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Due Tankmar M, Reichel M, Arribas-Hernández L, Brodersen P. A YTHDF-PABP interaction is required for m 6 A-mediated organogenesis in plants. EMBO Rep 2023; 24:e57741. [PMID: 38009565 DOI: 10.15252/embr.202357741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 10/25/2023] [Accepted: 10/27/2023] [Indexed: 11/29/2023] Open
Abstract
N6-methyladenosine (m6 A) in mRNA is key to eukaryotic gene regulation. Many m6 A functions involve RNA-binding proteins that recognize m6 A via a YT521-B Homology (YTH) domain. YTH domain proteins contain long intrinsically disordered regions (IDRs) that may mediate phase separation and interaction with protein partners, but whose precise biochemical functions remain largely unknown. The Arabidopsis thaliana YTH domain proteins ECT2, ECT3, and ECT4 accelerate organogenesis through stimulation of cell division in organ primordia. Here, we use ECT2 to reveal molecular underpinnings of this function. We show that stimulation of leaf formation requires the long N-terminal IDR, and we identify two short IDR elements required for ECT2-mediated organogenesis. Of these two, a 19-amino acid region containing a tyrosine-rich motif conserved in both plant and metazoan YTHDF proteins is necessary for binding to the major cytoplasmic poly(A)-binding proteins PAB2, PAB4, and PAB8. Remarkably, overexpression of PAB4 in leaf primordia partially rescues the delayed leaf formation in ect2 ect3 ect4 mutants, suggesting that the ECT2-PAB2/4/8 interaction on target mRNAs of organogenesis-related genes may overcome limiting PAB concentrations in primordial cells.
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Affiliation(s)
| | - Marlene Reichel
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Peter Brodersen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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Xie E, Chen J, Wang B, Shen Y, Tang D, Du G, Li Y, Cheng Z. The transcribed centromeric gene OsMRPL15 is essential for pollen development in rice. PLANT PHYSIOLOGY 2023; 192:1063-1079. [PMID: 36905369 PMCID: PMC10231452 DOI: 10.1093/plphys/kiad153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/19/2023] [Accepted: 02/15/2023] [Indexed: 06/01/2023]
Abstract
Centromeres consist of highly repetitive sequences that are challenging to map, clone, and sequence. Active genes exist in centromeric regions, but their biological functions are difficult to explore owing to extreme suppression of recombination in these regions. In this study, we used the CRISPR/Cas9 system to knock out the transcribed gene Mitochondrial Ribosomal Protein L15 (OsMRPL15), located in the centromeric region of rice (Oryza sativa) chromosome 8, resulting in gametophyte sterility. Osmrpl15 pollen was completely sterile, with abnormalities appearing at the tricellular stage including the absence of starch granules and disrupted mitochondrial structure. Loss of OsMRPL15 caused abnormal accumulation of mitoribosomal proteins and large subunit rRNA in pollen mitochondria. Moreover, the biosynthesis of several proteins in mitochondria was defective, and expression of mitochondrial genes was upregulated at the mRNA level. Osmrpl15 pollen contained smaller amounts of intermediates related to starch metabolism than wild-type pollen, while biosynthesis of several amino acids was upregulated, possibly to compensate for defective mitochondrial protein biosynthesis and initiate consumption of carbohydrates necessary for starch biosynthesis. These results provide further insight into how defects in mitoribosome development cause gametophyte male sterility.
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Affiliation(s)
- En Xie
- College of Agriculture, South China Agricultural University, Guangzhou 510642, China
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Jiawei Chen
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Bingxin Wang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Yi Shen
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Ding Tang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Guijie Du
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Yafei Li
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhukuan Cheng
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
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Ahouvi Y, Haber Z, Zach YY, Rosental L, Toubiana D, Sharma D, Alseekh S, Tajima H, Fernie AR, Brotman Y, Blumwald E, Sade N. The Alteration of Tomato Chloroplast Vesiculation Positively Affects Whole-Plant Source-Sink Relations and Fruit Metabolism under Stress Conditions. PLANT & CELL PHYSIOLOGY 2023; 63:2008-2026. [PMID: 36161338 DOI: 10.1093/pcp/pcac133] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 09/14/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Changes in climate conditions can negatively affect the productivity of crop plants. They can induce chloroplast degradation (senescence), which leads to decreased source capacity, as well as decreased whole-plant carbon/nitrogen assimilation and allocation. The importance, contribution and mechanisms of action regulating source-tissue capacity under stress conditions in tomato (Solanum lycopersicum) are not well understood. We hypothesized that delaying chloroplast degradation by altering the activity of the tomato chloroplast vesiculation (CV) under stress would lead to more efficient use of carbon and nitrogen and to higher yields. Tomato CV is upregulated under stress conditions. Specific induction of CV in leaves at the fruit development stage resulted in stress-induced senescence and negatively affected fruit yield, without any positive effects on fruit quality. Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9 (CRISPR/CAS9) knockout CV plants, generated using a near-isogenic tomato line with enhanced sink capacity, exhibited stress tolerance at both the vegetative and the reproductive stages, leading to enhanced fruit quantity, quality and harvest index. Detailed metabolic and transcriptomic network analysis of sink tissue revealed that the l-glutamine and l-arginine biosynthesis pathways are associated with stress-response conditions and also identified putative novel genes involved in tomato fruit quality under stress. Our results are the first to demonstrate the feasibility of delayed stress-induced senescence as a stress-tolerance trait in a fleshy fruit crop, to highlight the involvement of the CV pathway in the regulation of source strength under stress and to identify genes and metabolic pathways involved in increased tomato sink capacity under stress conditions.
