Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains...Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains poorly understood.Our previous studies have established GmMYBA2 and GmMYBA3 as the regulators of seed coat and floral anthocyanin production in soybean(Glycine max),respectively.In this study,we reveal the functional divergence of their paralog GmMYBA1 in orchestrating light-responsive anthocyanin biosynthesis in juvenile tissues and stems.In brief,hypocotyl/stem-and young leaf-predominant expression of GmMYBA1 correlates with photoprotective anthocyanin accumulation.Ectopic overexpression of GmMYBA1 induces systemic pigmentation across leaves,stems,and reproductive organs,whereas RNAi-mediated silencing of GmMYBA1 significantly reduces anthocyanin accumulation in the hypocotyl.Light-dark shift assays confirmed that GmMYBA1 is required for hypocotyl pigmentation,while dual-luciferase assays revealed the specific regulation of the GmMYBA paralogs by GmSTF1/2(soybean TGACG-motif binding factor 1/2).GmSTF1/2 both activate GmMYBA1,with only GmSTF2 weakly inducing GmMYBA2 and neither affecting GmMYBA3.Further investigation indicated that the differential transactivation of GmMYBA promoters largely resulted from their cis-element difference,suggesting regulatory divergence as a driver of MYB paralog diversification.Our findings position GmMYBA1 as the central MYB activator integrating light signaling with anthocyanin biosynthesis,with paralog specialization reflecting evolutionary subfunctionalization post-gene duplication.展开更多
microRNAs （miRNAs） are an abundant class of-22 nucleotide （nt） regulatory RNAs that are pervasive in higher eukaryotic genomes. In order to fully understand their prominence in genomes, it is necessary to elucidat...microRNAs （miRNAs） are an abundant class of-22 nucleotide （nt） regulatory RNAs that are pervasive in higher eukaryotic genomes. In order to fully understand their prominence in genomes, it is necessary to elucidate the molecular mechanisms that can diversify miRNA activities. In this review, we describe some of the many strategies that allow novel miRNA functions to emerge, with particular emphasis on how miRNA genes evolve in animals. These mechanisms include changes in their sequence, processing, or expression pattern; acquisition of miRNA^＊ functionality or antisense processing; and de novo gene birth. The facility and versatility of miRNAs to evolve and change likely underlies how they have become dominant constituents of higher genomes.展开更多
The realization that body parts of animals and plants can be recruited or coopted for novel functions dates back to, or even predates the observations of Darwin. S.J. Gould and E.S. Vrba recognized a mode of evolution...The realization that body parts of animals and plants can be recruited or coopted for novel functions dates back to, or even predates the observations of Darwin. S.J. Gould and E.S. Vrba recognized a mode of evolution of characters that differs from adaptation. The umbrella term aptation was supplemented with the concept of exaptation. Unlike adaptations, which are restricted to features built by selection for their current role, exaptations are features that currently enhance fitness, even though their present role was not a result of natural selection. Exaptations can also arise from nonaptations; these are characters which had previously been evolving neutrally. All nonaptations are potential exaptations. The concept of exaptation was expanded to the molecular genetic level which aided greatly in understanding the enormous potential of neutrally evolving repetitive DNA—including transposed elements, formerly considered junk DNA—for the evolution of genes and genomes. The distinction between adaptations and exaptations is outlined in this review and examples are given. Also elaborated on is the fact that such distinctions are sometimes more difficult to determine; this is a widespread phenomenon in biology, where continua abound and clear borders between states and definitions are rare.展开更多
基金supported by the Department of Science and Technology of Jilin Province(20220508112RC).The founders had no role in this study design,data collection,analysis,decision to publish,or preparation of the manuscript.
文摘Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains poorly understood.Our previous studies have established GmMYBA2 and GmMYBA3 as the regulators of seed coat and floral anthocyanin production in soybean(Glycine max),respectively.In this study,we reveal the functional divergence of their paralog GmMYBA1 in orchestrating light-responsive anthocyanin biosynthesis in juvenile tissues and stems.In brief,hypocotyl/stem-and young leaf-predominant expression of GmMYBA1 correlates with photoprotective anthocyanin accumulation.Ectopic overexpression of GmMYBA1 induces systemic pigmentation across leaves,stems,and reproductive organs,whereas RNAi-mediated silencing of GmMYBA1 significantly reduces anthocyanin accumulation in the hypocotyl.Light-dark shift assays confirmed that GmMYBA1 is required for hypocotyl pigmentation,while dual-luciferase assays revealed the specific regulation of the GmMYBA paralogs by GmSTF1/2(soybean TGACG-motif binding factor 1/2).GmSTF1/2 both activate GmMYBA1,with only GmSTF2 weakly inducing GmMYBA2 and neither affecting GmMYBA3.Further investigation indicated that the differential transactivation of GmMYBA promoters largely resulted from their cis-element difference,suggesting regulatory divergence as a driver of MYB paralog diversification.Our findings position GmMYBA1 as the central MYB activator integrating light signaling with anthocyanin biosynthesis,with paralog specialization reflecting evolutionary subfunctionalization post-gene duplication.
文摘microRNAs （miRNAs） are an abundant class of-22 nucleotide （nt） regulatory RNAs that are pervasive in higher eukaryotic genomes. In order to fully understand their prominence in genomes, it is necessary to elucidate the molecular mechanisms that can diversify miRNA activities. In this review, we describe some of the many strategies that allow novel miRNA functions to emerge, with particular emphasis on how miRNA genes evolve in animals. These mechanisms include changes in their sequence, processing, or expression pattern; acquisition of miRNA^＊ functionality or antisense processing; and de novo gene birth. The facility and versatility of miRNAs to evolve and change likely underlies how they have become dominant constituents of higher genomes.
文摘The realization that body parts of animals and plants can be recruited or coopted for novel functions dates back to, or even predates the observations of Darwin. S.J. Gould and E.S. Vrba recognized a mode of evolution of characters that differs from adaptation. The umbrella term aptation was supplemented with the concept of exaptation. Unlike adaptations, which are restricted to features built by selection for their current role, exaptations are features that currently enhance fitness, even though their present role was not a result of natural selection. Exaptations can also arise from nonaptations; these are characters which had previously been evolving neutrally. All nonaptations are potential exaptations. The concept of exaptation was expanded to the molecular genetic level which aided greatly in understanding the enormous potential of neutrally evolving repetitive DNA—including transposed elements, formerly considered junk DNA—for the evolution of genes and genomes. The distinction between adaptations and exaptations is outlined in this review and examples are given. Also elaborated on is the fact that such distinctions are sometimes more difficult to determine; this is a widespread phenomenon in biology, where continua abound and clear borders between states and definitions are rare.
