Undaria pinnatifida (Harvey) Suringar aqueous extract activates potato defense responses against Phytophthora infestans

LOBATO, MARÍA CANDELA; OLIVIERI, FLORENCIA PÍA; MACHINANDIARENA, MILAGROS FLORENCIA; BECHERUCCI, MARÍA EUGENIA; FELDMAN, MARIANA LAURA

PHYSIOLOGICAL AND MOLECULAR PLANT PATHOLOGY

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2023 vol. 127

0885-5765

Undaria pinnatifida is an invasive macroalga on the Argentinean coast and its use as abiostimulant was rarely investigated. The present work aimed to evaluate the effect ofU. pinnatifida aqueous extract (AE) as an inducer of potato defense responses. Ourresults showed that AE protected potato plants against Phytophthora infestans infection.Application of AE by foliar spray (10% dilution), resulted in a significant reduction in disease severity. However, when antimicrobial activity was tested in vitro, a higher concentration of AE was needed to reduce P. infestans growth, showing hyphae morphological alterations and a reduction in the number of sporangia. These results indicate that AE at 10% induced defense responses in treated plants. The analysis ofPR1 and IPII genes (Salicylic Acid and Jasmonic acid pathways markers, respectively),showed that the SA pathway would participate in the AE-induced resistance.Additionally, the accumulation of β-1,3-glucanase, guaiacol peroxidase activity, andchanges in free polyamines were analyzed. An accumulation or enhanced activity wasstimulated by AE. Moreover, the effect of AE treatment might be positive for the plantperformance, since all the dilutions of AE tested showed an increment of chlorophyllcontent. These preliminary results strongly encourage further studies of the potential use of AE as an alternative tool for potato disease management using locally available seaweed in environmentally friendly conditions.