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
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.
