入侵昆虫基因组研究进展

随着全球贸易的加速发展,入侵物种对农林业、生态环境及人类健康的威胁日益严重。基因组学研究为阐明外来有害生物入侵的分子机制与生态适应性过程以及研发新型防控技术提供了新手段、新平台与大数据。本文综述了入侵昆虫基因组学研究的发展现状,系统总结了基因/基因家族、转座子/重复序列等基因组信息在决定昆虫入侵性中的重要作用,着力探讨了基因组学研究在助力害虫RNAi、昆虫不育技术(SIT)、化学生态防治和物理防治等防控新技术/新产品开发方面的潜力,并展望了基因组学研究应用于入侵昆虫综合防控的前景。     

Genes related to flooding tolerance during germination and early growth of weedy rice

Evolution of flooding tolerance in weedy rice has occurred in several rice-growing regions, but the genes related to this process and the environmental effects are unknown. The objective of this study was to analyse the expression of genes related to flooding tolerance in response to temperature and flooding during the initial establishment of weedy rice. The experiments were carried out with rice cultivars IRGA 417 and Nipponbare, which are sensitive to flooding, and weedy rice ITJ03 and AV04 genotypes that have high and intermediate tolerance to flooding, respectively. The expression of genes related to reserve mobilisation, anaerobic respiration, escape and quiescence strategies was analysed at periods up to 24 days after sowing. The flooding tolerance of weedy rice genotype ITJ03 was associated with the expression of RAmy3D and OsTPP7 , which are involved in the mobilisation of carbohydrate reserves, ADH1 and ADH2, which participate in anaerobic respiration, and SNRKL1 that triggers rapid elongation of the coleoptile and emergence. Although the genes PDC1, SUS3 and SUB1 are important for flooding tolerance in cultivated rice, their expression was not directly related to flooding tolerance in weedy rice. A temperature of 20°C reduced levels of expression of the RAmy3D, ADH2 and SNRKL1 genes and low temperature had a negative effect on the establishment of weedy rice. Breeding of rice genotypes with tolerance of low temperatures and anaerobic conditions may be a viable strategy to improve the control of weedy rice in paddy fields.     

Effect of long non-coding RNA MEG3 on invasion and migration of colorectal cancer cells

AIM: To investigate the expression of long non-coding RNA maternally expressed gene 3(MEG3) in colorectal cancer(CRC) cells, and to observe the effect of MEG3 on the invasion and migration of CRC cells. METHODS: The levels of MEG3 in human normal colon cell NCM460 and CRC cells SW48 and LoVo were detected by real- time PCR. MEG3 was over-expressed by plasmid transfection, and the effects of MEG3 on the invasion and migration of SW48 and LoVo cells were analyzed by Transwell assay and wound healing assay. The expression of matrix metalloproteinase(MMP) family proteins was determined by Western blotting. RESULTS: The level of MEG3 was down-regulated in CRC cells compared with normal colon cell NCM460. The invasion and migration of CRC cells were reduced after MEG3 over-expression. Transwell invasion and migration assays showed that the numbers of transmembrane SW48 and LoVo cells were smaller in MEG3 over-expression group than control group(CONCLUSION: The expression of MEG3 is down-regulated in CRC cells. Over-expression of MEG3 inhibits the invasion and migration of CRC cells. TIMP-2, MMP-2 and MMP-9 might play an important role in this regulation.     

ER-α36 and miR-143 involved in invasion of gastric cancer cells

AIM: To investigate the relationship between the expression of estrogen receptor α36 (ER-α36) and the invasion of gastric cancer cells. METHODS: SGC7901 cells were treated with 17β-estradiol at high or low concentration. The invasion of gastric cancer cells and the expression of ER-α36 were detected. The SGC7901 cells with the characteristics of stable low expression and high expression of ER-α36 were constructed. The invasion ability and microRNA sequences were determined in above-mentioned recombinant cells. RESULTS: The decreased invasion ability and ER-α36 expression were detected in SGC7901 cells treated with low concentration of 17β-estradiol. The situation was the opposite in the cells treated with high concentration of 17β-estradiol. The expression of miR-143 was significantly decreased in the SGC7901 cells with stable high expression of ER-α36 and was increased in the SGC7901 cells with stable low expression of ER-α36. CONCLUSION: The expression of ER-α36 is positively related to the invasion of gastric cancer cells. It is possible that miR-143 plays an important role in the regulation of gastric cancer invasion.     

生物入侵种喜旱莲子草的染色体核型特征

对外来人侵植物喜旱莲子草(Atlernanthera philoxeroides)的染色体核型进行了分析.结果表明,该入侵种的染色体数为2n=96,属六倍体物种,各染色体间形态差异不明显,均为中着丝粒或近中着丝粒染色体,最长与最短染色体相对长度比为2.10,全套染色体未见随体,核型公式为2n=96=60 m+36 sm,核型类型为进化程度较高的2B型.喜旱莲子草的多倍性特征及2B核型为其生物入侵性提供了重要的细胞学证据,文中同时提出不改变基因组DNA序列结构的表观遗传变异可能是喜旱莲子草成功入侵的重要机制.     

