Subcellular Journey of Rare Cold Inducible 2 Protein in Plant Under Stressful Condition

Abstract

Rare cold inducible 2 (RCI2) proteins are small hydrophobic membrane proteins in plants, and it has been widely reported that RCI2 expressions are dramatically induced by salt, cold, and drought stresses in many species. The RCI2 proteins have been shown to regulate plasma membrane (PM) potential and enhance abiotic stress tolerance when over-expressed in plants. RCI2 protein structures contain two transmembrane domains that are thought to be PM intrinsic proteins and have been observed at the PM and endomembranes. However, cellular trafficking of RCI2s are not fully understood. In this review, we discussed (i) general properties of RCI2s characterized in many species, (ii) the uses of RCI2s as a tracer in live cell imaging analyses and when they are fused to fluorescence proteins during investigations into vesicle trafficking, and (iii) RCI2 functionalities such as their involvement in rapid diffusion, endocytosis, and protein interactions. Consequently, the connection between physiological characteristics of RCI2s and traffic of RCI2s interacting membrane proteins might be helpful to understand role of RCI2s contributing abiotic stresses tolerance.

Genome-Wide Identification and Characterization of the RCI2 Gene Family in Allotetraploid Brassica napus Compared with Its Diploid Progenitors

“…The three basic species B. rapa (AA, 2n = 2x = 20), B. nigra (BB, 2n = 2x = 16), and B. oleracea (CC, 2n = 2x = 18) crossed with each other and formed B. juncea (AABB, 2n = 4x = 36), B. napus (AACC, 2n = 4x = 38) and B. carinata (BBCC, 2n = 4x = 34) by chromosome doubling. At present, the identification and analysis of the RCI2 gene family have been carried out in many plants, for example: Arabidopsis thaliana [ 29 ], Zea mays [ 25 ], Cucumis sativus L. [ 30 ], Triticum aestivum [ 31 ], and the function of individual members of the family has been explored [ 32 , 33 , 34 ]. However, the effect of whole-genome polyploidization and hybridization on the RCI2 gene family in Brassica is not clear.…”

Specific CBF transcription factors and cold‐responsive genes fine‐tune the early triggering response after acquisition of cold priming and memory

“…A further gene is RCI2A which was described as highly inducible by cold, ABA, dehydration, and salt. The small protein with two transmembrane domains is highly hydrophobic (Medina et al, 2001) and was localized at the plasma membrane and endomembranes (Kim et al, 2020). An ectopic expression of RCI2A from Arabidopsis in tomato positively influenced cold stress tolerance by reducing photooxidative damage and lipid peroxidation due to increased activity of ascorbate peroxidases (APX) and peroxidases (Sivankalyani et al, 2015).…”

Overexpression of MsRCI2A, MsRCI2B, and MsRCI2C in Alfalfa (Medicago sativa L.) Provides Different Extents of Enhanced Alkali and Salt Tolerance Due to Functional Specialization of MsRCI2s

“…For example, in transformed tobacco plants, the expression of AltMP1 and AltMP2 transgenes increases the stability of the cell membrane, maintains the ion balance in the cells and induces the expression of stress-related genes to improve tolerance to drought, low temperature, salt, heat shock, osmotic stress and H 2 O 2 stress (Ben et al, 2017(Ben et al, , 2018. Nearly all studies on the overexpression of the PMP3 gene have shown that transgenic plants present enhanced resistance to abiotic stress (Rocha, 2016;Kim et al, 2021Kim et al, , 2020. In this study, the MsRCI2A, MsRCI2B, and MsRCI2C genes were cloned from alfalfa and further analyzed.…”

“…The rare cold-inducible 2 ( RCI2 ) gene encodes a highly conserved small-molecule hydrophobic peptide that is ubiquitous in prokaryotes and eukaryotes. The small membrane-localized protein encoded by the RCI2 gene belongs to the plasma membrane protein 3 ( PMP3 ) family, whose members are closely related to the abiotic stress response ( Kim et al, 2021 ) and is similar to Pmp3p in terms of regulating ion homeostasis on the basis of similarities in protein structure and location as well as evidence of RCI2 involvement in regulating Na + and K + levels ( Kim et al, 2020 ). Overexpression of AtRCI2A or MpRCI in Arabidopsis reduced its Na + content in shoots and increased its K + content in both shoots and roots when growing in high Na + or high K + conditions ( Mitsuya et al, 2006 ; Liu et al, 2012 ).…”