Morphology and high-quality genome assembly of the Sinojackia xylocarpa. a Flowering and fruiting branches of S. xylocarpa. b Genome features across 12 chromosomes of S. xylocarpa. From the outermost to innermost circles are chromosome ideograms, gene density (from blue to red), GC content, TE (transposable elements) density (from blue to red), and collinear genomic blocks.
Newswise — The Jacktree (Sinojackia xylocarpa), native to China, is renowned for its unique spindle-shaped fruits and ornamental appeal. However, its survival is threatened by factors such as limited population size, fragmented habitats, and low germination rates caused by tough, lignified pericarps. Addressing these challenges requires in-depth genetic research to develop effective conservation measures.
Scientists from Nanjing Forestry University and Nanjing Agricultural University published a study (DOI: 10.1093/hr/uhae166) in the journal Horticulture Research on June 18, 2024. This research presents the first chromosome-scale genome assembly of the Jacktree, revealing genetic insights into its endangered status and identifying key factors behind its germination barriers. The study integrates genome sequencing, population genomics, and molecular biology to address the conservation challenges of this valuable plant.
The study links the Jacktree’s population decline to genetic bottlenecks following the last glacial period. Genomic analysis showed that the tree’s fruit pericarps accumulate high levels of lignin, cellulose, and hemicellulose, forming a rigid structure that inhibits seed germination. Elevated expression of key lignin biosynthesis genes contributes to the hardening of the pericarps. The findings emphasize the critical role of lignin in restricting seed growth, highlighting the need for targeted conservation strategies, including genetic diversity enhancement through artificial breeding and environmental adjustments, such as increased soil moisture, to support germination. These insights offer a roadmap for better management and restoration of this endangered species.
Dr. Jia-Yu Xue, lead researcher, emphasized, “This study provides vital genetic insights into the factors limiting Jacktree germination and conservation. By identifying the genetic basis of lignified pericarps, we can devise targeted strategies to improve germination rates and promote the sustainable recovery of this endangered species.”
The study’s findings have far-reaching implications for conserving the Jacktree and similar endangered ornamental plants. By understanding the genetic basis of lignified pericarps, conservation efforts can focus on breeding new cultivars with reduced lignin content. Additionally, environmental management, such as optimizing soil moisture and enhancing beneficial microbial interactions, could further boost germination and restoration efforts for this valuable species.
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References
DOI
Original Source URL
https://doi.org/10.1093/hr/uhae166
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number two in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.
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