Bo slammed the allegations as "contradictory" and denied that he needed to take the money as his wife earned millions of dollars from her five law firms.
Under the bribery indictment, prosecutors accuse Bo of using his political posts to secure influence for others. They say that between 2000 and 2012, Bo, Gu and their son, Bo Guagua, received about 22 million renminbi ($3.6 million) in bribes from businessmen in Dalian.
Bo's fall from grace
Bo is a princeling, a term that refers to the children of revolutionary veterans who boast of political connections and influence. His late father, Bo Yibo, was a revolutionary contemporary of Chairman Mao Zedong and the late paramount leader Deng Xiaoping.
Over the past three decades, Bo rose to power as a city mayor, provincial governor, minister of commerce and member of the Politburo, the powerful policy-making body of the Communist Party.
A charismatic and urbane politician, Bo -- with the help of Wang -- was credited with a spectacular, albeit brutal, crackdown on organized crime during his time as the top party official of Chongqing.
Bo's glittering career, in which he drew admirers and detractors for his populist policies, fell apart last year amid a scandal involving murder, corruption and betrayal.
Wang's attempted defection precipitated Bo's political demise. After Gu's sentencing last August, Wang was convicted of bending the law for selfish ends, defection, abuse of power and bribe-taking. He received a 15-year prison sentence.
Bo's trial is seen as a potentially concluding chapter in the scandal.
His high profile and connections among the nation's ruling elite have made his case -- with its tales of greed and wrongdoing by a top official and his family -- an extremely delicate matter for Chinese authorities.
It's taken more than a year, during which time the Communist Party has undergone a major leadership change, to bring him to trial.
Many observers had expected proceedings to stick closely to a pre-planned script, seeing the trial's outcome as the result of a political deal struck between Bo and China's top leaders.
But as he often did in his political career, Bo has so far stolen the show, mounting a robust attack on the prosecution's case and ridiculing witness testimony. That has left China watchers trying to figure out how far he's veered off script.
Journalists from the international news media haven't been allowed inside the courtroom. But the court's official microblog account has delivered updates on developments inside, attracting more than half a million followers on Weibo, China's Twitter-like service.
CNN hasn't been able to verify how accurate and comprehensive the court's version of proceedings has been. But many observers have interpreted it as a reasonably close, albeit filtered, account.