气候变化对农业产生了重大影响。但大多数研究基于历史气象数据的分析，缺乏与作物生长发育和土壤水分相关联的长期监测。本研究收集了甘肃省农业科学院镇原试验站1957-2020年气象数据和1981-2019年作物生育期数据，并在陇东和宁南开展了相关田间长期试验。研究结果表明，60年来，每10年平均气温增加0.36°C和降水减少11.2mm；1981-2019年的39年间旱地冬小麦田间耗水量平均362.1mm，呈现出每10年减少22.1mm的趋势，但1985-2019年的35年间春玉米耗水量平均405.5mm，保持基本稳定。气候干暖化导致旱地作物生育期发生了明显变化，每10年冬小麦和春玉米生育期缩短5.19天和6.47天，播前推迟3.56天和1.8天，成熟期提前1.76天和5.51天。全膜双垄沟集雨种植使小雨量在垄沟集雨效率达到65.7-92.7%，水分向土壤深层入渗，作物根域水分成倍增加，作物水分满足率提高110-160%，连续15年全膜双垄沟较半膜平作覆盖旱地玉米增产19.87%。旱地玉米群体大小是影响产量和水分利用效率的关键因素，种植密度从3000提高到4500株/亩，玉米产量和水分利用效率增加20.6%和17.4%，从4500提高到6000株/亩再增加12.0%和12.7%。然而，不同降水量地区旱地玉米产量与种植密度均呈现二次曲线关系，曲线性状、最高产量对应的最大密度在地区之间差异很大。在300-500mm年降水量地区，种植密度随降水量的增加而增加，适水种植密度为每1mm降水可种植玉米12株/亩，但超过500mm时种植密度随降水量变化不大。因此，旱地农田抗旱节水应集中在压夏扩秋适水型种植结构建立、垄沟覆盖集雨种植、以水定密适水种植等，以减少气候变化引起的负面影响，增强旱地玉米生产的可持续。

由禾柄锈菌（Puccinia graminis f. sp. tritici）引起的小麦秆锈病是小麦生产中最为严重的真菌病害之一，严重威胁着全球小麦的安全生产。种植抗病品种是防治该病害最为经济有效的方法，而抗病品种的选育要以小麦秆锈菌种群毒力变化为依据。为此，我们持续不断的开展小麦秆锈菌种群毒力变异监测工作，在鉴定中发现了3个来自于小麦秆锈菌转主寄主小檗上产生的锈孢子的新小种34C0MRGQM、34C3MKGQM和34C6MTGSM，特别是发现小种34C0MRGQM和34C6MTGSM对我国小麦抗病育种中广泛使用的抗病基因Sr5和Sr11具有联合毒力，在我国鉴定的13310个菌株中尚未发现对Sr5和Sr11具有联合毒力的菌株。为此，本研究利用42个已知小麦秆锈病抗病基因（Sr）的小麦品系对这3个小种的毒力特征进行了分析，同时鉴定了69份我国主要小麦品种对这3个小种在苗期和成株期的抗性水平。结果表明含有Sr9e、Sr17、Sr21、Sr22、Sr26、Sr30、Sr31、Sr33、Sr35、Sr36、Sr37、Sr38、Sr47、SrTmp和SrTt3的单基因系在苗期和成株期对34C0MRGQM、34C3MKGQM和34C6MTGSM均具有良好的抗性。相反，含有Sr5、Sr6、Sr7b、Sr9a、Sr9d、Sr9f、Sr9g、Sr9b、Sr16、Sr24、Sr28和Sr39的单基因系在苗期和成株期都对这些小种高度感病。含有Sr8a、Sr10、Sr11、Sr13、Sr14、Sr15、Sr18、Sr20、Sr19、Sr23、Sr25、Sr27、Sr29、Sr32和Sr34的单基因品系对供试小种中的一个或2个表现抗性。在供试的69份小麦材料中，有41份小麦品种对供试小种在苗期和成株期都表现出良好的抗性，占59.4%。进一步分子检测表明，有20个品种可能含有抗病基因Sr31，9个品种含有Sr38，4个品种含有Sr2，没有检测到含有Sr24、Sr25和Sr26的品种。研究结果为开展兼抗高致病性的Ug99及我国小麦秆锈菌抗病基因的合理利用与抗病育种提供理论依据。

