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 performance and production of reactive oxygen species (ROS). It has been proposed that different processes, such as pigments accumulation (mostly anthocyanins), can delay leaf senescence. In this sense, many species have been found to display green or red leaves, amongst these Prunus cerasifera Ehrh. Although several studies produced transcriptomic data on foliar senescence and leaf color, just few works attempted to underpin differences in leaf genotypes throughout ontogenesis and exclusively at physiological and biochemical level. In this work, a transcriptomic approach has been exploited on green (clone 29C) and red (var. Pissardii) leaves of P. cerasifera from mature to senescent (6 weeks later) transition. Our analysis revealed 3,070 differentially expressed genes (DEGs) during green leaf transition, whereas red morph showed a slightly high gene regulation (4,925 DEGs). Most of observed DEGs where shared between the two genotypes and involved into transcription factor activity (such as NAC, MYB and AP2), senescing processes (SAGs) and cell wall remodeling (Expansins and Exostosin). Nevertheless, significant differences were detected in cellular functions of red leaves compared to green: genes involved in photosynthetic processes (e.g. tyranscripts encoding for Chlorophyll binding proteins) were highly down-regulated in green genotype, whereas transcript involved in pigment synthesis (e.g. flavonoid 3-O-glucosyltransferase) were up-regulated exclusively in red leaves. In addition, cellular functions related to ROS scavenging (glutathione-Stransferase, Pathogen Related-genes) and to sugar metabolism (e.g. Trehalose-6-phosphate synthase) were activated specifically in senescent red leaf. In conclusion, RNA-seq analysis suggests that P. cerasifera red genotype can regulate a set of genes and molecular functions which cope senescence, promoting a more delayed leaf ontogenesis compared to the green one.
Red versus green leaves: transcriptomic comparison of foliar senescence between two Prunus cerasifera genotypes.
VANGELISTI A.;GUIDI L.;CAVALLINI A.;NATALI L.;LO PICCOLO E.;LANDI M.;LORENZINI G.;MALORGIO F.;MASSAI R.;NALI C.;PELLEGRINI E.;RALLO G.;REMORINI D.;VERNIERI P.;GIORDANI T.
2019-01-01
Abstract
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 performance and production of reactive oxygen species (ROS). It has been proposed that different processes, such as pigments accumulation (mostly anthocyanins), can delay leaf senescence. In this sense, many species have been found to display green or red leaves, amongst these Prunus cerasifera Ehrh. Although several studies produced transcriptomic data on foliar senescence and leaf color, just few works attempted to underpin differences in leaf genotypes throughout ontogenesis and exclusively at physiological and biochemical level. In this work, a transcriptomic approach has been exploited on green (clone 29C) and red (var. Pissardii) leaves of P. cerasifera from mature to senescent (6 weeks later) transition. Our analysis revealed 3,070 differentially expressed genes (DEGs) during green leaf transition, whereas red morph showed a slightly high gene regulation (4,925 DEGs). Most of observed DEGs where shared between the two genotypes and involved into transcription factor activity (such as NAC, MYB and AP2), senescing processes (SAGs) and cell wall remodeling (Expansins and Exostosin). Nevertheless, significant differences were detected in cellular functions of red leaves compared to green: genes involved in photosynthetic processes (e.g. tyranscripts encoding for Chlorophyll binding proteins) were highly down-regulated in green genotype, whereas transcript involved in pigment synthesis (e.g. flavonoid 3-O-glucosyltransferase) were up-regulated exclusively in red leaves. In addition, cellular functions related to ROS scavenging (glutathione-Stransferase, Pathogen Related-genes) and to sugar metabolism (e.g. Trehalose-6-phosphate synthase) were activated specifically in senescent red leaf. In conclusion, RNA-seq analysis suggests that P. cerasifera red genotype can regulate a set of genes and molecular functions which cope senescence, promoting a more delayed leaf ontogenesis compared to the green one.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
