Plant Diversity最新文献

Plants and their interaction partners offer unparalleled views of evolutionary ecology. Nectar larceny, entailing nectar extraction without pollinating, is thought to be an example of a harmful, antagonistic behavior, but the precise consequences of floral larceny on plant reproductive success remain contentious. We conducted a comprehensive meta-analysis of 153 studies across 120 plant species, using 14 moderators to assess the effects of floral larceny on plant reproductive success and examine the key moderators. We found that floral larceny negatively impacts flower traits, pollinator visitation, pollen deposition, and fruit set, while having a neutral effect on critical female fitness indicators, such as seed set and seed quality, as well as on male fitness. By altering pollinator behavior, floral larceny may reduce geitonogamy, potentially enhancing genetic diversity. Additionally, factors such as pollinator type, plant mating system, and pollen limitation were identified as key moderators of these effects. Our analysis reveals an ultimately neutral effect of floral larceny on plant reproductive success, with potential benefits in certain contexts. These findings suggest that floral larceny plays a complex and multifaceted role within plant-pollinator interactions, facilitating the evolutionary stability and coexistence of floral larcenists and host plants.

Latitudinal patterns of tree β-diversity reveal important insights into the biogeographical processes that influence forest ecosystems. Although previous studies have extensively documented β-diversity within relatively small spatial extents, the potential drivers of β-diversity along latitudinal gradients are still not well understood at larger spatial extents. In this study, we determined whether tree β-diversity is correlated with latitude in forests of southeastern China, and if so, what ecological processes contribute to these patterns of tree β-diversity. We specifically aimed to disentangle the relative contributions from interspecific aggregation and environmental filtering across various spatial extents. We delineated regional communities comprising multiple nearby national forest inventory (NFI) plots around random focal plots. The number of NFI plots in a regional community served as a surrogate for spatial extent. We also used a null model to simulate randomly assembled communities and quantify the deviation (β-deviation) between observed and expected β-diversity. We found that β-diversity decreased along a latitudinal gradient and that this pattern was clearer at larger spatial extents. In addition, latitudinal patterns of β-deviation were explained by the degree of species spatial aggregation. We also identified environmental factors that drive β-deviation in these forests, including precipitation, seasonality, and temperature variation. At larger spatial extents, these environmental variables explained up to 84% of the β-deviation. Our results reinforce that ecological processes are scale-dependent and collectively contribute to the β-gradient in subtropical forests. We recommend that conservation efforts maintain diverse forests and heterogeneous environments at multiple spatial extents to mitigate the adverse effects of climate change.

Single-stranded DNA-binding proteins (SSBs) play essential roles in the replication, recombination and repair processes of organellar DNA molecules. In Arabidopsis thaliana, SSBs are encoded by a small family of two genes (SSB1 and SSB2). However, the functional divergence of these two SSB copies in plants remains largely unknown, and detailed studies regarding their roles in the replication and recombination of organellar genomes are still incomplete. In this study, phylogenetic, gene structure and protein motif analyses all suggested that SSB1 and SSB2 probably diverged during the early evolution of seed plants. Based on accurate long-read sequencing results, ssb1 and ssb2 mutants had decreased copy numbers for both mitochondrial DNA (mtDNA) and plastid DNA (ptDNA), accompanied by a slight increase in structural rearrangements mediated by intermediate-sized repeats in mt genome and small-scale variants in both genomes. Our findings provide an important foundation for further investigating the effects of DNA dosage in the regulation of mutation frequencies in plant organellar genomes.

Rapid growth is an innovative trait of woody bamboos that has been widely studied. However, the genetic basis and evolution of this trait are poorly understood. Taking advantage of genomic resources of 11 representative bamboos at different ploidal levels, we integrated morphological, physiological, and transcriptomic datasets to investigate rapid growth. In particular, these bamboos include two large-sized and a small-sized woody species, compared with a diploid herbaceous species. Our results showed that gibberellin A1 was important for the rapid shoot growth of the world's largest bamboo, Dendrocalamus sinicus, and indicated that two gibberellins (GAs)-related genes, KAO and SLRL1, were key to the rapid shoot growth and culm size in woody bamboos. The expression of GAs-related genes exhibited significant subgenome asymmetry with subgenomes A and C demonstrating expression dominance in the large-sized woody bamboos while the generally submissive subgenomes B and D dominating in the small-sized species. The subgenome asymmetry was found to be correlated with the subgenome-specific gene structure, particularly UTRs and core promoters. Our study provides novel insights into the molecular mechanism and evolution of rapid shoot growth following allopolyploidization in woody bamboos, particularly via subgenome asymmetry. These findings are helpful for understanding of how polyploidization in general and subgenome asymmetry in particular contributed to the origin of innovative traits in plants.

Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae, comprising approximately 520 species from the Northern Hemisphere. A comprehensive infrageneric classification, supported by robust phylogenetic trees and corroborated by morphological and other data, has not yet been published. For the first time, we recovered a well-resolved nuclear phylogeny of Saussurea consisting of four main clades, which was also supported by morphological data. Our analyses show that ancient hybridization is the most likely source of deep cytoplasmic-nuclear conflict in Saussurea, and a phylogeny based on nuclear data is more suitable than one based on chloroplast data for exploring the infrageneric classification of Saussurea. Based on the nuclear phylogeny obtained and morphological characters, we proposed a revised infrageneric taxonomy of Saussurea, which includes four subgenera and 13 sections. Specifically, 1) S. sect. Cincta, S. sect. Gymnocline, S. sect. Lagurostemon, and S. sect. Strictae were moved from S. subg. Saussurea to S. subg. Amphilaena, 2) S. sect. Pseudoeriocoryne was moved from S. subg. Eriocoryne to S. subg. Amphilaena, and 3) S. sect. Laguranthera was moved from S. subg. Saussurea to S. subg. Theodorea.

DNA barcoding has been extensively used for species identification. However, species identification of mixed samples or degraded DNA is limited by current DNA barcoding methods. In this study, we use plant species in Juglandaceae to evaluate an assembly-free reads accurate identification (AFRAID) method of species identification, a novel approach for precise species identification in plants. Specifically, we determined (1) the accuracy of DNA barcoding approaches in delimiting species in Juglandaceae, (2) the minimum size of chloroplast dataset for species discrimination, and (3) minimum amount of next generation sequencing (NGS) data required for species identification. We found that species identification rates were highest when whole chloroplast genomes were used, followed by taxon-specific DNA barcodes, and then universal DNA barcodes. Species identification of 100% was achieved when chloroplast genome sequence coverage reached 20% and the original sequencing data reached 500,000 reads. AFRAID accurately identified species for all samples tested after 500,000 clean reads, with far less computing time than common approaches. These results provide a new approach to accurately identify species, overcoming limitations of traditional DNA barcodes. Our method, which uses next generation sequencing to generate partial chloroplast genomes, reveals that DNA barcode regions are not necessarily fixed, accelerating the process of species identification.

Alpine plants possess unique traits to adapt alpine environments. Whether leaf trait relationships of alpine plants can be captured by the two trait dimensions of organ size and resource economics is unknown. We hypothesized that, beyond the trait dimensions of leaf size and resource economics, non-structured carbohydrates (NSC) would reflect a dimension of cold-tolerance in alpine plants. To test this hypothesis, we measured 12 leaf traits critical to leaf construction and growth in 143 species across 7 sites ranging from alpine steppes to alpine meadows along an environmental gradient on the Tibetan Plateau. Furthermore, a cold resistance experiment was conducted at one of these sites to estimate the lethal temperature causing 50% frost damage (LT₅₀) of 11 alpine species. The majority of variations in 12 leaf traits of alpine plants were captured by three trait axes, in which leaf carbon (LCC) and NSC (including leaf starch; LSC and leaf soluble sugars; LSS) were clustered in a new dimension (PC3) beyond leaf size and structure, and resource economics. Although LCC, LSC and LSS all showed negative correlations with mean annual temperature, a significant negative correlation was only found between LSS and LT₅₀. It indicated that PC3 was able to reflect the cold-tolerance of alpine plants to some extent, in which LSS was the most critical trait. The storage and transformation of NSC under stressful conditions could reflect a dimension of long-term metabolic adaptation and cold-tolerance, which is an extension of the resource-utilization strategy beyond construction cost and growth.

Evolutionary transitions from sexual to asexual reproduction should have significant influences on genetic divergence and polymorphism at the genome level. Plant lineages with diverse reproductive systems provide opportunities to investigate this question using comparative approaches and studies of molecular evolution. We investigated evidence for differences among the transcriptomes of 19 Dioscorea species (wild yams) with diverse reproductive systems. These included sexual species, those that propagate primarily by bulbils, and those with mixed sexual and asexual reproductive modes. We examined how transitions between these reproductive systems affected between-species divergence and within-species polymorphism. Primarily asexual species exhibited a reduced efficacy of natural selection and accumulation of deleterious mutations for both divergence and polymorphism. In contrast, species with mixed reproductive strategies involving both seed and clonal reproduction showed no evidence of an increased fixation of harmful mutations at the divergence level, while an accumulation of genetic load present in polymorphism was evident. Our study indicates that the genetic consequences of evolutionary transitions from sexual to predominantly clonal reproduction is likely to depend on both the duration and extent of asexuality occurring in populations.

•We present 'U.Taxonstand Online', a user-friendly web application for scientific name matching of both plants and animals.•U.Taxonstand Online provides a solution for the users with limited abilities of programming and data mining.•We add several new functions to clean and format the data for R package U.Taxonstand.

•Three types of Symplocos from the late Oligocene and Miocene of Guangxi showcase the diversity of Symplocos during this time.•Earliest Asian megafossils of Symplocos are from the late Oligocene of Nanning Basin, Guangxi, China.•Fossils and modeling reveal Symplocos was quite diverse and has persisted at low latitudes within Asia since late Oligocene.•Climate probably plays a crucial role in driving the diversification of Symplocos in low latitudes of Asia.