Weird line in my grass textures?

Every time I make a grass texture and paint with it, a weird line keeps showing up on the left side of the image (it's yellow, sometimes black). I've checked to make sure there's nothing actually there in Photoshop, tried making multiple different files saved different ways... and nothing. It still gives me that stupid line.

Anyone have any idea why this is happening? :/

UPDATE: I don't know if this is the cause or not, but I know a lot of times you have a background color under the foliage/grass/whatever that's similar in color to help prevent weird/glowing outlines around the foliage/grass/whatever. I wasn't thinking about that since the issue is so far from the subject of the texture, but I haven't been doing this. I've been having issues keeping the alpha intact when I add a background color on another layer. If anyone could help me with saving the file out of Photoshop properly (we're using .png), I can at least see if this helps.

While I wait to see if I get an answer to the above and see if it helps, I have found a temporary "fix." I just applied the texture to a poly plane with its UVs slightly smaller than max, so it cuts off the line, and I loaded it as a detail object instead of grass. From some angles you can still see a small line, and this isn't the most ideal solution, but it works well enough for now. I have other fish to fry and will just have to revisit the issue later.