Bitkilerde Mitojenler Tarafından Aktive Edilen Protein Kinazlar (MAPK)

Abstract

Mitogen-activated protein kinase (MAPK) cascades play roles in signal transduction of eukaryotes, including
yeasts, animals and plants. MAPKs are encoded by a large family of serine:threonine protein kinases. Distinct
MAPK pathways (MAPK, MAPKK, MAPKKK) are regulated by different extracellular stimuli and lead to a
cellular response by transducing the signals to the relevant metabolic pathways. Because of their sessile habit,
plants are exposed to a variety of environmental stresses, such as changes in temperature, drought, radiation
and wind. In plants there is evidence for MAPKs playing a role in the signaling of abiotic stresses, pathogens
and plant hormones. Molecular and biochemical studies using specifi c antibodies to particular MAPKs have
revealed that MAPK activation correlates with stimulatory treatments such as pathogen infection, wounding, low
temperature, drought, hyper- and hypo-osmolarity, high salinity, touch, and reactive oxygen species. It is known
that there are numerous of plant MAPK enzymes proportional to the diversity of stimuli. Although studies have
been undertaken intensively on the plant MAPK pathways, working mechanisms of many MAPK enzymes need
to be elucidated.