共查询到20条相似文献，搜索用时 0 毫秒
1.
2.
3.
4.
Heiko Tobias Schumacher Evgenia Vamvaka Kriton Kalantidis 《The Plant journal : for cell and molecular biology》2016,88(5):839-853
Proteins belonging to the enhancer of RNA interference‐1 subfamily of 3′–5′ exoribonucleases participate in divergent RNA pathways. They degrade small interfering RNAs (siRNAs), thus suppressing RNA interference, and are involved in the maturation of ribosomal RNAs and the degradation of histone messenger RNAs (mRNAs). Here, we report evidence for the role of the plant homologue of these proteins, which we termed ENHANCED RNA INTERFERENCE‐1‐LIKE‐1 (ERIL1), in chloroplast function. In vitro assays with AtERIL1 proved that the conserved 3′–5′ exonuclease activity is shared among all homologues studied. Confocal microscopy revealed that ERL1, a nucleus‐encoded protein, is targeted to the chloroplast. To gain insight into its role in plants, we used Nicotiana benthamiana and Arabidopsis thaliana plants that constitutively overexpress or suppress ERIL1. In the mutant lines of both species we observed malfunctions in photosynthetic ability. Molecular analysis showed that ERIL1 participates in the processing of chloroplastic ribosomal RNAs (rRNAs). Lastly, our results suggest that the missexpression of ERIL1 may have an indirect effect on the microRNA (miRNA) pathway. Altogether our data point to an additional piece of the puzzle in the complex RNA metabolism of chloroplasts. 相似文献
5.
Tamara Muñoz‐Nortes José Manuel Pérez‐Pérez María Rosa Ponce Héctor Candela José Luis Micol 《The Plant journal : for cell and molecular biology》2017,89(5):870-884
The characterization of mutants with altered leaf shape and pigmentation has previously allowed the identification of nuclear genes that encode plastid‐localized proteins that perform essential functions in leaf growth and development. A large‐scale screen previously allowed us to isolate ethyl methanesulfonate‐induced mutants with small rosettes and pale green leaves with prominent marginal teeth, which were assigned to a phenotypic class that we dubbed Angulata. The molecular characterization of the 12 genes assigned to this phenotypic class should help us to advance our understanding of the still poorly understood relationship between chloroplast biogenesis and leaf morphogenesis. In this article, we report the phenotypic and molecular characterization of the angulata7‐1 (anu7‐1) mutant of Arabidopsis thaliana, which we found to be a hypomorphic allele of the EMB2737 gene, which was previously known only for its embryonic‐lethal mutations. ANU7 encodes a plant‐specific protein that contains a domain similar to the central cysteine‐rich domain of DnaJ proteins. The observed genetic interaction of anu7‐1 with a loss‐of‐function allele of GENOMES UNCOUPLED1 suggests that the anu7‐1 mutation triggers a retrograde signal that leads to changes in the expression of many genes that normally function in the chloroplasts. Many such genes are expressed at higher levels in anu7‐1 rosettes, with a significant overrepresentation of those required for the expression of plastid genome genes. Like in other mutants with altered expression of plastid‐encoded genes, we found that anu7‐1 exhibits defects in the arrangement of thylakoidal membranes, which appear locally unappressed. 相似文献
6.
Jean‐Sébastien Parent Nathalie Bouteiller Taline Elmayan Hervé Vaucheret 《The Plant journal : for cell and molecular biology》2015,81(2):223-232
Dicer proteins are central to the different mechanisms involving RNA interference. Plants have evolved multiple DICER‐LIKE (DCL) copies, thus enabling functional diversification. In Arabidopsis, DCL2 and DCL4 process double‐stranded RNA into 22 and 21 nucleotide small interfering (si)RNAs, respectively, and have overlapping functions with regards to virus and transgene silencing. Nonetheless, some studies have reported that dcl2 or dcl4 single mutations are sometimes sufficient to hinder silencing. To better dissect the role of DCL2 and DCL4, we analyzed silencing kinetics and efficiencies using different transgenic systems in single and double mutant backgrounds. The results indicate that DCL2 stimulates transitivity and secondary siRNA production through DCL4 while being sufficient for silencing on its own. Notably, silencing of 35S‐driven transgenes functions more efficiently in dcl4 mutants, indicating that DCL4 mostly obscures DCL2 in wild‐type plants. Nonetheless, in a dcl4 mutant compromised in phloem‐originating silencing, ectopically expressed DCL2 allows restoration of silencing, suggesting that DCL2 is not, or poorly, expressed in phloem. Remarkably, this ectopic DCL2 contribution to phloem‐originating silencing is dependent on the activity of RNA‐DEPENDENT RNA POLYMERASE6. These results indicate that, despite differences in the silencing activity of their small RNA products, DCL2 and DCL4 mostly act redundantly yet hierarchically when present simultaneously. 相似文献
7.
