Cadmium (Cd) is one of the most toxic heavy metal elements and can cause
serious damage to plant cells. The team of Shubao Hu from Nanjing
Agricultural University in China hypothesized that the transcription factor
OsMYB45 is involved in Cd stress response in rice.
OsMYB45 was found to be highly expressed in rice leaves, husks, stamens,
pistils, and lateral roots, and its expression is induced by Cd stress.
Mutation of OsMYB45 resulted in hypersensitivity to Cd treatment, which
doubled the concentration of hydrogen peroxide in the leaves of the mutants,
while the activity of catalase (CAT), which catalyzes the breakdown of
hydrogen peroxide to water and oxygen, was halved.
Further analysis indicated that the expression of OsCATA and OsCATC, genes
related to catalase, is significantly lower in the mutants than in
wildtypes. Overexpression of OsMYB45 in the mutant also rescued the mutant
phenotype.
These results reveal that OsMYB45 plays an important role in tolerance to Cd
stress in rice.
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