Quantitative Proteome and PTMome Analysis of Arabidopsis thaliana Root Responses to Persistent Osmotic and Salinity Stress

Abstract

Abiotic stresses such as drought result in large annual economic losses around the world. As sessile organisms, plants cannot escape the environmental stresses they encounter, but instead must adapt to survive. Studies investigating plant responses to osmotic and/or salt stress have largely focused on short-term systemic responses, leaving our understanding of intermediate to longer-term adaptation (24 h - days) lacking. In addition to protein abundance and phosphorylation changes, evidence suggests reversible lysine acetylation may also be important for abiotic stress responses. Therefore, to characterize the protein-level effects of osmotic and salt stress, we undertook a label-free proteomic analysis of Arabidopsis thaliana roots exposed to 300 mM Mannitol and 150 mM NaCl for 24 h. We assessed protein phosphorylation, lysine acetylation and changes in protein abundance, detecting significant changes in 245, 35 and 107 total proteins, respectively. Comparison with available transcriptome data indicates that transcriptome- and proteome-level changes occur in parallel, while PTMs do not. Further, we find significant changes in PTMs and protein abundance involve different proteins from the same networks, indicating a multifaceted regulatory approach to prolonged osmotic and salt stress. In particular, we find extensive protein-level changes involving sulphur metabolism under both osmotic and salt conditions as well as changes in protein kinases and transcription factors that may represent new targets for drought stress signaling. Collectively, we find that protein-level changes continue to occur in plant roots 24 h from the onset of osmotic and salt stress and that these changes differ across multiple proteome levels.

Growth-limiting drought stress induces time-of-day-dependent transcriptome and physiological responses in hybrid poplar

“…We also showed that genes involved in protein folding and translation initiation were reduced in water-limited samples in the morning but were unchanged in response to drought later in the day. This finding may be consistent with the growing literature showing that stress responses may be regulated in part by translation ( Reynoso et al 2019 ; Bonnot and Nagel 2021 ) and posttranslational modifications ( Rodriguez et al 2021 ). Together, these findings highlight the importance of including multiple time points in experimental design for capturing the full suite of stress response mechanisms.…”

Multi-omic analysis of the Arabidopsis clock activator mutantrve 4 6 8reveals connections to carbohydrate metabolism and proteasome regulation

“…Correspondingly, we see an increase in a number of glutathione transferases (GSTs); GSTF2, GSTF6 (AT1G02930) and GSTF7 (AT1G02920), which are a subclass of the plant-specific Phi-family of GSTs implicated in mitigating oxidative (GSTF2) and salt (GSTF6/7) stress, respectively (Lee et al, 2014; Seok et al, 2020). In previous proteomic and phosphoproteomic analyses of persistent osmotic and salt-stress, increased abundance of sulfur metabolic enzymes (Rodriguez et al, 2021), indicates a potential connection between sulfur metabolism / assimilation and drought-stress tolerance. In maize, the application of sulfur-supplemented fertilizers to drought stressed plants was shown to mitigate the effects of drought (Usmani et al, 2020).…”

BREVIPEDICELLUS Positively Regulates Salt-Stress Tolerance in Arabidopsis thaliana

“…Other Na + transporters, including Na + /H + exchanger 1 (NHX1), high-affinity K + transporter 1 (HKT1) and vacuolar membrane H + -pyrophosphatase (VP), are also important players in ionic homeostasis under saline conditions [ 7 , 8 , 9 ]. In addition, transcriptome remodeling, cellular structural-dynamics, hormonal adjustment, reactive-oxygen-species scavenging, osmolytes accumulation, and post-translational decoration, are all mobilized to gain a systemic resistance to salt stress [ 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”