38 research outputs found
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Dormancy-defense syndromes and tradeoffs between physical and chemical defenses in seeds of pioneer species
Seeds of tropical pioneer trees have chemical and physical characteristics that determine their capacity to persist in the soil seed bank. These traits allow seeds to survive in the soil despite diverse predators and pathogens, and to germinate and recruit even decades after dispersal. Defenses in seedlings and adult plants often are described in terms of tradeoffs between chemical and physical defense, but the interplay of defensive strategies has been evaluated only rarely for seeds. Here we evaluated whether classes of seed defenses were negatively correlated across species (consistent with tradeoffs in defense strategies), or whether groups of traits formed associations across species (consistent with seed defense syndromes). Using 16 of the most common pioneer tree species in a neotropical lowland forest in Panama we investigated relationships among four physical traits (seed fracture resistance, seed coat thickness, seed permeability, and seed mass) and two chemical traits (number of phenolic compounds and phenolic peak area), and their association with seed persistence. In addition, seed toxicity was assessed with bioassays in which we evaluated the activity of seed extracts against representative fungal pathogens and a model invertebrate. We did not find univariate tradeoffs between chemical and physical defenses. Instead, we found that seed permeability – a trait that distinguishes physical dormancy from other dormancy types – was positively associated with chemical defense traits and negatively associated with physical defense traits. Using a linear discriminant analysis and a hierarchical cluster analysis we found evidence to distinguish three distinct seed defense syndromes that correspond directly with seed dormancy classes (i.e., quiescent, physical, and physiological). Our data suggest that short and long‐term persistence of seeds can be achieved via two strategies: having permeable seeds that are well defended chemically, corresponding to the physiologically dormant defense syndrome; or having impermeable seeds that are well defended physically, corresponding to the physically dormant defense syndrome. In turn, transient seeds appear to have a lower degree of chemical and physical defenses, corresponding to the quiescent defense syndrome. Overall, we find that seed defense and seed dormancy are linked, suggesting that environmental pressures on seed persistence and for delayed germination can select for trait combinations defining distinct dormancy‐defense syndromes
The use of fatty acid profile as a potential marker for Brazilian coffee (Coffea arabica L.) for corn adulteration
Fatty acid methyl ester (FAME) composition of the coffee (Coffea arabica L.) varieties Catuai, Catucaí, Bourbom, Mundo Novo, Rubí and Topázio known to produce beverage of intermediate, excellent, excellent, intermediate, intermediate and poor quality, respectively, was determined for the first time. Average area % of the FAMEs of the six varieties was: palmitic (38.2), stearic (8.3), oleic (8.6), linoleic (38.5), linolenic (1.6) and arachidic (3.6) acids, respectively. The method was very quick with complete characterization (>99%) of the samples studied being possible in less than 6 min. While these values may provide insights for evaluating the coffee quality, no significant effect (p < 0.05) of coffee variety was found on area % of the FAMEs. In addition, FAMEs of six corn samples, six commercial coffee brands and one commercial coffee sample intentionally contaminated with three levels of corn were compared. Although the linoleic/stearic ratio was significantly different in coffee and corn FAMEs, this probe could not be used a marker to detect corn adulteration in commercial coffees
A high-protein soybean cultivar contains lower isoflavones and saponins but higher minerals and bioactive peptides than a low-protein cultivar
a b s t r a c t Soybean is a major source of protein and other nutrients and non-nutrient bioactives for human health. The objective was to compare the bioactive compounds of a low-protein (BRS 133) soybean in comparison to a high-protein (BRS 258) soybean cultivar. The high-protein soybean contained 17% lower carbohydrates and a lower chemical score (63) in relation to the low-protein soybean, which had a higher chemical scor
