在双翅目昆虫中，transformer是调控性别决定的开关基因，与在两性中均表达的transformer-2基因共同调节雌雄分化。然而，双翅目害虫瓜实蝇作为世界上广泛分布的重要农业害虫，其性别决定调控机制目前仍未阐明。本文研究发现，在胚胎早期通过RNA干扰下调transformer或transformer-2表达能够显著减少雌性比例；在由抑制了transformer或transformer-2表达的胚胎发育而成的雄虫中，大部分都能与雌虫交配并产生雌雄混合的正常后代，仅有一只雄虫在与雌虫交配后产生全雌后代，同时有少部分雄虫因不能与雌虫交配而无法产生后代。通过检测Y染色体连锁基因Maleness-on-the-Y发现，这些无法产生后代或后代性比异常的雄虫均是基因型为XX的假雄虫。性比数据和杂交实验结合分析表明，大部分的XX假雄虫无法存活。本研究结果表明transformer和transformer-2是瓜实蝇雌性发育所必需的，并在性别决定中起着关键作用。我们的研究结果将有助于理解瓜实蝇性别决定机制，并为开发用于生物防治的遗传性别品系提供思路。

由于金属纳米颗粒具有较高的抗菌性能，且不易导致病原体产生耐药性的风险，纳米颗粒作为杀菌剂在可持续农业中的潜在应用发展迅速。近几年，氧化铜纳米颗粒(CuO NPs)因其低毒、经济以及高效的抗菌性被广泛应用于农业病害防控领域，但是有关 CuO NPs对土传真菌的抑制作用还不清楚。本研究通过室内毒力测定和盆栽试验方法，旨在探讨CuO NPs对烟草疫霉菌（Phytophthora nicotianae）的体外抗真菌活性及灌根施用对烟草黑胫病的防治效果。结果表明，CuO NPs极大地干扰了该真菌的生殖生长过程，在特定浓度下显著性抑制了菌丝生长、孢子萌发和孢子囊的产生，且抑真菌效应表现出明显的浓度依赖性。此外，菌丝形态损伤、细胞内ROS积累和菌丝SOD酶活性升高也是CuO NPs的抗真菌作用机制。另外，盆栽试验发现相比于对照，100 mg/L CuO NPs灌根处理对烟草黑胫病的防治效果达到33.69%，且未影响作物生长。CuO NPs能显著激活烟草的一系列防御酶和抗性基因，这进一步解释CuO NPs抑制真菌侵染烟草植株的机制。另外，100 mg/L CuO NPs处理后烟叶和根中的铜含量分别比健康烟叶提高了50.03%和27.25%，根中铜含量明显高于叶片。本研究探索了CuO NPs作为纳米杀菌剂和真菌抗性诱导剂的潜力，通过抑制病原菌侵染和刺激植物防御来防控烟草黑胫病，研究结果为拓宽金属纳米粒子在植保抗菌领域中的应用提供了有力的科学依据。

Phosphomannose isomerase (PMI) encoding gene manA is a desirable selective marker in transgenic research. Understanding of its expression patterns in transgenic plant and establishing highly sensitive detection method based on immunoassay have great impacts on the application of PMI. In this study, PMI-specific monoclonal antibodies were generated using recombinant protein as immunogen, and could be used in Western blot to detect as little as 0.5 ng His-tagged PMI protein or rice expressed PMI protein in sample accounted for 0.4% of single rice grain (about 0.08 mg). PMI protein driven by CaMV-35S promoter was detected in dozens of tested tissues, including root, stem, leaf, panicle, and seed at all developmental stages during rice growing, and PMI protein accounted for about 0.036% of total protein in the leaves at seedling stage. The established method potentially can be used to monitor PMI protein in rice grains.

