Photosynthetic acclimation to high light conditions in mature leaves of Coffea arabica L.: role of xanthophylls, quenching mechanisms and nitrogen nutrition

摘要: Young coffee plants (Coffea arabica L. cv. Catuai), originally from a shaded habitat, were separated in three groups to be grown under different levels of N fertilization: 0.3 mmol supplements given the soil every 7 days (high treatment, 2N), 15 (medium 1N) and 45 (low 0N). These later exposed high sunlight irradiance (noon PPFD up 1500 µmol m–2 s–1 ) for period 12 or days. Among others, values electron trans-port capacity, maximum carboxylation activity, photosynthetic capacity (Amax) several fluorescence parameters (Fv/Fm, Fv´/Fm´, qP, pe) first showed reduction (until 4th–7th day) all treatments, followed by an N-dependent recovery. The 2N less affected few and, at end stress period, better recovery most studied highest increase saturating net photosynthesis A max . present work shows that ability acclimate displayed mature leaves was accompanied energy dis-sipation mechanisms. include ‘high energy’ quenching mostly, presence higher contents some xanthophylls (zeaxanthin lutein) carotenes, which helped decrease energetic overcharge photosystems. Pigment changes suggest can promote specific mechanisms acclimation others than those might expected preferential partition element into components.