Reduction of MDHAR activity in cherry tomato suppresses growth and yield and MDHAR activity is correlated with sugar levels under high light.
Ascorbate is oxidized into the radical monodehydroascorbate (MDHA) through ascorbate oxidase or peroxidase activity or non-enzymatically by reactive oxygen species. Regeneration of ascorbate from MDHA is ensured by the enzyme MDHA reductase (MDHAR). Previous work has shown that growth processes and yield can be altered by modifying the activity of enzymes that recycle ascorbate; therefore, we have studied similar processes in cherry tomato (Solanum lycopersium L.) under- or overexpressing MDHAR. Physiological and metabolic characterization of these lines was carried out under different light conditions or by manipulating the source-sink ratio. Independently of the light regime, slower early growth of all organs was observed in MDHAR silenced lines, decreasing final fruit yield. Photosynthesis was altered as was the accumulation of hexoses and sucrose in a light-dependent manner in plantlets. Sucrose accumulation was also repressed in young fruits and final yield of MDHAR silenced lines showed a stronger decrease under carbon limitation, and the phenotype was partially restored by reducing fruit load. Ascorbate and MDHA appear to be involved in control of growth and sugar metabolism in cherry tomato and the associated enzymes could be potential targets for yield improvement.
INRA, UR-1052, Génétique et Amélioration des Fruits et Légumes, CS60094, 84143, Montfavet, France.|INRA, UR-1115, Plantes et Systèmes de Culture Horticoles, CS40509, 84914, Avignon Cedex 9, France.
Vincent
V
Truffault
INRA, UR-1052, Génétique et Amélioration des Fruits et Légumes, CS60094, 84143, Montfavet, France.
Noé
N
Gest
INRA, UR-1052, Génétique et Amélioration des Fruits et Légumes, CS60094, 84143, Montfavet, France.
Cécile
C
Garchery
Max-Planck-Institute of Molecular Plant Physiology, Am Muehlenberf 1, 14476, Potsdam-Golm, Germany.
Alexandra
A
Florian
Max-Planck-Institute of Molecular Plant Physiology, Am Muehlenberf 1, 14476, Potsdam-Golm, Germany.
Alisdair R
AR
Fernie
INRA, UR-1115, Plantes et Systèmes de Culture Horticoles, CS40509, 84914, Avignon Cedex 9, France.
Hélène
H
Gautier
INRA, UR-1052, Génétique et Amélioration des Fruits et Légumes, CS60094, 84143, Montfavet, France.
Rebecca G
RG
Stevens
D001205:Ascorbic Acid / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002734:Chlorophyll / Q000378:metabolism; D003683:Dehydroascorbic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D008027:Light; D018551:Solanum lycopersicum / Q000201:enzymology / Q000254:growth & development / Q000502:physiology*; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010788:Photosynthesis; D018526:Plant Transpiration
D002734:Chlorophyll; C000820:semidehydroascorbic acid; D009247:NADH, NADPH Oxidoreductases; C023927:monodehydroascorbate reductase (NADH); D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid
Solanum lycopersicum; ascorbate recycling; carbon limitation; growth; monodehydroascorbate; oxidative stress; redox status; yield