Relationships between biodiversity and multiple ecosystem functions (that is, ecosystem multifunctionality) are context-dependent. Both plant and soil microbial diversity have been reported to regulate ecosystem multifunctionality, but how their relative importance varies along environmental gradients remains poorly understood. Here, we relate plant and microbial diversity to soil multifunctionality across 130 dryland sites along a 4,000 km aridity gradient in northern China. Our results show a strong positive association between plant species richness and soil multifunctionality in less arid regions, whereas microbial diversity, in particular of fungi, is positively associated with multifunctionality in more arid regions. This shift in the relationships between plant or microbial diversity and soil multifunctionality occur at an aridity level of ∼0.8, the boundary between semiarid and arid climates, which is predicted to advance geographically ∼28% by the end of the current century. Our study highlights that biodiversity loss of plants and soil microorganisms may have especially strong consequences under low and high aridity conditions, respectively, which calls for climate-specific biodiversity conservation strategies to mitigate the effects of aridification.

We conclude that there have been huge population migrations from surrounding lowland onto the Tibetan Plateau via the Tibetan-Yi Corridor since the initial formation of Tibetans probably in Neolithic Time, which leads to the current genetic structure of Tibeto-Burman speaking populations.

Myostatin (Mstn) is postulated to be a key determinant of muscle loss and cachexia in cancer. However, no experimental evidence supports a role for Mstn in cancer, particularly in regulating the survival and growth of cancer cells. In this study, we showed that the expression of Mstn was significantly increased in different tumor tissues and human cancer cells. Mstn knockdown inhibited the proliferation of cancer cells. A knockout (KO) of Mstn created by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) 9 (CRISPR/Cas9) induced mitochondria-dependent apoptosis in HeLa cells. Furthermore, KO of Mstn reduced the lipid content. Molecular analyses demonstrated that the expression levels of fatty acid oxidation-related genes were upregulated and then increased rate of fatty acid oxidation. Mstn deficiency-induced apoptosis took place along with generation of reactive oxygen species (ROS) and elevated fatty acid oxidation, which may play a role in triggering mitochondrial membrane depolarization, the release of cytochrome c (Cyt-c), and caspase activation. Importantly, apoptosis induced by Mstn KO was partially rescued by antioxidants and etomoxir, thereby suggesting that the increased level of ROS was functionally involved in mediating apoptosis. Overall, our findings demonstrate a novel function of Mstn in regulating mitochondrial metabolism and apoptosis within cancer cells. Hence, inhibiting the production and function of Mstn may be an effective therapeutic intervention during cancer progression and muscle loss in cachexia.

Hypoxia facilitates the progression of numerous cancers. Circular RNAs (circRNA) have been revealed to be involved in the process of tumors mediated by hypoxia. However, the role and molecular mechanism of circular RNA hsa_circ_0008450 (circ_0008450) in hepatocellular cancer (HCC) under hypoxic conditions has been rarely reported. Expression levels of circ_0008450, microRNA(miR)-431 and A-kinase anchor protein 1 (AKAP1) were examined using reverse transcription-quantitative PCR. Cell viability, apoptosis and glycolysis were assessed via Cell Counting Kit-8, flow cytometry and glycolysis assays, respectively. The association between circ_0008450 or AKAP1 and miR-431 was verified via dual-luciferase reporter assays. Protein levels of AKAP1 were detected by western blotting. Effect of hsa_circ_0008450 on tumor growth in vivo was confirmed by xenograft assays. Circ_0008450 was upregulated in HCC tissues and hypoxia-disposed HCC cells. Depletion of circ_0008450 suppressed tumor growth in vivo and reversed the repression of apoptosis and the acceleration of viability and glycolysis of HCC cells induced by hypoxia treatment in vitro. Notably, circ_0008450 regulated AKAP1 expression by sponging miR-431. Furthermore, miR-431 inhibition reversed the circ_0008450 silencing-mediated effects on viability, apoptosis and glycolysis in hypoxia-treated HCC cells. Additionally, AKAP1 enhancement abolished the effects of miR-431 upregulation on the viability, apoptosis and glycolysis in hypoxia-treated HCC cells. In conclusion, circ_0008450 repression mitigated the progression of HCC under hypoxia by downregulating AKAP1 via miR-431, providing a potential target for HCC treatment.

Plant biomass allocation patterns are important to understanding and predicting ecosystem carbon cycles and other important ecological processes. Consequently, many attempts have been made to study these patterns. However, most studies focus on data from species in temperate forests to the neglect of data from desert species adapted to arid conditions. We hypothesize that different life history strategies drive or at least participate in different plant biomass allocation patterns, as, for example, the life history differences between desert ephemeral and shrub species. We tested this hypothesis using field data gathered directly from the entire desert vegetation in Northwestern China. When the data from each of the two species groups are pooled, ephemeral and shrub species manifest different scaling relationships between above‐ and belowground biomass, unlike the isometric scaling relationships typically reported for forest tree species. The observed scaling relationships are sensitive to water stress and temperature gradients. The scaling exponents numerically decrease with increasing drought stress, and relatively more biomass is allocated to shoot growth in ephemeral species (presumably to rapidly complete their life history). In the case of shrubs, the numerical value of the scaling exponent is insensitive to rainfall, presumably because these species allocate more biomass to root growth to access belowground water. However, the scaling exponent is significantly sensitive to temperature, which also regulates root growth. Moreover, for the two species groups, root–shoot ratios are jointly regulated by precipitation and temperature. The different biomass allocation patterns appear to result from different life histories that maximize either competition among neighboring plants, or escaping damage from drought and low temperatures. These findings show how overall body size and life histories jointly regulate biomass allocation patterns under different extreme conditions and provide insights into estimating the dry carbon content in dryland ecosystems.