Sun-shade patterns of leaf carotenoid composition in 86 species of neotropical forest plants

Abstract

Abstract.A survey of photosynthetic pigments, including 86 species from 64 families, was conducted for leaves of neotropical vascular plants to study sun-shade patterns in carotenoid biosynthesis and occurrence of a-carotene (a-Car) and lutein epoxide (Lx). Under low light, leaves invested less in structural components and more in light harvesting, as manifested by low leaf dry mass per area (LMA) and enhanced mass-based accumulation of chlorophyll (Chl) and carotenoids, especially lutein and neoxanthin. Under high irradiance, LMA was greater and b-carotene (b-Car) and violaxanthin-cycle pool increased on a leaf area or Chl basis. The majority of plants contained a-Car in leaves, but the a-to b-Car ratio was always low in the sun, suggesting preference for b-Car in strong light. Shade and sun leaves had similar b,e-carotenoid contents per unit Chl, whereas sun leaves had more b,b-carotenoids than shade leaves. Accumulation of Lx in leaves was found to be widely distributed among taxa: >5 mmol mol Chl À1 in 20% of all species examined and >10 mmol mol Chl À1 in 10% of woody species. In Virola elongata (Benth.) Warb, having substantial Lx in both leaf types, the Lx cycle was operating on a daily basis although Lx restoration in the dark was delayed compared with violaxanthin restoration.

From ecophysiology to phenomics: some implications of photoprotection and shade–sun acclimation in situ for dynamics of thylakoids in vitro

“…(table 1). This distinctive pigment composition, arising from the co-occurrence of two xanthophyll cycles (the Lx-and V-cycles) that differ markedly in epoxidation kinetics, is now known to be quite widespread in plants [27][28][29]. Although in vivo deepoxidation of Lx is sometimes slower and requires higher light intensity than V, the de-epoxidation products L and A þ Z now are recognized to have two main functions: amplification of energy-dependent photoprotection and protection against photo-oxidation.…”

Generality of relationships between leaf pigment contents and spectral vegetation indices in Mallorca (Spain)

“…At the same time, they also participate in the dissipation of excess absorbed energy and quenching of chlorophyll excitations (Marin et al 2011). In shade conditions, the relative share of lutein increases, while at high-light availability, the pools of β-carotene and especially xanthophyll cycle pigments are increased (Niinemets et al 1998;Krause et al 2001;Demmig-Adams and Adams 2006;Matsubara et al 2009;Esteban et al 2015a, b). Hence, the change in leaf total carotenoid content or carotenoid to chlorophyll ratio can be modest during light acclimation corresponding to multiple contrasting adjustments in pigment composition (Hallik et al 2012).…”

Canopy conundrums: building on the Biosphere 2 experience to scale measurements of inner and outer canopy photoprotection from the leaf to the landscape

“…Recent surveys of woody plants (Esteban et al 2007;Matsubara et al 2008Matsubara et al , 2009 (Matsubara et al 2008) and of avocado in Eastern Australian orchards further confirmed this distinctive pigment composition of inner and outer canopy leaves in these species. However, it should be noted that some other Lx-rich species show little difference in [Lx] between inner and outer canopy leaves (Matsubara et al 2009).…”

“…However, it should be noted that some other Lx-rich species show little difference in [Lx] between inner and outer canopy leaves (Matsubara et al 2009).…”

“…and avocado is presumably a product of metabolic pathways and leaf environment (Matsubara et al 2003;García-Plazoala et al 2007;Esteban et al 2008). In Inga, avocado and other plants (Matsubara et al 2009) a 'leaky' zeaxanthin epoxidase (ZE) with some affinity for L, evidently catalyses the slow production of Lx from L in the dark. Evidently, Lx accumulates in deeply shaded inner canopy leaves because they are infrequently exposed to light strong enough to activate violaxanthin de-epoxidase (VDE) for conversion of Lx back to L. This enzyme has affinity for both V and Lx in vivo and is activated each day in the outer canopy (as evidenced by conversion of V to A + Z) where it maintains low levels of Lx.…”