通讯机构：
[Huilin Yang] C;College of Resources and Environment, Hunan Agricultural University, Changsha 410128, Hunan, China<&wdkj&>Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Changsha 410128, Hunan, China
摘要：
Spiders are believed to have enormous potential for indicating heavy metal pollution in ecosystems. The diversity of influencing factors caused significant differences in the toxicities of cadmium (Cd) on spiders. There is limited understanding of the underlying mechanism and response to acute Cd exposure at different concentrations and different poisoning times. We exposed adult female P. subpiraticus to 0.2 mM and 2 mM Cd for 6 and 12 h, respectively, to explore acute Cd toxicities by RNA-seq. We measured the bioaccumulation levels in P. subpiraticus and tested the activities of superoxide dismutase (SOD) and glutathione S-transferase (GST). There were 187, 292, 101 and 155 differentially expressed genes (DEGs) after exposure to 0.2 mM and 2 mM Cd for 6 and 12 h, respectively. The results revealed that Cd accumulated in P. subpiraticus, changed the SOD and GST activities, and caused significant adverse effects at the molecular level on metabolism and immune and oxidative stress, with time-and concentration-dependent differences. Transcriptome analysis showed that acute Cd exposure depressed lipid metabolism and induced protein metabolism, especially serine metabolism. Genes encoding lipoproteins were depressed when exposed to 0.2 mM Cd, while fatty acid-related genes were downregulated under 2 mM Cd stress. In total, 46 cuticle-related genes were upregulated, and 6 cytoskeleton-related genes changed notably in the immune process. Peroxidase-related genes were further upregulated significantly. Meanwhile, the pathways related to metabolism, immunity and oxidative stress were significantly enriched. This report illustrated that acute Cd exposure exerts toxicities on P. subpiraticus and the spiders against acute Cd toxicities by selective differential expression of the genes associated with the physiological process of metabolism and immune and antioxidant stress. This study provides a comprehensive transcriptional basis for understanding the response of the P. sublimations to heavy metals at different concentrations and different treatment times. (c) 2021 Published by Elsevier B.V.
关键词：
"rice field spider";"study advances";China;"predation function"
摘要：
Many laboratory and field studies have been conducted on rice field spiders in China. There are 375 species, 108 genera, and 22 families of rice field spiders distributed within the major rice growing areas and 17 dominant species. The biological and ecological characteristics of 17 rice field spider species have been reported in detail. The biology and ecology of these species show significant differences among regions, farmland habitats, and agricultural practices. Future research should focus on rice field habitat diversity, enhancing the insecticide resistance of dominant spider populations, implementing large-scale breeding of spiders and augmentative release, breeding more leaf dominant species, conducting biosafety assessment of spiders in transgenic crops.
摘要：
Since the birth of transgenic crops expressing Bacillus thuringiensis (Bt) toxin for pest control, the public debate regarding ecological and environmental risks as well as benefits of Bt crops has continued unabated. The impact of Bt crops, especially on non-target invertebrates, has received particular attention. In this review, we summarize and analyze evidences for non-target effects of Bt rice on spiders, major predators in rice fields. Bt rice has been genetically modified to express the Bt protein, which has been shown to be transferred and accumulate in spiders as part of their food chain. Moreover, the Bt protein exhibits unintended effects on the physiology of spiders and spreads to higher trophic levels. Spiders possess unique physiological and ecological characteristics, revealing traits of surrogate species, and are thus considered to be excellent non-target arthropod model systems for study of Bt protein impacts. Due to the complexities of Bt protein transfer and accumulation mechanisms, as well as the apparent lack of information about resulting physiological, biochemical, and ecological effects on spiders, we raise questions and provide recommendations for promising further research.
摘要：
This paper estimates carbon emissions from agricultural production in China's Hunan Province during the period from 1998 to 2012. It also analyzes trends in the development of agricultural carbon emissions and the decoupling relationship between carbon emissions and the agricultural output of Hunan. In this study, emissions from two key segments of the agricultural sector were quantified: (1) crop production and (2) livestock and poultry production (singular). A combined method of principal component analysis (PCA), multiple regression analysis, and decoupling analysis was employed to assess the drivers of agricultural carbon emissions. This showed that there was a weak and unstable decoupling relationship between agricultural carbon emissions and their output value during the period of study. The PCA revealed that two main factors-urbanization rate and nitrogen fertilization per acre-explained 92.51 % of the variation in the 11 factors that affected carbon emissions from crops. Also, two main factors (i.e., agriculture per capita GDP and the ratio of beef production to total livestock production) explained 86.27 % of the variation in nine factors that affected carbon emissions from the livestock and poultry industry. Using the PCA scores as independent variables, a multiple regression analysis of carbon emissions from the crop industry and the livestock and poultry industry showed the following patterns. (1) Theoretically, given a 10 % reduction in nitrogen fertilization per acre, crop carbon emissions would decrease by 519 units. If the rate of urbanization were to increase by 1 %, crop carbon emissions would increase by 83 units; (2) similarly, a 1 % reduction in the beef: total livestock and poultry production ratio would reduce carbon emissions from that industry by 329 units, and with "agricultural per capita GDP'' growth of 1 unit, those emissions would increase by 0.354 units. The results of this study contribute to evaluating the sustainability of agricultural production in the region, and they provide a foundation of knowledge for future development of related agricultural mitigation policy and low-carbon agricultural technology.