Maize/peanut intercropping system shows the significant yield advantage. Soil microbes play major roles in soil nutrient cycling and were affected by intercropping plants. This experiment was carried out to evaluate the changing of rhizosphere microbial community composition, and the relationship between microbial community and soil enzymatic activities, soil nutrients in maize/peanut intercropping system under the following three treatments: maize (Zea mays L.) and peanut (Arachis hypogaea L.) were intercropped without any separation (NS), by half separation (HS) using a nylon net (50 μm) and complete separation (CS) by using a plastic sheet, respectively. The soil microbial communities were assessed by phospholipid fatty acid (PLFA). We found that soil available nutrients (available nitrogen (Avail N) and available phosphorus (Avail P)) and enzymatic activities (soil urase and phosphomonoesterase) in both crops were improved in NS and HS treatments as compared to CS. Both bacterial and fungal biomasses in both crops were increased in NS followed by HS. Furthermore, Gram-positive bacteria (G+) in maize soils were significant higher in NS and HS than CS, while the Gram-negative (G–) was significant higher in peanut soil. The ratio of normal saturated to monounsaturated PLFAs was significantly higher in rhizosphere of peanut under CS treatment than in any other treatments, which is an indicator of nutrient stress. Redundancy analysis and cluster analysis of PLFA showed rhizospheric microbial community of NS and HS of both plants tended to be consistent. The urase and Avail N were higher in NS and HS of both plants and positively correlated with bacteria, fungi (F) and total PLFAs, while negatively correlated with G+/G– and NS/MS. The findings suggest that belowground interactions in maize/peanut intercropping system play important roles in changing the soil microbial composition and the dominant microbial species, which was closely related with the improving of soil available nutrients (N and P) and enzymatic activities.

Phosphorus (P) is one of the three primary macronutrients that are required in large amounts for plant growth and development. To better understand molecular mechanism of maize and identify relevant genes in response to phosphorus deficiency, we used Solexa/Illumina’s digital gene expression (DGE) technology to investigate six genome-wide expression profiles of seedling roots of the low-P tolerant maize inbred line 178. DGE studies were conducted at 6, 24 and 72 h under both phosphorus deficient and sufficient conditions. Approximately 3.93 million raw reads for each sample were sequenced and 6 816 genes exhibited significant levels of differential expressions in at least one of three time points in response to P starvation. The number of genes with increased expression increased over time from 6 to 24 h, whereas genes with decreased expression were more abundant at 72 h, suggesting a gradual response process for P deficiency at different stages. Gene annotations illustrated that most of differentially expressed genes (DEGs) are involved in different cellular and molecular processes such as environmental adaptation and carbohydrate metabolism. The expression of some known genes identified in other plants, such as those involved in root architecture, P metabolism and transport were found to be altered at least two folds, indicating that the mechanisms of molecular and morphological adaptation to P starvation are conserved in plants. This study provides insight into the general molecular mechanisms underlying plant adaptation to low-P stress and thus may facilitate molecular breeding for improving P utilization in maize.

The German wheat cultivar Ibis has excellent adult plant resistance (APR) to stripe rust in Gansu, a hotspot for stripe rust in China. To elucidate the genetic basis of APR to stripe rust in Ibis, 237 F3 lines derived from the cross Ibis/Huixianhong were evaluated at Tianshui, Gansu, in the 2008-2009 and 2009-2010 cropping seasons, and at Chengdu, Sichuan Province, China, in the 2009-2010 cropping season. Inoculations were conducted with a mixture of several prevalent Pst races in both locations. Maximum disease severity (MDS) data showed a continuous distribution of response, indicating quantitative nature of resistance to stripe rust in Ibis. The broad-sense heritability of MDS was 0.75 based on the mean values averaged across three environments. A total of 723 simple sequence repeat (SSR) markers were used to map the QTL for APR by inclusive composite interval mapping (ICIM). QTLs mapping to chromosomes 2BS and 6BS, designated as QYr.caas-2BS.1 and QYr.caas-6BS.1, respectively, explained 4.1-40.7% of the phenotypic variance in MDS across environments. The major effect QTL QYr.caas-2BS.1, flanked by Xgwm148 and Xwmc360, was consistently detected at all three sites as well as the averaged data over three environments, accounting for 40.7, 24.2, 5.2 and 29.9% of phenotypic variance, respectively. The molecular markers closely linked to this QTL have potential for use in marker-assisted selection and gene pyramiding to improve the durability of stripe rust resistance in wheat breeding.