly affected by soybean agglutinin, but the dry weight and the RNA of the jejunum tended to increase with higher levels of soybean agglutinin in the diet. In conclusion, purified soybean agglutinin, at moderate levels in the rats diet, had negative effects on digestive function, such as nitrogen digestibility, nitrogen retention and nitrogen balance. As the level of soybean agglutinin increased, the effects became more pronounced. Meanwhile, hypertrophy of the pancreas was observed with higher doses of soybean agglutinin incorporation in the diets.

Animal Feed↗
PubMed2003

Effects of soybean agglutinin on nitrogen metabolism and on characteristics of intestinal tissues and pancreas in rats.

Two experiments were conducted to investigate the effects of increasing concentrations of supplemental purified soybean agglutinin on performance, apparent nitrogen digestibility, plasma insulin and cholecystokinine (CCK) levels in rats as well as on the growth of the small intestine and pancreas. In Experiment 1, a 10-day nitrogen balance trial was conducted with 24 male Sprague-Dawley rats (mean BW 85 g) that were randomly allotted to one of four dietary treatments. Rats in each group were provided daily with 7 g of a casein-cornstarch based diet (control) or a diet supplemented with purified soybean agglutinin at 0.4, 0.6 or 0.8 mg/g. Urine and faeces were collected daily and stored at -20 degrees C until analysis. In Experiment 2, 30 male Sprague-Dawley rats (mean BW 75 g) were divided into five groups for a 20-day growth experiment. Each rat was fed daily 7 g of a casein-cornstarch based diet (control) or a diet supplemented with purified soybean agglutinin at 0.4, 0.8, 1.2 or 2.0 mg/g. All experimental diets were adjusted to contain a similar level of nutrients. Results from the two experiments showed that supplementation of soybean agglutinin below 2.0 mg/g diet had no significant effect on rat performance. However, rats receiving 2.0 mg soybean agglutinin per gram of diet showed a significant reduction in weight gain compared to the control group. Incorporation of soybean agglutinin in the diet reduced apparent nitrogen digestibility and the retention of dietary nitrogen by increasing nitrogen loss from the faeces and urine. In addition, plasma CCK level increased with increasing inclusion of soybean agglutinin in the diet. On the contrary, the plasma insulin level declined as soybean agglutinin level increased. Soybean agglutinin induced a polyamine-dependent hyperplastic and hypertrophic growth of the small intestine and pancreas by increasing the contents of protein, RNA and DNA, though the increase in weight of small intestine was not significant. Furthermore, 1.2 and 2.0 mg soybean agglutinin per gram of diet promoted proliferation of the jejunum mucosa, while the structure of the brush border epithelium of small intestinal had no damaging change and no diarrhoea was observed in any treatment group. Based on these results, supplementation of low doses of soybean agglutinin or soy protein to parenterally-fed animals affected by atrophic small intestine may promote small intestinal growth.

Animals↗
PubMed1993

The effect of pre- and postweaning exposure to soybean meal on growth performance and on the immune response in the early-weaned pig.

