Transcriptomic comparison of foliar senscence between red and green morphs of P. cerasifera

The final stage of leaf ontogenesis is represented by senescence, a highly regulated process driven by a sequential cellular breakdown involving, as first step, chloroplast dismantling with consequent reduction of photosynthetic efficiency. It has been proposed that different processes, such as pigments accumulation, can protect the vulnerable photosynthetic apparatus of senescent leaves. Although several studies produced transcriptomic data on foliar senescence, just few works attempted to underpin differences in red and green leaves throughout ontogenesis. In this work, a transcriptomic approach has been exploited on green and red leaves of Prunus cerasifera to unveil molecular differences from leaf maturity to senescence.Our analysis revealed a higher gene regulation in red genotype compared to green one, during leaf transition. Overall we retrieved 3,070 and 4,925 differentially expressed genes (DEGs) respectively during red and green foliar senescence.Most of the observed DEGs were shared and involved into transcription factor activities, senescing processes and cell wall remodelling. Nevertheless, significant differences were detected in cellular functions: genes related to photosynthesis were highly down-regulated in the green genotype, whereas transcripts involved in pigment formation were exclusively up-regulated in red leaves. In addition, cellular functions involved into stress response and to sugar metabolism were specifically activated in senescent red leaves. In conclusion, data suggests that P. cerasifera red genotype can regulate a set of genes and molecular mechanisms, which cope senescence, promoting more advantages during leaf ontogenesis compared to the green one.