Effects of glucosinolates and their hydrolysis products on energy balances and performance parameters and histological parameters in broiler chicken diets
Glucosinolates are important bioactive molecules and widely found in Brassicaceae species (cress, brussels sprouts, mustard, broccoli, kale etc.). Depending on the amount of these vegetables consumed, both positive and negative metabolic effects from glucosinolate metabolites may occur. The aims of this study were to; investigate inexpensive animal food sources that both increases weight gain and provides enhanced performance parameters without adversely affecting the animal’s health and metabolism; to evaluate dose adjustment of food containing glucosinolates in animals; and to evaluate changes in the biochemical and performance status of chickens on these glucosinolate containing diets. A total of 624 one-day-old Ross 308 broiler line chicks were divided into one control and three treatment groups. Cress seed (Lepidium sativum) was added 0.05% for the first treatment groups (Group 1, 10 g/kg), 0.10% for the second treatment groups (Group 2, 20 g/kg) and 0.15% for the last treatment groups (Group 3, 30 g/kg) to the diet. Serum samples were evaluated for serum glucose, adiponectin, leptin, growth hormone, estradiol and cortisol levels. Performance parameters investigated included feed intake, live body weight and feed conversion ratio. . The villus length, number of goblet cells, crypt depth were determined for histological analyses. According to histological results, villus length was significant at p < 0.05 level between control and group 1 and at p < 0.001 level with groups 2 and 3 at 21 days. The depth of the crypts belonging to the control and experimental groups was not significant between the control group and the group 1 when the statistic was evaluated on the 21st day, whereas between the control group and the group 2, p < 0.05 and p < 0.01; statistical significance was found at p < 0.001 level between group 3 and control group. The results showed that dietary glucosinolate supplementation as feed additive (10, 20 and 30 g/kg) did not significantly improve the dietary performance, or carcass parameters of broiler chickens. Feed intake was the highest in group 2 (20 g/kg), female live weight was the highest in group 2 (20 g/kg) and 3 (30 g/kg). In conclusion, the rates of the cress seed (0.05, 0.10 and 0.15%) that contain glucotropaeolin were not affected for feed additive on performance (especially live weight and live weight gain) and carcass parameters
Caecal Absorption of Vitexin-2-O-xyloside and its Aglycone Apigenin, in the Rat
The in vivo bioavailability of the flavone-C-glycosides has been little studied compared to their O30
glycoside analogues, which are both more common in nature and considered more easily
31 hydrolyzed than C-glycosides, by both enterocytes and gut microbiota. In this study, we used
32 vitexin-2-O-xyloside (VOX), an apigenin-8-C-glucoside-2-O-xyloside, purified from seeds of Swiss
33 chard (Beta vulgaris cicla), to investigate VOX absorption into portal blood compared to its
34 aglycone, apigenin. We used a rat model in which we ligated the ileo- and colo-caecal junctions,
35 then administered apigenin or VOX directly into the caecum. Blood samples were drawn from the
36 portal vein at timed intervals over 40 min. The kinetic profile of appearance in portal blood of the
37 compounds and their metabolites was evaluated by HPLC-ESI-MS. Apigenin was found in portal
38 blood both as the aglycone and as an apigenin-glucuronide derivative. The VOX was found
39 unchanged and as a reduced monoglycoside, which underwent glucuronidation. By collecting the
40 bile, we confirmed that the liver received unchanged VOX, which was returned to the gut by
41 enterohepatic recirculation for reabsorption from the ileum. The amount of apigenin and VOX
42 remaining in the caecum accounted for ~15% and ~26%, respectively. These data show for the first
43 time that the C-glycoside VOX is absorbed unchanged and undergoes enterohepatic recirculation in
44 addition to hydrolysis to the monoglycoside, reduction and conjugation to form a bioavailable
45 glucuronide
