Plant-associated microbiomes are key determinants of host-plant fitness, productivity, and function. However, compared to bacterial community, we still lack fundamental knowledge concerning the variation in the fungal microbiome at the plant niche level. In this study, we quantified the fungal communities in the rhizosphere soil, as well as leaf and root endosphere compartments of a subtropical island shrub, Mussaenda kwangtungensis, using high-throughput DNA sequencing. We found that fungal microbiomes varied significantly across different plant compartments. Rhizosphere soil exhibited the highest level of fungal diversity, whereas the lowest level was found in the leaf endosphere. Further, the fungal communities inhabiting the root endosphere shared a greater proportion of fungal operational taxonomic units (OTUs) with rhizosphere communities than with leaf fungal endophyte communities, despite significant separation in community structure between the two belowground compartments. The fungal co-occurrence networks in the three compartments of M. kwangtungensis showed scale-free features and non-random co-occurrence patterns and matched the topological properties of small-world and evidently modular structure. Additionally, the rhizosphere network was more complex and showed higher centrality and connectedness than the leaf and root endosphere networks. Overall, our findings provide comprehensive insights into the structural variability, niche differentiation, and co-occurrence patterns in the plant associated fungal microbiome.

Background: Malvaceae is an economically important plant family of 4,225 species in nine subfamilies. Phylogenetic relationships among the nine subfamilies have always been controversial, especially for Brownlowioideae, whose phylogenetic position remains largely unknown due to the lack of samples in previous analysis datasets. To greatly clarify the phylogenetic relationship of Malvaceae, we newly sequenced and assembled the plastome of Diplodiscus trichospermus taxonomically located in Brownlowioideae, and downloaded the allied genomes from public database to build a dataset covering all subfamily members of Malvaceae. Results: The annotation results showed that the plastome of Diplodiscus trichospermus has a typical quadripartite structure, comprising 112 unique genes, namely 78 protein-coding genes, 30 tRNA genes and 4 rRNA genes. The total length was 158,570 bp with 37.2% GC content. Based on the maximum likelihood method and Bayesian inference, a robust phylogenetic backbone of Malvaceae was reconstructed. The topology showed that Malvaceae was divided distinctly into two major branches which were previously recognized as Byttneriina and Malvadendrina. In the Malvadendrina clade, Malvoideae and Bombacoideae formed, as always, a close sister clade named as Malvatheca. Subfamily Helicteroideae occupied the most basal position and was followed by Sterculioideae which was sister to the alliance of Malvatheca, Brownlowioideae, Dombeyoideae, and Tilioideae. Brownlowioideae together with the clade comprising Dombeyoideae and Tilioideae formed a sister clade to Malvatheca. In addition, one specific conservation SSR and three specific palindrome sequences were observed in Brownlowioideae. Conclusions: In this study, the phylogenetic framework of subfamilies in Malvaceae has been resolved clearly based on plastomes, which may contribute to a better understanding of the classification and plastome evolution for Malvaceae.

Aims: Plant–pollinator interaction networks are dynamic entities, and seasonal variation in plant phenology can reshape their structure on both short and long timescales. However, such seasonal dynamics are rarely considered, especially for oceanic island pollination networks. Here, we assess changes in the temporal dynamics of plant–pollinator interactions in response to seasonal variation in floral resource richness in oceanic island communities. Methods: We evaluated seasonal variations of pollination networks in the Yongxing Island community. Four temporal qualitative pollination networks were analyzed using plant–pollinator interaction data of the four seasons. We collected data on plant–pollinator interactions during two consecutive months in each of the four seasons. Four network-level indices were calculated to characterize the overall structure of the networks. Statistical analyses of community dissimilarity were used to compare this community across four seasons to explore the underlying factors driving these patterns. We also evaluated the temporal variation in two species-level indices of plant and pollinator functional groups. Important Findings: Both network-level specialization and modularity showed a significantly opposite trend compared with plant species richness across four seasons. Increased numbers of plant species might promote greater competition among pollinators, leading to increased niche overlap and causing decreased specialization and modularity and vice versa. Further analyses suggested that the season-to-season turnover of interactions was dominated by interaction rewiring. Thus, the seasonal changes in niche overlap among pollinators lead to interaction rewiring, which drives interaction turnover in this community. Hawkmoths had higher values of specialization and Apidae had higher values of species strength compared with other pollinator functional groups. These findings should be considered when exploring plant–pollinator interactions in ecosystems of isolated oceanic islands and in other ecosystems.

The genus Paracladopus was established based on the type species P. chiangmaiensis in 2006. The two Paracladopus species are distributed in Thailand and Laos; however, neither of them has been documented in China to date. During our field work in 2020, we collected a river-weed in Wuzhi Mountain, Hainan Province of China. After checking the morphological characters, it was identified as P. chiangmaiensis. Then, we assembled and annotated its chloroplast genome based on the genome skimming data. The results showed that the complete chloroplast genome was 133,748 bp with 35% GC content, consisting of 76 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. A maximum-likelihood tree constructed based on the matk genes showed that WuMS109 was clustered with P. chiangmaiensis (AB537420, AB698348) without base difference and together with the remains of Paracladopus formed a sister clade to Cladopus. This is the first report of P. chiangmaiensis that represents a new generic record for China. The discovery of this river-weed could lay the foundation for investigating their biogeographical patterns and species evolution in further studies.

Sclerotinia sclerotiorum is a devastating soilborne fungal pathogen that causes Sclerotinia stem rot in many economically important crops. It forms sclerotia, resilient dormant structures that can persist in soil for years. Understanding the molecular mechanism of sclerotia formation is crucial for developing effective control strategies, but only a limited number of signaling components have been uncovered in this process. Through independent forward genetic screens, we identified SsLae1 and SsVel1, two core components of the conserved fungal velvet complex, as essential regulators of sclerotia formation and virulence in S. sclerotiorum. Disruption of either gene abolished sclerotia formation, impaired compound appressorium development, and significantly reduced virulence. Further RNA-seq analysis using the Ssvel1 mutant revealed widespread downregulation of known developmental and virulence regulators. Collectively, these findings establish the velvet complex as a master regulator for both sclerotia development and virulence in S. sclerotiorum.