SACRAMENTO—Judges and executives representing 49 trial courts are calling on Gov. Jerry Brown to add $159 million to the judiciary’s budget, saying his hold-the-line spending plan will lead to employee layoffs and courtroom closures.

Although the governor’s budget proposal in January added a small amount of money to fund higher employee health care and retirement costs and to offset expected declines in fines and penalties, it did not include significant new spending on the judiciary.