Differences in defence strategies against herbivores between two pioneer tree species: Alnus glutinous (L.) Gaertn. and Betula pendular Roth (original) (raw)
Related papers
Polish Journal of Ecology
The different defence strategies of trees against herbivores are very often connected with succession status, leaf life span and the level of secondary metabolites. We examined the effect of simulated leaf grazing on the differences in the leaf life span and defence chemistry of two pioneer tree species that belongs to the same family (Betulaceae), black alder (Alnus glutinosa (L.) Gaertn.) and European white birch (Betula pen-dula Roth.). At the beginning of the growing season , mature leaves were perforated using a paper punch. The holes removed about 10% of the leaf surface. Each species was represented by six trees – one branch was chosen for perforation and one branch as a control. All leaves were counted every week until their abscission. Additional damages caused by grazing insects were also noted. Undamaged birch leaves were held much longer than those of alder. The average difference in half leaf life span between control and perforated leaves was 28 days in birch and 6 day...
Annals of botany, 2004
Betula ermanii, B. maximowicziana and B. platyphylla var. japonica have heterophyllous leaves (i.e. early leaves and late leaves) and are typical pioneer species in northern Japan. Chemical and physical defences against herbivores in early and late leaves of these species were studied. Two-year-old seedlings were grown under full sunlight in a single growing season. Three-week-old leaves of each seedling were harvested three times (May, July and October). Total phenolics and condensed tannin content were determined for chemical defence and leaf toughness and trichome density were assessed for physical defence. Defoliation of early leaves in May was also performed to study the contribution of early leaves to subsequent growth. Chemical and physical defences were greater in early than late leaves in B. platyphylla and B. ermanii, whereas the reverse was true in B. maximowicziana. In contrast to its weak chemical defences, the trichome density in B. maximowicziana was very high. In B. ...
Induced Defense in Japanese White Birch Seedlings against Insect Herbivores
Eurasian Journal of …, 2010
Plants defend themselves against herbivores, pests and abiotic stresses. Although some defense traits in plants are constitutive, some are switched on, or increased, only when the plants have suffered from stresses (i.e. induced defense). Growth (i.e. lignin) and the synthesis of most defensive compounds in broad-leaved trees derive from phenylalanine. If, therefore, plants allocate photosynthates mainly to defense, these resources would not be available for growth (lignin synthesis). In this study, we examined the defense induced against grazing by the gypsy moth (Lymantria dispar) in seedlings of the white birch (Betula platyphylla var. japonica) grown under two nitrogen levels. We exposed white birch leaves to be grazed by gypsy moths, and we cut the leaves with scissors in early spring. The defenses of white birch seedlings, especially the amount of total phenolics and condensed tannin, were found to be induced by cutting, to extents that were influenced by the soil nitrogen condition. Induced defense of white birch seedlings may depend on the heterophyllous type of shoot development.
Plant Defense Characteristics and Hypotheses in Birch Species
Eurasian Journal of Forest Research, 2010
Birches employ defense when under pressure, either biotic or abiotic or both. They have at least three types of defense against herbivores, involving physical, chemical and phenological strategies, whether the defense is constitutive or induced. Leaves usually use both types of defense, whereas woody parts (stems, branches, or twigs) deploy mostly chemical defense. Other studies scarcely differentiate between proposed plant defense models such as CNBH and GDBH, and the defensive responses of birches, since there is a large variation in defensive responses. The evidence supports neither the carbon-nutrient balance (CNB) nor the growth-differentiation balance (GDB) hypothesis in birch defense, indicating that defense is genetically regulated. In our review, we may conclude that birches deploy their various defenses in parallel, since these derive from distinct chemical and physical mechanisms.
Journal of Chemical Ecology, 2000
Insect damage changes plant physiology and chemistry, and such changes may influence the performance of herbivores. We introduced larvae of the autumnal moth (Epirrita autumnata Borkh.) on individual branches of its main host plant, mountain birch (Betula pubescens ssp. czerepanovii (Orlova) Hämet-Ahti) to examine rapid-induced plant responses, which may affect subsequent larval development. We measured systemic responses to herbivory by analyzing chemistry, photosynthesis, and leaf growth, as well as effects on larval growth and feeding, in undamaged branches of damaged and control trees. Larvae reared on leaves from intact branches of the herbivore-damaged trees grew faster than those reared on leaves of control trees, indicating systemicinduced susceptibility. Herbivore damage did not lead to systemic changes in levels of primary nutrients or phenolic compounds. The analyses of photosynthetic activity and individual hydrolyzable tannins revealed a reversal of leaf physiology-herbivore defense patterns. On control trees, consumption by E. autumnata larvae was positively correlated with photosynthetic activity; on damaged trees, this correlation was reversed, with consumption being negatively correlated with photosynthetic activity. A similar pattern was found in Plenum Publishing Corporation 304 LEMPA ET AL. the relationship between monogalloylglucose, the most abundant hydrolyzable tannin of mountain birch, and leaf consumption. Among the control trees, consumption was positively correlated with concentrations of monogalloylglucose, whereas among herbivore-damaged trees, this correlation was reversed and became negative. Our results suggest that herbivore performance is related to both concentrations of phenolic compounds and photosynthetic activity in leaves. This linkage between herbivore performance, leaf chemistry, and physiology was sensitive to induced plant responses caused by slight herbivore damage.