The effect of pre- and postweaning exposure to soybean meal on postweaning growth performance and immune response by the early-weaned pig was analyzed. In Exp. 1, treatments were assigned in a 2 x 2 x 2 factorial arrangement. Pigs were derived from gilts fed either a soybean meal- or a corn gluten meal-based diet during gestation and lactation. Six to eight pigs per litter were either stomach-infused with or without (placebo) soybean meal during d 5 to 9 after farrowing. At weaning, 240 pigs (initially 5.1 kg, 21 +/- 1 d) were randomly allotted to either a corn-soybean meal or a corn-dried skim milk-dried whey diet based on gilt and infusion treatments. Average daily gain, ADFI, and gain:feed ratio were decreased (P < .05) on d 0 to 14 postweaning for pigs fed a soybean meal diet compared with pigs fed a milk diet. Skin-fold thickness after intradermal injection of soy protein and casein extracts on d 6 and measured on d 7 postweaning was not affected (P > .10) by dietary treatment, but serum immunoglobulin G titers to soybean glycinin and beta-conglycinin were increased (P < .01). From d 14 to 35 postweaning, all pigs were fed a common (1.25% lysine) corn-soybean meal diet containing 10% dried whey. Average daily gain, ADFI, and gain:feed ratio were decreased (P < .05) from d 14 to 35 for pigs fed a milk diet on d 0 to 14 postweaning. Serum immunoglobulin G titers were higher (P < .01) on d 21 postweaning for pigs fed soybean meal for the entire nursery period. Cumulative ADG (d 0 to 35) and gain:feed ratio were decreased (P < .05) for pigs fed a milk diet from d 0 to 14 compared with pigs fed a soybean meal diet. In Exp. 2, 104 pigs (initially 5.3 kg, 21 +/- 1 d of age) were used to determine the effect of 0, 7.5, 15.0, and 22.5% soybean meal in a high-nutrient-dense starter pig diet. Differences were not detected (P > .10) in ADG, ADFI, and gain:feed ratio during d 0 to 14, but ADFI decreased (linear, P < .05) and gain:feed ratio increased (linear, P < .05) during d 14 to 35 and for the entire 35-d trial as the level of soybean meal increased.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed2001

Apparent ileal digestibility of amino acids and the digestible and metabolizable energy content of dry extruded-expelled soybean meal and its effects on growth performance of pigs.

We conducted three experiments to determine the apparent ileal digestibility of amino acids (Exp. 1), metabolizable and digestible energy (Exp. 2), and feeding value (Exp. 3) of dry extruded-expelled soybean meal with (DEH) or without (DENH) hulls compared with solvent-extracted soybean meal with hulls removed (SBMNH). Soybeans used to produce DEH were unadulterated prior to extrusion, but those used for DENH were dehulled prior to extrusion. In Exp. 1, six nonlittermate barrows (initially 39 kg) were fitted with ileal T-cannulas and used in a replicated 3 x 3 Latin square design digestion trial. Experimental diets (0.80% total lysine) were cornstarch-based and contained soybean meal from one of the three different sources as the sole source of lysine. Apparent ileal digestibilies of nutrients were similar (P > 0.10) for DEH and DENH. Apparent ileal digestibilies of CP, Lys, Ile, Leu, Arg, Phe, and Val were greater (P < 0.05) for DEH and DENH than for SBMNH. In Exp. 2, six barrows (initially 41 kg) were fed three corn-based diets containing 25% of one of the three soybean meal sources. A fourth diet was fed at the end of the trial containing all ingredients except soybean meal, so that energy values of the soybean meal could be determined by difference. Digestible energy and ME contents were similar (P > 0.10) for DEH and DENH and both had greater (P < 0.05) DE and ME contents than SBMNH. In Exp. 3, pigs (n = 216, initially 10.6 +/- 1.3 kg and 35 +/- 3 d of age) were blocked by weight and allotted to six dietary treatments. Corn-soybean meal-based diets (0.95% digestible lysine and 3.44 kcal/g ME) containing DEH or DENH were compared with similar diets containing SBMNH or solvent-extracted soybean meal with hulls (SBMH). In addition, a diet containing a second expelled soybean meal with hulls (ESBM) was compared with a diet containing SBMH and soy oil. Growth performance of pigs fed diets containing DEH or DENH was not different (P > 0.10) than that of pigs fed corresponding diets containing SMBH or SBMNH. Pigs fed ESBM had lower (P < 0.05) ADG and G/F compared with its corresponding SBMH and soy oil diet. In conclusion, DEH and DENH are more digestible than conventional soybean meal and can be successfully used in swine diets.

Amino Acids↗
PubMed1997

Low linolenate and commercial soybean oils diminish serum HDL cholesterol in young free-living adult females.

