1. 突然…起来
If you burst into tears, laughter, or song, you suddenly begin to cry, laugh, or sing.

2. （花、叶等）突然绽放，突然长出
When plants burst into leaf or flower, their leaves or flowers suddenly open.

3. 突然变成
If you say that something bursts into a particular situation or state, you mean that it suddenly changes into that situation or state.

4. to burst into flames - see flame