Fuente: WIPO "tobacco agriculture" The invention discloses a transcription factor NtMYB44a capable of improving drought resistance of tobacco and a site-directed mutation method and an application thereof. The transcription factor NtMYB44a capable of improving the drought resistance of tobacco has a nucleotide sequence shown in SEQ ID NO:1. An encoding protein has the amino acid sequence shown in SEQ ID NO:2. Two sgRNA target lociare designed by a CRISPR/Cas9 technology and are located at 236 bp and 230 bp away from a termination codon (TGA) respectively; the mutation of the gene at a target locus is caused by tobacco transformation; after selfing and seed harvesting, site-directed homozygous mutant progenies of the NtMYB44a gene are obtained from screening. Physiological experiments show that the water loss rate of mutanttobacco leaves is significantly slower than that of wild-type control plants. Water cover experiments after drought stress show that the survival rate of the mutant plants is significantly higher than that of wild type plants. The homozygous mutant tobacco material of the NtMYB44a gene produced by using the CRISPR/Cas9 technology and aiming at the tail of the NtMYB44a gene (namely in a 200 bp to300 bp sequence range away from the translation termination codon (TGA) of the NtMYB44a) is showed to have higher drought resistance than that of wild tobacco. The genetic resources and technical support are provided for an application of the NtMYB44a gene and the coding protein thereof in tobacco drought resistance breeding.