cDNA encoding a wheat (Triticum aestivum cv. Chinese spring) glycine-rich RNA-binding protein

The Glycine-Rich RNA-Binding Protein Is a Vital Post-Transcriptional Regulator in Crops

Glycine-rich RNA binding proteins (GR-RBPs), a branch of RNA binding proteins (RBPs), play integral roles in regulating various aspects of RNA metabolism regulation, such as RNA processing, transport, localization, translation, and stability, and ultimately regulate gene expression and cell fate. However, our current understanding of GR-RBPs has predominantly been centered on Arabidopsis thaliana, a model plant for investigating plant growth and development. Nonetheless, an increasing body of literature has emerged in recent years, shedding light on the presence and functions of GRPs in diverse crop species. In this review, we not only delineate the distinctive structural domains of plant GR-RBPs but also elucidate several contemporary mechanisms of GR-RBPs in the post-transcriptional regulation of RNA. These mechanisms encompass intricate processes, including RNA alternative splicing, polyadenylation, miRNA biogenesis, phase separation, and RNA translation. Furthermore, we offer an exhaustive synthesis of the diverse roles that GR-RBPs fulfill within crop plants. Our overarching objective is to provide researchers and practitioners in the field of agricultural genetics with valuable insights that may inform and guide the application of plant genetic engineering for enhanced crop development and sustainable agriculture.

Classification and comparative analysis of Curcuma longa L. expressed sequences tags (ESTs) encoding glycine-rich proteins (GRPs)

Glycine-rich proteins (GRPs) are a group of proteins characterized by their high content of glycine residues often occurring in repetitive blocs. The diverse expression pattern and sub cellular localization of various GRPs suggest their implication in different physiological processes. Several GRPs has been isolated and characterized from different monocots and dicots. However, little or no information is available about the structure and function of GRPs in asexually reproducing plants. In this study, in-silico analysis of expressed sequence tag database resulted in the isolation of fifty-one GRPs from Curcuma longa L., an asexually reproducible plant of great medicinal and economic significance. Phylogenetic analysis grouped the GRPs into four distinct classes based on conserved motifs and nature of glycine-rich repeats. Majority of the isolated GRPs exhibited high homology with known GRPs from other plants that are expressed in response to various stresses. The presence of high structural diversity and signal peptide in some GRPs suggest their diverse physiological role and tissue specific localization. The isolated sequences can be used as a framework for cloning, characterization and expressional analysis of GRPs in response to various biotic and abiotic stresses in Curcuma longa as well as other asexually reproducing plants.

Gene expression and genetic mapping analyses of a perennial ryegrass glycine-rich RNA-binding protein gene suggest a role in cold adaptation

A perennial ryegrass cDNA clone encoding a putative glycine-rich RNA binding protein (LpGRP1) was isolated from a cDNA library constructed from crown tissues of cold-treated plants. The deduced polypeptide sequence consists of 107 amino acids with a single N-terminal RNA recognition motif (RRM) and a single C-terminal glycine-rich domain. The sequence showed extensive homology to glycine-rich RNA binding proteins previously identified in other plant species. LpGRP1-specific genomic DNA sequence was isolated by an inverse PCR amplification. A single intron which shows conserved locations in plant genes was detected between the sequence motifs encoding RNP-1 and RNP-2 consensus protein domains. A significant increase in the mRNA level of LpGRP1 was detected in root, crown and leaf tissues during the treatment of plants at 4 degrees C, through which freezing tolerance is attained. The increase in the mRNA level was prominent at least 2 h after the commencement of the cold treatment, and persisted for at least 1 week. Changes in mRNA level induced by cold treatment were more obvious than those due to treatments with abscisic acid (ABA) and drought. The LpGRP1 protein was found to localise in the nucleus in onion epidermal cells, suggesting that it may be involved in pre-mRNA processing. The LpGRP1 gene locus was mapped to linkage group 2. Possible roles for the LpGRP1 protein in adaptation to cold environments are discussed.

