Leaf and canopy photosynthesis of a chlorophyll deficient soybean mutant

Karolina Sakowska (1, 2, 3) , Giorgio Alberti (4, 5) , Lorenzo Genesio (6, 7) , Alessandro Peressotti (4) , Gemini Delle Vedove (4) , Damiano Gianelle (3, 7) , Roberto Colombo (8) , Mirco Rodeghiero (3) , Cinzia Panigada (8) , Radoslaw Juszczak (2) , Marco Celesti (8) , Micol Rossini (8) , Matthew Haworth (9) , Benjamin W. Campbell (10) , Jean-Philippe Mevy (11) , Loris Vescovo (3) , M. Pilar Cendrero‐mateo (12) , Uwe Rascher (12) , Franco Miglietta (6, 7, 13)

1 Universität Innsbruck [Innsbruck]
2 Department of Meteorology
3 Sustainable Agroecosystems and Bioresources Department
4 Department of Agricultural, Food, Environmental and Animal Sciences
5 Institute of Biometeorology
6 Institute of Biometeorology
7 FoxLab [Italia]
8 Department of Earth and Environmental Sciences [Milano]
9 Tree and Timber Institute
10 UMN - University of Minnesota [Twin Cities]
11 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
12 IBG - Institute of Bio- and Geosciences [Jülich]
13 IMéRA - Institute for Advanced Studies - Aix-Marseille University

The photosynthetic, optical and morphological characteristics of a chlorophyll-deficient (Chldeficient) “yellow” soybean mutant (MinnGold) were examined in comparison with two green varieties (MN0095 and Eiko). Despite the large difference in Chl content, similar leaf photosynthesis rates were maintained in the Chl-deficient mutant by offsetting the reduced absorption of red photons by a small increase in photochemical efficiency and lower non-photochemical quenching (NPQ). When grown in the field, at full canopy cover, the mutants reflected a significantly larger proportion of incoming shortwave radiation, but the total canopy light absorption was only slightly reduced, most likely due to a deeper penetration of light into the canopy space. As a consequence, canopy-scale grossprimary production and ecosystem respiration were comparable between the Chl-deficient mutant and the green variety. However, total biomass production was lower in the mutant, which indicates that processes other than steady state photosynthesis, caused a reduction in biomass accumulation over time. Analysis of NPQ relaxation and gas exchange in Chl-deficient and green leaves after transitions from high to low light conditions suggested that dynamic photosynthesis might be responsible for the reduced biomass production in the Chl-deficient mutant under field conditions.

Mots clés: Canopy photosynthesis; Steady state and dynamic photosynthesis; NPQ relaxation 31; Leaf

Domaines: Biodiversité et Ecologie

Karolina Sakowska, Giorgio Alberti, Lorenzo Genesio, Alessandro Peressotti, Gemini Delle Vedove, et al.. Leaf and canopy photosynthesis of a chlorophyll deficient soybean mutant. Plant, Cell and Environment, 2018, 41 (6), pp.1427-1437. ⟨10.1111/pce.13180⟩. ⟨hal-01802827⟩