Glycine-Rich RNA-Binding Protein Functions in Nickel and Lead Tolerance in .

Plant glycine-rich RNA-binding proteins (GRPs) play crucial roles in the response to environmental stresses. However, the functions of in plants under heavy metal stress remain unclear. In the present study, in , the transcript level of was markedly increased by Ni but was decreased by Pb.

Exogenous Cysteine Improves Mercury Uptake and Tolerance in by Regulating the Expression of Heavy Metal Chelators and Antioxidative Enzymes.

Cysteine (Cys) is an essential amino acid component of the major heavy metal chelators, such as glutathione (GSH), metallothioneins (MTs), and phytochelatins (PCs), which are involved in the pathways of mercury (Hg) tolerance in plants. However, the mechanism through which Cys facilitates Hg tolerance in plants remains largely unclear. In this study, we investigated the effects of exogenous Cys on Hg uptake in the seedlings, roots, and shoots of throughout 6 and 36 h of Hg exposure and on the regulation of Hg detoxification by heavy metal chelators and antioxidative enzymes.

Engineering plants with carbon nanotubes: a sustainable agriculture approach.

Sustainable agriculture is an important conception to meet the growing food demand of the global population. The increased need for adequate and safe food, as well as the ongoing ecological destruction associated with conventional agriculture practices are key global challenges. Nanomaterials are being developed in the agriculture sector to improve the growth and protection of crops.

Overexpression of phytochelatin synthase AtPCS2 enhances salt tolerance in Arabidopsis thaliana.

Phytochelatin synthase (PCS) is an enzyme that synthesizes phytochelatins, which are metal-binding peptides. Despite the important role of PCS in heavy metal detoxification or tolerance, the functional role of PCS with respect to other abiotic stresses remains largely unknown. In this study, we determined the function of Arabidopsis thaliana phytochelatin synthase 2 (AtPCS2) in the salt stress response.

Comparative expression analysis of genes encoding metallothioneins in response to heavy metals and abiotic stresses in rice (Oryza sativa) and Arabidopsis thaliana.

To get insights into the functions of metallothionein (MT) in plant response to multiple stresses, expressions of 10 rice MT genes (OsMTs) and 7 Arabidopsis MT genes (AtMTs) were comprehensively analyzed under combined heavy metal and salt stress. OsMT1a, OsMT1b, OsMT1c, OsMT1g, and OsMT2a were increased by different heavy metals. Notably, ABA remarkably increased OsMT4 up to 80-fold.

A chloroplast-targeted cabbage DEAD-box RNA helicase BrRH22 confers abiotic stress tolerance to transgenic Arabidopsis plants by affecting translation of chloroplast transcripts.

Although the roles of many DEAD-box RNA helicases (RHs) have been determined in the nucleus as well as in cytoplasm during stress responses, the importance of chloroplast-targeted DEAD-box RHs in stress response remains largely unknown. In this study, we determined the function of BrRH22, a chloroplast-targeted DEAD-box RH in cabbage (Brassica rapa), in abiotic stress responses. The expression of BrRH22 was markedly increased by drought, heat, salt, or cold stress and by ABA treatment, but was largely decreased by UV stress.

Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells.

Despite the increasing understanding of the crucial roles of glutathione (GSH) in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg) tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd), copper (Cu), or zinc (Zn), whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of , tobacco, and pepper.

An RRM-containing mei2-like MCT1 plays a negative role in the seed germination and seedling growth of Arabidopsis thaliana in the presence of ABA.

Despite an increasing understanding of the essential role of the Mei2 gene encoding an RNA-binding protein (RBP) in premeiotic DNA synthesis and meiosis in yeasts and animals, the functional roles of the mei2-like genes in plant growth and development are largely unknown. Contrary to other mei2-like RBPs that contain three RNA-recognition motifs (RRMs), the mei2 C-terminal RRM only (MCT) is unique in that it harbors only the last C-terminal RRM. Although MCTs have been implicated to play important roles in plants, their functional roles in stress responses as well as plant growth and development are still unknown.

A chloroplast-localized S1 domain-containing protein SRRP1 plays a role in Arabidopsis seedling growth in the presence of ABA.

Although the roles of S1 domain-containing proteins have been characterized in diverse cellular processes in the cytoplasm, the functional roles of a majority of S1 domain-containing proteins targeted to the chloroplast are largely unknown. Here, we characterized the function of a nuclear-encoded chloroplast-targeted protein harboring two S1 domains, designated SRRP1 (for S1 RNA-binding ribosomal protein 1), in Arabidopsis thaliana. Subcellular localization analysis of SRRP1-GFP fusion proteins revealed that SRRP1 is localized to the chloroplast.

