Remodelled Ribosomes Synthesise a Specific Proteome in Proliferating Plant Tissue during Cold

Abstract

Plant acclimation to low temperatures occurs through system-wide mechanisms that include proteome shifts, some of which occur at the level of protein synthesis. All proteins are synthesised by ribosomes. Rather than being monolithic, transcript-to-protein translation machines, ribosomes can be selective and cause effective proteome shifts required for successful temperature acclimation. Here, we use apical root meristems of germinating seedlings of the monocotyledonous plant barley as a model to study changes in protein abundance and synthesis rates during cold acclimation. We measure metabolic and physiological parameters that allow us to compare protein synthesis rates in different physiological states, e.g., in cold acclimation compared to the optimal temperature state. We show that ribosomal proteins are independently synthesised and assembled into ribosomal complexes in root proliferative tissue, and assess how the ribo-proteome shifts during cold may be associated with changes in synthesis and accumulation of macromolecular complexes. We demonstrate that translation initiation is the limiting step during cold acclimation and based on our data propose a model of a ribosomal code that depends on a reconfigured ribosome population, where as a mode of cold acclimation, specific ribosomal protein compositions may confer selective association capabilities between 60S subunits and 48S initiation complexes.

Transcriptome Analysis and QTL Mapping Identify Candidate Genes and Regulatory Mechanisms Related to Low-Temperature Germination Ability in Maize

“…Low-temperature tolerance is a complex biological process that usually involves sophisticated regulatory mechanisms. Of these, ribosome synthesis and processing have been found to correlate with low-temperature tolerance in many plants, including Arabidopsis [53,54], maize [38][39][40], and rice [55,56]. In our results, at the low-temperature germination stage, a large number of ribosome synthesis and processing biological processes were found only in Ye478 but not in Q1 (Figure 4A).…”