Plant Glycine-Rich Proteins in Stress Response: An Emerging, Still Prospective Story

Abstract

Seed plants are sessile organisms that have developed a plethora of strategies for sensing, avoiding, and responding to stress. Several proteins, including the glycine-rich protein (GRP) superfamily, are involved in cellular stress responses and signaling. GRPs are characterized by high glycine content and the presence of conserved segments including glycine-containing structural motifs composed of repetitive amino acid residues. The general structure of this superfamily facilitates division of GRPs into five main subclasses. Although the participation of GRPs in plant stress response has been indicated in numerous model and non-model plant species, relatively little is known about the key physiological processes and molecular mechanisms in which those proteins are engaged. Class I, II, and IV members are known to be involved in hormone signaling, stress acclimation, and floral development, and are crucial for regulation of plant cells growth. GRPs of class IV [RNA-binding proteins (RBPs)] are involved in alternative splicing or regulation of transcription and stomatal movement, seed, pollen, and stamen development; their accumulation is regulated by the circadian clock. Owing to the fact that the overexpression of GRPs can confer tolerance to stress (e.g., some are involved in cold acclimation and may improve growth at low temperatures), these proteins could play a promising role in agriculture through plant genetic engineering. Consequently, isolation, cloning, characterization, and functional validation of novel GRPs expressed in response to the diverse stress conditions are expected to be growing areas of research in the coming years. According to our knowledge, this is the first comprehensive review on participation of plant GRPs in the response to diverse stress stimuli.

Time-resolved proteomic profile ofAmblyomma americanumtick saliva during feeding

“…Some of the glycine-rich proteins were secreted from the 144-h time point, long after tick cement formation; these might regulate other tick feeding functions. Although glycine-rich proteins are mostly known for their potential role in tick cement formation, indirect evidence in other organisms indicate that these proteins might be involved in other functions such as host defense and stress response as in plants (133).…”

Craterostigma plantagineumcell wall composition is remodelled during desiccation and the glycine‐rich protein CpGRP1 interacts with pectins through clustered arginines

“…In addition, a cysteine-rich region, an oleosin domain, RNA-recognition motifs, a cold-shock domain or zinc-finger motifs are found in GRPs. Although several GRPs have been characterised, the function of the glycine-rich domains in these proteins is poorly understood (Czolpinska and Rurek, 2018). GRPs are classified according to the arrangement of the glycine-rich repeats and the presence of additional domains (Sachetto-Martins et al, 2000;Fusaro et al, 2001;Bocca et al, 2005;Mangeon et al, 2010).…”

Genome-wide identification and expression analysis of glycine-rich protein genes in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

“…The function of the plant GRP family is varied in plant growth and development. The GRPs of class Ⅰ & Ⅱ are almost the active components of cell walls, which play a positive regulatory role in plant cell division and organ differentiation [10]. The AtGRPs, belong to class Ⅱ, can interact with cell wall-associated receptor protein kinase AtWak1 to participate in the signal transduction, and prevent viruses from invading plants [5].…”

“…The AtGRPs, belong to class Ⅱ, can interact with cell wall-associated receptor protein kinase AtWak1 to participate in the signal transduction, and prevent viruses from invading plants [5]. The GRPs of class Ⅲ regulates pollen development and hydration while the class Ⅳ GRPs with an RNA recognition domain are involved in molecular processes such as alternative splicing or transcriptional regulation and played an important role in stomatal regulation, seed and stamen development [10,11]. Plant GRP genes are often specifically expressed and plays a distinctive role in different development stage or in different tissues [10].…”

“…The GRPs of class Ⅲ regulates pollen development and hydration while the class Ⅳ GRPs with an RNA recognition domain are involved in molecular processes such as alternative splicing or transcriptional regulation and played an important role in stomatal regulation, seed and stamen development [10,11]. Plant GRP genes are often specifically expressed and plays a distinctive role in different development stage or in different tissues [10]. Compared with the wild type, the deletion mutant of AtGR-RBP5 showed shorter roots, smaller leaves, and shorter flower axes, meanwhile overexpressed AtGR-RBP5 promoted cell elongation and tissue growth in Arabidopsis [2].…”