02135nam a2200253Ia 4500 MX-MdCICY 20260521091329.0 CICY B-12836 Relationships between Salicylic Acid Content, Phenylalanine Ammonia-lyase (PAL)Activity, and Resistance of Barley to Aphid Infestation J. Agric. Food Chem., 51(8), p.2227-2231, 2003 It has been suggested that salicylic acid (SA)is a signal in acquired resistance to pathogens in several plants. Also, it has been suggested that infestation of plants causes an increase in the activity of phenylalanine ammonia-lyase (PAL), a key phenolic biosynthesis enzyme. The purpose of this work was to investigate whether the induction of SA and PAL activity is related to the susceptibility of barley to aphid infestation. The induction of free and conjugated SA in two barley cultivars that differ in susceptibility to aphids was analyzed. Analyses of several physiological parameters showed that cv. UNA-80 was more susceptible to the aphid Schizaphis graminum than cv. LM-109. Salicylic acid was not detected in noninfested plants. Levels of free and conjugated SA in cv. LM-109 and of conjugated SA in cv. UNA-80 increased with aphid infestation, whereas the levels of free SA in cv. UNA-80 remained high under all infestation degrees. Maximum values reached in both cultivars were not significantly different. With respect to PAL activity, cv. LM-109 showed a significantly higher specific activity than cv. UNA-80, the more susceptible cultivar. The relationship between the susceptibility of a plant to aphid and SA induction and PAL activity is discussed. HORDEUM VULGARE GREENBUG SCHIZAPHIS GRAMINUM SALICYLIC ACID PAL Chaman, M.E. Copaja, S.V. Argandoña, V.H. https://drive.google.com/file/d/1uEqPAq4sZs1k91-YRyVFY26Ox3hbVGO0/view?usp=drivesdk Para ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx Loc REF1 250602s9999 xx |||||s2 |||| ||und|d 22980 22980 0 0 Loc 0 0 F1 CICY CICY RE 2025-06-25 0 B-12836 2025-06-25 15:39:10 2025-06-25 REF1