Stress-related genes define essential steps in the response of maize seedlings to smoke-water.

Smoke from burning vegetation is widely recognised as a germination cue for seed germination and recent reports suggest that smoke treatments can improve seedling vigour also. We investigated the effect of smoke-water on seedling vigour and changes of the global transcriptome in the early post-germination phase in maize. Application of smoke-water improved the germination characteristics and seedling vigour. The transcriptional response of embryos and emerging radicles 24 and 48 h after the onset of smoke treatment was investigated. The microarray study revealed a number of smoke-responsive genes amongst which stress- and abscisic acid (ABA)-related genes were over-represented. The global promoter analysis of the smoke-responsive genes revealed a tight correlation with the results obtained from Gene Ontology annotations. This concerted over-expression shows that smoke treatment induces stress and ABA-related responses in the early post-germination phase which leads to better adaptation to environmental stress factors occurring during germination, eventually resulting in greater seedling vigour.