Disease-fighting mutation accelerates plant aging

Researchers at Osaka Metropolitan University have discovered that a mutant protein, although it helps the plant Arabidopsis thaliana to resist powdery mildew, it can accelerate leaf aging. Plants with the altered version of the Actin Depolymerizing Factor (ADF) protein yellow more quickly over time and in dark conditions than plants without the mutation.

The study involved student Tomoko Matsumoto and professors Noriko Inada, from the Faculty of Agriculture, and Koichi Kobayashi, from the Faculty of Science. They observed that the mutation affects a group of proteins known as ADFs, which act on the dynamics of actin microfilaments, important for plant growth and defense.

Arabidopsis with the ADF4 protein knocked out or with all ADF subclass I genes silenced showed early senescence.

Genes associated with leaf aging, such as SAG13, SGR1, PPH and WRKY53, were activated earlier in these mutants than in wild-type plants.

The reduction in ADF4 gene expression during natural leaf aging suggests a central role for this protein in controlling senescence.

The nuclear localization of ADF4 was also shown to be essential in this process.

According to Professor Inada, ADFs influence not only aging, but also disease response and plant growth.

More information at doi.org/10.1093/pcp/pcaf027