OBJECTIVE: A mutant soybean line (A16) low in linolenic acid content (2% of oil by weight) was developed to increase oil oxidative stability. It was unknown whether serum lipid and lipoprotein concentrations in humans would be affected should A16 soybean oil (A16 oil) replace commercial soybean oil in diets. This study was conducted to examine the hypothesis that in free-living normolipidemic women, the consumption of A16 oil at approximately 10% of energy intake (en%) would not affect serum lipids and lipoproteins differently than would the consumption of the same amount of a commercial soybean oil with 7% of linolenic acid content. DESIGN: Fifteen free-living female college students consumed the soybean oil daily with regular meals for 9 weeks in different orders, with each test oil being eaten for 3 weeks. During the study, 13 en% was provided by each test oil and a total of 35 en% was from dietary fat. Serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), low-density lipoprotein cholesterol (LDL cholesterol) and triacylglycerides (TAG) were measured. Serum total fatty acid patterns were analyzed as well. RESULTS: Each of the three test oils decreased serum total cholesterol, LDL cholesterol and TAG concentrations from the baseline values. The feeding of A16 and commercial soybean oils decreased serum HDL cholesterol significantly compared with coconut oil (p < 0.05). Dietary inclusion of coconut oil increased serum myristic acid significantly more than did either soybean oil (p < 0.01). Serum arachidonic acid concentrations were significantly greater with A16 consumption than with commercial soybean oil consumption (p < 0.001). CONCLUSION: A16 and commercial soybean oils both diminished serum HDL cholesterol. Although the fatty acid composition differed between the two soybean oils, A16 oil and commercial oil had similar effects on serum concentrations of lipoproteins and lipids. With increased oxidative stability, A16 oil is a good alternative to commercial soybean oil.

Adolescent↗
PubMed2001

Allergenicity test of genetically modified soybean in Sprague Dawley rats.

Allergenicity of genetically-modified (GM) soybean was evaluated in male Sprague Dawley rats. To confirm the GM soybean used in this study, the polymerase chain reaction (PCR) was performed using the chromosomal DNA of soybeans. The PCR result provided the clear discrimination of genetically-modified (GM) soybeans. To evaluate the allergenicity of GM soybean and non-GM control one, the soybean homogenate was sensitized subcutaneously 3 times a week for 3 weeks. The doses of soybean were 0, 2 and 20 mg/kg in the protein basis. A week after the last sensitization, antisera were recovered from individual animals. When the sera were injected intradermally on the clipped back of unsensitized rats with various dilutions, followed by a challenge with 20 mg/kg of soybean homogenate containing 1% Evans blue, no sign of passive cutaneous anaphylaxis reaction was detected. In addition, when the sera were treated in the cultures of peritoneal mast cells, the increase of histamine release by anti-(GM soybean) sera was not observed when compared to that by anti-(non-GM soybean) sera. The present results indicate that the GM soybean might not act as a strong allergen in male Sprague Dawley rats.

Animals↗
PubMed1998

Gas chromatography determination of polychlorinated biphenyls in powdered and liquid soybean milks.

A method previously validated for the analysis of individual congeners of polychlorinated biphenyls (PCBs) in soybean infant formulas is now used to determine PCB levels in dairy-like soybean derivatives, including liquid and powdered soybean milks. Some differences were found among PCB levels and profiles calculated from the different liquid and powdered soybean milks investigated when compared to previously reported for soybean infant formulas, and those most common in dairy-products from Spain and from other countries. PCB levels detected in liquid soybean milks were lower than those found in powdered soybean milks. Levels reported for these two dairy-like derivatives were lower than those detected in soybean infant formulas. The most apparent difference among soybean derivatives and cow's milk was that individual PCB levels detected in the former were lower than those reported for the latter, except for congeners 126 and, specifically, 77, which showed the opposite trend. This feature was common to all soybean products investigated including infant formulas, powdered and liquid soybean milks.

Chromatography, Gas↗
PubMed1997

Expression and subcellular targeting of a soybean oleosin in transgenic rapeseed. Implications for the mechanism of oil-body formation in seeds.

