I tried this command but result in an error shown below
figure
plot(1:10)
dim = [.2 .5 .3 .3];
str = 'Straight Line Plot from 1 to 10';
h = annotation('textbox',dim,'String',str,'FitBoxToText','on');
set(h,'Rotation',90)
Error using matlab.graphics.shape.TextBox/set
There is no Rotation property on the TextBox class.