The in vivo functions of ARPF2 and ARRS1 in ribosomal RNA processing and ribosome biogenesis in Arabidopsis

Abstract

Yeast Rpf2 plays a critical role in the incorporation of 5S rRNA into pre-ribosomes by forming a binary complex with Rrs1. The protein characteristics and overexpression phenotypes of Arabidopsis Ribosome Production Factor 2 (ARPF2) and Arabidopsis Regulator of Ribosome Synthesis 1 (ARRS1) have been previously studied. Here, we analyze loss-of-function phenotypes of ARPF2 and ARRS1 using virus-induced gene silencing to determine their functions in pre-rRNA processing and ribosome biogenesis. ARPF2 silencing in Arabidopsis led to pleiotropic developmental defects. RNA gel blot analysis and circular reverse transcription–PCR revealed that ARPF2 depletion delayed pre-rRNA processing, resulting in the accumulation of multiple processing intermediates. ARPF2 fractionated primarily with the 60S ribosomal subunit. Metabolic rRNA labeling and ribosome profiling suggested that ARPF2 deficiency mainly affected 25S rRNA synthesis and 60S ribosome biogenesis. ARPF2 and ARRS1 formed the complex that interacted with the 60S ribosomal proteins RPL5 and RPL11. ARRS1 silencing resulted in growth defects, accumulation of processing intermediates, and ribosome profiling similar to those of ARPF2-silenced plants. Moreover, depletion of ARPF2 and ARRS1 caused nucleolar stress. ARPF2-deficient plants excessively accumulated anthocyanin and reactive oxygen species. Collectively, these results suggest that the ARPF2–ARRS1 complex plays a crucial role in plant growth and development by modulating ribosome biogenesis.

Identification of loci controlling timing of stem elongation in red clover using genotyping by sequencing of pooled phenotypic extremes

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Genomic regions and candidate genes affect root anatomical traits in diverse rice accessions

“…This gene is expressed in root stele tissue according to online microarray expression data (RiceXPro). The Arabidopsis ortholog is expressed in root vascular tissue and root primordia (Maekawa et al, 2018;Choi et al, 2020). Further research is needed to determine whether these SNPs represent functional polymorphisms that alter expression of Os01g0513500 to increase MXA, or whether they are markers closely linked to other genes in the region that control MXA variation.…”

Impaired Inosine Monophosphate Dehydrogenase Leads to Plant-Specific Ribosomal Stress Responses in Arabidopsis thaliana

“…However, research on this aspect in plants has been delayed, mainly because of the absence of a homologous gene for p53 (Rutkowski et al 2010). The plant-speci c transcription factor SRIW1/ANAC083 was found to be an important factor in ribosomal stress signaling in plants (Ohbayashi et al 2017), and several reports on ribosomal stress have since been published (Maekawa et al 2018;Choi et al 2020; Wang et al 2020;Hang et al 2021). Additionally, prior to the keystone report (Ohbayashi et al 2017), several characteristic phenotypes of ribosome-related mutants were reported, including delayed germination, growth defects, enhanced resistance to translation inhibitors, and abnormalities in vascularization and leaf shape (Weis et al 2015;Zhu et al 2016; Maekawa et al 2018; Xiong et al 2021).…”