Two genomic clones, encoding isoforms A and B of the 24 kDa soybean oleosin and containing 5 kbp and 1 kbp, respectively, of promoter sequence, were inserted separately into rapeseed plants. T2 seeds from five independent transgenic lines, three expressing isoform A and two expressing isoform B, each containing one or two copies of the transgene, were analysed in detail. In all five lines, the soybean transgenes exhibited the same patterns of mRNA and protein accumulation as the resident rapeseed oleosins, i.e. their expression was absolutely seed-specific and peaked at the mid-late stages of cotyledon development. The 24 kDa soybean oleosin was targeted to and stably integrated into oil bodies, despite the absence of a soybean partner isoform. The soybean protein accumulated in young embryos mainly as a 23 kDa polypeptide, whereas a 24 kDa protein predominated later in development. The ratio of rapeseed:soybean oleosin in the transgenic plants was about 5:1 to 6:1, as determined by SDS-PAGE and densitometry. Accumulation of these relatively high levels of soybean oleosin protein did not affect the amount of endogenous rapeseed oleosin. Immunoblotting studies showed that about 95% of the recombinant soybean 24 kDa oleosin (and the endogenous 19 kDa rapeseed oleosin) was targeted to oil bodies, with the remainder associated with the microsomal fraction. Sucrose density-gradient centrifugation showed that the oleosins were associated with a membrane fraction of buoyant density 1.10-1.14 g ml-1, which partially overlapped with several endoplasmic reticulum (ER) markers. Unlike oleosins associated with oil bodies, none of the membrane-associated oleosins could be immunoprecipitated in the presence of protein A-Sepharose, indicating a possible conformational difference between the two pools of oleosin. Complementary electron microscopy-immunocytochemical studies of transgenic rapeseed revealed that all oil bodies examined could be labelled with both the soybean or rapeseed anti-oleosin antibodies, indicating that each oil body contained a mixed population of soybean and rapeseed oleosins. A small but significant proportion of both soybean and rapeseed oleosins was located on ER membranes in the vicinity of oil bodies, but none were detected on the bulk ER cisternae. This is the first report of apparent targeting of oleosins via ER to oil bodies in vivo and of possible associated conformational/processing changes in the protein. Although oil-body formation per se can occur independently of oleosins, it is proposed that the relative net amounts of oleosin and oil accumulated during the course of seed development are a major determinant of oil-body size in desiccation-tolerant seeds.

Brassica↗
PubMed2000

Effect of imazaquin applications on the growth, leaf chlorophyll and yield of soybean in the Guinea savanna of Nigeria.

Field trials were conducted during the wet seasons of 1989, 1991, 1994 and 1995 to evaluate the effects of pre-emergence and post-emergence applications of four rates of imazaquin (0.00; 0.15; 0.30 and 0.45kg a.i/ha) on the growth, leaf chlorophyll types and grain yield of soybean c.v. SAMSOY 2. Imazaquin applications had no significant effect on the growth of soybean roots on most of the sampling dates, but pre-and post-emergence applications of imazaquin at 0.30 and 0.45kg a.i/ha reduced soybean root nodules at 5 and 7 weeks after planting (WAP). Soybean shoot growth was generally reduced at 5WAP by the pre-emergence and at 7WAP by the higher rates (0.30 & 0.45kg a.i/ha) of post-emergence application of imazaquin. Pre-and post-emergence applications of imazaquin showed a strong tendency to reduce the concentration of chlorophyll a and total chlorophyll at 3 and 5WAP respectively. The concentrations of chlorophyll types in soybean leaves at 9WAP was generally comparable among most treatments especially in 1991. Whole plant fresh weight of soybean at 7WAP was reduced by all rates of post-emergence application of imazaquin. However, there was no significant difference in the whole plant dry weight of soybean at 3 to 7 WAP in 1989 and at 3, 5 and 9WAP in 1991. In each trial, pre-and post-emergence applications of soybean significantly increased the grain yield of soybean compared with the control treatment. This study showed that, inhibition of soybean shoot growth and leaf chlorophyll concentration was transient and that soybean plants require about 6 weeks for complete recovery from imazaquin phytotoxicity.

