Potassium phosphite increases tolerance to UV-B in potato

OYARBURO N; MACHINANDIARENA MF; FELDMAN M.L.; DALEO GR; ANDREU AB; OLIVIERI FP

PLANT PHYSIOLOGY AND BIOCHEMISTRY

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2015 vol. 88 p. 1 - 8

0981-9428

The use of biocompatible chemical compounds that enhance plant disease resistance through InducedResistance (IR) is an innovative strategy to improve the yield and quality of crops. Phosphites (Phi), inorganicsalts of phosphorous acid, are environment friendly, and have been described to induce disease control. Phi,similar to other plant inductors, are thought to be effective against different types of biotic and abiotic stress,and it is assumed that the underlying signaling pathways probably overlap and interact. The signalingpathways triggered by UV-B radiation, for instance, are known to crosstalk with other signaling routes thatrespond that biotic stress. In the present work, the effect of potassium phosphite (KPhi) pre-treatment onUV-B stress tolerance was evaluated in potato leaves. Plants were treated with KPhi and, after 3 days,exposed to 2 h/day of UV-B (1.5Wattm2) for 0, 3 and 6 days. KPhi pre-treatment had a beneficial effect ontwo photosynthetic parameters, specifically chlorophyll content and expression of the psbA gene. Oxidativestress caused by UV-B was also prevented by KPhi. A decrease in the accumulation of hydrogen peroxide(H2O2) in leaves and an increase in guaiacol peroxidase (POD) and superoxide dismutase (SOD) activitieswere also observed. In addition, the expression levels of a gene involved in flavonoid synthesis increased inUV-B-stressed plants only when pre-treated with KPhi. Finally, accumulation of glucanases and chitinaseswas induced by UV-B stress and markedly potentiated by KPhi pre-treatment. Altogether, this is the firstreport that shows a contribution of KPhi in UV-B stress tolerance in potato plants.