Natural population re-sequencing detects the genetic basis of local
adaptation to low temperature in a woody plant
Abstract
Local adaptation to temperature is essential for woody plants to against
changeable climate and safely survive the winter. To uncover the
specific molecular mechanism of low temperature adaptation in woody
plants, we performed selective-sweep analysis and genome-wide
association study (GWAS) on a wild woody plant naturally distributed in
different climate zones and latitudes. We sequenced a core collection of
134 accessions selected from 494 paper mulberry (Broussonetia papyrifera
L.), phenotyped the accessions in high latitudes of 40º N for two
overwintering traits. We further performed genome-phenotype and
genome-environment associations, and genome-wide scans for temperature
selection. The population structure analysis indicated that accessions
showed forceful geographic distribution patterns because of the
adaptation to local climate. We detected 75 selective regions possibly
undergone temperature selection and identified 14 trait-associated SNPs
corresponded to 16 candidate genes. Meanwhile, low temperature
adaptation was also supported by other three SNPs with values lower than
threshold but harboring different primary genotype among geographic
groups. Overall, we propose a possible network of cold signal perception
and responses in woody plants, some genes are considered unique to woody
plants while others have been studied in herbs, which highlighting a key
hit for studying the specific molecular mechanism of low temperature
adaptation or overwintering in woody plants.