Gelatinous fibers develop asymmetrically to support bends and coils in common bean vines (Phaseolus vulgaris).

Premise: Gelatinous (G)-fibers are specialized fibers that generate tensile force to bend and straighten many plant organs; this phenomenon has been intensively studied in tension wood of trees. Previous work has shown that G-fibers are common within the stems of twining vines, but we lack the spatiotemporal developmental data required to determine whether, or how, G-fibers contribute to the movement and/or stabilization of twining tissues.

Methods: We employed multiple histochemical approaches to characterize the formation and cell wall architecture of G-fibers in twining and shrub phenotypes of common bean across a developmental time series.

Mind the leaf anatomy while taking ground truth with portable chlorophyll meters.

A wide range of portable chlorophyll meters are increasingly being used to measure leaf chlorophyll content as an indicator of plant performance, providing reference data for remote sensing studies. We tested the effect of leaf anatomy on the relationship between optical assessments of chlorophyll (Chl) against biochemically determined Chl content as a reference. Optical Chl assessments included measurements taken by four chlorophyll meters: three transmittance-based (SPAD-502, Dualex-4 Scientific, and MultispeQ 2.

Leaf Functional Traits in Relation to Species Composition in an Arctic-Alpine Tundra Grassland.

The relict arctic-alpine tundra provides a natural laboratory to study the potential impacts of climate change and anthropogenic disturbance on tundra vegetation. The -dominated relict tundra grasslands in the Krkonoše Mountains have experienced shifting species dynamics over the past few decades. Changes in species cover of the four competing grasses-, , , and -were successfully detected using orthophotos.

Regulation of Phenolic Compound Production by Light Varying in Spectral Quality and Total Irradiance.

Photosynthetically active radiation (PAR) is an important environmental cue inducing the production of many secondary metabolites involved in plant oxidative stress avoidance and tolerance. To examine the complex role of PAR irradiance and specific spectral components on the accumulation of phenolic compounds (PheCs), we acclimated spring barley () to different spectral qualities (white, blue, green, red) at three irradiances (100, 200, 400 µmol m s). We confirmed that blue light irradiance is essential for the accumulation of PheCs in secondary barley leaves (in UV-lacking conditions), which underpins the importance of photoreceptor signals (especially cryptochrome).

Barley Genotypes Vary in Stomatal Responsiveness to Light and CO Conditions.

Changes in stomatal conductance and density allow plants to acclimate to changing environmental conditions. In the present paper, the influence of atmospheric CO concentration and light intensity on stomata were investigated for two barley genotypes-Barke and Bojos, differing in their sensitivity to oxidative stress and phenolic acid profiles. A novel approach for stomatal density analysis was used-a pair of convolution neural networks were developed to automatically identify and count stomata on epidermal micrographs.

Light and CO Modulate the Accumulation and Localization of Phenolic Compounds in Barley Leaves.

Barley () accumulates phenolic compounds (PhCs), which play a key role in plant defense against environmental stressors as antioxidants or UV screening compounds. The influence of light and atmospheric CO concentration ([CO]) on the accumulation and localization of PhCs in barley leaves was examined for two varieties with different tolerances to oxidative stress. PhC localization was visualized in vivo using fluorescence microscopy.