Effect of phosphorus deficiency on chlorophyll fluorescence of cotyledon and root exudates of rape

YARYURA, PABLO M.; CORDÓN, GABRIELA; LEÓN, MARIANA; RUBIO, GERARDO; KERBER, NORMA L.; PUCHEU, NORMA L.; GARCÍA, AUGUSTO F.; LAGORIO, MARÍA GABRIELA

Mar del Plata, Buenos Aires, Argentina

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

The study of the spectroscopic properties is a non destructive procedure monitoring energy transfer and, consequently, plant health. In particular, Chlorophyll-a fluorescence (Chl-F) emitted by leaves brings information concerning the plants response to external factors. Cotyledons of rape (Brassica rapa L.) young plants under phosphorous (P) deficiency showed a Chl-F ratio in the red/far red region (F685/F737) lower than the corresponding value for non-stressed plants. Moreover, minimal differences in F685/F740 were detected in leaves. These results showed that P deficiencies may better be detected by measuring changes in Chl-F emission in cotyledons than in leaves. Stressed cotyledons showed different emission spectra in the blue-green (maxima at 469 and 555 nm) compared to non-stressed cotyledons. The use of the spectroscopic correction, as described by Cordon et al. (Photochem. Photobiol. Sci., 2006, 5, 735-740), allowed us to present here F spectra that are not distorted by differential energy absorption by pigments. On the other hand, we also studied the F in root exudates emitting approximately at 410 nm in both the stressed and non-stressed plants. The intensity of those emission signals is identical in stressed and non-stressed plants.