Post-transfer adaptation of HGT-acquired genes and contribution to guanine metabolic diversification in land plants.

Horizontal gene transfer (HGT) is a major driving force in the evolution of prokaryotic and eukaryotic genomes. Despite recent advances in distribution and ecological importance, the extensive pattern, especially in seed plants, and post-transfer adaptation of HGT-acquired genes in land plants remain elusive. We systematically identified 1150 foreign genes in 522 land plant genomes that were likely acquired via at least 322 distinct transfers from nonplant donors and confirmed that recent HGT events were unevenly distributed between seedless and seed plants. HGT-acquired genes evolved to be more similar to native genes in terms of average intron length due to intron gains, and HGT-acquired genes containing introns exhibited higher expression levels than those lacking introns, suggesting that intron gains may be involved in the post-transfer adaptation of HGT in land plants. Functional validation of bacteria-derived gene GuaD in mosses and gymnosperms revealed that the invasion of foreign genes introduced a novel bypass of guanine degradation and resulted in the loss of native pathway genes in some gymnosperms, eventually shaping three major types of guanine metabolism in land plants. We conclude that HGT has played a critical role in land plant evolution.

GinkgoDB: an ecological genome database for the living fossil, Ginkgo biloba.

Although an increasing number of species-specific databases have been constructed to facilitate the global research community, comprehensive databases remain rare with multidimensional research resources rather than genomic data solely, in particular for non-model species. Here we introduced GinkgoDB, the ecological genome database for the world-renowned living fossil, Ginkgo biloba L., a tree species with extreme longevity, exceptional resistance, global landscape application and dioecy. The present version of GinkgoDB consists of four modules of genome, occurrence, quadrat and gallery. The genome module includes two versions of chromosome-level assembled genomes with high-quality annotation, expression profiles of each sex for different tissues and variants from 545 ginkgo genomes. A suite of tools were also deployed online for search, blast and further analyses. The occurrence module contains distribution information of over one million records across the world with an emphasis on 8926 individual-level tagged trees with phenotypic trait data in eastern Asia. The quadrat module provides monitoring data of both species and habitats from 27 plots of natural ginkgo forests and periodic data of functional traits measured for the entire plant communities. The gallery module collects field morphological photos and scanned phenotypic images of various ginkgo materials. GinkgoDB showcases a comprehensive and persistently growing database for a single non-model species. Database URL: https://ginkgo.zju.edu.cn/.

Spatial Difference of Interactive Effect Between Temperature and Daylength on Ginkgo Budburst.

Climate warming-induced shifts in spring phenology have substantially affected the structure and function of terrestrial ecosystems and global biogeochemical cycles. Spring phenology is primarily triggered by spring temperature and is also affected by daylength and winter chilling, yet the relative importance of these cues across spatial gradients remains poorly understood. Here, we conducted a manipulative experiment with two daylength and three temperature treatments to investigate spatial differences in the response of ginkgo budburst to temperature and daylength, using twigs collected at three sites across a spatial gradient: a control site at a low latitude and low elevation on Tianmu Mountain (TMlow), a low latitude and high elevation site on Tianmu Mountain (TMhigh), and a high latitude site on Jiufeng mountain (JF). The mechanisms were also tested using in situ phenological observations of ginkgo along latitudes in China. We found that, compared to TMlow individuals, budburst dates occurred 12.6 (JF) and 7.7 (TMhigh) days earlier in high-latitude and high-elevation individuals when exposed to the same temperature and daylength treatments. Importantly, daylength only affected budburst at low latitudes, with long days (16 h) advancing budburst in low-latitude individuals by, on average, 8.1 days relative to short-day (8 h) conditions. This advance was most pronounced in low-elevation/latitude individuals (TMlow = 9.6 days; TMhigh = 6.7 days; JF = 1.6 days). In addition, we found that the temperature sensitivity of budburst decreased from 3.4 to 2.4 days °C-1 along latitude and from 3.4 to 2.5 days °C-1 along elevation, respectively. The field phenological observations verified the experimental results. Our findings provide empirical evidence of spatial differences in the relative effects of spring temperature and daylength on ginkgo budburst, which improved our understanding of spatial difference in phenological changes and the responses of terrestrial ecosystem to climate change.