Improved recombinant cellulase expression in chloroplast of tobacco through promoter engineering and 5' amplification promoting sequence.

Economical production of bioethanol from lignocellulosic biomass still faces many technical limitations. Cost-effective production of fermentable sugars is still not practical for large-scale production of bioethanol due to high costs of lignocellulolytic enzymes. Therefore, plant molecular farming, where plants are used as bioreactors, was developed for the mass production of cell wall degrading enzymes that will help reduce costs.

Role of pCeMT, a putative metallothionein from Colocasia esculenta, in response to metal stress.

Metallothioneins (MTs) play a major role in metal homeostasis and/or detoxification in plants. In this study, a novel gene, pCeMT, was isolated from Colocasia esculenta and characterized. Our results indicate that Escherichia coli cells expressing pCeMT exhibited enhanced Cd, Cu, and Zn tolerance and accumulation compared with control cells.

The transgenic poplar as an efficient bioreactor system for the production of xylanase.

Plants are attractive expression systems for large-scale, low-cost production of high-value proteins. The xylanase 2 gene (Xyn2), encoding an endo-β-1,4-xylanase from Trichoderma reesei, was cloned and expressed in Escherichia coli and the poplar (Populus spp.).

Zn tolerance of novel Colocasia esculenta metallothionein and its domains in Escherichia coli and tobacco.

Contrary to extensive researches on the roles of metallothioneins (MTs) in metal tolerance of animals, the roles of plant MTs in metal tolerance are largely under investigation. In this study, we evaluated the functional role of type 2 MT from Colocasia esculenta (CeMT2b) in Zn tolerance of tobacco and E. coli cells.

High cadmium-binding ability of a novel Colocasia esculenta metallothionein increases cadmium tolerance in Escherichia coli and tobacco.

Experimental evidence in vivo as to the functional roles and binding properties to cadmium (Cd) of type-2 plants metallothionein (MT) has been limited thus far. We investigated the biological role of metallothionein from Colocasia esculenta (CeMT2b) in Escherichia coli and tobacco, and developed a new model for the relationship between Cd tolerance and Cd-binding ability. Heterologous expression of CeMT2b in Escherichia coli greatly enhanced Cd tolerance and accumulated Cd content as compared to control cells.

In planta differential targeting analysis of Thermotoga maritima Cel5A and CBM6-engineered Cel5A for autohydrolysis.

The heterologous expression of glycosyl hydrolases in bioenergy crops can improve the lignocellulosic conversion process for ethanol production. We attempted to obtain high-level expression of an intact Thermotoga maritima endoglucanase, Cel5A, and CBM6-engineered Cel5A in transgenic tobacco plants for the mass production and autohydrolysis of endoglucanase. Cel5A expression was targeted to different subcellular compartments, namely, the cytosol, apoplast, and chloroplast, using the native form of the pathogenesis-related protein 1a (PR1a) and Rubisco activase (RA) transit peptides.

Cold shock domain proteins affect seed germination and growth of Arabidopsis thaliana under abiotic stress conditions.

Unlike the well-known functions of cold shock proteins in prokaryotes during cold adaptation, the biological functions of cold shock domain proteins (CSDPs) in plants remain largely unknown. Here, we examined the functional roles of two structurally different CSDPs, CSDP1 harboring a long C-terminal glycine-rich region interspersed with seven CCHC-type zinc fingers and CSDP2 containing a far shorter glycine-rich region interspersed with two CCHC-type zinc fingers, in Arabidopsis thaliana under stress conditions. CSDP1 overexpression delayed the seed germination of Arabidopsis under dehydration or salt stress conditions, whereas CSDP2 overexpression accelerated the seed germination of Arabidopsis under salt stress conditions.

A MAPK pathway is involved in the control of cortical granule reaction and mitosis during bovine fertilization.

In order to understand the mechanism by which mitogen-activated protein kinase (MAPK) regulates fertilization, we examined the effect of the MAPK pathway inhibitor U0126 on polyspermy, cortical granule reaction and mitosis in bovine oocytes during and after fertilization. Oocytes were treated with 30 microM U0126 for 30 min prior to insemination, or from 15 to 27 hr following insemination. Western blotting with antibodies that detect active, phosphorylated MAPK revealed that MAPK activity was decreased in U0126 treated oocytes.