Analysis of expressed sequence tags from oil palm (Elaeis guineensis)

This is the first report of a systematic study of genes expressed by means of expressed sequence tag (EST) analysis in oil palm, a species of the Arecales order, a phylogenetically key clade of monocotyledons that is not widely represented in the sequence databases. Five different cDNA libraries were generated from male and female inflorescences, shoot apices and zygotic embryos and unidirectional systematic sequencing was performed. A total of 2411 valid EST sequences were thus obtained. Cluster analysis enabled the identification of 209 groups of related sequences and 1874 singletons. Putative functions were assigned to 1252 of the set of 2083 non-redundant ESTs obtained. The EST database described here is a first step towards gene discovery and cDNA array-based expression analysis in oil palm.

A cDNA encoding a cold-induced glycine-rich RNA binding protein from Prunus avium expressed in embryonic axes

A cDNA clone encoding a presumed full-length glycine-rich ribonucleic acid (RNA) binding protein was isolated from a lambda-ZAP Express cDNA library generated from primarily nondormant Prunus avium (wild cherry) embryonic axes. The cDNA, designated Pa-RRM-GRP1 (Prunus avium RNA recognition motif glycine-rich protein 1), contains a single N-terminal RNA recognition motif (RRM) and single C-terminal glycine-rich domain. The glycine-rich domain is unusually long at 91 amino acids, 58 of which are glycines. The 534-base pair (bp) open reading frame (ORF) of this clone encodes a 178-amino-acid polypeptide with a predicted molecular weight of 17.33 kDa and pI of 7.84. Comparative sequence alignment of Pa-RRM-GRP1 reveals extensive homology to known and presumed glycine-rich RNA binding proteins from angiosperms and gymnosperms. Genomic Southern blot analysis suggests that this gene exists as a single copy in P. avium. Expression of this gene in P. avium embryonic axes during low-temperature dormancy-breaking treatments was studied and found to be induced by cold (3 degrees C) using real-time PCR of total cDNA supported by Northern blot analysis of total RNA. Expression dropped during prolonged storage at 3 degrees C and was reduced to control levels by interruption of cold treatment by warming to 20 degrees C.

Plant glycine-rich proteins: a family or just proteins with a common motif?

Twelve years ago a set of glycine-rich proteins (GRP) of plants were characterized and since then a wealth of new GRPs have been identified. The highly specific but diverse expression pattern of grp genes, taken together with the distinct sub-cellular localisation of some GRP groups, clearly indicate that these proteins are implicated in several independent physiological processes. Notwithstanding the absence of a clear definition of the role of GRPs in plant cells, studies conducted with these proteins have provided new and interesting insights on the molecular and cell biology of plants. Complex regulated promoters and distinct mechanisms of gene expression regulation have been demonstrated. New protein targeting pathways, as well as the exportation of GRPs from different cell types have been discovered. These data show that GRPs can be useful as markers and/or models to understand distinct aspects of plant biology. In this review, the structural and functional features of this family of plant proteins will be summarised. Special emphasis will be given to the gene expression regulation of GRPs isolated from different plant species, as it can help to unravel their possible biological functions.

Isolation and characterization of a cDNA clone encoding a putative white spruce glycine-rich RNA binding protein

A presumably full-length cDNA encoding a putative glycine-rich RNA binding protein was isolated from a lambdaZAP cDNA library prepared from mRNAs extracted from needles of 2year old white spruce seedlings, which had been either wounded or jasmonate-treated. The cDNA, designated PgRNP (Picea glauca RNP protein), presents a 468bp open reading frame encoding a 155 amino acid protein. This polypeptide possesses an RNA binding domain (RNP-CS) and a glycine-rich domain. Comparative alignment reveals extensive homologies to glycine-rich RNA binding proteins containing an RNP-CS found in other angiosperm species. Genomic hybridization experiments suggest that the PgRNP gene is part of a small multigene family with at least four members. RNA blot analysis revealed that the PgRNP transcript is expressed in all tissues from non-stressed plants. Constitutive mRNA level was found in needle tissue from control as well as methyl-jasmonate treated plants. Wounding had no clear induction effect. Jasmonic acid treatment and systemic wound response had a positive effect on transcript accumulation. Transcript accumulation was slightly induced by cold in needles, and repressed by drought stress in both needle and root tissues of 2year old plants. Finally, the level of PgRNP accumulation was induced by wounding and repressed in 2week old dark-grown seedlings upon jasmonate treatments.