Diurnal rhythms in durum wheat triggered by Rhopalosiphum padi (bird cherry-oat aphid)
Wheat is a staple crop and one of the most widely consumed grains globally Wheat yields can experience significant losses due to the damaging effects of herbivore infestation However little is known about the effect aphids have on the natural diurnal rhythms in plants Our timeseries transcriptomics and metabolomics study reveals intriguing molecular changes occurring in plant diurnal rhythmicity upon aphid infestation Under control conditions 15366 out of the 66559 genes in the tetraploid wheat cultivar Svevo representing approximately 25 of the transcriptome exhibited diurnal rhythmicity Upon aphid infestation 5682 genes lost their rhythmicity while 5203 genes began to exhibit diurnal rhythmicity only in the presence of aphids The genes exhibiting aphid induced rhythmicity were associated with defense related GO terms such as protein phosphorylation and cellular response to ABA and were enriched with motifs of the WRKY transcription factor families Conversely the genes showing aphid-inhibited rhythmicity were enriched for motifs of TCP and ERF transcription factor families While the core circadian clock genes maintain their rhythmicity during infestation we observed that approximately 60 of rhythmic genes experience disruptions in their rhythms during aphid infestation These changes can influence both the plants growth and development processes as well as defense responses Furthermore analysis of rhythmic metabolite composition revealed that several monoterpenoids gained rhythmic activity under infestation while saccharides retained their rhythmic patterns Our findings highlight the ability of insect infestation to disrupt the natural diurnal cycles in plants expanding our knowledge of the complex interactions between plants and insects