IS SALICYLIC ACID INVOLVED IN PHOSPHITE INDUCED POLYAMINES UPON UV-B EXPOSURE?

MACHINANDIARENA MF; OLIVIERI FP; LOBATO MC; DALEO GR; OYARBURO N

SALTA

Congreso; PABMB-SAIB 2019; 2019

PABMB-SAIB

Late Blight, caused by the oomycete Phytophthora infestans, is the most important potato disease that seriously affects crop yield. A strategy to diminish the use of toxic agrochemicals is the use of biocompatible compounds. Phosphites are metallic salts of phosphorous acid (H3PO3), non toxic for the environment or human health. They are effective in increasing potato tolerance against various diseases, UV-B radiation, and also cause positive effects on physiological parameters related to crop quality and yield. However, their mode of action have not been completely elucidated yet. Previous results in our laboratory have shown that potassium phosphite (KPhi) induce enzymes related to the antioxidant system and the reinforcement of the cell wall in potato. Polyamines (PAs) are aliphatic amines present in almost all organisms, including plants. They are involved in many growth and development processes and also in the response to biotic and abiotic stresses. Most common PAs in plants are: Putrescine (PUT), Spermidine (SPD) and Spermine (SPM). The objective of the present work was to study the participation of PAs in the resistance mechanism induced by KPhi against P. infestans in potato plants. The results indicated that PAs differentially accumulate in potato leaves depending on the treatments. The expression of different genes involved in PA metabolism showed that many of them stayed unchanged or decreased in non treated inoculated leaves 48 hpi, compared to control non inoculated leaves. However, this was not observed in KPhi treated and inoculated leaves, where an increase in the expression of various genes was observed. These results suggest that polyamine metabolism could be involved in the resistance mechanism induced by KPhi in potato plants against P. infestans.