Camelina sativa defatted seed meal contains both alkyl sulfinyl glucosinolates and quercetin that synergize bioactivity
Camelina sativa L. Crantz is under development as a novel oilseed crop, yet bioefficacy of camelina phytochemicals is unknown. Defatted camelina seed meal contains two major aliphatic glucosinolates (GSLs), glucoarabin (9-(methylsulfinyl)nonylglucosinolate; GSL 9) and glucocamelinin (10-(methylsulfinyl)decylglucosinolate; GSL 10), with traces of a third, 11(methylsulfinyl)undecylglucosinolate and several flavonoids, mostly quercetin glycosides. In Hepa1c1c7 cells, hydrolyzed GSLs (hGSLs) 9 and 10 upregulated the phase II detoxification enzyme quinone reductase (NQO1), with no effect on cytochrome P450 (CYP) 1A1 activity. Isobologram graphs revealed synergy of NQO1 induction for a combination of hGSL 9 and quercetin. These findings suggest that defatted camelina seed meal should be evaluated for anticancer activity, similar to broccoli and other Brassicaceae family members. Interestingly, synergy of NQO1 induction was also seen for physiologically relevant doses of sulforaphane (SF) and quercetin, two key bioactives present in broccoli. This suggests that SF within broccoli may be more potent than purified SF
Utilization of Quercetin as an Oviposition Stimulant by Lab-Cultured Coleomegilla maculata in the Presence of Conspecifics and a Tissue Substrate
Background: The discovery of natural products to improve the reproductive performance of mass-reared predators is an important aim for successful augmentative biological control. We tested the hypothesis that quercetin (a bioflavonoid) stimulates oviposition by the ladybird beetle Coleomegillamaculata in the presence of conspecifics and a tissue substrate. Methods: We conducted bioassays in solitary cages (housing one female) and communal cages (housing 10 females) to estimate daily oviposition site preferences, egg production in response to quercetin in the presence or absence of a tissue paper substrate, and female “resting” positions. Results: Females preferentially oviposited within 1–2 cm of quercetin powder, held in a tiny dish, at the base of cages. When given a choice, females oviposited in the dish with quercetin over a tissue paper substrate. In one of two experiments, they produced more egg clutches, regardless of oviposition site, when the quercetin and tissue were in close juxtaposition. Females “rested” on the tissue in the presence or absence of quercetin. Conclusion: This study provides evidence that quercetin can be utilized as an oviposition stimulant by C. maculata in a rearing system. Future research should determine if quercetin stimulates oviposition in other ladybird beetle species
Response of sorghum stalk pathogens to \u3ci\u3ebrown midrib\u3c/i\u3e plants and soluble phenolic extracts from near isogenic lines
Sorghum [Sorghum bicolor (L.) Moench] has drawn attention as potential feedstock for lignocellulosic biofuels production, and reducing lignin is one way to increase conversion efficiency. Little research has been previously conducted to assess the response of reduced lignin sorghum lines to the Fusarium stalk rot pathogens Fusarium verticillioides and Fusarium proliferatum and the charcoal rot pathogen, Macrophomina phaseolina. Loss of function mutations in either the Brown midrib (Bmr) 6 or 12 gene that both encode a monolignol biosynthetic enzyme in the pathway that produces subunits of the lignin polymer, results in reduced lignin content. Near-isogenic bmr6, bmr12, and bmr6 bmr12 lines had previously been developed, which were shown to have significantly reduced lignin content and increased levels of soluble phenolics. In the current study, these lines in two backgrounds were shown to not be more susceptible to F. verticillioides, F. proliferatum and M. phaseolina inoculations, and some bmr lines exhibited increased resistance to F. proliferatum and M. phaseolina, compared to wild-type lines. When the Fusarium stalk rot pathogen, Fusarium thapsinum, was grown on methanol soluble stalk extracts from bmr6 and wild-type plants, it grew significantly faster on medium with bmr6 extract than on wild-type extract or controls. This result suggested that factors other than soluble phenolics from the extract, such as cell wall bound phenolics or inducible defense compounds, contributed to increased resistance observed in bmr6 plants