Nitric oxide and hydrogen peroxide during development and senescence of soybean cotyledons

SIMONTACCHI M; GALATRO A; JASID S; PUNTARULO S

Current Topics in Plant Biology

Research Trends

Lugar: Poojapura; Año: 2006

The aim of this work was to characterize the presence of nitric oxide and hydrogen peroxide during the development and senescence of soybean cotyledons. Soybean cotyledons showed an initial increase in water content, followed by constant fresh weight of the cotyledons up to day 16 of growth, and a significant decay afterwards. Dry weight, on the basis of cotyledon number, started to decrease after day 7 of seedling development. Both nitric oxide (NO) content and nitrite-dependent NO generation assessed by electron paramagnetic resonance (EPR) showed a maximum around day 6 of development. H2O2 generation by intact cotyledons was assessed employing DCFH/HRP in the presence of DTPA to minimize metal catalysis. H2O2 diffusion from cotyledons increased dramatically in cotyledons from seedlings after 12 days of development, and remains in higher values. NO could be related to the mechanism which assures the optimal functionality of the cotyledons during the initial phase after germination started. Meanwhile, reactive oxygen species, probably H2O2 could be a part of a complex signaling pathway that triggers the starting of senescence and further falling of the cotyledons.