Arnaud Germain Maureen R. Hanson Stéphane Bentolila 《The Plant journal : for cell and molecular biology》2015,83(3):546-554
RNA editing in plants, animals, and humans modifies genomically encoded cytidine or adenosine nucleotides to uridine or inosine, respectively, in mRNAs. We customized the MassARRAY System (Sequenom Inc., San Diego, CA, USA, www.sequenom.com ) to assay multiplex PCR‐amplified single‐stranded cDNAs and easily analyse and display the captured data. By using appropriate oligonucleotide probes, the method can be tailored to any organism and gene where RNA editing occurs. Editing extent of up to 40 different nucleotides in each of either 94 or 382 different samples (3760 or 15 280 editing targets, respectively) can be examined by assaying a single plate and by performing one repetition. We have established this mass spectrometric method as a dependable, cost‐effective and time‐saving technique to examine the RNA editing efficiency at 37 Arabidopsis thaliana chloroplast editing sites at a high level of multiplexing. The high‐throughput editing assay, named Multiplex RT‐PCR Mass Spectrometry (MRMS), is ideal for large‐scale experiments such as identifying population variation, examining tissue‐specific changes in editing extent, or screening a mutant or transgenic collection. Moreover, the required amount of starting material is so low that RNA from fewer than 50 cells can be examined without amplification. We demonstrate the use of the method to identify natural variation in editing extent of chloroplast C targets in a collection of Arabidopsis accessions. 相似文献
8.
9.
10.
11.
Zhi‐Yan Du Mo‐Xian Chen Qin‐Fang Chen Shi Xiao Mee‐Len Chye 《The Plant journal : for cell and molecular biology》2013,74(2):294-309
A family of six genes encoding acyl‐CoA‐binding proteins (ACBPs), ACBP1–ACBP6, has been characterized in Arabidopsis thaliana. In this study, we demonstrate that ACBP1 promotes abscisic acid (ABA) signaling during germination and seedling development. ACBP1 was induced by ABA, and transgenic Arabidopsis ACBP1‐over‐expressors showed increased sensitivity to ABA during germination and seedling development, whereas the acbp1 mutant showed decreased ABA sensitivity during these processes. Subsequent RNA assays showed that ACBP1 over‐production in 12‐day‐old seedlings up‐regulated the expression of PHOSPHOLIPASE Dα1 (PLDα1) and three ABA/stress‐responsive genes: ABA‐RESPONSIVE ELEMENT BINDING PROTEIN1 (AREB1), RESPONSE TO DESICCATION29A (RD29A) and bHLH‐TRANSCRIPTION FACTOR MYC2 (MYC2). The expression of AREB1 and PLDα1 was suppressed in the acbp1 mutant in comparison with the wild type following ABA treatment. PLDα1 has been reported to promote ABA signal transduction by producing phosphatidic acid, an important lipid messenger in ABA signaling. Using lipid profiling, seeds and 12‐day‐old seedlings of ACBP1‐over‐expressing lines were shown to accumulate more phosphatidic acid after ABA treatment, in contrast to lower phosphatidic acid in the acbp1 mutant. Bimolecular fluorescence complementation assays indicated that ACBP1 interacts with PLDα1 at the plasma membrane. Their interaction was further confirmed by yeast two‐hybrid analysis. As recombinant ACBP1 binds phosphatidic acid and phosphatidylcholine, ACBP1 probably promotes PLDα1 action. Taken together, these results suggest that ACBP1 participates in ABA‐mediated seed germination and seedling development. 相似文献
12.
13.
14.
15.
Y.‐C. Hsueh K. Nicolaisen L. E. Gross J. Nöthen N. Schauer L. Vojta F. Ertel I. Koch R. Ladig H. Fulgosi A. R. Fernie E. Schleiff 《Plant biology (Stuttgart, Germany)》2018,20(5):825-833
- The Omp85 proteins form a large membrane protein family in bacteria and eukaryotes. Omp85 proteins are composed of a C‐terminal β‐barrel‐shaped membrane domain and one or more N‐terminal polypeptide transport‐associated (POTRA) domains. However, Arabidopsis thaliana contains two genes coding for Omp85 proteins without a POTRA domain. One gene is designated P39, according to the molecular weight of the encoded protein. The protein is targeted to plastids and it was established that p39 has electrophysiological properties similar to other Omp85 family members, particularly to that designated as Toc75V/Oep80.
- We analysed expression of the gene and characterised two T‐DNA insertion mutants, focusing on alterations in photosynthetic activity, plastid ultrastructure, global expression profile and metabolome.
- We observed pronounced expression of P39, especially in veins. Mutants of P39 show growth aberrations, reduced photosynthetic activity and changes in plastid ultrastructure, particularly in the leaf tip. Further, they display global alteration of gene expression and metabolite content in leaves of mature plants.
