To provide a gene that controls the deep rooting of a plant, a transgenic plant introduced with the gene, a method for controlling the deep rooting of a plant using the gene, and such, high-resolution linkage analysis was performed for a genetic locus (Dro1 locus) capable of controlling the deep rooting of a plant, which was detected between a shallow-rooted rice cultivar IR64 and a deep-rooted rice cultivar Kinandang Patong in a large-scale segregating population. As a result, it was revealed that the gene region of Dro1 is located in a region of 6.0 kbp sandwiched between Dro1-INDEL09, which is an InDel marker, and Dro1-CAPS05, which is a CAPS marker. Furthermore, it was confirmed that a transgenic plant transformed with the Kinandang Patong-type Dro1 gene shows a significantly high ratio of deep rooting. It was also confirmed that a plant having the Kinandang Patong-type Dro1 gene is resistant to drought.
