Francisco J.EscarayAmelia Felipo-BenaventCristian J.AntonelliBego?a Balaguer...
1073-1089页
查看更多>>摘要：The gray mold fungus Botrytis cinerea is a necrotrophic pathogen that causes diseases in hundreds of plant species,including high-value crops.Its polyxenous nature and pathogenic success are due to its ability to perceive host signals in its favor.In this study,we found that laticifer cells of Euphorbia lathyris are a source of susceptibility factors required by B.cinerea to cause disease.Consequently,poor-in-latex(pil)mutants,which lack laticifer cells,show full resistance to this pathogen,whereas Iot-of-latex mutants,which produce more laticifer cells,are hypersusceptible.These S factors are triterpenoid saponins,which are widely distributed natural products of vast structural diversity.The downregulation of laticifer-specific oxy-dosqualene cyclase genes,which encode the first committed step enzymes for triterpene and,therefore,saponin biosynthesis,conferred disease resistance to B.cinerea.Likewise,the Medicago truncatula Iha-1 mutant,compromised in triterpenoid saponin biosynthesis,showed enhanced resistance.Interestingly,the application of different purified triterpenoid saponins pharmacologically complemented the disease-resistant phenotype of pil and hla-1 mutants and enhanced disease susceptibility in different plant species.We found that triterpenoid saponins function as plant cues that signal transcriptional reprogramming in B.cinerea,leading to a change in its growth habit and infection strategy,culminating in the abundant for-mation of infection cushions,the multicellular appressoria apparatus dedicated to plant penetration and biomass destruction in B.cinerea.Taken together,these results provide an explanation for how plant tri-terpenoid saponins function as disease susceptibility factors to promote B.cinerea pathogenicity.
查看更多>>摘要：The precise control of receptor levels is crucial for initiating cellular signaling transduction in response to specific ligands;however,such mechanisms regulating nodulation factor(NF)receptor(NFR)-mediated perception of NFs to establish symbiosis remain unclear.In this study,we unveil the pivotal role of the NFR-interacting RING-type E3 ligase 1(NIRE1)in regulating NFR1/NFR5 homeostasis to optimize rhizobial infection and nodule development in Lotus japonicus.We demonstrated that NIRE1 has a dual function in this regulatory process.It associates with both NFR1 and NFR5,facilitating their degradation through K48-linked polyubiquitination before rhizobial inoculation.However,following rhizobial inoculation,NFR1 phosphorylates NIRE1 ata conserved residue,Tyr-109,inducing afunctional switch in NIRE1,which enables NIRE1 to mediate K63-linked polyubiquitination,thereby stabilizing NFR1/NFR5 in infected root cells.The introduction of phospho-dead NIRE1Y109F leads to delayed nodule development,underscoring the signifi-cance of phosphorylation at Tyr-109 in orchestrating symbiotic processes.Conversely,expression of the phospho-mimic NIRE1Y109E results in the formation of spontaneous nodules in L.japonicus,further empha-sizing the critical role of the phosphorylation-dependent functional switch in NIRE1.In summary,these find-ings uncover a fine-tuned symbiotic mechanism that a single E3 ligase could undergo a phosphorylation-dependent functional switch to dynamically and precisely regulate NF receptor protein levels.
查看更多>>摘要：Spatiotemporal regulation of gene expression by polycomb repressive complex 2(PRC2)is critical for animal and plant development.The Arabidopsis fertilization independent seed(FIS)-PRC2 complex functions specifically during plant reproduction from gametogenesis to seed development.After a double fertilization event,triploid endosperm proliferates early,followed by the growth of a diploid embryo,which replaces the endosperm in Arabidopsis and many dicots.Key genes critical for endosperm proliferation such as IKU2 and MINI3 are activated after fertilization.Here we report that two MADS-box AGAMOUS-LIKE(AGL)proteins associate with the key endosperm proliferation loci and recruit the FIS-PRC2 repressive complex at 4-5 days after pollination(DAP).Interestingly,AGL9 and AGL15 only accumulate toward the end of endosperm proliferation at 4-5 DAP and promote the deposition of H3K27me3 marks at key endosperm proliferation loci.Disruption of AGL9 and AGL15 or overexpression of AGL9 or AGL15 significantly influence endosperm proliferation and cellularization.Genome-wide analysis with cleavage Under Targets and tagmentation(CUT&Tag)sequencing and RNA sequencing revealed the landscape of endosperm H3K27me3 marks and gene expression profiles in Col-0 and agl9 agl15.CUT&Tag qPCR also demonstrated the occupancy of the two MADS-box pro-teins and FIS-PRC2 on a few representative target loci.Our studies suggest that MADS-box proteins could potentially recruit PRC2 to regulate many other developmental processes in plants or even in fungi and animals.
Paula BermanLuis Alejandro de HaroAna-Rita CavacoSayantan Panda...
1129-1150页
查看更多>>摘要：Mescaline,among the earliest identified natural hallucinogens,holds great potential in psychotherapy treatment.Nonetheless,despite the existence of a postulated biosynthetic pathway for more than half a century,the specific enzymes involved in this process are yet to be identified.In this study,we investigated the cactus Lophophora williamsii(Peyote),the largest known natural producer of the phenethylamine mescaline.We employed a multi-faceted approach,combining de novo whole-genome and transcriptome sequencing with comprehensive chemical profiling,enzymatic assays,molecular modeling,and pathway engineering for pathway elucidation.We identified four groups of enzymes responsible for the six catalytic steps in the mescaline biosynthetic pathway,and an N-methyltransferase enzyme that N-methylates all phenethylamine intermediates,likely modulating mescaline levels in Peyote.Finally,we reconstructed the mescaline biosynthetic pathway in both Nicotiana benthamiana plants and yeast cells,providing novel insights into several challenges hindering complete heterologous mescaline production.Taken together,our study opens up avenues for exploration of sustainable production approaches and responsible utiliza-tion of mescaline,safeguarding this valuable natural resource for future generations.
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