本研究基于20头成华猪和30头青裕猪的简化代表性甲基化测序数据使用全基因组分析的方法识别成华猪和青裕猪差异甲基化位点。当甲基化位点的甲基化差异大于0.25以及q值小于0.01时，把该位点识别为差异甲基化位点，然后基于差异甲基化位点搜索对应的差异甲基化基因。结果发现成华猪的几个肉质性状，包括45分钟的pH值 (pH_45min)，45分钟的肉色亮度值（L45_min）以及24小时的肉色亮度值（L_24h），均显著高于青裕猪。然后我们检测到10699个差异甲基化位点，并基于这些位点搜索到2760个差异甲基化基因。通过基因功能分析我们发现这些差异甲基化基因主要涉及AMPK信号通路，II型糖尿病，胰岛素信号通路，mTOR信号通路以及胰岛素抵抗等。此外，通过相关文献和研究资料，发现一些差异甲基化基因与脂质代谢，肌肉发育以及肉质性状相关。本研究结果表明成华猪和青裕猪有着不同的甲基化模式，这些甲基化模式的差异反映了二者表型性状的差异。本研究基于简化甲基化测序数据对成华猪和青裕猪进行全基因组甲基化差异分析，研究结果系统解析了成华猪和青裕猪的DNA甲基化模式和表观遗传调控机制。

坡耕地氮素流失是农业面源污染的重要原因之一，严重影响着水环境。本研究以顺坡垄作、横坡垄作坡面为研究对象，通过两年(2017-2018年)野外定外观测，开展玉米生长期黄壤坡耕地地表径流、壤中流及其氮素流失特征。研究结果表明：随着降雨量的增加，地表径流量和壤中流量也随之增加。顺坡垄作的地表径流量和氮素流失量均显著高于横坡垄作；横坡垄作0 -20 cm和20 -40 cm壤中流量和氮素流失量均显著高于顺坡垄作。地表径流的总氮流失量占径流总氮流失的54.95 -81.25%，因此，我们推断地表径流是研究区氮素流失的主要途径。不同耕作措施下可溶性总氮是氮素流失的主要形式，其流失量占氮素流失量的55.82-94.41%，而可溶性有机氮占可溶性总氮流失量的52.81-87.06%。因此，我们推断可溶性氮为研究区氮素流失的主要形式。应在玉米苗期，进一步开展氮素流失防控方面研究，以减少通过径流途径铵态氮流失造成的环境污染。

以往关于脱硫石膏改良盐碱土壤的效果研究，大多评测其对土壤理化性质的影响。然而，脱硫石膏对土壤微生物指标的影响研究鲜见报道，尤其是在其施用多年之后。为探究脱硫石膏改良盐碱土壤的长期效应，在内蒙古托克托县采集了轻度、中度和重度(碱化度分别为6.1-20%、20-30%和30-78.4%)3种碱化区施用脱硫石膏17年后的剖面(0-40 cm)土样，分析了土壤有机碳、养分、微生物量和酶活性的变化情况。结果表明：与对照(不施用脱硫石膏)处理相比，3种碱化区施用脱硫石膏处理0-20 cm和20-40 cm土壤有机碳含量平均值分别增加了18%和35%，0-20 cm土壤速效钾含量平均值增加了51%，20-40 cm土壤微生物量碳和微生物量氮含量平均值也分别增加了69%和194%。除了重度碱化区外，脱硫石膏处理0-40 cm土壤脲酶活性显著高于对照处理。此外，脱硫石膏处理显著提高了3种碱化区20-40 cm土壤碱性磷酸酶活性，但其对0-20 cm土壤过氧化氢酶和蔗糖酶活性的作用效果参差不齐。皮尔逊相关分析结果显示，土壤肥力和生物活性的提高归功于脱硫石膏施用后降低了土壤电导率、pH和碱化度。由此可见，施用脱硫石膏对土壤肥力和生物活性有积极的影响，有助于土壤生态系统的可持续发展，是一种切实可行的碱土改良方法。

