Insect vectors are required for the transmission of many species of parasitic nematodes, but the mechanisms by which the vectors and nematodes coordinate their life cycles are poorly understood. Here, we report that ascarosides, an evolutionarily conserved family of nematode pheromones, are produced not only by a plant-parasitic nematode, but also by its vector beetle. The pinewood nematode and its vector beetle cause pine wilt disease, which threatens forest ecosystems world-wide. Ascarosides secreted by the dispersal third-stage nematode LIII larvae promote beetle pupation by inducing ecdysone production in the beetle and up-regulating ecdysone-dependent gene expression. Once the beetle develops into the adult stage, it secretes ascarosides that attract the dispersal fourth-stage nematode LIV larvae, potentially facilitating their movement into the beetle trachea for transport to the next pine tree. These results demonstrate that ascarosides play a key role in the survival and spread of pine wilt disease.

Manually delaying pollination in maize restricted kernel growth and induced abortion by suppressing cell wall invertase activity and repartitioning assimilates.

Aim Whether richness patterns and determinants are consistent between common and rare species remains controversial, and the answer is fundamental for the conservation of species in vulnerable habitats. Although effects of climate and geological history on species richness have been widely explored, their relative contribution among common and rare species is poorly understood. Here, using a valuable ornamental plant family Gesneriaceae, we evaluated how contemporary climate, habitat heterogeneity and long‐term climate change affect the distribution of rare and common species. Additionally, we identified hotspots of Gesneriaceae diversity and evaluated its protection gap in China. Location China. Methods Distribution of Gesneriaceae was compiled at a spatial resolution of 50 × 50 km. Species were grouped as rare and common based on the number of grid cells they occupied, and their richness patterns and hotspots were estimated separately. Generalized linear models and Random Forest were used to compare effects of different factors on species richness. Results Richness of Gesneriaceae peaked in south‐western China. The Yunnan–Guizhou Plateau and Hengduan Mountains were identified as hotspots for overall and common species, while only the former was hotspot for rare species. Temperature seasonality, winter coldness and temperature change since the Last Glacial Maximum (LGM) dominated species richness patterns, but their relative effects differed between species range size. Temperature seasonality had strongest effects on richness of common species, whereas temperature change since the LGM was strongest for rare species. Neither current nor past precipitation affects richness patterns significantly. Main conclusions Gesneriaceae species richness is strongly influenced by temperature changes. Specifically, rare and common species are primarily dominated by long‐ and short‐term temperature changes, respectively. These findings suggest that most Gesneriaceae species may face high risk under future climate changes, and hence, more conservation efforts are urgently needed, especially in Yunnan–Guizhou Plateau, which is hotspot of rare species.

Previous studies on large‐scale patterns in plant richness and underlying mechanisms have mostly focused on forests and mountains, while drylands covering most of the world's grasslands and deserts are more poorly investigated for lack of data. Here, we aim to 1) evaluate the plant richness patterns in Inner Asian drylands; 2) compare the relative importance of contemporary environment, historical climate, vegetation changes, and mid‐domain effect (MDE); and 3) explore whether the dominant drivers of species richness differ across growth forms (woody vs herbaceous) and range sizes (common vs rare). Distribution data and growth forms of 13 248 seed plants were compiled from literature and species range sizes were estimated. Generalized linear models and hierarchical partitioning were used to evaluate the relative contribution of different factors. We found that habitat heterogeneity strongly affected both woody and herbaceous species. Precipitation, climate change since the mid‐Holocene and climate seasonality dominated herbaceous richness patterns, while climate change since the Last Glacial Maximum dominated woody richness patterns. Rare species richness was strongly correlated with precipitation, habitat heterogeneity and historical climatic changes, while common species richness was strongly correlated with MDE (woody) or climate seasonality (herbaceous). Temperature had little effects on the species richness patterns of all groups. This study represents the first evaluation of the large‐scale patterns of plant species richness in the Inner Asian drylands. Our results suggest that increasing water deficit due to anthropogenic activities combined with future global warming may increase the extinction risk of many grassland species. Rare species (both herbaceous and woody) may face severe challenges in the future due to increased habitat destruction caused by urbanization and resource exploitation. Overall, our findings indicate that the hypotheses on species richness patterns based on woody plants alone can be insufficient to explain the richness patterns of herbaceous species.

1. Climate and land-cover changes are major threats to biodiversity, and their impacts are expected to intensify in the future. Protected areas (PAs) are crucial for biodiversity conservation. However, their effectiveness under future climate and land-cover changes remains to be evaluated. Moreover, the impacts of climate and land-cover changes on multi-dimensions of biodiversity are rarely considered when expanding PAs.2. Using distributions of 8,732 woody species in China and species distribution models, we identified species that will be threatened by future climate and land-cover changes (i.e. species with significant projected loss of suitable habitats by the 2070s) under different dispersal scenarios. We then estimated the geographical patterns in species richness (SR) and phylogenetic diversity (PD) of threatened species, evaluated the effectiveness (i.e. the changes in SR and PD) of Chinese PAs and identified conservation priorities for future PA expansion.3. Approximately 12%-38% of woody species will be threatened under different scenarios. These species tend to be clustered in the tree of life, and their SR and PD show consistent spatial patterns, being highest at low latitudes. PAs currently protect 90% of threatened species. However, their SR and PD of threatened species within PAs will decrease by 30%-40% by the 2070s, which reduces the PA effectiveness, especially for PAs at low elevations and those with low topographic heterogeneity and high natural vegetation loss.4. The conservation priorities identified from the SR and PD of the threatened species are mainly in mountains in southern China, the Yunnan-Guizhou Plateau and Taiwan Island. PA expansion and ecological corridors in these regions are needed to conserve threatened species. Synthesis and applications.We present a systematic study of the impacts of future climate and land-cover changes on the conservation status of woody species and PA effectiveness in China. Our results suggest that future climate and land-cover changes will reduce PA effectiveness, and the spatial prioritization of biodiversity conservation should consider the influences of future global changes on biodiversity. These results shed new light on the conservation priorities for the post-2020 expansion of PAs in China.