Stalk lodging, which is generally determined by stalk strength, results in considerable yield loss and has become a primary threat to maize (Zea mays) yield under high-density planting. However, the molecular genetic basis of maize stalk strength remains unclear, and improvement methods remain inefficient. Here, we combined map-based cloning and association mapping and identified the gene stiff1 underlying a major quantitative trait locus for stalk strength in maize. A 27.2-kb transposable element insertion was present in the promoter of the stiff1 gene, which encodes an F-box domain protein. This transposable element insertion repressed the transcription of stiff1, leading to the increased cellulose and lignin contents in the cell wall and consequently greater stalk strength. Furthermore, a precisely edited allele of stiff1 generated through the CRISPR/Cas9 system resulted in plants with a stronger stalk than the unedited control. Nucleotide diversity analysis revealed that the promoter of stiff1 was under strong selection in the maize stiff-stalk group. Our cloning of stiff1 reveals a case in which a transposable element played an important role in maize improvement. The identification of stiff1 and our edited stiff1 allele pave the way for efficient improvement of maize stalk strength.
- MeSH
- alely MeSH
- buněčná stěna metabolismus MeSH
- CRISPR-Cas systémy MeSH
- fenotyp MeSH
- kukuřice setá genetika MeSH
- lignin metabolismus MeSH
- lokus kvantitativního znaku MeSH
- mapování chromozomů MeSH
- promotorové oblasti (genetika) * MeSH
- rostlinné geny MeSH
- rostlinné proteiny genetika metabolismus MeSH
- sekvenční analýza MeSH
- transformace genetická MeSH
- transpozibilní elementy DNA genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Centromere position may change despite conserved chromosomal collinearity. Centromere repositioning and evolutionary new centromeres (ENCs) were frequently encountered during vertebrate genome evolution but only rarely observed in plants. The largest crucifer tribe, Arabideae (∼550 species; Brassicaceae, the mustard family), diversified into several well-defined subclades in the virtual absence of chromosome number variation. Bacterial artificial chromosome-based comparative chromosome painting uncovered a constancy of genome structures among 10 analyzed genomes representing seven Arabideae subclades classified as four genera: Arabis, Aubrieta, Draba, and Pseudoturritis Interestingly, the intra-tribal diversification was marked by a high frequency of ENCs on five of the eight homoeologous chromosomes in the crown-group genera, but not in the most ancestral Pseudoturritis genome. From the 32 documented ENCs, at least 26 originated independently, including 4 ENCs recurrently formed at the same position in not closely related species. While chromosomal localization of ENCs does not reflect the phylogenetic position of the Arabideae subclades, centromere seeding was usually confined to long chromosome arms, transforming acrocentric chromosomes to (sub)metacentric chromosomes. Centromere repositioning is proposed as the key mechanism differentiating overall conserved homoeologous chromosomes across the crown-group Arabideae subclades. The evolutionary significance of centromere repositioning is discussed in the context of possible adaptive effects on recombination and epigenetic regulation of gene expression.
The membrane-embedded FtsH proteases found in bacteria, chloroplasts, and mitochondria are involved in diverse cellular processes including protein quality control and regulation. The genome of the model cyanobacterium Synechocystis sp PCC 6803 encodes four FtsH homologs designated FtsH1 to FtsH4. The FtsH3 homolog is present in two hetero-oligomeric complexes: FtsH2/3, which is responsible for photosystem II quality control, and the essential FtsH1/3 complex, which helps maintain Fe homeostasis by regulating the level of the transcription factor Fur. To gain a more comprehensive insight into the physiological roles of FtsH hetero-complexes, we performed genome-wide expression profiling and global proteomic analyses of Synechocystis mutants conditionally depleted of FtsH3 or FtsH1 grown under various nutrient conditions. We show that the lack of FtsH1/3 leads to a drastic reduction in the transcriptional response to nutrient stress of not only Fur but also the Pho, NdhR, and NtcA regulons. In addition, this effect is accompanied by the accumulation of the respective transcription factors. Thus, the FtsH1/3 complex is of critical importance for acclimation to iron, phosphate, carbon, and nitrogen starvation in Synechocystis.plantcell;31/12/2912/FX1F1fx1.
