• High-light leaves of the evergreen herb Galax urceolata exhibit a striking color change from green to red during winter months due anthocyanin synthesis in outermost mesophyll cells. Here we investigate three possible functions this change. To test hypothesis that anthocyanins function as light attenuators, maximum photosystem II efficiency (Fv/Fm) and was measured after exposure wavelengths either strongly or poorly absorbed by anthocyanin. determine whether elevate radical-scavenging...

Juvenile leaves in high-light environments commonly appear red as a result of anthocyanin pigments, which play photoprotective role during light-sensitive ontogenetic stages. The loss leaf development presumably corresponds to decreased need for photoprotection, photosynthetic maturation allows utilize higher light intensities. However, the relationship between and decline has yet be quantitatively described. In this study, concentration was measured against photopigment content, lamina...

• Red-pigmented leaf margins are common, but their functional significance is unknown. We hypothesized that red reduce herbivory by signalling to herbivorous insects the presence of increased chemical defences. Leaves were collected from a natural population Pseudowintera colorata. Margin size, damage, anthocyanin content and concentrations polygodial, sesquiterpene dialdehyde with antifeedant properties, quantified. Feeding trials involving larvae Ctenopseustis obliquana, generalist...

Although anthocyanin coloration in lower (abaxial) leaf cells has been documented for numerous species, the functional significance of this character not comprehensively investigated according to habitat or orientation. Here, we demonstrate that abaxial may function as a photoprotectant, similarly its purported role upper (adaxial) cells, leaves vulnerable high irradiance incident on surfaces. Spectral scans were derived Galax urceolata with following phenotypes: adaxial only, and...

Leaves of many evergreen species turn red when exposed to high sunlight during winter due production photoprotective anthocyanin pigments, while leaves other species, lacking anthocyanin, remain green. Why some synthesise pigments others do not is currently unknown. Furthermore, the relative photosynthetic performance anthocyanic (red) and acyanic (green) evergreens has yet be described. Here we present seasonal ecophysiological data for five green broadleaf species. We hypothesise that...

Leaves of many evergreen angiosperm species turn red under high light during winter due to the production anthocyanin pigments, while leaves other remain green. There is currently no explanation for why some exhibit reddening others do not. Conditions associated with low leaf water potentials (Ψ) have been shown induce in plant species. Because differ susceptibility stress winter, it hypothesized that which undergo colour change correspond those experience/tolerate most severe daily declines...

Leaves of many angiosperm evergreen species change colour from green to red during winter, corresponding with the synthesis anthocyanin pigments. The ecophysiological function winter (if any), and why it occurs in some not others, are yet understood. It was hypothesized that anthocyanins play a compensatory photoprotective role limited capacity for energy dissipation. Seasonal xanthophyll pigment content, chlorophyll fluorescence, leaf nitrogen, low molecular weight antioxidants (LMWA) five...

Observations and models indicate that human activity is altering cloud patterns on a global scale. Clouds impact incident visible infrared radiation during both day night, driving daily seasonal variability in plant temperatures—a fundamental driver of all physiological processes. To understand the impacts changing essential plant-based processes such as carbon sequestration food production, changes local regimes must be linked, via ecophysiology, with affected systems. This review provides...

A red/purple coloration of lower (abaxial) leaf surfaces is commonly observed in deeply-shaded understorey plants, especially the tropics. However, functional significance red abaxial coloration, including its role photosynthetic adaptation, remains unclear. The objective this study was to test back-scatter hypothesis for which posits that pigments internally reflect/scatter light transmitted by upper surface back into mesophyll, thereby enhancing photon capture light-limited environments....

Seedling establishment is an important factor dictating the altitudinal limits of treeline species. Factors which affect seedling mortality and survival, however, have yet to be fully characterized, especially for deciduous Here we describe microsite characteristics successfully established Betula litwinowii seedlings at alpine-treeline ecotone. Possible harmful effects sky exposure on physiology (i.e. photoinhibition photosynthesis) were also examined, as well possible facilitative...

Photosynthetic adaptation in terrestrial vascular plants involves a complex interaction of components that extend across broad structural and spatial hierarchy, often functioning concert with one another at multiple scales. Thus, understanding the evolutionary mechanisms leading to these adaptations requires evaluation entire spectrum plant form from chloroplast landscape. Adaptive traits this structural/spatial hierarchy can emerge any level then feed-back or feed-forward cause adaptive...

Background and AimsRed or purple coloration of leaf margins is common in angiosperms, found approx. 25 % New Zealand Veronica species. However, the functional significance margin unknown. We hypothesized that anthocyanins correspond with increased phenolic content and/or entire, signalling low palatability quality to edge-feeding insects.

Plants growing in high-light environments during winter often exhibit leaf reddening due to synthesis of anthocyanin pigments, which are thought alleviate photooxidative stress associated with low-temperature photoinhibition through light attenuation and/or antioxidant activity. Seasonal can be further exacerbated by a limited photosynthetic capacity, such as nitrogen-deficiency. In the present study, we test following hypotheses using three populations semi-evergreen vine Lonicera japonica:...

Response-validated multiple-choice assessments are used in college courses to assess student learning gains. The ability of a test accurately reflect gains is highly dependent on the students' effort. Within our institution, lackluster effort common response-validated concept that not included as portion semester grade but inform curricular changes. Thus, we set out determine whether increasing testing stakes by assigning performance had an effect score and self-reported Test Scientific...