Leaf anatomy affects optical properties and enhances photosynthetic performance under oblique light.

Photosynthesis under oblique illumination has not been studied extensively despite being the prevailing light regime under natural conditions. We studied how photosynthetic rate (An) is affected by the geometrical arrangement between leaf lamina and light rays, in conjunction with key anatomical features; studied plant species selected based on the absence (homobaric) or the occurrence of bundle sheath extensions (BSEs; heterobaric) and the arrangement of these structures, that is, parallel (monocots) or reticulated (dicots). The direction of light ray affected leaf absorptance (Abs) and An; both were maximal when the angle of incidence of light on leaf surface (polar angle, θ) was 90°.

Acclimation of the Grapevine L. cv. Assyrtiko to Water Deficit: Coordination of Structural and Functional Leaf Traits and the Dynamic of Calcium Oxalate Crystals.

Grapevine leaves contain abundant CaO crystals located either within the mesophyll in the form of raphides, or in the bundle sheaths as druses. CaO crystals function as internal carbon pools providing CO for a baseline level of photosynthesis, named "alarm photosynthesis", despite closed stomata; thus, preventing the photoinhibition and the oxidative risk due to carbon starvation under adverse conditions. Structural and functional leaf traits of acclimated grapevine plants ( L.

Dynamic changes in cell wall composition of mature sunflower leaves under distinct water regimes affect photosynthesis.

In previous work, we identified that exposure to limited water availability induced changes in cell wall composition of mature Helianthus annuus L. leaves that affected mesophyll conductance to CO2 diffusion (gm). However, it is unclear on which timescale these changes in cell wall composition occurred.

The Optical Properties of Leaf Structural Elements and Their Contribution to Photosynthetic Performance and Photoprotection.

Leaves have evolved to effectively harvest light, and, in parallel, to balance photosynthetic CO assimilation with water losses. At times, leaves must operate under light limiting conditions while at other instances (temporally distant or even within seconds), the same leaves must modulate light capture to avoid photoinhibition and achieve a uniform internal light gradient. The light-harvesting capacity and the photosynthetic performance of a given leaf are both determined by the organization and the properties of its structural elements, with some of these having evolved as adaptations to stressful environments.

Decomposition of Calcium Oxalate Crystals in under CO Limiting Conditions.

Calcium oxalate (CaOx) crystals are widespread among plant species. Their functions are not yet completely understood; however, they can provide tolerance against multiple environmental stress factors. Recent evidence suggested that CaOx crystals function as carbon reservoirs since its decomposition provides CO that may be used as carbon source for photosynthesis.