- MeSH
- aklimatizace genetika MeSH
- bakteriální proteiny genetika metabolismus MeSH
- dusík nedostatek metabolismus MeSH
- exprese genu MeSH
- fosfáty nedostatek metabolismus MeSH
- fosforylace MeSH
- fotosystém II - proteinový komplex chemie genetika metabolismus MeSH
- metaloproteasy genetika metabolismus MeSH
- mutace MeSH
- proteiny vázající fosfáty genetika metabolismus MeSH
- proteolýza MeSH
- proteom genetika metabolismus MeSH
- proteomika MeSH
- regulace genové exprese u bakterií genetika MeSH
- regulon genetika MeSH
- represorové proteiny genetika metabolismus MeSH
- ribozomální proteiny genetika metabolismus MeSH
- Synechocystis enzymologie metabolismus MeSH
- transkripční faktory genetika metabolismus MeSH
- uhlík nedostatek metabolismus MeSH
- živiny nedostatek metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Plant phospholipase Ds (PLDs), essential regulators of phospholipid signaling, function in multiple signal transduction cascades; however, the mechanisms regulating PLDs in response to pathogens remain unclear. Here, we found that Arabidopsis (Arabidopsis thaliana) PLDδ accumulated in cells at the entry sites of the barley powdery mildew fungus, Blumeria graminis f. sp hordei Using fluorescence recovery after photobleaching and single-molecule analysis, we observed higher PLDδ density in the plasma membrane after chitin treatment; PLDδ also underwent rapid exocytosis. Fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy showed that the interaction between PLDδ and the microdomain marker AtREMORIN1.3 (AtREM1.3) increased in response to chitin, indicating that exocytosis facilitates rapid, efficient sorting of PLDδ into microdomains upon pathogen stimulus. We further unveiled a trade-off between brefeldin A (BFA)-resistant and -sensitive pathways in secretion of PLDδ under diverse conditions. Upon pathogen attack, PLDδ secretion involved syntaxin-associated VAMP721/722-mediated exocytosis sensitive to BFA. Analysis of phosphatidic acid (PA), hydrogen peroxide, and jasmonic acid (JA) levels and expression of related genes indicated that the relocalization of PLDδ is crucial for its activation to produce PA and initiate reactive oxygen species and JA signaling pathways. Together, our findings revealed that the translocation of PLDδ to papillae is modulated by exocytosis, thus triggering PA-mediated signaling in plant innate immunity.plantcell;31/12/3015/FX1F1fx1.
- MeSH
- Arabidopsis genetika imunologie metabolismus mikrobiologie MeSH
- Ascomycota patogenita MeSH
- brefeldin A imunologie metabolismus MeSH
- buněčná membrána metabolismus MeSH
- chitin imunologie metabolismus MeSH
- cyklopentany metabolismus MeSH
- exocytóza účinky léků imunologie MeSH
- fosfolipasa D genetika metabolismus MeSH
- kyseliny fosfatidové metabolismus MeSH
- nemoci rostlin imunologie mikrobiologie MeSH
- oxylipiny metabolismus MeSH
- peroxid vodíku metabolismus MeSH
- přirozená imunita * účinky léků MeSH
- proteiny huseníčku metabolismus MeSH
- proteiny Qa-SNARE metabolismus MeSH
- proteiny R-SNARE metabolismus MeSH
- proteiny SNARE genetika metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- signální transdukce imunologie fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Complexes of diploid and polyploid species have formed frequently during the evolution of land plants. In false flax (Camelina sativa), an important hexaploid oilseed crop closely related to Arabidopsis (Arabidopsis thaliana), the putative parental species as well as the origin of other Camelina species remained unknown. By using bacterial artificial chromosome-based chromosome painting, genomic in situ hybridization, and multi-gene phylogenetics, we aimed to elucidate the origin and evolution of the polyploid complex. Genomes of diploid camelinas (Camelina hispida, n = 7; Camelina laxa, n = 6; and Camelina neglecta, n = 6) originated from an ancestral n = 7 genome. The allotetraploid genome of Camelina rumelica (n = 13, N6H) arose from hybridization between diploids related to C. neglecta (n = 6, N6) and C. hispida (n = 7, H), and the N subgenome has undergone a substantial post-polyploid fractionation. The allohexaploid genomes of C. sativa and Camelina microcarpa (n = 20, N6N7H) originated through hybridization between an auto-allotetraploid C. neglecta-like genome (n = 13, N6N7) and C. hispida (n = 7, H), and the three subgenomes have remained stable overall since the genome merger. Remarkably, the ancestral and diploid Camelina genomes were shaped by complex chromosomal rearrangements, resembling those associated with human disorders and resulting in the origin of genome-specific shattered chromosomes.plantcell;31/11/2596/FX1F1fx1.