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Affiliation(s)
- Yoav Ahouvi
- School of Plant Sciences and Food Security, Tel Aviv University, P.O.B. 39040, 55 Haim Levanon St., Tel Aviv 6139001, Israel
| | - Zechariah Haber
- School of Plant Sciences and Food Security, Tel Aviv University, P.O.B. 39040, 55 Haim Levanon St., Tel Aviv 6139001, Israel
| | - Yair Yehoshua Zach
- School of Plant Sciences and Food Security, Tel Aviv University, P.O.B. 39040, 55 Haim Levanon St., Tel Aviv 6139001, Israel
| | - Leah Rosental
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, 1 David Ben Gurion Blvd., Beer-Sheva 8410501, Israel
| | - David Toubiana
- School of Plant Sciences and Food Security, Tel Aviv University, P.O.B. 39040, 55 Haim Levanon St., Tel Aviv 6139001, Israel
| | - Davinder Sharma
- School of Plant Sciences and Food Security, Tel Aviv University, P.O.B. 39040, 55 Haim Levanon St., Tel Aviv 6139001, Israel
| | - Saleh Alseekh
- Department of Root Biology and Symbiosis, Max Planck Institute of Molecular Plant Physiology, 1 Am Mühlenberg, Golm, Potsdam 14476, Germany
- Department of Plant Metabolomics, Center for Plant Systems Biology and Biotechnology, 139 Ruski Blvd., Plovdiv 4000, Bulgaria
| | - Hiromi Tajima
- Department of Plant Sciences, University of California, 1 Shields Ave., Davis, CA 95616, USA
| | - Alisdair R Fernie
- Department of Root Biology and Symbiosis, Max Planck Institute of Molecular Plant Physiology, 1 Am Mühlenberg, Golm, Potsdam 14476, Germany
- Department of Plant Metabolomics, Center for Plant Systems Biology and Biotechnology, 139 Ruski Blvd., Plovdiv 4000, Bulgaria
| | - Yariv Brotman
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, 1 David Ben Gurion Blvd., Beer-Sheva 8410501, Israel
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, 1 Shields Ave., Davis, CA 95616, USA
| | - Nir Sade
- School of Plant Sciences and Food Security, Tel Aviv University, P.O.B. 39040, 55 Haim Levanon St., Tel Aviv 6139001, Israel
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Krzyszton M, Kufel J. Analysis of mRNA-derived siRNAs in mutants of mRNA maturation and surveillance pathways in Arabidopsis thaliana. Sci Rep 2022; 12:1474. [PMID: 35087200 PMCID: PMC8795450 DOI: 10.1038/s41598-022-05574-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/14/2022] [Indexed: 02/05/2023] Open
Abstract
Defects in RNA maturation and RNA decay factors may generate substrates for the RNA interference machinery. This phenomenon was observed in plants where mutations in some RNA-related factors lead to the production of RNA-quality control small interfering RNAs and several mutants show enhanced silencing of reporter transgenes. To assess the potential of RNAi activation on endogenous transcripts, we sequenced small RNAs from a set of Arabidopsis thaliana mutants with defects in various RNA metabolism pathways. We observed a global production of siRNAs caused by inefficient pre-mRNA cleavage and polyadenylation leading to read-through transcription into downstream antisense genes. In addition, in the lsm1a lsm1b double mutant, we identified NIA1, SMXL5, and several miRNA-targeted mRNAs as producing siRNAs, a group of transcripts suggested being especially sensitive to deficiencies in RNA metabolism. However, in most cases, RNA metabolism perturbations do not lead to the widespread production of siRNA derived from mRNA molecules. This observation is contrary to multiple studies based on reporter transgenes and suggests that only a very high accumulation of defective mRNA species caused by specific mutations or substantial RNA processing defects trigger RNAi pathways.
