Search Results (3)

Ormosia microphylla is a national first-class protected wild plant in China that faces conservation challenges, including weak natural regeneration and limited environmental adaptability. Plant-associated bacterial communities are important components of host-associated microecosystems, but bacterial community patterns across the whole-plant continuum of O. microphylla remain poorly understood. To provide a descriptive micro-ecological baseline, we characterized bacterial communities across the rhizosphere–root–stem–leaf continuum of O. microphylla in three geographic habitats in Southwest China: karst mountainous area, a plateau-to-plain transitional slope zone, and a hilly area. High-throughput amplicon sequencing was used to analyze bacterial diversity and composition, and co-occurrence network analysis was used to describe statistical associations among bacterial taxa. Three main patterns were observed. First, bacterial alpha diversity generally declined from the rhizosphere to internal tissues (rhizosphere > root > stem > leaf). Second, bacterial composition varied by plant compartment and habitat. Dominant rhizosphere taxa differed among habitats, whereas internal tissues were generally dominated by Proteobacteria. Delftia showed relatively high abundance in several endophytic compartments, suggesting that this genus may be considered a candidate endophytic taxon for future validation. Third, co-occurrence network analysis showed habitat- and compartment-associated differences in network size, complexity, and positive/negative co-occurrence patterns. Overall, these results describe compartment- and habitat-associated bacterial community patterns in O. microphylla and provide a micro-ecological baseline for future culture-dependent and functional studies. Full article

Conservation and management of endangered species are crucial to reveal the restriction mechanisms of climate change on the distribution change pattern of endangered species. Due to human interference and a limited natural capacity for regeneration, the wild resources of Ormosia microphylla Merr. & H. Y. Chen have progressively dwindled. Therefore, this study reconstructed the historical migration dynamics of the geographical distribution of O. microphylla since the last interglacial period and analyzed its adaptation to climatic conditions, aiming to provide an important reference for the protection of O. microphylla. Using data from 40 distribution resources of O. microphylla and nine climate factors, an optimized MaxEnt model, in conjunction with ArcGIS 10.4.1 software, was used for predicting and visualizing the distribution ranges and the associated changes under historical, current, and future climate scenarios. This analysis was also used to determine the dominant climate factors constraining the distribution of species. The results show that contemporary suitable habitats of O. microphylla are primarily concentrated in the mountainous regions of southern China, including Fujian, Guangdong, Guangxi, and Guizhou. The precipitation of driest quarter (bio17), the temperature seasonality (bio4), the min temperature of coldest month (bio6), and the elevation (elev) were the key limiting factors in the current geographical distribution pattern of O. microphylla. In the SSP126 and SSP585 climate scenarios, the total suitable area of O. microphylla showed a downward trend. The change in the spatial pattern of O. microphylla shows that the increase area is less than the loss area under different climate scenarios in the future. Climate warming may cause fragmentation risk to the suitable area of O. microphylla. Therefore, the corresponding protection suggestions bear significant importance for the conservation and sustainable development of O. microphylla resources. Full article

The genus Ormosia comprises approximately 130 species, which are found in tropical regions all over the world. The taxonomy and evolutionary history are still ambiguous due to the lack of a solid phylogeny at the species level. Due to the fast advancement of high-throughput sequencing technology, it is now possible to retrieve the full chloroplast (cp) genome sequence, providing a molecular basis for phylogenetic analysis. Five species of Ormosia were used in this work, and their whole cp genomes were sequenced. One circular, quadripartite-structured molecule, ranging from 169,797 to 173,946 base pairs in length, was present in all five Ormosia species. The cp genomes of the five newly sequenced Ormosia species were further compared with the published cp genomes of O. pinnata. Ten hypervariable regions (Pi > 0.025) were uncovered in the Ormosia chloroplast genomes, among which petN-psbM showed the highest Pi value. Phylogenetic analysis revealed that O. microphylla and O. olivacea clustered with strong support. O. balansae was resolved as a sister to O. pinnata, and they were further found to be sisters to the remaining 13 Ormosia species. The cp genes of O. elliptica showed a close relationship to O. hosiei, and O. semicastrata clustered with O. emarginata. Taken together, the comprehensive analysis of the complete cp genomes of five Ormosia species offers valuable insight and information for reconstructing their phylogeny and sheds light on the evolutionary dynamics of the chloroplast genome in Ormosia. Full article