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1.
Tree resistance to Lymantria dispar caterpillars: importance and limitations of foliar tannin composition 总被引:1,自引:0,他引:1
Raymond V. Barbehenn Adam Jaros Grace Lee Cara Mozola Quentin Weir Juha-Pekka Salminen 《Oecologia》2009,159(4):777-788
The ability of foliar tannins to increase plant resistance to herbivores is potentially determined by the composition of the
tannins; hydrolyzable tannins are much more active as prooxidants in the guts of caterpillars than are condensed tannins.
By manipulating the tannin compositions of two contrasting tree species, this work examined: (1) whether increased levels
of hydrolyzable tannins increase the resistance of red oak (Quercus rubra L.), a tree with low resistance that produces mainly condensed tannins, and (2) whether increased levels of condensed tannins
decrease the resistance of sugar maple (Acer saccharum Marsh.), a tree with relatively high resistance that produces high levels of hydrolyzable tannins. As expected, when Lymantria dispar L. caterpillars ingested oak leaves coated with hydrolyzable tannins, levels of hydrolyzable tannin oxidation increased in
their midgut contents. However, increased tannin oxidation had no significant impact on oxidative stress in the surrounding
midgut tissues. Although growth efficiencies were decreased by hydrolyzable tannins, growth rates remained unchanged, suggesting
that additional hydrolyzable tannins are not sufficient to increase the resistance of oak. In larvae on condensed tannin-coated
maple, no antioxidant effects were observed in the midgut, and levels of tannin oxidation remained high. Consequently, neither
oxidative stress in midgut tissues nor larval performance were significantly affected by high levels of condensed tannins.
Post hoc comparisons of physiological mechanisms related to tree resistance revealed that maple produced not only higher levels
of oxidative stress in the midgut lumen and midgut tissues of L. dispar, but also decreased protein utilization efficiency compared with oak. Our results suggest that high levels of hydrolyzable
tannins are important for producing oxidative stress, but increased tree resistance to caterpillars may require additional
factors, such as those that produce nutritional stress. 相似文献
2.
Mitchell L. Wise Hassan K. Sreenath Ronald W. Skadsen Heidi F. Kaeppler 《Plant Cell, Tissue and Organ Culture》2009,97(1):81-90
Oats produce a group of secondary metabolites termed avenanthramides (avn). These compounds are biosynthesized through the
action of the enzyme hydroxycinnamoyl CoA: hydroxyanthranilate N-hydroxycinnamoyl transferase (HHT) which catalyzes the condensation of one of several cinnamate CoA thioesters with the amine
functionality of anthranilic acid, 4-hydroxy- or 5-hydroxy-anthranilic acid. In oat leaf tissue the biosynthesis of avenanthramides
appears to result from elicitation by fungal infection. Here we demonstrate the biosynthesis of several avenanthramides in
suspension cultures of oat apical meristem callus tissue. This phenomenon appears as a generalized pathogen response, evidenced
by the production of PR-1 mRNA, in response to elicitation with chitin (poly-N-acetyl glucosamine). The suspension cultures also produce relatively large quantities of avnA and G in response to chitin
elicitation. Under certain culture conditions avnB and C are also produced as well as three additional metabolites tentatively
identified as avnH, O and R. These findings portend the utility of oat suspension culture as a tool for more detailed investigation
of the mechanisms triggering their biosynthesis as well as the factors dictating the particular types of avenanthramides biosynthesized. 相似文献
3.
The health-relevant functionality of Mucuna pruriens was improved by priming the seeds with elicitors of the pentose phosphate pathway (PPP) such as fish protein hydrolysates (FPHs), lactoferrin (LF) and oregano extract (OE) followed by dark germination. FPH elicited the highest phenolic content of 19 mg/g FW on day 1, which was 38% higher than control sprouts. OE enhanced Parkinson’s disease-relevant L-DOPA content by 33% on day 1 compared to control sprouts. Anti-diabetes-relevant α-amylase inhibition percent (AIP) and α-glucosidase inhibition percent (GIP) were high in the cotyledons and decreased following elicitation and sprouting. For potential anti-diabetic applications, low AIP and high GIP with moderate L-DOPA content on day 4 of dark germination could be optimal. Improved L-DOPA concentrations in a soluble phenolic and antioxidant-rich M. pruriens background on day 1 sprouts have potential for Parkinson’s disease management. 相似文献
4.