- We conclude that the function of the plastid‐localised and vein‐specific Omp85 family protein p39 is important, but not essential, for maintenance of metabolic homeostasis of full‐grown A. thaliana plants. Further, the function of p39 in veins influences the functionality of other plant tissues. The link connecting p39 function with metabolic regulation in mature A. thaliana is discussed.
16.
Yonghong Zhou Georg Hölzl Katharina vom Dorp Helga Peisker Michael Melzer Margrit Frentzen Peter Dörmann 《The Plant journal : for cell and molecular biology》2017,89(2):221-234
Phosphatidylglycerol (PG) is the only phospholipid in the thylakoid membranes of chloroplasts of plants, and it is also found in extraplastidial membranes including mitochondria and the endoplasmic reticulum. Previous studies showed that lack of PG in the pgp1‐2 mutant of Arabidopsis deficient in phosphatidylglycerophosphate (PGP) synthase strongly affects thylakoid biogenesis and photosynthetic activity. In the present study, the gene encoding the enzyme for the second step of PG synthesis, PGP phosphatase, was isolated based on sequence similarity to the yeast GEP4 and Chlamydomonas PGPP1 genes. The Arabidopsis AtPGPP1 protein localizes to chloroplasts and harbors PGP phosphatase activity with alkaline pH optimum and divalent cation requirement. Arabidopsis pgpp1‐1 mutant plants contain reduced amounts of chlorophyll, but photosynthetic quantum yield remains unchanged. The absolute content of plastidial PG (34:4; total number of acyl carbons:number of double bonds) is reduced by about 1/3, demonstrating that AtPGPP1 is involved in the synthesis of plastidial PG. PGP 34:3, PGP 34:2 and PGP 34:1 lacking 16:1 accumulate in pgpp1‐1, indicating that the desaturation of 16:0 to 16:1 by the FAD4 desaturase in the chloroplasts only occurs after PGP dephosphorylation. 相似文献
17.
18.
Alexander Sullivan Priyank K. Purohit Nowlan H. Freese Asher Pasha Eddi Esteban Jamie Waese Alison Wu Michelle Chen Chih Y. Chin Richard Song Sneha R. Watharkar Agnes P. Chan Vivek Krishnakumar Matthew W. Vaughn Chris Town Ann E. Loraine Nicholas J. Provart 《The Plant journal : for cell and molecular biology》2019,100(3):641-654
19.
Yubing Li Rajneesh Singhal Isaiah W. Taylor Patrick H. McMinn Xien Yu Chua Kenneth Cline Donna E. Fernandez 《The Plant journal : for cell and molecular biology》2015,84(4):647-658
Biogenesis of chloroplasts involves a series of protein trafficking events. Nuclear‐encoded proteins are imported into the organelle, and then trafficked to various chloroplast locations by systems that are directly homologous to bacterial systems. Although the thylakoid‐based systems have been studied extensively, much less is known about the systems that reside and function in the inner envelope membrane. One such system, the Sec2 system, is homologous to both the thylakoid‐based Sec1 system and bacterial Sec systems, and may mediate both integration and translocation across the inner envelope. At a minimum, this system is expected to include three components, but only two, SCY2 and SECA2, have been identified in Arabidopsis. Bioinformatics and protein modeling were used to identify the protein encoded by At4g38490 as a candidate for the missing component (SECE2). Cellular localization, biochemistry, protein interaction assays in yeast, and co‐immunoprecipitation experiments were used to establish that this protein is an integral membrane protein of the inner envelope, and specifically interacts with the SCY2 component in vivo. Sequence analyses indicated that SECE2 proteins are found in a variety of plants, and differ from the thylakoid SECE1 proteins in a stroma‐exposed helical domain, which may contribute to their specificity. Finally, a genetic analysis indicated that SECE2 plays an essential role in plant growth and development. 相似文献
20.
Thioredoxins (Trxs) regulate the activity of various chloroplastic proteins in a light‐dependent manner. Five types of Trxs function in different physiological processes in the chloroplast of Arabidopsis thaliana. Previous in vitro experiments have suggested that the f‐type Trx (Trx f) is the main redox regulator of chloroplast enzymes, including Calvin cycle enzymes. To investigate the in vivo contribution of each Trx isoform to the redox regulatory system, we first quantified the protein concentration of each Trx isoform in the chloroplast stroma. The m‐type Trx (Trx m), which consists of four isoforms, was the most abundant type. Next, we analyzed several Arabidopsis Trx‐m‐deficient mutants to elucidate the physiological role of Trx m in vivo. Deficiency of Trx m impaired plant growth and decreased the CO2 assimilation rate. We also determined the redox state of Trx target enzymes to examine their photo‐reduction, which is essential for enzyme activation. In the Trx‐m‐deficient mutants, the reduction level of fructose‐1,6‐bisphosphatase and sedoheptulose‐1,7‐bisphosphatase was lower than that in the wild type. Inconsistently with the historical view, our in vivo study suggested that Trx m plays a more important role than Trx f in the activation of Calvin cycle enzymes. 相似文献