- MeSH
- Arabidopsis genetika MeSH
- Brassicaceae klasifikace genetika MeSH
- chromothripsis * MeSH
- chromozomy rostlin MeSH
- diploidie * MeSH
- fylogeneze MeSH
- genom rostlinný * MeSH
- hybridizace genetická MeSH
- molekulární evoluce * MeSH
- polyploidie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Oxygenic photosynthesis relies on accessory factors to promote the assembly and maintenance of the photosynthetic apparatus in the thylakoid membranes. The highly conserved membrane-bound rubredoxin-like protein RubA has previously been implicated in the accumulation of both PSI and PSII, but its mode of action remains unclear. Here, we show that RubA in the cyanobacterium Synechocystis sp PCC 6803 is required for photoautotrophic growth in fluctuating light and acts early in PSII biogenesis by promoting the formation of the heterodimeric D1/D2 reaction center complex, the site of primary photochemistry. We find that RubA, like the accessory factor Ycf48, is a component of the initial D1 assembly module as well as larger PSII assembly intermediates and that the redox-responsive rubredoxin-like domain is located on the cytoplasmic surface of PSII complexes. Fusion of RubA to Ycf48 still permits normal PSII assembly, suggesting a spatiotemporal proximity of both proteins during their action. RubA is also important for the accumulation of PSI, but this is an indirect effect stemming from the downregulation of light-dependent chlorophyll biosynthesis induced by PSII deficiency. Overall, our data support the involvement of RubA in the redox control of PSII biogenesis.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biologické pigmenty izolace a purifikace MeSH
- chlorofyl biosyntéza MeSH
- fotosyntéza fyziologie MeSH
- fotosystém I - proteinový komplex metabolismus MeSH
- fotosystém II - proteinový komplex metabolismus MeSH
- mutace MeSH
- rubredoxiny chemie genetika metabolismus MeSH
- Synechocystis genetika růst a vývoj metabolismus MeSH
- tylakoidy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The maintenance of genome integrity over cell divisions is critical for plant development and the correct transmission of genetic information to the progeny. A key factor involved in this process is the STRUCTURAL MAINTENANCE OF CHROMOSOME5 (SMC5) and SMC6 (SMC5/6) complex, related to the cohesin and condensin complexes that control sister chromatid alignment and chromosome condensation, respectively. Here, we characterize NON-SMC ELEMENT4 (NSE4) paralogs of the SMC5/6 complex in Arabidopsis (Arabidopsis thaliana). NSE4A is expressed in meristems and accumulates during DNA damage repair. Partial loss-of-function nse4a mutants are viable but hypersensitive to DNA damage induced by zebularine. In addition, nse4a mutants produce abnormal seeds, with noncellularized endosperm and embryos that maximally develop to the heart or torpedo stage. This phenotype resembles the defects in cohesin and condensin mutants and suggests a role for all three SMC complexes in differentiation during seed development. By contrast, NSE4B is expressed in only a few cell types, and loss-of-function mutants do not have any obvious abnormal phenotype. In summary, our study shows that the NSE4A subunit of the SMC5-SMC6 complex is essential for DNA damage repair in somatic tissues and plays a role in plant reproduction.
- MeSH
- Arabidopsis embryologie genetika imunologie MeSH
- duplikace genu MeSH
- genom rostlinný MeSH
- oprava DNA * genetika MeSH
- podjednotky proteinů metabolismus MeSH
- poškození DNA * genetika MeSH
- proteiny buněčného cyklu genetika metabolismus MeSH
- proteiny huseníčku genetika metabolismus MeSH
- pyl genetika MeSH
- regulace genové exprese u rostlin MeSH
- semena rostlinná genetika metabolismus MeSH
- transkriptom genetika MeSH
- upregulace genetika MeSH
- vajíčko rostlin genetika MeSH
- vazba proteinů MeSH
- vývojová regulace genové exprese MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The function of the plant hormone jasmonic acid (JA) in the development of tomato (Solanum lycopersicum) flowers was analyzed with a mutant defective in JA perception (jasmonate-insensitive1-1, jai1-1). In contrast with Arabidopsis (Arabidopsis thaliana) JA-insensitive plants, which are male sterile, the tomato jai1-1 mutant is female sterile, with major defects in female development. To identify putative JA-dependent regulatory components, we performed transcriptomics on ovules from flowers at three developmental stages from wild type and jai1-1 mutants. One of the strongly downregulated genes in jai1-1 encodes the MYB transcription factor SlMYB21. Its Arabidopsis ortholog plays a crucial role in JA-regulated stamen development. SlMYB21 was shown here to exhibit transcription factor activity in yeast, to interact with SlJAZ9 in yeast and in planta, and to complement Arabidopsis myb21-5 To analyze SlMYB21 function, we generated clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR associated protein 9 (Cas9) mutants and identified a mutant by Targeting Induced Local Lesions in Genomes (TILLING). These mutants showed female sterility, corroborating a function of MYB21 in tomato ovule development. Transcriptomics analysis of wild type, jai1-1, and myb21-2 carpels revealed processes that might be controlled by SlMYB21. The data suggest positive regulation of JA biosynthesis by SlMYB21, but negative regulation of auxin and gibberellins. The results demonstrate that SlMYB21 mediates at least partially the action of JA and might control the flower-to-fruit transition. .