Chlorophyll↗
PubMed2005

The biology and behavior of the longhorned beetle, Dectes texanus on sunflower and soybean.

The biology and behavior of the longhorned beetle Dectes texanus LeConte (Coleoptera: Cerambycidae) was studied on two host plants that suffer economic losses from this pest; sunflower, Helianthus annuus, and soybean, Glycines max. Reciprocal crosses of D. texanus collected from the two plants all produced viable progeny, indicating that conspecific insects attack both crops. Pupae from soybean stalks weighed about 40% less than those from sunflower, and adults fed on soybean lived a mean of 23 days, compared to a mean of 53 days (males) and 76 days (females) for those fed sunflower. A female's larval host plant had no effect on her tendency to ovipuncture plants of either type in a greenhouse trial. A field-tested population collected exclusively from sunflower contained three types of females in similar proportions: those that laid eggs only on sunflower, those that laid only on soybean, and those that laid equally on both host plants. Females in field trials fed more on the plant they had fed on in the laboratory, but soybean-fed females fed more on soybean than did sunflower-fed females. Females fed soybean also made more ovipunctures on soybean plants in field trials than sunflower-fed females, but their responses to sunflower plants were similar. Females displayed higher total ovipositional activity when they encountered sunflower first in the field, and lower total activity when they encountered soybean first. Feeding scores were significantly correlated with ovipunctures and eggs on both plant types. We conclude that sunflower is the preferred host plant, although females will accept soybean when it is the only available food. The results suggest that D. texanus is still in the initial stages of a host range expansion with female host selection behavior demonstrating both genetic influences and phenotypic flexibility. Sunflower represents a nutritionally superior, ancestral host plant and relatively high fitness costs are still associated with utilization of the novel host plant, soybean, costs that may be offset by benefits such as reduced intraspecific competition. These potential benefits and their consequent implications for D. texanus host range evolution are hypothesized and discussed.

Animals↗
PubMed1981

Examination of Le and lele Genotypes of Glycine max (L.) Merr. for Membrane-Bound and Buffer-Soluble Soybean Lectin.

Membrane fractions from seedlings of four soybean [Glycine max (L.) Merr.] lines were examined by radioimmunoassay and hemagglutination assay for the 120,000 dalton soybean lectin. Two of the lines (Sooty and T-102) are genotypically lele and lack buffer-soluble soybean lectin; the remaining two lines (Beeson and Harosoy 63) are Le and produce seeds that contain the lectin (Su et al. 1980 Biochim. Biophys. Acta 629: 292-304). Both Triton X-100 (0.5% v/v) and nonidet P-40 (0.05% v/v) solubilized soybean lectin from membrane fractions of Le cotyledons. Triton X-100 interfered substantially with the assay of protein and hemagglutinating activity and was unacceptable for use in quantitative measurements. The nonidet P-40-solubilized soybean lectin from Le cotyledons was consistently present both in washed 13,000g and 82,500g membrane fractions, but it accounted for less than 1.5% of the total (buffer-soluble plus membrane-bound) soybean lectin. The membrane lectin was purified by the affinity chromatography procedure devised for soluble soybean lectin, and it was immunologically indistinguishable from authentic soybean lectin. Membrane fractions from Le cotyledons contained insignificant amounts of radioisotope-labeled soybean lectin that had been added during homogenization, and purified membrane fractions did not bind the lectin in the presence of the hapten, d-galactose. These controls make it unlikely that the membrane soybean lectin was of cytoplasmic origin. Soybean lectin and other hemagglutinins were not present in buffer-soluble or membrane fractions from lele cotyledons or from roots and hypocotyls of any of the lines.

Journal Article↗