The 'Yudh' star announced it on Twitter yesterday that he has been named as the brand ambassador for the western state's Horticultural Ministry.
"We have done a few print campaigns in this regard but on August 3, we are going to do some work for the TV as well," Bachchan said on the sidelines of an event here to mark India's triumph over polio.
"I have dedicated myself to the polio campaign and though we have made India polio-free, my services to the campaign shall continue for any future noble cause in this direction," he said.
The 71-year-old actor, who is also the face of Gujarat tourism, is already a face of Gujarat tourism and polio eradication campaign.
"Being associated with polio campaign for the last one decade and having many medical episodes during my career, my respect for the Indian medical profession has only grown.
"So, promoting nation's health or Gujarat's culture or Maharashtra's fruit produce, I am always ready to volunteer for a good cause," Bachchan said.