Daizy R. Batish K. Lavanya Harminder Pal Singh Ravinder Kumar Kohli 《Plant Growth Regulation》2007,51(2):119-128
The present study was conducted to investigate the effect of the residue of Chenopodium murale L. on growth, nodulation and macromolecule content of two legume crops, viz., Cicer arietinum L. (chickpea) and Pisum sativum L. (pea). A significant reduction in root and shoot length as well as dry matter accumulation occurred when both the legumes
were grown in the soil amended with 5, 10, 20 and 40 g residue kg−1 soil. In general, a gradual decline in growth was associated with an increasing amount of residues in the soil. There was
also a significant reduction in total chlorophyll content and the amounts of protein and carbohydrates (macromolecules) in
plants growing in the residue-amended soil. The nodulation was completely absent in chickpea and pea when the plants were
grown in the soil amended with 10 and 20 g residue kg−1 soil, respectively. At a lower rate of residue amendment (5 g kg−1 soil), a significant decline in nodule number and weight, and leghaemoglobin content was recorded. Root oxidizability, an
indirect measure of tissue viability and cellular respiration, was adversely affected in both the legumes under various treatments
of residue amendment. The observed growth reduction concomitant with increased proline accumulation indicated the presence
of some inhibitory compounds in the residue-amended soil. It was rich in phenolics identified as protocatechuic, ferulic,
p-coumaric and syringic acid with 12.8, 30.4, 20.2 and 33.6% relative content, respectively. The results suggest that the residue
of C. murale releases phenolic allelochemicals, which deleteriously affect the growth, nodulation and macromolecule content of chickpea
and pea. 相似文献
5.
Yanbao Lei Ke Chen Xiangrong Tian Helena Korpelainen Chunyang Li 《Trees - Structure and Function》2007,21(5):569-580
The cuttings of Populus cathayana were exposed to four different manganese (Mn) concentrations (0, 0.1, 0.5 and 1 mM) in a greenhouse to investigate the toxicity
of Mn and the detoxifying responses of woody plants. Two contrasting populations of P. cathayana, which were from wet and dry climate regions in western China, respectively, were examined in our study. The results showed
that high concentration of Mn caused significant decrease in shoot height, biomass accumulation, and leaf number and leaf
areas. Injuries to the anatomical features of leaves were also found as the reduced thickness of palisade and spongy parenchyma,
the decreased density in the conducting tissue and the collapse and split in the meristematic tissue in the central vein.
Moreover, Mn treatments caused the accumulation of hydrogen peroxide (H2O2), and then resulted in oxidative stress indicated by the oxidation of proteins and DNA. Many physiological responses were
employed to cope with the toxicity of Mn, including the increase in the contents of non-protein thiol (NP-SH), phytochelatins
(PCs) and phenolics compounds and the stimulated activities of guaiacol peroxidase (GPX) and polyphenol oxidase (PPO) for
the chelation of Mn and for the antioxidation of reactive oxygen species. The population from dry climate habitat showed a
lower leaf concentration of Mn, higher contents of the chelators, and higher activities of GPX and PPO than did the wet climate
population at the same Mn treatment, thereby possessing a superior Mn tolerance. In both populations, most of the Mn was accumulated
in the shoot, which is favorable regarding phytoremediation. 相似文献
6.
One sesquiterpene lactone – 9α-hydroxy-3-deoxyzaluzanin C, three benzopyrans: desmethoxyencecalin (6-acetyl-2,2-dimethylchromene), desacetylripariochromen B and 6-(1-hydroxyethyl)-2,2-dimethylchromene, one coumarin – scopoletin and two eugenol derivatives were isolated from the roots of Tolpis barbata (L.) Gaertn, hitherto unexamined species. In the extract from aerial parts of the plant, five known phenolic compounds, namely: esculin, esculetin, chlorogenic acid (5-CQA), luteolin 7-O-glucoside and 3,5-dicaffeoylquinic acid (3,5-DCQA) were identified as major constituents. Except for the two coumarins – scopoletin and esculetin, which were previously obtained from Tolpis webbii Sch.Bip. and T. proustii Pit., the isolated and identified compounds have not been previously reported as constituents of Tolpis spp. Though benzopyrans were found in numerous species of the Asteraceae, their occurrence in the tribe Cichorieae has not been demonstrated before. 相似文献
7.
