The genome of hibiscus hamabo reveals its adaptation to saline and waterlogged habitat

Hibiscus hamabo is a semi-mangrove species with strong tolerance to salt and waterlogging stress. However, the molecular basis and mechanisms that underlie this strong adaptability to harsh environments remain poorly understood. Here, we assembled a high-quality, chromosome-level genome of this semi-mangrove plant and analyzed its transcriptome under different stress treatments to reveal regulatory responses and mechanisms. Our analyses suggested that H. hamabo has undergone two recent successive polyploidy events, a whole-genome duplication followed by a whole-genome triplication, resulting in an unusually large gene number (107 309 genes). Comparison of the H. hamabo genome with that of its close relative Hibiscus cannabinus, which has not experienced a recent WGT, indicated that genes associated with high stress resistance have been preferentially preserved in the H. hamabo genome, suggesting an underlying association between polyploidy and stronger stress resistance. Transcriptomic data indicated that genes in the roots and leaves responded differently to stress. In roots, genes that regulate ion channels involved in biosynthetic and metabolic processes responded quickly to adjust the ion concentration and provide metabolic products to protect root cells, whereas no such rapid response was observed from genes in leaves. Using co-expression networks, potential stress resistance genes were identified for use in future functional investigations. The genome sequence, along with several transcriptome datasets, provide insights into genome evolution and the mechanism of salt and waterlogging tolerance in H. hamabo, suggesting the importance of polyploidization for environmental adaptation.DATA AVAILABILITY: The data supporting the findings of this work are available within the paper and its Supporting Information files. The data sets generated and analyzed during this study are available from the corresponding author upon request. All the whole-genome raw data generated during this study have been deposited in the SRA database under BioProject number PRJNA759075. Transcriptome clean data have been deposited in the SRA database under BioProject number PRJNA759717. The final chromosome-scale genome assembly and annotation data have been deposited in the Figshare database (https://doi.org/10.6084/m9.figshare.19142558.v1).Six Talent Peaks Project of Jiangsu Province (NY-042); Open Fund of the Jiangsu Key Laboratory for the Research and Utilization of Plant Resources (JSPKLB201928); Talent Training Funds of the Institute of Botany, Jiangsu Province and Chinese Academy of Sciences.https://academic.oup.com/hrBiochemistryGeneticsMicrobiology and Plant Patholog

New Ideas for Improving China's Coastal Zone Management Legislation：Drawing on the Experiences of the United States

姜玉环，厦门大学海洋与环境学院。 方珑杰，厦门大学海洋与环境学院。【中文摘要】中美两国都是海洋大国，对海岸带的合理开发和有效管理已成为中美两国海洋管理面临的共同现实问题。美国在海岸带综合管理理念上一直走在世界前列，依靠其制度的不断变革和创新，逐步迈向海岸带可持续发展的方向。中国海岸带资源开发与生态环境的可持续发展需要海岸带管理体制和政策、法律的不断完善，美国海岸带管理的实践经验和不断发展为中国提供了重要借鉴，本文重点讨论完善中国海岸带管理法律制度的对策，并提出建议。 【Abstract】As maritime powers, both the United States and China are facing the common issue of rational development and effective management of coastal zones. The United States, who has always been leading the world with its innovative concept of integrated coastal zone management, and relying on its ongoing institutional reform and innovation, is now gradually moving towards sustainable coastal zone development. China has yet to improve its coastal zone management system as well as relevant policies and laws in order to achieve sustainable development in coastal zone resource exploitation and ecological environment, while the United States' practical experience and continuous development of coastal zone management provide an important reference to China. This article focuses on measures to improve China's legal system for coastal zone management and attempts to make relevant suggestions

The identification, adaptive evolutionary analyses and mRNA expression levels of homeobox (hox) genes in the Chinese mitten crab Eriocheir sinensis

Abstract Background Arthropods are the largest group in the animal kingdom and are morphologically characterized by heterorhythmic segments. Brachyuran decapod crustaceans undergo brachyurization metamorphosis in the early developmental process, characterized by a reduced abdomen that is folded beneath the cephalothorax and inserted between the pereiopods or in a special cavity. As the main cause of major alterations in the evolution of animal body plans, Hox genes encode transcription factors and are involved in bilaterian anterior-posterior axis patterning. Results We found eight Hox genes (labial, proboscipedia, Deformed, zerknüllt, Sex combs reduced, Antennapedia, Ultrabithorax, fushi tarazu, abdominal-A and Abdominal-B) in Eriocheir sinensis. The phylogenetic topology of 13 arthropod Hox genes was closely related to traditional taxonomic groupings. Genome collinearity analysis was performed using genomic data and chromosomal location data of E. sinensis and Portunus trituratus. We found that their chromosomes were highly collinear, and there was a corresponding collinear relationship between the three Hox genes (lab, ftz and Abd-B). The mRNA expression levels of Scr and Antp fluctuated significantly in different developmental stages of E. sinensis, especially in the brachyurization stages. Evolutionary analysis indicated the presence of positively selected sites in Ubx. Conclusions In this study, we used genome-wide analysis to identify and analyze all members of the Hox genes in E. sinensis. Our data will contribute to a better understanding of Hox genes in E. sinensis and provide useful molecular evolutionary information for further investigation on their roles in the brachyurization of crabs

The genome of Hibiscus hamabo reveals its adaptation to saline and waterlogged habitat

Hibiscus hamabo is a semi-mangrove species with strong tolerance to salt and waterlogging stress. However, the molecular basis and mechanisms that underlie this strong adaptability to harsh environments remain poorly understood. Here, we assembled a high-quality, chromosome-level genome of this semi-mangrove plant and analyzed its transcriptome under different stress treatments to reveal regulatory responses and mechanisms. Our analyses suggested that H. hamabo has undergone two recent successive polyploidy events, a whole-genome duplication followed by a whole-genome triplication, resulting in an unusually large gene number (107 309 genes). Comparison of the H. hamabo genome with that of its close relative Hibiscus cannabinus, which has not experienced a recent WGT, indicated that genes associated with high stress resistance have been preferentially preserved in the H. hamabo genome, suggesting an underlying association between polyploidy and stronger stress resistance. Transcriptomic data indicated that genes in the roots and leaves responded differently to stress. In roots, genes that regulate ion channels involved in biosynthetic and metabolic processes responded quickly to adjust the ion concentration and provide metabolic products to protect root cells, whereas no such rapid response was observed from genes in leaves. Using co-expression networks, potential stress resistance genes were identified for use in future functional investigations. The genome sequence, along with several transcriptome datasets, provide insights into genome evolution and the mechanism of salt and waterlogging tolerance in H. hamabo, suggesting the importance of polyploidization for environmental adaptation