Basic helix-loop-helix(bHLH)transcription factors regulate diverse plant processes,particularly anthocyanin biosynthesis through the MYB-bHLH-WD40 complex.Despite snapdragon(Antirrhinum majus)serving as a classical mo...Basic helix-loop-helix(bHLH)transcription factors regulate diverse plant processes,particularly anthocyanin biosynthesis through the MYB-bHLH-WD40 complex.Despite snapdragon(Antirrhinum majus)serving as a classical model for studying flower pigmentation genetics,its bHLH gene family has rarely been comprehensively characterized.Here,we performed a genome-wide identification and systematic characterization of the bHLH gene family in A.majus,with a focus on candidates involved in anthocyanin biosynthesis.A total of 150 AmbHLH genes were identified and subjected to in-silico analyses,including phylogenetic classification,structural analysis,and promoter cis-element characterization.Comparative transcriptomic profiling between anthocyanin-poor(“SIPPE50”,Green)and anthocyanin-rich(“JI2R”,Red)snapdragon lines highlighted eight differentially expressed AmbHLHs.AmbHLH001,AmbHLH002,and AmbHLH042 showed significant upregulation in the anthocyanin-rich line and showed positive correlations with the expression of key anthocyanin biosynthetic genes.Among these,AmbHLH002 was prioritized as a candidate and was assessed via heterologous overexpression in tomatoes.Notably,AmbHLH002 is a newly identified regulator whose overexpression in tomato resulted in visible purple pigmentation and increased anthocyanin accumulation.These findings support the view that AmbHLH002 acts as a positive regulator,with phylogenetic evidence for conservation of anthocyanin biosynthesis,presenting valuable potential for engineering pigmentation traits in ornamental plants and serving as a candidate visible marker for plant genetic transformation.展开更多
The corrosion behaviors of IN718 in a high-temperature pressurized water environment were investigated to assess the effect of secondary phases on the corrosion mechanisms.The oxide scale formed on IN718 after exposur...The corrosion behaviors of IN718 in a high-temperature pressurized water environment were investigated to assess the effect of secondary phases on the corrosion mechanisms.The oxide scale formed on IN718 after exposure to a 290℃water environment consists of double layers:the outer layer is Fe_(2)(Cr,Ni)O_(4)spinel phase and the inner one is Cr_(2)O_(3).The NbC inclusions located within the grains provide conducive sites for localized corrosion.Oxidation leads to the fragmentation of NbC particles,resulting in the formation of cavities on the surface.The Ni_(3)Nb precipitates located at the grain boundaries exhibit a higher susceptibility to oxidation than the surrounding matrix.This preferential oxidation of the Ni_(3)Nb precipitates effectively consumes the available oxygen atoms,thereby acting as a protective barrier that inhibits the propagation of oxidation along the grain boundaries.The oxidation of NbC and Ni_(3)Nb phases initially occurs in an amorphous state and then transforms into a crystalline structure.展开更多
Lettuce(Lactuca sativa)is a globally important leafy vegetable.Understanding the genetic factors underlying its growth and regeneration is critical for advancing agricultural productivity and biotechnological applicat...Lettuce(Lactuca sativa)is a globally important leafy vegetable.Understanding the genetic factors underlying its growth and regeneration is critical for advancing agricultural productivity and biotechnological applications.To address this,the study aimed to comprehensively identify and characterize the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE(SPL)gene family in lettuce and investigate their potential roles in plant development and regeneration.As a result,22 SPL genes were identified within the lettuce genome.Fourteen of these genes contain recognition sites for microRNA156,suggesting post-transcriptional regulation.Each LsSPL protein has the highly conserved SBP domain and is predicted to localize in the nucleus.Analysis of public RNA-seq datasets revealed tissue-specific expression patterns of the 22 LsSPL genes,with five highly expressed in leaves,four in roots,and three in stems,indicating their distinct roles in plant development.Overexpression of lettuce miRNA156c(miR156-OX)led to reduced leaf size and delayed flowering time,whereas suppression of miR156(miR156-STTM)resulted in increased leaf size.Surprisingly,cotyledon explants from miR156-OX lettuce lines exhibited a 1.9-fold increase in shoot regeneration compared to wild-type,whereas miR156-STTM lines exhibited a 54.3%decrease.This enhanced in vitro shoot regeneration was also observed in ectopic miR156-overexpression tomato lines,suggesting a conserved mechanism.Quantitative RT-PCR analysis confirmed the downregulation of LsSPL13A.1,LsSPL13A.2,and LsSPL12.2 in miR156-OX lines and their upregulation in miR156-STTM lines after 5 days of callus induction,implicating their specific roles in in vitro organo genesis and plant re generation.This comprehensive analysis provides valuable insights into the SPL gene family and the miR156-SPLs regulatory network,specifically highlighting its role in regeneration.These findings hold the potential for improving plant growth,development,and biotechnological applications.展开更多
基金funded by the USDANIFA grant 2019-67013-29236the USDA HATCH program FLA-MFC-006387,awarded to Heqiang Huo.