- MeSH
- cyklopentany metabolismus MeSH
- down regulace MeSH
- fenotyp MeSH
- fertilita MeSH
- gibereliny metabolismus MeSH
- květy genetika fyziologie MeSH
- kyseliny indoloctové metabolismus MeSH
- mutace MeSH
- neplodnost rostlin MeSH
- ovoce genetika fyziologie MeSH
- oxylipiny metabolismus MeSH
- proteiny huseníčku genetika metabolismus MeSH
- regulace genové exprese u rostlin * MeSH
- regulátory růstu rostlin metabolismus MeSH
- rostlinné proteiny genetika metabolismus MeSH
- Solanum lycopersicum genetika fyziologie MeSH
- transkripční faktory genetika metabolismus MeSH
- vajíčko rostlin genetika fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The plastid-localized phosphoglucose isomerase isoform PGI1 is an important determinant of growth in Arabidopsis thaliana, likely due to its involvement in the biosynthesis of plastidial isoprenoid-derived hormones. Here, we investigated whether PGI1 also influences seed yields. PGI1 is strongly expressed in maturing seed embryos and vascular tissues. PGI1-null pgi1-2 plants had ∼60% lower seed yields than wild-type plants, with reduced numbers of inflorescences and thus fewer siliques and seeds per plant. These traits were associated with low bioactive gibberellin (GA) contents. Accordingly, wild-type phenotypes were restored by exogenous GA application. pgi1-2 seeds were lighter and accumulated ∼50% less fatty acids (FAs) and ∼35% less protein than wild-type seeds. Seeds of cytokinin-deficient plants overexpressing CYTOKININ OXIDASE/DEHYDROGENASE1 (35S:AtCKX1) and GA-deficient ga20ox1 ga20ox2 mutants did not accumulate low levels of FAs, and exogenous application of the cytokinin 6-benzylaminopurine and GAs did not rescue the reduced weight and FA content of pgi1-2 seeds. Seeds from reciprocal crosses between pgi1-2 and wild-type plants accumulated wild-type levels of FAs and proteins. Therefore, PGI1 is an important determinant of Arabidopsis seed yield due to its involvement in two processes: GA-mediated reproductive development and the metabolic conversion of plastidial glucose-6-phosphate to storage reserves in the embryo.
- MeSH
- Arabidopsis enzymologie metabolismus MeSH
- gibereliny metabolismus MeSH
- glukosa-6-fosfát metabolismus MeSH
- glukosa-6-fosfátisomerasa genetika metabolismus MeSH
- membránové proteiny genetika metabolismus MeSH
- oxidoreduktasy působící na CH-NH vazby genetika metabolismus MeSH
- plastidy metabolismus MeSH
- proteiny huseníčku genetika metabolismus MeSH
- regulace genové exprese u rostlin MeSH
- semena rostlinná enzymologie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Programmed cell death in plants occurs both during stress responses and as an integral part of regular plant development. Despite the undisputed importance of developmentally controlled cell death processes for plant growth and reproduction, we are only beginning to understand the underlying molecular genetic regulation. Exploiting the Arabidopsis thaliana root cap as a cell death model system, we identified two NAC transcription factors, the little-characterized ANAC087 and the leaf-senescence regulator ANAC046, as being sufficient to activate the expression of cell death-associated genes and to induce ectopic programmed cell death. In the root cap, these transcription factors are involved in the regulation of distinct aspects of programmed cell death. ANAC087 orchestrates postmortem chromatin degradation in the lateral root cap via the nuclease BFN1. In addition, both ANAC087 and ANAC046 redundantly control the onset of cell death execution in the columella root cap during and after its shedding from the root tip. Besides identifying two regulators of developmental programmed cell death, our analyses reveal the existence of an actively controlled cell death program in Arabidopsis columella root cap cells.
- MeSH
- Arabidopsis genetika metabolismus MeSH
- kořeny rostlin genetika metabolismus MeSH
- meristém genetika metabolismus MeSH
- proteiny huseníčku genetika metabolismus MeSH
- regulace genové exprese u rostlin MeSH
- transkripční faktory genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
