José M. Palma

TL;DR: Peroxisomes can be broadly defined as subcellular organelles bounded by a single membrane that contain as basic enzymatic constituents catalase and hydrogen peroxide (H2O2)-producing flavin oxidases and occur in almost all eukaryotic cells.

TL;DR: The recent demonstration of the presence of nitric oxide synthase (NOS) in plant peroxisomes implies that these organelles could also have a function in plant cells as a source of signal molecules like nitricoxide (NO*), superoxide radicals, hydrogen peroxide, and possibly S-nitrosoglutathione (GSNO).

TL;DR: Results obtained demonstrate the participation of both oxidative stress, probably mediated by H 2 O 2 , and proteolytic degradation in the mechanism of Cd toxicity in leaves of pea plants, and they appear to be involved in the Cd-induced senescence previously reported in these plants.

TL;DR: The presence of exo- and endoproteolytic activity in plant peroxisomes is analyzed, and the role of peroxISomal proteases in different physiological events that take place under oxidative stress situations is discussed.

TL;DR: Senescence is a genetically regulated oxidative process that involves a general degradation of the cellular structures and enzymes and the mobilization of the products of degradation to other parts of the plant.