Plant Diversity最新文献

Myanmar is one of the most biodiverse countries in the Asia–Pacific region due to a wide range of climatic and environmental heterogeneity. Floristic diversity in Myanmar is largely unknown, resulting in a lack of comprehensive conservation plans. We developed a database of higher plants in Myanmar derived from herbarium specimens and literature sources, and analyzed patterns of diversity inventories and collection inconsistencies, aiming to provide a baseline floristic data of Myanmar and act as a guide for future research efforts. We collected 1,329,354 records of 16,218 taxa. Results show that the collection densities at the township level was variable, with 5% of townships having no floristic collections. No ecoregion had an average collection density of greater than 1 specimen/km² and the lowest collection density was found in the Kayah-Karen Montane Rainforests, which covered 8% of Myanmar's total area. The highest sampling densities were found in Mandalay Region, Chin State, and Yangon Region. Despite floristic collections over the past three centuries, knowledge of the distribution of the vast majority of plant taxa remained limited, particularly for gymnosperms, pteridophytes, and bryophytes. More botanical surveys and further analyses are needed to better describe Myanmar's floristic diversity. An important strategy to promote knowledge of the biodiversity patterns in Myanmar is to improve the collection and digitalization of specimens and to strengthen cooperation among countries.

Plants classified as Near Threatened (NT) are at high risk of becoming threatened because of anthropogenic interference and climate change. Especially in conservation efforts, such species have however long been overlooked. Here, we obtained 98,419 precise occurrence points for 2442 NT plants in China, and used species richness, species complementarity, and weighted endemism that consider all, endemic and narrow-ranged species in order to identify the diversity hotspots of NT plants. Then we evaluated the conservation effectiveness of current nature reserves for them. Our results indicate that the diversity hotspots of NT plants were mainly confined to southwestern and southern China, and only 35.87% of hotspots and 71.5% of species were protected by nature reserves. Numerous hotspots in southwestern China (e.g., Sichuan, Yunnan, Guangxi, and Hainan) were identified as conservation gaps. Given that NT plants include large proportions of endemic and narrow-ranged species, they represent an important value in conservation priority. So, more conservation efforts in the future should be tilted towards NT plants. Additionally, when comparing with the recently updated NT list, there are already 87 species raised to threatened categories, while 328 species were lowered to least concern, 56 species were now categorized as data deficient, and 119 species considered as uncertain due to changes of scientific names. It is essential to carry out a continuous assessment of species' threatened categories to realize targeting conservation.

The previously released packages of the PhyloMaker series (i.e. S.PhyloMaker, V.PhyloMaker, and V.PhyloMaker2) have been broadly used to generate phylogenetic trees for ecological and biogeographical studies. Although these packages can be used to generate phylogenetic trees for any groups of plants and animals for which megatrees are available, they focus on generating phylogenetic trees for plants based on the megatrees provided by the packages. How to use these packages to generate phylogenetic trees based on other megatrees is not straightforward. Here, we present a new tool, which is called ‘U.PhyloMaker’, and a simple R script that can be used to easily generate large phylogenetic trees for both plants and animals at a relatively fast speed.

Verticillium wilt, caused by Verticillium dahliae, seriously restricts the yield and quality improvement of cotton. Previous studies have revealed the involvement of WRKY members in plant defense against V. dahliae, but the underlying mechanisms involved need to be further elucidated. Here, we demonstrated that Gossypium hirsutum WRKY DNA-binding protein 33 (GhWRKY33) functions as a negative regulator in plant defense against V. dahliae. GhWRKY33 expression is induced rapidly by V. dahliae and methyl jasmonate, and overexpression of GhWRKY33 reduces plant tolerance to V. dahliae in Arabidopsis. Quantitative RT-PCR analysis revealed that expression of several JA-associated genes was significantly repressed in GhWRKY33 overexpressing transgenic plants. Yeast one-hybrid analysis revealed that GhWRKY33 may repress the transcription of both AtERF1 and GhERF2 through its binding to their promoters. Protein–protein interaction analysis suggested that GhWRKY33 interacts with G. hirsutum JASMONATE ZIM-domain protein 3 (GhJAZ3). Similarly, overexpression of GhJAZ3 also decreases plant tolerance to V. dahliae. Furthermore, GhJAZ3 acts synergistically with GhWRKY33 to suppress both AtERF1 and GhERF2 expression. Our results imply that GhWRKY33 may negatively regulate plant tolerance to V. dahliae via the JA-mediated signaling pathway.

Knowledge of which biological and functional traits have, or lack, phylogenetic signal in a particular group of organisms is important to understanding the formation and functioning of biological communities. Allometric biomass models reflecting tree growth characteristics are commonly used to predict forest biomass. However, few studies have examined whether model parameters are constrained by phylogeny. Here, we use a comprehensive database (including 276 tree species) compiled from 894 allometric biomass models published in 302 articles to examine whether parameters a and b of the model $W=a{D}^b$ (where W stands for aboveground biomass, D is diameter at breast height) exhibit phylogenetic signal for all tree species as a whole and for different groups of tree species. For either model parameter, we relate difference in model parameter between different tree species to phylogenetic distance and to environmental distance between pairwise sites. Our study shows that neither model parameter exhibits phylogenetic signals (Pagel's λ and Blomberg's K both approach zero). This is the case regardless of whether all tree species in our data set were analyzed as a whole or tree species in different taxonomic groups (gymnosperm and angiosperm), leaf duration groups (evergreen and deciduous), or ecological groups (tropical, temperate and boreal) were analyzed separately. Our study also shows that difference in each parameter of the allometric biomass model is not significantly related to phylogenetic and environmental distances between tree species in different sites.