Subtilisin-like proteases induced during the senescence of wheat leaves

IRMA N. ROBERTS

Arvidsjaur, Suecia

Congreso; 4th European Senescence Network Meeting; 2009

Umeå University

PRESENTACION ORAL The induction of two subtilisin-like proteases in the flag leaf of wheat plants during grain filling was studied by western blot. Previously, these proteases were shown to be up-regulated during the senescence of wheat leaves induced by light or nutrient deprivation. Here, we show that one of them, named P1, was detected very late in the life cycle of the plants (89 days after sowing, 9 days post-anthesis) and seven days later reached a 2.5-fold increment respect to the initial value at flowering. The other one, named P2, was already detected previous to anthesis, and began to increase soon after flowering reaching a 4-fold increment by the end of the grain filling. At the same time, a decrease in both Rubisco subunits and an increase in the nitrogen content in the developing grains were observed. These findings show that both proteases are induced during age-dependent senescence of wheat plants and suggest that they might be involved in nitrogen remobilization.