The cytosine DNA methylation and demethylation have a role in regulating plant responses to the environment by affecting the promoter regions of most plant defense-related genes through the CpG islands or the CCGG motifs. Salicylic acid, a defense and signaling plant hormone, is seen playing crucial role in the variation of the methylome. In this study, the effects of salicylic acid and feeding of the millet headminer (Heliocheilus albipunctella de Joannis) on pearl millet DNA methylome changes were evaluated through MSAP epigenotyping during panicle development. The results showed that millet headminer feeding increased the level of genomic methylation while application of salicylic acid caused DNA demethylation occurring mostly at external cytosine and accompanied by a decrease of the number of larvae per panicle. This suggests that hemimethylation (external cytosine methylation) has key role in regulating defense responses and conferring tolerance to pearl millet through salicylic acid application.

Efficacy of augmentative release of the parasitoid wasp Bracon hebetor against the pearl millet headminer ABSTRACT: The yield losses in pearl millet, estimated to be about 85%, are mainly due to millet headminer, Heliocheilus albipunctella. This study is aimed at determining the status of this serious insect pest in the pearl millet production system within the groundnut basin of Senegal and to assess the efficacy of augmentative releases of its parasitoid wasp, Bracon hebetor, to control it. The study area was divided into three homogenous blocks (Northern, Southern and Eastern parts) where a set of three villages was selected for release of the parasitoid and another three as control villages where no releases were made. The results revealed that in all the villages where the parasitoid was released, an increase in larval mortality due to parasitism ranging between 9% and 26% was recorded in comparison with the control villages. Consequently, damages recorded were significantly lower in the villages with parasitoid releases.

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