It will always be a transgene, regardless the fact you express an 'endogenous' gene. The transferred DNA will harbour sequences, ie cloning sites, promoter, terminator, selection marker foreign to the plant genome, so you always will transfer sequences new to the plant genome.

If you have inserted additional copies of genes from an organism itself then it can be referred to as cisgenic, or an upregulated mutant for that gene. As Mr. van der Graaf has said, though, there will always be foreign sequences that will be inserted into the genome as they are necessary for the process of modification and may include a stronger promoter than what is normally associated with said gene. There is nothing wrong with referring to your plant as a transgenic specimen.

1. Cisgenes are genes isolated from crossable species. Schouten et al. (2006), who defined a cisgenic plant as “a crop plant that has been genetically modified with one or more genes isolated from a crossable donor plant.” [see attachment]

2. Cisgenic plants should not contain 'selectable marker genes (SMG)' such as kanamycin-resistant gene. I guess that the overexpression line from Abdulrahman Idoko Adam should still contain a SMG (which usually built with the gene-of-interest in a cassette, such as a T-DNA cassette), unless an approach has been taken to remove the SMG. So, it should not be considered as a cisgenic plant.

3. It should still be called transgenic line, as Eric mentioned, you have the promoter (ex. 35S), SMG and other components with a stretch of foreign DNA involved.

It should be identify as transgenic plant. It may be consider cisgenic plants but I agree with the previous comments: it depends on the type of construct you used for transformation.

Transgenic