getting form:options value in AJAX

Jsp code is as follows:

<form:select id="taxId" path="taxSeqNo" cssClass="defaultText"        <form:options items="${taxListItemsBean.taxList}" itemValue="key" itemLabel="label"/>
</form:select>

Where ${taxListItemsBean.taxList} is declared as

private List<KeyItemDto> taxList;

in the form.java class.

I want to pass this taxList through ajax to controller. Can you please help me get the list of KeyItemDto(taxList) in the controller?