开发高活性、环境友好的绿色新农药是保护农作物健康和食品安全的重要手段。为了发现新的候选杀菌剂，本研究论文采用Pictet–Spengler反应制备了一系列新颖的1,2,3,4-四氢-β-咔啉（THC）衍生物，并评估了其对水稻白叶枯病菌（Xoo）、柑橘溃疡病菌（Xac）和猕猴桃溃疡病菌（Psa）的离体和活体生物活性。结果表明，大多数目标化合物对三种植物病原细菌都表现出良好的生物活性。其中，化合物A₁₇对水稻白叶枯病菌和柑橘溃疡病菌表现出优异的抑菌活性，其EC₅₀值分别为7.27 mg mL^-1和4.89 mg mL^-1。化合物A₈对猕猴桃溃疡病菌显示出较好的抑制活性，其EC₅₀值为4.87 mg mL^-1。此外，在200 mg mL^-1浓度下，化合物A₁₇对水稻白叶枯病（52.67%）和柑橘溃疡病（79.79%）表现出优异的防治效果，化合物A₈对猕猴桃溃疡病的防治效果为84.31%。构效关系研究表明：THC的A环的C6位无取代基时有利于提高其抑菌活性；对于 THC的C环，当N2位是NH基团是有利于提高其抑菌活性；此外，THC的C环的NH位置引入长链可以增强其抗菌活性。通过大量的生物学实验验证，THC衍生物能扰乱细菌体内的氧化还原系统，造成细菌活性氧的爆发和细胞膜的破坏，最终导致细菌的死亡。上述的研究工作为以THC为活性骨架的新型杀菌剂创制提供了重要参考。

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。

禽致病性大肠杆菌（Avian pathogenic Escherichia coli ,APEC）是一种肠外致病性大肠杆菌（Extraintestinal pathogenic E. coli , ExPEC），可引起禽类和人类肠道以外组织的严重感染。MprA（microcin production regulation, locus A，现更名为AbsR，a blood survival regulator）是MarR（multiple antibiotic resistance regulator）转录调节因子家族的成员。它调控人源ExPEC中荚膜生物合成基因的表达，并且具有作为药物靶标的潜力。然而，目前的研究尚未完全阐明AbsR的靶基因及其调控机制。本研究利用ChIP-Seq和RNA-Seq技术对APEC AbsR调节子进行了系统分析，结果表明，AbsR直接调控99个基因，间接调控667个基因。接下来通过实时荧光定量PCR和体外实验证实了AbsR对靶基因转录水平和功能的影响。研究发现，AbsR在APEC XM中直接调控K1荚膜基因簇的表达，从而使菌株能够抵抗巨噬细胞的吞噬、血清杀伤，并发挥毒力作用。此外，AbsR还直接激活酸感应信号系统基因evgAS及耐酸相关基因hdeBAD和gadE，从而发挥体外耐酸能力。它还通过直接激活T2SS基因簇的表达，进而影响SslE蛋白的表达和分泌促进生物膜形成。此外，AbsR还间接调控I-F CRISPR系统基因的表达。在小鼠模型中，我们探索了AbsR及其靶基因对APEC XM毒力的影响，证实AbsR主要通过荚膜基因簇发挥毒力。在另外三株不同来源的ExPEC分离株中，AbsR可以抑制1型菌毛基因和I-F CRISPR系统相关基因的表达，同时激活酸感应信号系统基因evgAS、Group 2荚膜基因的表达；表明这些调控对于ExPEC共同的靶基因具有普适性。本研究首次系统梳理了MarR家族转录调控因子AbsR在肠道外致病性大肠杆菌的调控网络及其调控机制，明确了AbsR作为一类调控蛋白的调控方式及其致病机制。研究还首次证实AbsR对肠道外致病性大肠杆菌中的共同靶基因的调控具有普适性，这大大增进了我们对AbsR调控和功能的理解，并拓展了AbsR调控网络的广度。这对于预防及治疗大肠杆菌病的药物选择及维持宿主共生菌群稳态提供了重要参考。此外，该研究结果也为将来基于AbsR的药物筛选和研发提供理论依据。

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。

以优质丰产杂交中籼稻徽两优898和Y两优900为试验材料开展田间小区试验，钵苗机插条件下设置5个施氮量处理 (0、75、150、225、300 kg ha^-1)，利用不同生育时期水稻地上部干物质量累积和植株氮浓度构建钵苗机插杂交籼稻临界氮浓度稀释曲线，利用该曲线计算NNI和N_and诊断氮素营养状况，进而探究NNI 与N_and和相对产量（RY）的关系。施氮处理显著增加钵苗机插杂交籼稻地上部生物量和植株氮浓度（P<0.05），钵苗机插杂交籼稻临界氮浓度（N_c）与地上部生物量（DM）之间符合幂函数曲线N_c=4.02DM^-0.42（R²=0.97），模型RMSE 和n-RMSE 分别为0.23、10.61%，表明模型具有较好的准确性和稳定性。整个生育期内植株NNI 值范围为0.58~1.31，与之对应的N_and值为-55~109 kg ha^-1。各生育时期NNI与N_and的存在显著线性模型关系（0.53<R²<0.99，P<0.01），而NNI与RY间满足线性平台模型关系（0.73<R²<0.92，P<0.01）。本研究构建模型可用于诊断钵苗机插杂交籼稻氮素营养状况，为定量氮肥管理提供依据。

