The invention relates to the field of
gene engineering, and discloses a CRISPRi (clustered regularly interspaced short palindromic repeats i)
system, a recombinant strain containing the CRISPRi
system, a construction method and application of the recombinant strain, and a method for producing
gibberellin. The CRISPRi
system comprises a coding
gene of a dCas9
mutant protein without cleavage activity, sgRNA and an induction regulation component, wherein the induction regulation component is used for regulating the expression of the dCas9
mutant protein coding
gene; the sgRNA guides the dCas9
mutant protein to be combined to a
target gene, so that the expression of the
target gene is inhibited; the dCas9
mutant protein is obtained by
mutation on the basis of a Cas9 protein, and
mutation sites are D10A and H840A of the dCas9 protein; the target genes comprise
squalene synthase encoding genes,
fatty acid synthase encoding genes and the like, the CRISPRi system can accurately and efficiently regulate and control
gibberellin gene expression, the
gibberellin yield is remarkably increased, the influence on strain growth is small, regulation and control are reversible, specificity is high, and the CRISPRi system is matched with gibberellin and has good industrial prospects.