Growth and photosynthetic responses of invasive Bidens frondosa to light and water availability: A comparison with invasive and native congeners

Bidens frondosa is a new invasive species in China. However, the mechanisms underlying its invasiveness are still not understood. This study compared the new invader with its invasive congener, Bidens pilosa, and two native congeners, Bidens biternata and Bidens tripartita, in terms of their morphology, growth, biomass allocation and photosynthetic parameters across variant light and water conditions, aiming to explore the traits that are associated with the invasiveness of the invasive species. All these species are annual herbs. The results showed that the four congeners had a similar tendency of plasticity in their morphological and growth traits to varying light and water, but their response was quantitatively different. Most of the morphological and growing variables, as well as the photosynthetic parameters, were affected more strongly by manipulated light levels. Although B. frondosa had a lower total biomass and relative growth rate than the invasive congener, B. pilosa, the trait values related to growth (e.g. plant height, total biomass, relative growth rate and specific leaf area) and the mean value of the plasticity index were higher for the invasive B. frondosa than for the native B. tripartita. These could contribute to the invasiveness of the invasive species. In addition, the native species, B. biternata, is a vigorous weed with a strong adaptive capacity across various light and water gradients, suggesting that it has the potential to be invasive if introduced into areas with suitable conditions for growth.     

粤东地区入侵植物的克隆性与入侵性研究

为了研究粤东地区外来种的入侵机制,通过野外调查与文献查阅,对粤东地区入侵植物的入侵性与克隆性进行统计和分析。结果表明,粤东地区入侵植物种类丰富,隶属38科约127种,其中70.08%的植物原产美洲,尤其是南美洲(51.18%);各入侵性（强、中、弱）包含的入侵植物种数依次为22、42、63种;具有克隆性的入侵植物共约55种,占全部入侵植物的43.31%;在强、中、弱3种入侵性中,具有克隆性的种数分别为10、15、30,所占比例分别为45.45%、35.71%、47.62%。粤东地区入侵植物的克隆性与入侵性之间存在一定的相关性,具有克隆性的植物能快速的增大植株和累积生物量而成为入侵群落中的单优种群,因此克隆性是部分外来植物成功入侵粤东地区的重要机制之一。     

Long-term monitoring of feral genetically modified herbicide-tolerant Brassica napus populations around unloading Japanese ports

Genetically modified, herbicide-tolerant (GMHT) Brassica napus plants originating from seed spill have recently been found along roadsides leading from Japanese ports that unload oilseed rape. Such introductions have potential biodiversity effects (as defined by the Cartagena Protocol): these include replacement of native elements in the biota through competitive suppression or hybridization. We conducted surveys in the period 2006–2011 to assess such threats. We examined shifts in the population distribution and occurrence of GMHT plants in 1,029 volunteer introduced assemblages of B. napus, 1,169 of B. juncea, and 184 of B. rapa around 12 ports. GMHT B. napus was found around 10 of 12 ports, but its proportion in the populations varied greatly by year and location. Over the survey period, the distributions of a pure non-GMHT population around Tobata and a pure GMHT population around Hakata increased significantly. However, there was no common trend of population expansion or contraction around the 12 ports. Furthermore, we found no herbicide tolerant B. juncea and B. rapa plants derived from crosses with GMHT B. napus. Therefore, GMHT B. napus is not invading native vegetation surrounding its populations and not likely to cross with congeners in Japanese environment.     

The importance of population growth, seed dispersal and habitat suitability in determining plant invasiveness

Summary This paper examines the roles of plant demography, seed dispersal ecology and habitat suitability in influencing invasiveness of horticulturally important species. Section one investigates the relative invasiveness of two woody species, Crataegus monogyna and Prunus mahaleb, and concentrates on differences in demographic and dispersal traits. The second section delineates the invasion of two Asparagus spp. and concentrates on differences in seed dispersal ecology. Section three reports the use of a geographical information system analysis to determine whether habitat suitability, seed dispersal or land management is more important in determining threat of invasion by adventive Olea europaea. C. monogyma, P. mahaleb are closely related with similar habits and overlapping home ranges in Europe. Crataegus monogyna is very invasive in northern New South Wales, having spread rapidly and conspicuously throughout the region and elsewhere in southern Australia at rates of 80–120 m yr⁻¹. Prunus mahaleb is far less invasive, being restricted to a small population, which is expanding at 20 m yr⁻¹. Demographic analysis showed that potential growth rates of P. mahaleb (1.713–1.490) are greater than those for C. monogyna (1.138–1.103). Assessment of the seed dispersal ecology of both species revealed that C. monogyna had seeds dispersed by one bird and three mammals over many kilometers. P. mahaleb had seeds dispersed by six birds and four mammals over distances generally < 100 m. The role of humans in introducing both species and the characteristics of seed dispersal are more influential than demography in determining invasiveness. The more invasive Asparagus asparagoides has smaller fruit with a bicoloured display up to 1.5 m above ground. Less invasive A. declinatus has larger, translucent white fruit displayed at heights < 0.5 m above ground. The role of humans has also been important in shaping the course of invasion. Sensitivity analysis confirms that land management practices, which affect Olea europaea seedling establishment and survival, are most important at a landscape scale in determining invasiveness. The main factors determining the difference in invasiveness relate directly to the changing nature of human management of each species and the ecological interactions between the plants and the invaded environment. This research has implications for the prediction and management of biological invasions; emphasizing the importance of seed dispersal and human activities in determining the course of invasions: both of which cannot be readily predicted.