Fecha de publicación: 06/11/2018 Fuente: WIPO "tobacco agriculture" The invention discloses a gene NtNHX1-3 capable of increasing the potassium content of tobacco leaves, and a cloning method and applications thereof. The nucleotide sequence of the gene NtNHX1-3 is represented by SEQ ID No.1, and the encoding amino acid sequence is represented by SEQ ID No.2. The invention also discloses a cloning method of the gene NtNHX1-3. The cloning method comprises followingsteps: step A, determining the NtNHX1-3 gene sequence; step B, extracting tobacco RNA, and carrying out inverse transcription to obtain first chain cDNA; step C, based on the NtNHX1-3 gene sequence,designing and synthesizing a specific primer, and taking the cDNA as a template to carry out PCR amplification; and step D, recovering and purifying the PCR product, and constructing an overexpressioncarrier containing the NtNHX1-3 gene. The overexpression carrier is over-expressed in tobaccos through agrobacterium-mediated conversion to prepare a transgenic plant; compared with a control group,the potassium content of the transgenic plant is obviously increased; and the result show that the NtNHX1-3 gene has an important application value in the breeding of tobaccos with a high potassium content.