I am interested in expressing e^(-x) in terms of an ordinary MeijerG function.

I used the MeijerGReduce command in Mathematica 11.3 and found that e^(-x) can be expressed in terms of a generalized MeijerG function. This expression is:

e^(-x)=1/(pi)^0.5*MeijerG[{{},{}},{{0,1/2},{}},x/2,1/2].

In this expression, there are two arguments past the four sets of braces which is what makes this expression a generalized MeijerG function.

I am seeking an expression for e^(-x) in terms of ordinary MeijerG functions, which have only one argument past the four sets of braces.

Any help with this question would be greatly appreciated.