文摘Basic helix-loop-helix(bHLH)transcription factors regulate diverse plant processes,particularly anthocyanin biosynthesis through the MYB-bHLH-WD40 complex.Despite snapdragon(Antirrhinum majus)serving as a classical model for studying flower pigmentation genetics,its bHLH gene family has rarely been comprehensively characterized.Here,we performed a genome-wide identification and systematic characterization of the bHLH gene family in A.majus,with a focus on candidates involved in anthocyanin biosynthesis.A total of 150 AmbHLH genes were identified and subjected to in-silico analyses,including phylogenetic classification,structural analysis,and promoter cis-element characterization.Comparative transcriptomic profiling between anthocyanin-poor(“SIPPE50”,Green)and anthocyanin-rich(“JI2R”,Red)snapdragon lines highlighted eight differentially expressed AmbHLHs.AmbHLH001,AmbHLH002,and AmbHLH042 showed significant upregulation in the anthocyanin-rich line and showed positive correlations with the expression of key anthocyanin biosynthetic genes.Among these,AmbHLH002 was prioritized as a candidate and was assessed via heterologous overexpression in tomatoes.Notably,AmbHLH002 is a newly identified regulator whose overexpression in tomato resulted in visible purple pigmentation and increased anthocyanin accumulation.These findings support the view that AmbHLH002 acts as a positive regulator,with phylogenetic evidence for conservation of anthocyanin biosynthesis,presenting valuable potential for engineering pigmentation traits in ornamental plants and serving as a candidate visible marker for plant genetic transformation.
基金supported by the National Natural Science Foundation of China (52271126)the National Center for Materials Service Safety Foundation (2021ZT09L227)
文摘The corrosion behaviors of IN718 in a high-temperature pressurized water environment were investigated to assess the effect of secondary phases on the corrosion mechanisms.The oxide scale formed on IN718 after exposure to a 290℃water environment consists of double layers:the outer layer is Fe_(2)(Cr,Ni)O_(4)spinel phase and the inner one is Cr_(2)O_(3).The NbC inclusions located within the grains provide conducive sites for localized corrosion.Oxidation leads to the fragmentation of NbC particles,resulting in the formation of cavities on the surface.The Ni_(3)Nb precipitates located at the grain boundaries exhibit a higher susceptibility to oxidation than the surrounding matrix.This preferential oxidation of the Ni_(3)Nb precipitates effectively consumes the available oxygen atoms,thereby acting as a protective barrier that inhibits the propagation of oxidation along the grain boundaries.The oxidation of NbC and Ni_(3)Nb phases initially occurs in an amorphous state and then transforms into a crystalline structure.
基金funded by the USDA-NIFA grant 2019-67013-29236the USDA HATCH program FLA-MFC-006387。
文摘Lettuce(Lactuca sativa)is a globally important leafy vegetable.Understanding the genetic factors underlying its growth and regeneration is critical for advancing agricultural productivity and biotechnological applications.To address this,the study aimed to comprehensively identify and characterize the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE(SPL)gene family in lettuce and investigate their potential roles in plant development and regeneration.As a result,22 SPL genes were identified within the lettuce genome.Fourteen of these genes contain recognition sites for microRNA156,suggesting post-transcriptional regulation.Each LsSPL protein has the highly conserved SBP domain and is predicted to localize in the nucleus.Analysis of public RNA-seq datasets revealed tissue-specific expression patterns of the 22 LsSPL genes,with five highly expressed in leaves,four in roots,and three in stems,indicating their distinct roles in plant development.Overexpression of lettuce miRNA156c(miR156-OX)led to reduced leaf size and delayed flowering time,whereas suppression of miR156(miR156-STTM)resulted in increased leaf size.Surprisingly,cotyledon explants from miR156-OX lettuce lines exhibited a 1.9-fold increase in shoot regeneration compared to wild-type,whereas miR156-STTM lines exhibited a 54.3%decrease.This enhanced in vitro shoot regeneration was also observed in ectopic miR156-overexpression tomato lines,suggesting a conserved mechanism.Quantitative RT-PCR analysis confirmed the downregulation of LsSPL13A.1,LsSPL13A.2,and LsSPL12.2 in miR156-OX lines and their upregulation in miR156-STTM lines after 5 days of callus induction,implicating their specific roles in in vitro organo genesis and plant re generation.This comprehensive analysis provides valuable insights into the SPL gene family and the miR156-SPLs regulatory network,specifically highlighting its role in regeneration.These findings hold the potential for improving plant growth,development,and biotechnological applications.
