Answer:
First of all, sunrise sectors of the economy refers to industries or business that have been recently created and you could say that are in their "infancy" stage, e.g. alternative energies like solar panels and wind turbines.
Generally sunrise sectors have the potential of achieving exponential growth rates, but they also include several startups that will end up failing.
May times governments offer incentives to sunrise sectors of the economy in order to facilitate their development, e.g. loan guarantees, research and development subsidies, special tax breaks, low interest loan, trade protection, production subsidies, etc.
Governments do this because sunrise sectors have a huge potential, and can provide huge benefits in the near future, but without a little help, they might not be able to develop properly.