Epigenetic control of plant immunity

ALVAREZ MARIA ELENA; NOTA FLORENCIA; CAMBIAGNO DAMIAN

MOLECULAR PLANT PATHOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2010 vol. 11 p. 563 - 576

1464-6722

In eukaryotic genomes, gene expression and DNA recombination are affected by structural chromatin traits. Chromatin structure is shaped by the activity of enzymes that either introduce covalent modifications in DNA and histone proteins or use energy from ATP to disrupt histone-DNA interactions. The genomic ‘marks’ that are generated by covalent modifications of histones and DNA or by the deposition of histone variants are susceptible to being altered in response to stress. Recent evidence suggests that proteins generating these epigenetic marks play crucial roles in the defence against pathogens. Histone deacetylases are involved in the activation of jasmonic acid- (JA) and ethylene- (ET) sensitive defence mechanisms. ATP-dependent chromatin remodelers mediate constitutive repression of the salicylic acid (SA)-dependent pathway, whereas histone methylation at the WRKY70 gene promoter affects activation of this pathway. Interestingly, bacterial-infected tissues show a net reduction in DNA methylation, which may affect disease resistance genes responsible for the surveillance against pathogens. Since some epigenetic marks can be erased or maintained and transmitted to offspring, epigenetic mechanisms may provide plasticity for the dynamic control of emerging pathogens without the generation of genomic lesions.