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Silicon partially preserves the photosynthetic performance of rice plants infected by Monographella albescens
Author(s) -
Tatagiba S.D.,
DaMatta F.M.,
Rodrigues F.A.
Publication year - 2016
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/aab.12246
Subject(s) - photosynthesis , chlorophyll fluorescence , photosystem ii , stomatal conductance , transpiration , biology , inoculation , quantum yield , chlorophyll , horticulture , quenching (fluorescence) , chlorophyll a , botany , fluorescence , physics , quantum mechanics
Abstract Leaf scald, caused by Monographella albescens , is one of the major diseases in rice worldwide. This study investigated the effect of silicon (Si) on the photosynthetic gas exchange parameters [net CO 2 assimilation rate ( A ), stomatal conductance to water vapour ( g s ), transpiration rate ( E )] and internal CO 2 concentration ( C i ), chlorophyll (Chl) fluorescence a parameters [minimal fluorescence ( F 0 ), maximum fluorescence ( F m ), maximum quantum yield of photosystem II ( F v / F m )], photochemical quenching coefficient ( q p ), effective quantum yield of PSII [Y(II)], quantum yield of regulated energy dissipation [Y(NPQ)] and quantum yield dissipation non‐regulated [Y(NO)] and the concentrations of pigments in rice plants grown in nutrient solutions containing either 0 (−Si) or 2 mM Si (+Si) and non‐inoculated or inoculated with M. albescens . Leaf scald severity decreased with higher foliar Si concentration. For the inoculated +Si plants, A , g s and E were significantly higher in comparison with the inoculated −Si plants, in which C i was significantly increased. Similarly, the concentrations of Chl a , Chl b , total Chl a+b and carotenoids were higher for the +Si plants in comparison with the −Si plants. Changes in the images of Chl a fluorescence were first observed precisely on the −Si plants leaves in comparison with the +Si plants. A decrease of q P and Y(II) in inoculated −Si plants, in comparison with the inoculated +Si plants, was accompanied by an increase in Y(NPQ) and Y(NO). Notably, the extent of the leaf areas was much more evident for Y(II) and q P in comparison with F 0 , F m and F v /F m , suggesting that Y(II) and q P were good predictors in detecting the early effects of leaf scald on the leaf photosynthesis. For the +Si non‐inoculated plants, changes in Y(II) were associated with alterations in both Y(NPQ) and Y(NO) compared with non‐inoculated −Si plants. In conclusion, the photosynthetic performance (as demonstrated by the gas exchange and Chl a fluorescence parameters) and the pigment pools of rice plants infected with M. albescens were preserved by Si supply and, therefore, provided an increase in rice resistance against leaf scald.