From the documentation, when you have a TextField it is, in fact, an abstraction component of several smaller components
Advanced Configuration
It's important to understand that the text field is a simple abstraction on top of the following components:
FormControl - InputLabel
List item
Input
FormHelperText
Blockquote
If you wish to alter the properties applied to the native input, you can do as follow:...
In your TextField you can pass props for the Input and Label as follow:
<TextField defaultValue="react-bootstrap" label="Bootstrap" InputProps={{ disableUnderline: true, classes: { root: classes.textFieldRoot, input: classes.textFieldInput, }, }} InputLabelProps={{ shrink: true, className: classes.textFieldFormLabel, }} />
this is taken from the last example given in this page.