草地贪夜蛾是一种重大农业害虫，于2018年12月中旬入侵中国。作为一种杂食性害虫，草地贪夜蛾对我国农业生产和粮食安全造成严重威胁。辣椒、番茄和茄子是我国3种重要的茄科蔬菜。本研究评估了草地贪夜蛾在辣椒、番茄和茄子上的适应性。结果表明，以番茄和辣椒为食时，草地贪夜蛾能完成生活史，以茄子为食则不能完成生活史。采用年龄-阶段两性生命表比较了草地贪夜蛾取食玉米和3种茄科蔬菜的种群参数差异。结果表明：（1）发育历期在幼虫期差异显著，蛹期差异不显著；（2）取食辣椒的草地贪夜蛾成虫前期最长（41.73 d）、蛹重最轻（0.1134 g）；（3）雌虫平均单雌产卵量差异显著，其中以取食番茄的单雌产卵量最高（943.95粒）；（4）取食玉米时，草地贪夜蛾的平均世代周期最短、内禀增长率和周限增长率最高，而净增殖率则以取食番茄的为最高。总体而言，草地贪夜蛾对3种茄科蔬菜的适应性为：番茄>辣椒>茄子。本研究为进一步评估草地贪夜蛾对茄科蔬菜的危害以及为建立相应的防治措施打下了一定基础。

As a short-day plant species, maize requires an optimal photoperiod for inducing reproductive growth. However, there is a lack of information regarding photoperiod-induced changes in maize mRNA and protein levels. In this study, a photoperiod-insensitive maize inbred line and its near isogenic photoperiod-sensitive line were used. By integrating RNAbased transcriptomic and iTRAQ LC-MS/MS-based proteomic approaches, we generated a comprehensive inventory of the transcripts and proteins with altered abundances in response to a long photoperiod (LP) during growth stage transitions. We detected 22 000 transcripts in RNA-sequence runs and 5 259 proteins from an iTRAQ-based analysis. A weak correlation between mRNA- and protein-level changes was observed, suggesting the LP-induced transition between maize growth stages is largely regulated post-transcriptionally. Differentially expressed genes influenced by LP conditions were associated with several regulatory processes in both maize inbred lines, especially phosphate ion transport and the circadian rhythm. Additionally, 31 transcripts and six proteins related to photoperiodic flowering in maize were identified by comparing transcriptomic and proteomic data. This transcriptomic and proteomic analysis represents the first comprehensive and comparative study of gene/protein-level changes occurring in photoperiod-sensitive and -insensitive maize inbred lines

Chinese vegetable production cooperatives supply their members, mostly smallholder farmers, with a rotation schedule for the year.  Since vegetable prices are not stable throughout the year, designing a rotation schedule that maximizes expected profits, distributes farmers’ profits more equitably, maintains the diversity of produce in the market, and reduces the risk of pests and diseases, requires adaptive, price-contingent rotation schedules (here, called “self-adaptive adjustment”).  This study uses an agent-based simulation (ABS) to design self-adaptive rotation schedules that deliver these aims.  The self-adaptive adjustment strategy was more profitable for farmers when faced with price volatility, and more equitable as well.  This work provides a decision-support tool for managers of Chinese vegetable production cooperatives to provide farmers with more profitable and equitable rotation schedules.   

