부산대학교 도서관

Hyperdiverse tropical rainforests, such as the aseasonal forests in Southeast Asia, are supported by high annual rainfall. Its canopy is dominated by the species-rich tree family of Dipterocarpaceae (Asian dipterocarps), which has both ecological (e.g., supports flora and fauna) and economical (e.g., timber production) importance. Recent ecological studies suggested that rare irregular drought events may be an environmental stress and signal for the tropical trees. We assembled the genome of a widespread but near threatened dipterocarp, Shorea leprosula, and analyzed the transcriptome sequences of ten dipterocarp species representing seven genera. Comparative genomic and molecular dating analyses suggested a whole-genome duplication close to the Cretaceous-Paleogene extinction event followed by the diversification of major dipterocarp lineages (i.e. Dipterocarpoideae). Interestingly, the retained duplicated genes were enriched for genes upregulated by no-irrigation treatment. These findings provide molecular support for the relevance of drought for tropical trees despite the lack of an annual dry season. Ng, Kobayashi, et al. present the genome assembly for the dipterocarp Shorea leprosula and present transcriptome data for ten more dipterocarp species of seven genera. The Shorea leprosula genome, along with drought stress experiments, demonstrate evidence for a whole-genome duplication (WGD) event dated to the Cretaceous-Paleogene boundary, with WGD duplicates enriched in genes upregulated during the drought response. [ABSTRACT FROM AUTHOR]