Mapping Grape Berry Photosynthesis by Chlorophyll Fluorescence Imaging: The Effect of Saturating Pulse Intensity in Different Tissues

Abstract

Grape berry development and ripening depends mainly on imported photosynthates from leaves, however, fruit photosynthesis may also contribute to the carbon economy of the fruit. In this study pulse amplitude modulated chlorophyll fluorescence imaging (imaging-PAM) was used to assess photosynthetic properties of tissues of green grape berries. In particular, the effect of the saturation pulse (SP) intensity was investigated. A clear tissue-specific distribution pattern of photosynthetic competence was observed. The exocarp revealed the highest photosynthetic capacity and the lowest susceptibility to photoinhibition, and the mesocarp exhibited very low fluorescence signals and photochemical competence. Remarkably, the seed outer integument revealed a photosynthetic ability similar to that of the exocarp. At a SP intensity of 5000 μmol m(-2) s(-1) several photochemical parameters were decreased, including maximum fluorescence in dark-adapted (F(m)) and light-adapted (F'(m)) samples and effective quantum yield of PSII (Φ(II)), but the inner tissues were susceptible to a SP intensity as low as 3200 μmol m(-2) s(-1) under light-adapted conditions, indicating a photoinhibitory interaction between SP and actinic light intensities and repetitive exposure to SP. These results open the way to further studies concerning the involvement of tissue-specific photosynthesis in the highly compartmentalized production and accumulation of organic compounds during grape berry development.

Potassium in the Grape (Vitis vinifera L.) Berry: Transport and Function

“…Grape berries also harbor stomata but at a much lower frequency than the leaves, and as the fruit grows their frequency declines even further and they evolve into non-functional lenticels occluded by wax ( Blanke, 1986 ; Rogiers et al, 2004 ). Nonetheless, early in development, stomata appear to be functional ( Blanke and Leyhe, 1987 ; Breia et al, 2013 ) and it was estimated that fruit photosynthesis supplies 10% of the carbon required for fruit development ( Ollat and Gaudillère, 2000 ). The grapevine Shaker channel VvSIRK (stomatal inward rectifying K + channel) identified by Pratelli et al (2002) has a promotor that is expressed in active guard cells.…”

Effect of varying NaCl doses on flavonoid production in suspension cells of Ginkgo biloba: relationship to chlorophyll fluorescence, ion homeostasis, antioxidant system and ultrastructure

“…Chlorophyll fluorescence measurements were performed according to the method of Breia et al (2013) and Osorio et al (2013) using a chlorophyll fluorescence imager (CF Imager, Technologica, UK). To determine the minimum (F o , dark fluorescence) and maximum (F m ) fluorescence, a 5 mm thick aliquot of suspension cells was placed on black paper maintained in the dark for 30 min before measuring the chlorophyll fluorescence.…”

Crop management impacts the efficiency of quantitative trait loci (QTL) detection and use: case study of fruit load×QTL interactions

“…Fruit photosynthesis may exceed respiratory CO 2 release during distinct developmental phases (e.g. Hiratsuka et al, 2012;Breia et al, 2013), and thus might contribute (marginally) to fruit growth (Marcelis & Baan Hofman-Eijer, 1995;Obiadalla-Ali et al, 2004) additional to more complex roles in fruit developmental processes (Lytovchenko et al, 2011). Photosynthetic assimilate production in leaves and fruit is carefully tuned to local metabolite concentrations, and it is therefore not surprising to find fruit photosynthesisrelated gene expression to be affected by fruit load (Table 2).…”