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Affiliation(s)
- Michal Krzyszton
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.
| | - Joanna Kufel
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Pawinskiego 5a, 02-106, Warsaw, Poland.
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Urquidi-Camacho RA, Lokdarshi A, von Arnim AG. Translational gene regulation in plants: A green new deal. WILEY INTERDISCIPLINARY REVIEWS. RNA 2020; 11:e1597. [PMID: 32367681 PMCID: PMC9258721 DOI: 10.1002/wrna.1597] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 01/09/2023]
Abstract
The molecular machinery for protein synthesis is profoundly similar between plants and other eukaryotes. Mechanisms of translational gene regulation are embedded into the broader network of RNA-level processes including RNA quality control and RNA turnover. However, over eons of their separate history, plants acquired new components, dropped others, and generally evolved an alternate way of making the parts list of protein synthesis work. Research over the past 5 years has unveiled how plants utilize translational control to defend themselves against viruses, regulate translation in response to metabolites, and reversibly adjust translation to a wide variety of environmental parameters. Moreover, during seed and pollen development plants make use of RNA granules and other translational controls to underpin developmental transitions between quiescent and metabolically active stages. The economics of resource allocation over the daily light-dark cycle also include controls over cellular protein synthesis. Important new insights into translational control on cytosolic ribosomes continue to emerge from studies of translational control mechanisms in viruses. Finally, sketches of coherent signaling pathways that connect external stimuli with a translational response are emerging, anchored in part around TOR and GCN2 kinase signaling networks. These again reveal some mechanisms that are familiar and others that are different from other eukaryotes, motivating deeper studies on translational control in plants. This article is categorized under: Translation > Translation Regulation RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Ricardo A. Urquidi-Camacho
- UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996
| | - Ansul Lokdarshi
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Albrecht G von Arnim
- Department of Biochemistry & Cellular and Molecular Biology and UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996
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Zhao T, Huan Q, Sun J, Liu C, Hou X, Yu X, Silverman IM, Zhang Y, Gregory BD, Liu CM, Qian W, Cao X. Impact of poly(A)-tail G-content on Arabidopsis PAB binding and their role in enhancing translational efficiency. Genome Biol 2019; 20:189. [PMID: 31481099 PMCID: PMC6724284 DOI: 10.1186/s13059-019-1799-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 08/22/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Polyadenylation plays a key role in producing mature mRNAs in eukaryotes. It is widely believed that the poly(A)-binding proteins (PABs) uniformly bind to poly(A)-tailed mRNAs, regulating their stability and translational efficiency. RESULTS We observe that the homozygous triple mutant of broadly expressed Arabidopsis thaliana PABs, AtPAB2, AtPAB4, and AtPAB8, is embryonic lethal. To understand the molecular basis, we characterize the RNA-binding landscape of these PABs. The AtPAB-binding efficiency varies over one order of magnitude among genes. To identify the sequences accounting for the variation, we perform poly(A)-seq that directly sequences the full-length poly(A) tails. More than 10% of poly(A) tails contain at least one guanosine (G); among them, the G-content varies from 0.8 to 28%. These guanosines frequently divide poly(A) tails into interspersed A-tracts and therefore cause the variation in the AtPAB-binding efficiency among genes. Ribo-seq and genome-wide RNA stability assays show that AtPAB-binding efficiency of a gene is positively correlated with translational efficiency rather than mRNA stability. Consistently, genes with stronger AtPAB binding exhibit a greater reduction in translational efficiency when AtPAB is depleted. CONCLUSIONS Our study provides a new mechanism that translational efficiency of a gene can be regulated through the G-content-dependent PAB binding, paving the way for a better understanding of poly(A) tail-associated regulation of gene expression.
