ena-STUDY-University of Wuppertal-12-11-2020-11:45:02:293-367
Differential degradation of RNA species by autophagy related pathways in plants
An important function of the plant vacuole is the recycling of delivered proteins and RNA by autophagy. We provide the first plant vacuolar small RNome by isolation of intact vacuoles from Arabidopsis plants, subsequent RNA purification and Next Generation Sequencing. In these vacuolar sRNomes, all types of cellular RNAs were found including those of chloroplast origin, suggesting a bulk-type of RNA transfer to, and breakdown in vacuoles. ATG5 is a major representative of autophagy genes and we observed that the vacuolar RNA composition in corresponding knockout plants (atg5-1) differed clearly from controls as most chloroplast derived RNA species were missing. Moreover, the read length distribution of RNAs found in atg5-1 differed to control samples, indicating altered RNA processing. In contrast, vacuolar RNA length and composition of plants lacking the vacuolar RNase2 (rns2-2), involved in cellular RNA homeostasis, showed minor alterations, only. Our data therefore suggests that mainly autophagy components are responsible for selective transport and targeting of different RNA species into the vacuole for degradation. In addition, mature miRNAs were detected in all vacuolar preparations, however in atg5-1 at much lower frequency, indicating a new biological role for vacuolar miRNAs apart from becoming degraded.
An important function of the plant vacuole is the recycling of delivered proteins and RNA by autophagy. We provide the first plant vacuolar small RNome by isolation of intact vacuoles from Arabidopsis plants, subsequent RNA purification and Next Generation Sequencing. In these vacuolar sRNomes, all types of cellular RNAs were found including those of chloroplast origin, suggesting a bulk-type of RNA transfer to, and breakdown in vacuoles. ATG5 is a major representative of autophagy genes and we observed that the vacuolar RNA composition in corresponding knockout plants (atg5-1) differed clearly from controls as most chloroplast derived RNA species were missing. Moreover, the read length distribution of RNAs found in atg5-1 differed to control samples, indicating altered RNA processing. In contrast, vacuolar RNA length and composition of plants lacking the vacuolar RNase2 (rns2-2), involved in cellular RNA homeostasis, showed minor alterations, only. Our data therefore suggests that mainly autophagy components are responsible for selective transport and targeting of different RNA species into the vacuole for degradation. In addition, mature miRNAs were detected in all vacuolar preparations, however in atg5-1 at much lower frequency, indicating a new biological role for vacuolar miRNAs apart from becoming degraded.