Brotado is the past participle of the verb brotar, which means 'to sprout' or 'to bud', like a plant. It's a beautifully poetic word that you won't hear in every song.
In "PERLA", the singer uses this word metaphorically to describe how love has suddenly grown inside him. He sings, "ha brotado una raíz de amor en mi corazón" (a root of love has sprouted in my heart), creating a powerful image of a new, organic feeling taking root.
This song is a full-on declaration of love, and the singer is not playing it cool. He starts by saying he's been waiting so long for this person that he became a "loco" [crazy person]. He feels like he's "Atrapado en un sueño" [Trapped in a dream] and he's completely head over heels, admitting, "No sé lo que me hiciste pero me encantas" [I don't know what you did to me but I love you].
He piles on the compliments, telling her she wears jewels but "brillas más que todas" [you shine more than all of them]. The whole song builds to the main image in the chorus: her eyes. He describes them as "ojitos blancos como las perlas del mar" [little white eyes like pearls from the sea]. It's this beautiful, slightly obsessive comparison that gives the song its name, "PERLA" [Pearl]. He's a self-proclaimed "loco enamorado" [crazy man in love], and he's totally happy about it.