Microsome-associated proteome modifications ofArabidopsisseedlings grown on board the International Space Station reveal the possible effect on plants of space stresses other than microgravity

Abstract

Growing plants in space for using them in bioregenerative life support systems during long-term human spaceflights needs improvement of our knowledge in how plants can adapt to space growth conditions. In a previous study performed on board the International Space Station (GENARA A experiment STS-132) we evaluate the global changes that microgravity can exert on the membrane proteome of Arabidopsis seedlings. Here we report additional data from this space experiment, taking advantage of the availability in the EMCS of a centrifuge to evaluate the effects of cues other than microgravity on the relative distribution of membrane proteins. Among the 1484 membrane proteins quantified, 227 proteins displayed no abundance differences between µ g and 1 g in space, while their abundances significantly differed between 1 g in space and 1 g on ground. A majority of these proteins (176) were over-represented in space samples and mainly belong to families corresponding to protein synthesis, degradation, transport, lipid metabolism, or ribosomal proteins. In the remaining set of 51 proteins that were under-represented in membranes, aquaporins and chloroplastic proteins are majority. These sets of proteins clearly appear as indicators of plant physiological processes affected in space by stressful factors others than microgravity.

Differential transcriptional profile through cell cycle progression in Arabidopsis cultures under simulated microgravity

“…This finding suggests a role of the graviresistance mechanism in the early cellular response to microgravity, as a complement to the gravitropism phenomena that relies on the gravity perception using specific organs present in plants root (statoliths), but not present in the cell culture used in this study [1]. It has also been reported that the function of some membranelinked proteins of Arabidopsis is modulated by real microgravity, in a study performed on board the International Space Station using Arabidopsis seedlings [47,48]. Interestingly, a possible basis for many of these responses may be traced back to a translation of changes in forces associated with the cytoskeleton and cell wall.…”

A Bird’s-Eye View of Molecular Changes in Plant Gravitropism Using Omics Techniques

“…Also proteomic studies of Arabidopsis microsomes and callus cultures supported the involvement of cell wall modifications ( Mazars et al, 2014b ). A subsequent comparison of 1 g space control and 1 g ground controls of the same flight could furthermore show that cell wall modifying proteins are largely not altered on the protein level, suggesting that cell wall modifying enzymes are necessary for a response specifically to microgravity ( Mazars et al, 2014a ; Zhang et al, 2015 ). A comparison of different studies furthermore showed that regulation of protein activity occurs on multiple levels.…”

“…PHOT2 is a blue light receptor and can trigger intracellular calcium increases. It was suggest that the calcium increase activates calcium sensors, such as TOUCH3 and PINOID BINDING PROTEIN 1 (PBP1) that interact with the AGC kinase PINOID (PID), a regulator of PAT ( Mazars et al, 2014a ). In the same experiment, TOUCH3 protein abundance was increased fourfold at the plasma membrane, indicating a calcium dependent regulation of PAT in response to microgravity.…”

Spaceflight Induces Novel Regulatory Responses in Arabidopsis Seedling as Revealed by Combined Proteomic and Transcriptomic Analyses

“…Within the last decade, a handful of spaceflight experiments have produced transcriptomic and proteomic data. Microarray (1-7), RNA-seq (8), and protein mass spec (9)(10)(11)(12) experiments have provided snapshots of the molecular environment under microgravity conditions. Because of the low cost and ubiquitous nature of next generation sequencing technology, RNA-seq has become the go-to molecular method for comparing gene expression between multiple samples.…”