Abstract: A tobacco arsenic transport gene NtNIP7-1 and a cloning method and application thereof are disclosed. A nucleotide sequence of the tobacco arsenic transport gene NtNIP7-1 is shown as SEQ ID: No. 1, and an encoded amino acid sequence thereof is shown as SEQ ID: No. 2. The cloning method of the tobacco arsenic transport gene NtNIP7-1 includes (S1) extracting RNA in tobacco, performing reverse transcription, and obtaining a first-strand cDNA; and (S2) taking the first-strand cDNA obtained by the reverse transcription as a template, synthesizing a specific primer according to sequences of the NtNIP7-1 gene, performing PCR amplification, recovering and purifying a product of the PCR amplification, and sequencing. In the present invention, inhibition of the expression of the tobacco endogenous gene NtNIP7-1 in tobacco plants is able to significantly reduce the arsenic content of tobacco leaves, and has broad application prospects in the field of low arsenic content breeding.

Abstract: The disclosure provides a method of screening tobacco germplasm for resistance to Alternaria alternata by ripening seedling leaves. The method includes ripening seedling leaves, spray inoculation, disease induction, and evaluation of disease resistance. Dense planting, fertilizer control, and potassium increment were used to forcibly ripening seedling leaves. A hospitable environment was simulated to induce disease in the ripened leaves. These treatments reduce differences in leaf maturity and avoid environmental changes. The technique of the disclosure provides greater accuracy and repeatability than the current technique of screening brown spot resistance, and offers the advantages of simple operation, reduced cost, space requirement, and labor intensity, high selection efficiency, and an accurate screening of tobacco phenotypes with resistance to brown spot, etc., used for large-scale screening of tobacco varieties with resistance to brown spot.

Abstract: The disclosure provides a method of screening tobacco germplasm for resistance to Alternaria alternata by ripening seedling leaves. The method includes ripening seedling leaves, spray inoculation, disease induction, and evaluation of disease resistance. Dense planting, fertilizer control, and potassium increment were used to forcibly ripening seedling leaves. A hospitable environment was simulated to induce disease in the ripened leaves. These treatments reduce differences in leaf maturity and avoid environmental changes. The technique of the disclosure provides greater accuracy and repeatability than the current technique of screening brown spot resistance, and offers the advantages of simple operation, reduced cost, space requirement, and labor intensity, high selection efficiency, and an accurate screening of tobacco phenotypes with resistance to brown spot, etc., used for large-scale screening of tobacco varieties with resistance to brown spot.

Abstract: A tobacco arsenic transport gene NtNIP7-1 and a cloning method and application thereof are disclosed. A nucleotide sequence of the tobacco arsenic transport gene NtNIP7-1 is shown as SEQ ID: No. 1, and an encoded amino acid sequence thereof is shown as SEQ ID: No. 2. The cloning method of the tobacco arsenic transport gene NtNIP7-1 includes (S1) extracting RNA in tobacco, performing reverse transcription, and obtaining a first-strand cDNA; and (S2) taking the first-strand cDNA obtained by the reverse transcription as a template, synthesizing a specific primer according to sequences of the NtNIP7-1 gene, performing PCR amplification, recovering and purifying a product of the PCR amplification, and sequencing. In the present invention, inhibition of the expression of the tobacco endogenous gene NtNIP7-1 in tobacco plants is able to significantly reduce the arsenic content of tobacco leaves, and has broad application prospects in the field of low arsenic content breeding.