Intron has been considered as "junk" in the past. However, in recent years, several studies have revealed biological significance of introns and found that introns that hosting functional elements play an indispensable regulatory role. In our recent study, we designed Intron-capture RNA-seq, to study intronic RNA from introns in Arabidopsis. Despite the increasing attention focused on introns, it seems that a comprehensive database on introns that hosting functional elements has not yet emerged as far as the current studies are concerned.

In summary, we take full advantage of large-scale sequencing data, and developed this user-friendly database: PlantIntronDB, which currently contains 100,126 introns that hosting functional elements, including 19,363 in Arabidopsis, 2,334 in cotton, 13,079 in maize, 31,370 in oilseed rape, and 33,980 in rice, all of which are available for free download. Using this database, users can not only grasp the rich details of introns that hosting functional elements, but also track these introns resources and reveal their novel functions and regulatory roles. We believe that this database will help the community to have a deeper understanding of introns that hosting functional elements.