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Affiliation(s)
- Taolan Zhao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Genetic Network Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qing Huan
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Genetic Network Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jing Sun
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chunyan Liu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiuli Hou
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xiang Yu
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ian M Silverman
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yi Zhang
- Laboratory for Genome Regulation and Human Health and Center for Genome Analysis, ABLife Inc, Wuhan, 430075, Hubei, China
| | - Brian D Gregory
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Chun-Ming Liu
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Wenfeng Qian
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- Key Laboratory of Genetic Network Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xiaofeng Cao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
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Zoltner M, Krienitz N, Field MC, Kramer S. Comparative proteomics of the two T. brucei PABPs suggests that PABP2 controls bulk mRNA. PLoS Negl Trop Dis 2018; 12:e0006679. [PMID: 30040867 PMCID: PMC6075789 DOI: 10.1371/journal.pntd.0006679] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 08/03/2018] [Accepted: 07/10/2018] [Indexed: 01/17/2023] Open
Abstract
Poly(A)-binding proteins (PABPs) regulate mRNA fate by controlling stability and translation through interactions with both the poly(A) tail and eIF4F complex. Many organisms have several paralogs of PABPs and eIF4F complex components and it is likely that different eIF4F/PABP complex combinations regulate distinct sets of mRNAs. Trypanosomes have five eIF4G paralogs, six of eIF4E and two PABPs, PABP1 and PABP2. Under starvation, polysomes dissociate and the majority of mRNAs, most translation initiation factors and PABP2 reversibly localise to starvation stress granules. To understand this more broadly we identified a protein interaction cohort for both T. brucei PABPs by cryo-mill/affinity purification-mass spectrometry. PABP1 very specifically interacts with the previously identified interactors eIF4E4 and eIF4G3 and few others. In contrast PABP2 is promiscuous, with a larger set of interactors including most translation initiation factors and most prominently eIF4G1, with its two partners TbG1-IP and TbG1-IP2. Only RBP23 was specific to PABP1, whilst 14 RNA-binding proteins were exclusively immunoprecipitated with PABP2. Significantly, PABP1 and associated proteins are largely excluded from starvation stress granules, but PABP2 and most interactors translocate to granules on starvation. We suggest that PABP1 regulates a small subpopulation of mainly small-sized mRNAs, as it interacts with a small and distinct set of proteins unable to enter the dominant pathway into starvation stress granules and localises preferentially to a subfraction of small polysomes. By contrast PABP2 likely regulates bulk mRNA translation, as it interacts with a wide range of proteins, enters stress granules and distributes over the full range of polysomes.
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Affiliation(s)
- Martin Zoltner
- School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Nina Krienitz
- School of Life Sciences, University of Dundee, Dundee, United Kingdom
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Mark C. Field
- School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Susanne Kramer
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany
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Gallie DR. Plant growth and fertility requires functional interactions between specific PABP and eIF4G gene family members. PLoS One 2018; 13:e0191474. [PMID: 29381712 PMCID: PMC5790229 DOI: 10.1371/journal.pone.0191474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/07/2018] [Indexed: 11/19/2022] Open
Abstract
The initiation of protein synthesis requires the involvement of the eukaryotic translation initiation factor (eIF) 4G to promote assembly of the factors needed to recruit a 40S ribosomal subunit to an mRNA. Although many eukaryotes express two eIF4G isoforms that are highly similar, those in plants, referred to as eIF4G and eIFiso4G, are highly divergent in size, sequence, and domain organization. Species of the Brassicaceae and the Cleomaceae also express a divergent eIFiso4G isoform, referred to as eIFiso4G2, not found elsewhere in the plant kingdom. Despite their divergence, eIF4G and eIFiso4G interact with eIF4A, eIF4B, and eIF4E isoforms needed for binding an mRNA. eIF4G and eIFiso4G also interact with the poly(A)-binding protein (PABP) which promotes ribosome recruitment to an mRNA. Increasing the complexity of such an interaction, however, Arabidopsis also expresses three PABP isoforms (PAB2, PAB4, and PAB8) in vegetative and reproductive tissues. In this study, the functional interactions among the eIF4G and the widely-expressed PABP isoforms were examined. Loss of PAB2 or PAB8 in combination with loss of eIF4G or eIFiso4G had little to no effect on growth or fertility whereas pab2 pab8 eif4g or pab2 pab8 eifiso4g1/2 mutants exhibited smaller stature and reduced fertility. Although the pab4 eifiso4g1 mutant grows normally and is fertile, pab4 eif4g or pab4 eifiso4g2 mutants could not be isolated. Even pab4/PAB4 eif4g/eIF4G heterozygous plants exhibited growth defects and low fertility. Mutant co-inheritance analysis in reciprocal crosses with wild-type plants revealed that most ovaries and pollen from pab4/PAB4 eif4g/eIF4G plants were PAB4 eif4g. Similarly, co-inheritance studies with pab4/PAB4 eifiso4g2/eIFiso4G2 plants suggested most ovaries were PAB4 eifiso4g2. These results suggest that a functional interaction between PAB4 and eIF4G and between PAB4 and eIFiso4G2 is required for growth and normal fertility.
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Affiliation(s)
- Daniel R. Gallie
- Department of Biochemistry, University of California, Riverside, CA, United States of America
- * E-mail:
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