We conducted a two-year study of deficit irrigation impact on peach yield and quality in semi-arid northwest China.  Over two years, four-year-old peach trees were irrigated at 100, 75, 50 and 25% of peach evapotranspiration (ET_c), here, ET_c= Coefficient (K_c)×Local reference evapotranspiration (ET_o).  During the April-July fruit production season we measured root zone soil water depletion, sap flow velocity, net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), water use efficiency (WUE=P_n/T_r), fruit quality, and yield under a mobile rain-out shelter.  Increased soil water depletion reasonably mirrored decreasing irrigation rates both years, causing progressively greater water stress.  Progressive water stress lowered G_s, which in turn translated into lower T_r as measured by sap flow.  However, mild deficit irrigation (75% ET_c) constricted T_r more than P_n.  P_n was not different between 100 and 75% ET_c treatments in both years, and it decreased only 5–8% in June with higher temperature than that in May with cooler temperature.  Concurrently under 75% ET_c treatment, T_r was reduced, and WUE was up to 13% higher than that under 100% ET_c treatment.  While total fruit yield was not different under the two treatments, because 75% ET_c treatment had fewer but larger fruit than 100% ET_c trees, suggesting mild water stress thinned fruit load.  By contrast, sharply decreased T_r and P_n of the driest treatments (50 and 25% ET_c) increased WUE, but less carbon uptake impacted total fruit yield, resulting 13 and 33% lower yield compared to that of 100% ET_c treatment.  Irrigation rates affected fruit quality, particularly between the 100 and 75% ET_c trees.  Fewer but larger fruit in the mildly water stressed  trees (75% ET_c) resulted in more soluble solids and vitamin C, firmer fruit, and improved sugar:acid ratio and fruit color compared to the 100% ET_c treatment.  Overall, trees deficit irrigated at 75% ET_c maintained yield while improving fruit quality and using less water. 

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.

Upland red soils have been identified as major CO2 and N2O sources induced by human activities such as fertilization. To monitor characteristics of soil surface CO2 and N2O fluxes in cropland ecosystems after continuous fertilizer applications over decades and to separate the respective contributions of root and heterotrophic respiration to the total soil CO2 and N2O fluxes, the measurements of soil surface CO2 and N2O fluxes throughout the maize growing season in 2009 were carried out based on a fertilization experiment (from 1990) through of the maize (Zea mays L.) growing season in red soil in southern China. Five fertilization treatments were chosen from the experiment for study: zero-fertilizer application (CK), nitrogen-phosphorus- potassium (NPK) fertilizer application only, pig manure (M), NPK plus pig manure (NPKM) and NPK with straw (NPKS). Six chambers were installed in each plot. Three of them are in the inter-row soil (NR) and the others are in the soil within the row (R). Each fertilizer treatment received the same amount of N (300 kg ha-1 yr-1). Results showed that cumulative soil CO2 fluxes in NR or R were both following the order: NPKS>M, NPKM>NPK>CK. The contributions of root respiration to soil CO2 fluxes was 40, 44, 50, 47 and 35% in CK, NPK, NPKM, M and NPKS treatments, respectively, with the mean value of 43%. Cumulative soil N2O fluxes in NR or R were both following the order: NPKS, NPKM>M>NPK>CK, and soil N2O fluxes in R were 18, 20 and 30% higher than that in NR in NPKM, M and NPKS treatments, respectively, but with no difference between NR and R in NPK treatment. Furthermore, combine with soil temperature at -5 cm depth and soil moisture (0-20 cm) together could explain 55-70% and 42-59% of soil CO2 and N2O emissions with root interference and 62- 78% and 44-63% of that without root interference, respectively. In addition, soil CO2 and N2O fluxes per unit yield in NPKM (0.55 and 0.10 kg C t-1) and M (0.65 and 0.13 g N t-1) treatments were lower than those in other treatments. Therefore, manure application could be a preferred fertilization strategy in red soils in South China.

The extraction and comparison of soil amino acids using different extractants (deionized water, K2SO4, Na2SO4, NaCl, KCl) were reported. Results showed that 0.5 mol L-1 K2SO4 with a 5 times extraction was a better method to assess the concentration of extractable amino acids in soils. The total amino acids extracted from soil planted for tea were similar to the total inorganic nitrogen. While they extracted from vegetable soil and paddy soil were much lower than the total inorganic nitrogen.

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.

Ginsenosides Rg1, Rb1, R1, Rd, and Re are major constituents of Panax notoginseng, a famous traditional Chinese medicinal herb, which has both stimulative and inhibitory effects on the central nervous system (CNS). The monoamine hypothesis proposes that depression is a result of the depletion of 5-hydroxytryptamine (5-HT), norepinephrine (NE) and dopamine (DA) in addition to the activation of monoamine oxidase in the CNS. The purpose of this study was to determine whether P. notoginseng Saponin (PNS) has an antidepressant activity. We investigated the antidepressant-like activities of Rg1, Rb1, R1, Rd, and Re in mice, using two animal models of depression. In addition, we analyzed the neurochemicals by the chronic unpredictable mild stress test. Our results showed that Rb1, Rd, and Re treatment at 10 mg kg-1 significantly reduced the duration of immobility in both the tail suspension and forced swimming tests. Rb1, Rd, and Re increases in 5- HT and NE levels at 10 mg kg-1 in both the frontal cortex and hippocampus. Dopamine levels increased in the hippocampus and the striatum. Moreover, 5-hydroxyindoleacetic acid (5-HIAA) levels were found increased in the hippocampus. These findings suggest that the antidepressant effects of Rb1, Rd, and Re may be related to the increase in 5-HT and NE in the CNS, and through the alterations in the synthesis or metabolism of dopamine.