That's up to your broker. Could be he will allow you to "wire" funds to make up the deficit, or they could sell enough shares "at market" to add cash to your account, and hound you for the rest.
But you have to have a phone conversation with your broker, ASAP.
Step aside son, you're blockin' the MOMO! ... .. Disproving absence of evidence should be easy, show the evidence of.