Trees, 2013
Plants respond to feeding injury by chewing insects by inducing both a general response to mechanical wounding and a specific response to herbivore-associated elicitors. In both cases, plant response involves complex biochemical and physiological changes. We compared chemical and physical responses of paper birch (B. papyrifera) and European white birch (B. pendula) stems to mechanical injury to determine if aspects of their wound response correspond with the much higher resistance of paper birch to bronze birch borer (Agrilus anxius). We also characterized stem responses to mechanical wounding plus bronze birch borer larval homogenate to determine if larval cues elicited a more specific response than mechanical wounding alone. In both species, wounding decreased concentrations of individual phenolics, total phenolics, and condensed tannins, perhaps because they were diverted to lignin biosynthesis, the concentration of which increased. Nitrogen concentration increased in both species while free amino acid concentrations declined, perhaps because they were utilized to synthesize proteins. Application of larval homogenate did not elicit a response different from that induced by mechanical injury. When comparing wound responses of the two birch species, phenolic profiles differed most conspicuously. However, multivariate analyses revealed no differences between constitutive and wound-induced phenolic profiles within each species, and the rate of wound periderm growth was equivalent between species. These results suggest that components of the wound response we measured may not contribute to interspecific variation in bronze birch borer resistance of paper birch and European white birch.
2001
We investigated the role of phenolic and phenolic-related traits of the leaves of mountain birch (Betula pubescens ssp. czerepanovii) as determinants of their suitability for the growth of larvae of the geometrid Epirrita autumnata. As parameters of leaf suitability, we determined the contents of total phenolics, gallotannins, soluble and cell-wall-bound proanthocyanidins (PAS and PAB, respectively), lignin, protein precipitation capacity of tannins (PPC), and leaf toughness.
Constitutive and induced chemical defenses as a function of leaf age in Quercus rubra (Red Oak)
2013
Limited resource availability results in a trade-off between growth and defense in plants. Natural selection has favored strategies in plants that efficiently allocate resources to achieve a high net benefit to cost ratio. As integral parts of their defense strategy, plants have evolved not only to have constitutive chemical defenses, but also the ability to induce defenses. Constitutive levels and inducibility may vary among leaves within a tree due to varying net benefit to cost ratio of defending different leaves. In this study, we examined the effect of leaf age on constitutive levels and inducibility of phenolics following a mechanical attack in Quercus rubra (Red Oak). Young leaves possessed higher constitutive levels of phenolics compared to older leaves on the same trees, which were sampled eight days later. Inducibility did not differ between leaf age categories. Constitutive phenolics, but not inducibility, was negatively correlated with leaf nitrogen and positively correlated with leaf C:N ratio. Our results suggests that natural selection may have favored the evolution of spring-feeding herbivores in part because of the inability of early season leaves to induce higher levels of chemical defenses.
Ranking of individual mountain birch trees in terms of leaf chemistry: seasonal and annual variation
Chemoecology, 2004
The quality of tree leaves as food for herbivores changes rapidly especially during the spring and early summer. However, whether the quality of an individual tree in relation to other trees in the population changes during the growing season and between years is less clear. We studied the seasonal and annual stability of chemical and physical traits affecting leaf quality for herbivores. Rankings of trees in terms of the contents of two major groups of phenolics in their leaves, hydrolyzable tannins and proanthocyanidins (condensed tannins), were very stable from the early spring to the end of the growing season. There were also strong positive within-season correlations in the levels of some other groups of phenolics in the leaves (kaempferol glycosides, myricetin glycosides and p-coumaroylquinic acid derivatives). The contents of individual sugars and the sum content of protein-bound amino acids showed patterns of seasonal consistency in mature leaves, but not in young developing leaves. The seasonal correlations in leaf water content and toughness were also strongest in mature leaves. The correlations between two years at corresponding times of the growing season were strongly positive for the major groups of phenolics throughout the season, but were more variable for the contents of proteins and some sugars. Leaf toughness and water content showed strong positive correlations in mature leaves. Despite the consistency of tree ranking in terms of leaf phenolics, the relative resistance status of trees may, however, change during a growing season because there was a negative correlation between the content of hydrolyzable tannins (early-season resistance compounds) in leaves early in the season and the content of proanthocyanidins (late-season resistance compounds) late in the season, and vice versa. Thus, assuming that phenolics affect herbivore preference and performance, different plants may suffer damage at different times of the growing season, and the overall variation between trees in the fitness consequences may be low. In addition, the adaptation of herbivorous insects to mountain birch foliage in general, as well as to specific tree individuals, may be constrained by variation in the relative resistance status of the trees.
Wound-induced oxidative responses in mountain birch leaves
Annals of botany, 2006
The aim of the study was to examine oxidative responses in subarctic mountain birch, Betula pubescens subsp. czerepanovii, induced by herbivory and manual wounding. Herbivory-induced changes in polyphenoloxidase, peroxidase and catalase activities in birch leaves were determined. A cytochemical dye, 3,3-diaminobenzidine, was used for the in situ and in vivo detection of H2O2 accumulation as a response to herbivory and wounding. To localize peroxidase activity in leaves, 10 mm H2O2 was applied to the dye reagent. Feeding by autumnal moth, Epirrita autumnata, larvae caused an induction in polyphenoloxidase and peroxidase activities within 24 h, and a concomitant decrease in the activity of antioxidative catalases in wounded leaves. Wounding also induced H2O2 accumulation, which may have both direct and indirect defensive properties against herbivores. Wound sites and guard cells showed a high level of peroxidase activity, which may efficiently restrict invasion by micro-organisms. Bir...