There is a strong natural light gradient from the top to the bottom in plant canopies and along gap-understorey continua. Leaf structure and photosynthetic capacities change close to proportionally along these gradients, leading to maximisation of whole canopy photosynthesis. However, other environmental factors also vary within the light gradients in a correlative manner. Specifically, the leaves exposed to higher irradiance suffer from more severe heat, water, and photoinhibition stresses. Research in tree canopies and across gap-understorey gradients demonstrates that plants have a large potential to acclimate to interacting environmental limitations. The optimum temperature for photosynthetic electron transport increases with increasing growth irradiance in the canopy, improving the resistance of photosynthetic apparatus to heat stress. Stomatal constraints on photosynthesis are also larger at higher irradiance because the leaves at greater evaporative demands regulate water use more efficiently. Furthermore, upper canopy leaves are more rigid and have lower leaf osmotic potentials to improve water extraction from drying soil. The current review highlights that such an array of complex interactions significantly modifies the potential and realized whole canopy photosynthetic productivity, but also that the interactive effects cannot be simply predicted as composites of additive partial environmental stresses. We hypothesize that plant photosynthetic capacities deviate from the theoretical optimum values because of the interacting stresses in plant canopies and evolutionary trade-offs between leaf- and canopy-level plastic adjustments in light capture and use

Niinemets, Ü.; Valladares, F. (2004). Photosynthetic acclimation to simultaneous and interacting environmental stresses along natural light gradients: optimality and constraints. PLANT BIOLOGY, 6 (3): 254-268. doi: 10.1055/s-2004-817881 handle: http://hdl.handle.net/10449/21633

Photosynthetic acclimation to simultaneous and interacting environmental stresses along natural light gradients: optimality and constraints

Niinemets, Ülo;
2004-01-01

Abstract

There is a strong natural light gradient from the top to the bottom in plant canopies and along gap-understorey continua. Leaf structure and photosynthetic capacities change close to proportionally along these gradients, leading to maximisation of whole canopy photosynthesis. However, other environmental factors also vary within the light gradients in a correlative manner. Specifically, the leaves exposed to higher irradiance suffer from more severe heat, water, and photoinhibition stresses. Research in tree canopies and across gap-understorey gradients demonstrates that plants have a large potential to acclimate to interacting environmental limitations. The optimum temperature for photosynthetic electron transport increases with increasing growth irradiance in the canopy, improving the resistance of photosynthetic apparatus to heat stress. Stomatal constraints on photosynthesis are also larger at higher irradiance because the leaves at greater evaporative demands regulate water use more efficiently. Furthermore, upper canopy leaves are more rigid and have lower leaf osmotic potentials to improve water extraction from drying soil. The current review highlights that such an array of complex interactions significantly modifies the potential and realized whole canopy photosynthetic productivity, but also that the interactive effects cannot be simply predicted as composites of additive partial environmental stresses. We hypothesize that plant photosynthetic capacities deviate from the theoretical optimum values because of the interacting stresses in plant canopies and evolutionary trade-offs between leaf- and canopy-level plastic adjustments in light capture and use
Humidity
Leaf temperature
Light availability
Photoinhibition
Photosynthesis acclimation
Plasticity
Stress
Vapour pressure deficit
Settore BIO/07 - ECOLOGIA
2004
Niinemets, Ü.; Valladares, F. (2004). Photosynthetic acclimation to simultaneous and interacting environmental stresses along natural light gradients: optimality and constraints. PLANT BIOLOGY, 6 (3): 254-268. doi: 10.1055/s-2004-817881 handle: http://hdl.handle.net/10449/21633
File in questo prodotto:
File Dimensione Formato  
2004 PB Niinemets et al.pdf

solo utenti autorizzati

Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 383.21 kB
Formato Adobe PDF
383.21 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10449/21633
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 203
  • ???jsp.display-item.citation.isi??? 189
social impact