应用15N同位素示踪技术,通过盆栽实验研究了香草醛和对羟基苯甲酸对杉木(Cunninghamia lanceolata)幼苗N素养分吸收、分配的影响,结果发现香草醛及其与对羟基苯甲酸的混合物(浓度比1∶1)明显抑制了杉木幼苗的生长和对15NO3-离子的吸收,10 mmol·L-1的香草醛使杉木幼苗根、茎、叶生物量分别下降了25.3%、13.5%、5.7%,15N吸收量分别减少了38.5%、48.1%、46.5%;10 mmol·L-1的混合物使杉木幼苗根、茎、叶生物量分别下降了33.5%、36.0%、21 相似文献
8.
Background
Based on the ethnomedicinal uses and the effective outcomes of natural products in various diseases, this study was designed to evaluate Isodon rugosus as possible remedy in oxidative stress, alzheimer’s and other neurodegenerative diseases. Acetylecholinestrase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of crude methanolic extract (Ir.Cr), resultant fractions (n-hexane (Ir.Hex), chloroform (Ir.Cf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq)), flavonoids (Ir.Flv) and crude saponins (Ir.Sp) of I. rugosus were investigated using Ellman’s spectrophotometric method. Antioxidant potential of I. rugosus was determined using DPPH, H2O2 and ABTS free radicals scavenging assays. Total phenolic and flavonoids contents of plant extracts were determined and expressed in mg GAE/g dry weight and mg RTE/g of dry sample respectively.Results
Among different fractions Ir.Flv and Ir.Cf exhibited highest inhibitory activity against AChE (87.44 ± 0.51, 83.73 ± 0.64%) and BChE (82.53 ± 0.71, 88.55 ± 0.77%) enzymes at 1 mg/ml with IC50 values of 45, 50 for AChE and 40, 70 μg/ml for BChE respectively. Activity of these fractions were comparable to galanthamine causing 96.00 ± 0.30 and 88.61 ± 0.43% inhibition of AChE and BChE at 1 mg/ml concentration with IC50 values of 20 and 47 μg/ml respectively. In antioxidant assays, Ir.Flv, Ir.Cf, and Ir.EtAc demonstrated highest radicals scavenging activities in DPPH and H2O2 assays which were comparable to ascorbic acid. Ir.Flv was found most potent with IC50 of 19 and 24 μg/ml against DPPH and H2O2 radicals respectively. Whereas antioxidant activates of plant samples against ABTS free radicals was moderate. Ir.Cf, Ir.EtAc and Ir.Cr showed high phenolic and flavonoid contents and concentrations of these compounds in different fractions correlated well to their antioxidant and anticholinestrase activities.Conclusion
It may be inferred from the current investigations that the Ir.Sp, Ir.Flv and various fractions of I. rugosus are good sources of anticholinesterase and antioxidant compounds. Different fractions can be subjected to activity guided isolation of bioactive compounds effective in neurological disorders. 相似文献9.
Summary The types and quantities of defense compounds found in plants occupying ecologically distinct habitats have received much theoretical and little empirical attention. Here we characterize the leaf phenolic chemistry of eight species in two genera of tropical rainforest shrubs; four species in each genus are typical of disturbed sites, and four are typical of mature forest understory. Two Miconia species growing in light gaps had significantly higher leaf tannin and total phenolic contents than congenors growing in the primary forest; this pattern was not found among the gap- and forest-adapted Piper species. Tannin patterns were not mirrored by leaf cinnamic acids. These results indicate that plant phylogeny must be considered when predicting plant defense investment. 相似文献
10.
S. E. Hartley 《Oecologia》1988,76(1):65-70
Summary 1. The leaves of Betula pendula Roth trees were damaged artificially, or by insect-grazing. Both induced an increase in phenolic levels in damaged leaves, larger in the case of insect attack.-2. Some of the damaged trees were sprayed with an inhibitor of phenolic biosynthesis, (aminoxy) acetic acid, which led to a reduction in phenolic levels in both undamaged and damaged leaves. Hence both the effects of damage per se and damage-induced changes in foliage phenolic levels on insect feeding preference could be examined using this technique.-3. Herbivore feeding preferences were assessed in the laboratory by comparing damaged and undamaged leaves, with or without phenolic inhibition, using caterpillars of a natural birch feeder, Apocheima pilosaria D. & S. (Lepidoptera: Geometridae) and a non-birch feeder, Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae). Neither species showed any significant preferences and appeared indifferent to damage, irrespective of whether the trees had their damage-induced phenolic synthesis blocked.-4. The implications of these results for induced defense theory are discussed. 相似文献