OsPPG encodes a pseudouridine-5'-phosphate glycosidase and regulates rice spikelet development

Florets are the basic structural units of spikelets,and their morphogenesis determines the yield and quality of rice grains.However,whether and how pseudouridine-5’-phosphate glycosidase participates in rice spikelet development remains an open question.In this study,we identified a novel gene,OsPPG,which encodes a peroxisome-localized pseudouridine-5’-phosphate glycosidase and regulates the development of rice spikelets.osppg mutants exhibited abnormal sterile lemma,lemma,palea,lodicule,stamens,and pistils;male sterility;shorter panicles;and reduced plant height.OsPPG was found to regulate several OsMADS genes,thereby affecting the morphogenesis of rice spikelets.Furthermore,metabolomics revealed that the OsPPG gene was involved in the decomposition of pseudouridine via the pyrimidine metabolism pathway and may affect the jasmonic acid signaling pathway.These results suggest that OsPPG is a key regulator of rice spikelet development.

Genomic basis of selective breeding from the closest wild relative of large-fruited tomato

The long and intricate domestication history of the tomato(Solanum lycopersicum)includes selection sweeps that have not been fully explored,and these sweeps show significant evolutionary trajectories of domestication traits.Using three distinct selection strategies,we represented comprehensive selected sweeps from 53 Solanum pimpinellifolium(PIM)and 166 S.lycopersicum(BIG)accessions,which are defined as pseudo-domestication in this study.We identified 390 potential selection sweeps,some of which had a significant impact on fruit-related traits and were crucial to the pseudo-domestication process.During tomato pseudo-domestication,we discovered a minor–effect allele of the SlLEA gene related to fruit weight(FW),as well as the major haplotypes of fw2.2/cell number regulator(CNR),fw3.2/SlKLUH,and fw11.3/cell size regulator(CSR)in cultivars.Furthermore,18 loci were found to be significantly associated with FW and six fruit-related agronomic traits in genome-wide association studies.By examining population differentiation,we identified the causative variation underlying the divergence of fruit flavonoids across the large-fruited tomatoes and validated BRI1-EMS-SUPPRESSOR 1.2(SlBES1.2),a gene that may affect flavonoid content by modulating the MYB12 expression profile.Our results provide new research routes for the genetic basis of fruit traits and excellent genomic resources for tomato genomics-assisted breeding.

Fabrication of immobilized nickel nanoclusters decorated by CxNy species for cellulose conversion to C2,3 oxygenated compounds:Rational design via typical C-and N-sources

Production of chemicals and fuels from microcrystalline cellulose has inspired scholars’ attention. Deactivation of metallic catalysts including acid leaching and hydrothermal aggregation is still one of the core issues in these systems. To address these problems, we designed and fabricated a series of Ni-W/SiO2 catalysts, which were decorated by CxNy species using C-and N- sources and applied in cellulose conversion to C2,3 oxygenated compounds. The Ni-W/SiO2@CxNy catalysts, underwent complexing and selfassembling process, exhibited special heterojunctions, accompanying strong interactions mainly among Ni phase and CxNy layers. Catalytic results showed that the heterojunctions and outer CxNy layers extensively enhanced productions of hydroxyacetone(HDA) and ethylene glycol(EG) and promoted the hydrothermal stability through prospering in concentration of Lewis pairs from Ni–N—N structure and immobilizing the metallic nanoclusters. 48.25% of EG was yielded under 5.0 MPa H2 pressurized 240 ℃ water for 2.0 h. The Lewis pair further improved the formation of HDA with 20.92% yield. High hydrothermal stability of NiW/SiO2@CxNy catalyst was proved according to the recycling results and trace leaching concentration of Ni and W. This construction of metallic catalysts exploited a new strategy to manufacture extraordinary durability of metallic nanoclusters for cellulose conversion under harsh reaction conditions.

Fine mapping and candidate gene analysis of qHD1b,a QTL that promotes flowering in common wild rice(Oryza rufipogon)by up-regulating Ehd1

Heading date(flowering time)determines the adaptability of cultivars to different environments.We report the fine mapping and candidate gene analysis of qHD1b,a quantitative trait locus(QTL)responsible for early flowering that was derived from common wild rice(O.rufipogon)under both short-day and longday conditions.The introgression line IL7391,which carried segments from common wild rice in a Zhonghui 8015(ZH8015)background,exhibited early heading compared to the background and was crossed with ZH8015 to generate BC_(5)F_(2:3) families for QTL analysis.This enabled the identification of two heading-date QTL,named qHD1b and qHD7,of which the first was selected for further research.High-resolution linkage analysis was performed in BC_(5)F_(4:5) and BC_(5)F_(6) populations,and the location of qHD1b was confined to a 112.7-kb interval containing 17 predicted genes.Five of these genes contained polymorphisms in the promoter or coding regions and were thus considered as candidates.Expression analysis revealed a positive association between LOC_Os01g11940 expression and early heading.This locus was annotated as OsFTL1,which encodes an ortholog of Arabidopsis Flowering Locus T and was the most likely candidate gene for qHD1b.Our study revealed that qHD1b acts as a floral activator that promotes flowering by up-regulating Ehd1,Hd3a,RFT1,OsMADS14,and OsMADS15 under both shortday and long-day conditions.Field experiments showed that qHD1b affected several yield-related agronomic traits including 1000-grain weight and grain length.qHD1b could be useful for marker-assisted selection and breeding of early-maturing cultivars.

A KNOX II transcription factor suppresses the NLR immune receptor BRG8-mediated immunity in rice

Nucleotide-binding site and leucine-rich repeat(NLR)proteins are activated by detecting pathogen effectors,which in turn trigger host defenses and cell death.Although many NLRs have been identified,the mechanisms responsible for NLR-triggered defense responses are still poorly understood.In this study,through a genome-wide association study approach,we identified a novel NLR gene,Blast Resistance Gene 8(BRG8),which confers resistance to rice blast and bacterial blight diseases.BRG8 overexpression and complementation lines exhibit enhanced resistance to both pathogens.Subcellular localization assays showed that BRG8 is localized in both the cytoplasm and the nucleus.Additional evidence revealed that nuclear-localized BRG8 can enhance rice immunity without a hypersensitive response(HR)-like phenotype.We also demonstrated that the coiled-coil domain of BRG8 not only physically interacts with itself but also interacts with the KNOX II protein HOMEOBOX ORYZA SATIVA59(HOS59).Knockout mutants of HOS59 in the BRG8 background show enhanced resistance to Magnaporthe oryzae strain CH171 and Xoo strain CR4,similar to that of the BRG8 background.By contrast,overexpression of HOS59 in the BRG8 background will compromise the HR-like phenotype and resistance response.Further analysis revealed that HOS59 promotes the degradation of BRG8 via the 26S proteasome pathway.Collectively,our study highlights HOS59 as an NLR immune regulator that fine-tunes BRG8-mediated immune responses against pathogens,providing new insights into NLR associations and functions in plant immunity.