Construction of ternary PEG200-based DESs lubrication systems via tailoring tribo-chemistry

Designing novel lubricants with easily customized structures,devisable compositions,and simple and economic synthesis over traditional lubricants is critical to fulfilling complex applications,prolonging machine lifetime,and saving energy.Deep eutectic solvents(DESs),which show tunable composition,adjustable structure,easy fabrication,and environmental friendliness,are promising candidates for variable and complicated lubricants applications.To promote the use of DESs as lubricants,a series of PEG200-based DESs with active heteroatoms were fabricated to tailor the tribological performance via tribo-chemistry.Thereinto,PEG200/boric acid(BA)DES shows optimal lubrication performance by forming tribo-chemical reaction film composited of B2O3,iron oxides,and FeOOH,and PEG200/thiourea(TU)DES displays abrasive wear-reducing property by producing FeS tribo-chemical film.Given the excellent abrasive wear-resistance of PEG200/TU DES and friction reduction of PEG200/BA DES,ternary PEG200/BA/TU DESs,composited of PEG200/TU DES and PEG200/BA DES,are first exploited.The ternary DESs possess superior wettability and thermal stability,which render them potential lubricants.Tribological tests of the ternary DESs demonstrate that synergistic lubrication is achieved by forming a transfer film consisting of FexBy,BN,B2O3,and FeS.Wherein FexBy,BN,and B2O3 increase load bearing of the film,and FeS mitigates severe abrasive wear.The proposed design philosophy of novel DESs as lubricants opens up a unique realm that is unattainable by traditional DESs lubrication mechanisms and provides a platform to design next-generation DESs lubrication systems.

Orthogroup and phylotranscriptomic analyses identify transcription factors involved in the plant cold response:Acase study of Arabidopsis BBX29

C-repeat binding factors(CBFs)are well-known transcription factors(TFs)that regulate plant cold acclimation.RNA sequencing(RNA-seq)data from diverse plant species provide opportunities to identify other TFs involved in the cold response.However,this task is challenging because gene gain and loss has led to an intertwined community of co-orthologs and in-paralogs between and within species.Using orthogroup(closely related homologs)analysis,we identified 10,549 orthogroups in five representative eudicots.A phylotranscriptomic analysis of cold-treated seedlings from eudicots identified 35 high-confidence conserved cold-responsive transcription factor orthogroups(CoCoFos).These 35 CoCoFos included the well-known cold-responsive regulators CBFs,HSFC1,ZAT6/10,and CZF1 among others.We used Arabidopsis BBX29 for experimental validation.Expression and genetic analyses showed that cold-induction of BBX29 is CBF-and abscisic acid-independent,and BBX29 is a negative regulator of cold tolerance.Integrative RNA-seq and Cleavage Under Targets and Tagmentation followed by sequencing analyses revealed that BBX29 represses a set of cold-induced TFs(ZAT12,PRR9,RVE1,MYB96,etc.).Altogether,our analysis yielded a library of eudicot CoCoFos and demonstrated that BBX29 is a negative regulator of cold tolerance in Arabidopsis.

Innovations and stepwise evolution of CBFs/DREB1s and their regulatory networks in angiosperms

The C-repeat binding factors/dehydrationresponsive element binding protein 1 s(CBFs/DREB1 s)have been identified as major regulators of cold acclimation in many angiosperm plants.However,their origin and evolutionary process associated to cold responsiveness are still lacking.By integrating multi-omics data of genomes,transcriptomes,and CBFs/DREB1 s genome-wide binding profiles,we unveil the origin and evolution of CBFs/DREB1 s and their regulatory network.Gene collinearity and phylogeny analyses show that CBF/DREB1 is an innovation evolved from tandem duplication-derived DREBⅢgene.A subsequent event of e-whole genome duplication led to two CBF/DREB1 archetypes(CladesⅠandⅡ)in ancient angiosperms.In contrast to cold-insensitivity of Clade I and their parent DREBⅢgenes,CladeⅡevolved a further innovation in cold-sensitive response and was stepwise expanded in eudicots and monocots by independent duplications.In geological time,the duplication events were mainly enriched around the Cretaceous-Paleogene(K-Pg)boundary and/or in the Late Cenozoic Ice Age,when the global average temperature significantly decreased.Consequently,the duplicated CBF/DREB1 genes contributed to the rewiring of CBFs/DREB1 s-regulatory network for cold tolerance.Altogether,our results highlight an origin and convergent evolution of CBFs/DREB1 s and their regulatory network probably for angiosperms adaptation to global cooling.