Parentheses and brackets should be in the same font style as the surrounding text, not same as the enclosed text.  For example, it the text inside the parentheses is in italics, and the outside text is roman, the parentheses will be roman.
Same is the case with quotation marks.

The banana plant (Musa) is the largest herbaceous flowering plant.

Not

The banana plant (Musa) is the largest herbaceous flowering plant.