{"title":"CRISPR/dCas9-KRAB mediated transcriptional suppression of NtbHLH47 enhances tolerance to iron stress and modulates iron content in tobacco","authors":"Anshu Alok , Hanny Chauhan , Biswaranjan Rout , Ashutosh Pandey , Kashmir Singh","doi":"10.1016/j.plantsci.2025.112449","DOIUrl":null,"url":null,"abstract":"<div><div>Iron homeostasis is a multifaceted regulatory process that needs to be studied to elucidate iron distribution, uptake, and storage in plants. <em>NtbHLH47,</em> a homologue to <em>AtbHLH47</em>, is a negative regulator of iron. The current study deploys CRISPR interference-dCas9-KRAB (Krüppel-associated box) in the transcriptional suppression of <em>NtbHLH47</em> and its effect on iron uptake by plants. The pHSN6I01 harbouring dCas9-KRAB and gRNA targeting <em>NtbHHLH47</em> was constructed. Four gRNAs were designed, G1, G2, G3, and G4, located at + 19, + 111, + 232, and + 335 bp upstream from the ATG start codon in the promoter region of <em>NtbHLH47</em>. The <em>NtbHLH47</em> was repressed in the developed transgenic lines of tobacco and the qRT-PCR analysis showed that target sites G1 and G2 suppressed <em>NtbHLH47</em> effectively. The transgenic pHSN6I01 +G1 plants were tolerant to the elevated levels of iron, copper, zinc, and magnesium. The root Ferric chelate reductase activity of pHSN6I01 +G1 lines was reduced against wild type. The Perl staining showed high iron content in the roots of the pHSN6I01 +G1 plants. ICP-MS analysis showed increased Fe content in the roots of pHSN6I01 +G1 line suggesting that <em>NtbHLH47</em> modulates it. The expression of <em>NtbHLH38, NtbHLH100, NtbHLH101,</em> and <em>NtFIT</em> was found to be upregulated in the pHSN6I01 +G1 line. This is the first report of using CRISPRi based on dCas9-KRAB in tobacco and its application in the functional validation of a gene. Using this, <em>NtbHLH47</em> was transcriptionally suppressed and the generated lines expressed increased levels of iron in the roots of <em>N. tabacum</em> and gave insight in the iron homeostasis.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"354 ","pages":"Article 112449"},"PeriodicalIF":4.2000,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant Science","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0168945225000676","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Iron homeostasis is a multifaceted regulatory process that needs to be studied to elucidate iron distribution, uptake, and storage in plants. NtbHLH47, a homologue to AtbHLH47, is a negative regulator of iron. The current study deploys CRISPR interference-dCas9-KRAB (Krüppel-associated box) in the transcriptional suppression of NtbHLH47 and its effect on iron uptake by plants. The pHSN6I01 harbouring dCas9-KRAB and gRNA targeting NtbHHLH47 was constructed. Four gRNAs were designed, G1, G2, G3, and G4, located at + 19, + 111, + 232, and + 335 bp upstream from the ATG start codon in the promoter region of NtbHLH47. The NtbHLH47 was repressed in the developed transgenic lines of tobacco and the qRT-PCR analysis showed that target sites G1 and G2 suppressed NtbHLH47 effectively. The transgenic pHSN6I01 +G1 plants were tolerant to the elevated levels of iron, copper, zinc, and magnesium. The root Ferric chelate reductase activity of pHSN6I01 +G1 lines was reduced against wild type. The Perl staining showed high iron content in the roots of the pHSN6I01 +G1 plants. ICP-MS analysis showed increased Fe content in the roots of pHSN6I01 +G1 line suggesting that NtbHLH47 modulates it. The expression of NtbHLH38, NtbHLH100, NtbHLH101, and NtFIT was found to be upregulated in the pHSN6I01 +G1 line. This is the first report of using CRISPRi based on dCas9-KRAB in tobacco and its application in the functional validation of a gene. Using this, NtbHLH47 was transcriptionally suppressed and the generated lines expressed increased levels of iron in the roots of N. tabacum and gave insight in the iron homeostasis.
期刊介绍:
Plant Science will publish in the minimum of time, research manuscripts as well as commissioned reviews and commentaries recommended by its referees in all areas of experimental plant biology with emphasis in the broad areas of genomics, proteomics, biochemistry (including enzymology), physiology, cell biology, development, genetics, functional plant breeding, systems biology and the interaction of plants with the environment.
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