Developmentally related responses of maize catalase genes to salicylic acid.
AUTOR(ES)
Guan, L
RESUMO
The response of the maize catalase genes (Cat1, Cat2, and Cat3) to salicylic acid (SA) was examined at two distinct developmental stages: embryogenesis and germination. A unique, germination-related differential response of each maize catalase gene to various doses of SA was observed. During late embryogenesis, total catalase activity in scutella increased dramatically with 1 mM SA treatment. The accumulation of Cat2 transcript and CAT-2 isozyme protein provided the major contribution to the observed increase in total catalase activity. This increase was paralleled by the enhanced growth of germinated embryos at that stage. In a CAT-2 null mutant line, a full compensation of total catalase activity by the CAT-1 isozyme was observed in the presence of SA. This suggests that catalase is important for maintenance of normal cellular processes under stress conditions. SA at 1 mM, which enhances growth of precociously germinated embryos, appeared to inhibit seed germination at 1 day after inhibition. Furthermore, Cat2 transcript accumulation was inhibited at this stage. SA is probably not a direct signal for the induction of the catalase genes. Other signals, possibly germination-related regulator(s), might be responsible for the induction of the catalase genes. The effect of SA on the activity of purified catalase protein was also examined.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=41615Documentos Relacionados
- Biosynthesis and metabolism of salicylic acid.
- Differential Accumulation of Salicylic Acid and Salicylic Acid-Sensitive Catalase in Different Rice Tissues.
- Two inducers of plant defense responses, 2,6-dichloroisonicotinec acid and salicylic acid, inhibit catalase activity in tobacco.
- A Salicylic Acid-Binding Activity and a Salicylic Acid-Inhibitable Catalase Activity Are Present in a Variety of Plant Species.
- Salicylic Acid Inhibits Synthesis of Proteinase Inhibitors in Tomato Leaves Induced by Systemin and Jasmonic Acid.