Survivin protein expression in bovine follicular oocytes and their in vitro developmental competence.

This study examined the relationship between survivin expression and the stage of development of in vitro cultured bovine oocytes and embryos; and whether survivin expression is affected by the quality of cumulus-oocyte complexes (COCS) or the quality of pre-implantation embryos. A polyclonal antibody was prepared using recombinant bovine survivin protein. Expression of survivin mRNA and protein was analyzed by real-time quantitative RT-PCR and immunocytochemistry.

A zinc finger-containing glycine-rich RNA-binding protein, atRZ-1a, has a negative impact on seed germination and seedling growth of Arabidopsis thaliana under salt or drought stress conditions.

Despite the fact that glycine-rich RNA-binding proteins (GRPs) have been implicated in the responses of plants to changing environmental conditions, the reports demonstrating their biological roles are severely limited. Here, we examined the functional roles of a zinc finger-containing GRP, designated atRZ-1a, in Arabidopsis thaliana under drought or salt stress conditions. Transgenic Arabidopsis plants overexpressing atRZ-1a displayed retarded germination and seedling growth compared with the wild-type plants under salt or dehydration stress conditions.

Cold shock domain proteins and glycine-rich RNA-binding proteins from Arabidopsis thaliana can promote the cold adaptation process in Escherichia coli.

Despite the fact that cold shock domain proteins (CSDPs) and glycine-rich RNA-binding proteins (GRPs) have been implicated to play a role during the cold adaptation process, their importance and function in eukaryotes, including plants, are largely unknown. To understand the functional role of plant CSDPs and GRPs in the cold response, two CSDPs (CSDP1 and CSDP2) and three GRPs (GRP2, GRP4 and GRP7) from Arabidopsis thaliana were investigated. Heterologous expression of CSDP1 or GRP7 complemented the cold sensitivity of BX04 mutant Escherichia coli that lack four cold shock proteins (CSPs) and is highly sensitive to cold stress, and resulted in better survival rate than control cells during incubation at low temperature.

Characterization of transgenic Arabidopsis plants overexpressing high mobility group B proteins under high salinity, drought or cold stress.

High mobility group B (HMGB) proteins found in the nuclei of higher eukaryotes play roles in various cellular processes such as replication, transcription and nucleosome assembly. The Arabidopsis thaliana genome contains eight genes encoding HMGB proteins, the functions of which remain largely unknown in the transcriptional regulation of plant stress responses. To understand better the functions of HMGB proteins in the responses of plants to environmental stimuli, we examined the effect of various abiotic stresses on germination and growth of transgenic Arabidopsis plants that overexpress a single isoform of HMGB.

The role of a zinc finger-containing glycine-rich RNA-binding protein during the cold adaptation process in Arabidopsis thaliana.

The mechanistic role of a glycine-rich RNA-binding protein designated atRZ-1a that contributes to enhance cold tolerance in Arabidopsis was investigated. Overexpression of atRZ-1a did not affect the expression of various cold-responsive genes such as COR6.6, COR15a, COR47, RD29A, RD29B and LTI29.

Characterization of transgenic Arabidopsis plants overexpressing GR-RBP4 under high salinity, dehydration, or cold stress.

A glycine-rich RNA-binding protein4 (GR-RBP4), one of the eight GR-RBP family members in Arabidopsis thaliana, was investigated for its stress-related expression, nucleic acid-binding property, and functional roles in plants subjected to various stresses including cold, high salinity, and dehydration. Real-time RT-PCR and GUS expression analyses showed that GR-RBP4 was abundantly expressed in young plants, root tips, and flowers, but weakly in mature leaves and stems, implying that GR-RBP4 is highly expressed in actively proliferating organs. The transcript level of GR-RBP4 increased markedly with cold stress, decreased significantly with salt stress, and decreased slightly with dehydration stress.

Cold-inducible zinc finger-containing glycine-rich RNA-binding protein contributes to the enhancement of freezing tolerance in Arabidopsis thaliana.

Glycine-rich RNA-binding proteins (GR-RBPs) have been implicated to play roles in post-transcriptional regulation of gene expression in plants under various stress conditions, but the functional roles of GR-RBPs under stress conditions remain to be verified. Here, we examine the biological roles of a GR-RBP, designated atRZ-1a, in Arabidopsis thaliana under stress conditions. atRZ-1a was expressed ubiquitously in various Arabidopsis organs including stems, roots, leaves, flowers, and siliques.