本研究旨在探讨日粮直链/支链淀粉比例对中国秦川牛生长性能、瘤胃发酵和血液参数、胴体特征和大理石花纹评分、肌肉脂肪酸和糖异生途径相关基因表达差异的影响。试验采用单因素随机设计，将45头肉牛随机分为3组。试验动物分别饲喂普通玉米添加日粮(对照组；n=15；中等直链/支链淀粉比=0.47)、蜡质玉米淀粉添加日粮(WS；n=15；低直链/支链淀粉比=0.23)或豌豆淀粉添加日粮(PS；n=15；高直链/支链淀粉比=0.60)，共饲喂90天。全混合日粮每日饲喂量至少按肉牛体重的2.1%供给，分成2次饲喂。每隔45天称重1次，并分别采集血液和瘤胃液样品。试验结束后，每组选取接近平均体重的6头健康肉牛，颈静脉放血屠宰，并采集背最长肌样品进行肉质测定。试验数据采用SAS9.3统计软件中的单因素方差分析，并采用LSD法进行多重比较。与PS组相比，在0～45天，对照组和WS组的平均日增重(ADG)和饲料转化率均提高(P<0.05)。然而，在46～90天，PS组的饲料转化率比对照组和WS组更高(P<0.05)。在试验全期，对照组和WS组的ADG比PS组有更高的趋势(0.05<P<0.1)。与PS组相比，WS组血清胰岛素浓度在第45天时显著升高(P<0.05)，而在第90天时无明显差异(P>0.05)。与对照组和WS组相比，PS组血清超氧化物歧化酶和总抗氧化能力在第45天时显著升高(P<0.05)，而在第90天时无明显差异(P>0.05)。与对照组相比，WS组和PS组的瘤胃微生物蛋白(MCP)含量在第1天时显著升高(P<0.05)，而在第45天时对照组和WS组的MCP含量比PS组更高(P<0.05)，在第90天时3组间无明显差异(P>0.05)。与PS组相比，对照组和WS组的背膘厚度显著升高(P<0.05)，而在大理石花纹评分和肝脏中糖异生相关基因表达量上3组间无显著差异(P>0.05)。3组间背最长肌(LT)的常规成分和理化特性上也无显著差异(P>0.05)。综上所述，低或中等直链/支链淀粉比的日粮会增加背膘厚度，并有改善ADG的趋势，但对秦川牛其它胴体性状、肌内脂肪和糖异生相关基因表达量上无影响。创新性：1) 在育肥期的秦川公牛上进行不同直链/支链淀粉比日粮饲喂试验，比较不同淀粉原料的有效利用率；2) 通过生长性能、血液和瘤胃发酵参数、大理石纹评分以及糖异生关联基因表达量的综合比较，从饲料淀粉中直支链比例的角度观察了育肥期肉牛糖代谢和肌内脂肪生成量的变化。

外来入侵物种是指被引入到其原产地范围以外的地区，并对当地的经济、生物多样性和生态环境造成了严重危害的物种。明确入侵性的遗传机制对于开发生态友好型的方法来防控外来入侵物种至关重要，同时，揭示外来物种的基因组特征有利于准确预测其入侵性潜能。然而，尽管已经有大量外来入侵物种的基因组被测序，但这些数据存放零散，缺少一个综合的外来入侵物种基因组数据管理与分析平台。因此，我们通过文献调研和数据库检索，收集了已完成基因组测序的外来入侵物种的组学相关数据，构建了InvasionDB数据库。该数据库包含131个外来入侵物种（100种入侵动物和31种入侵植物）的基因组和转录组数据，其中，76个物种的基因组被详细注释，并提供基因功能（包括Pfam、KEGG和NR注释信息）查询、序列比对和基因组可视化，以及全部数据下载功能。为了提供更多与入侵性相关的信息，我们进一步分析了19个与入侵昆虫的入侵性相关的基因家族，以及非编码RNAs（包括135494 个miRNAs, 89294 个rRNAs和2671941 个tRNAs）。因此，InvasionDB对于从基因组水平来研究外来入侵物种的入侵性，以及发展新的防控技术具有重要指导意义。

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

Nitrogen (N), the major forms of which are nitrate (NO₃^–) and ammonium (NH₄⁺), plays an important role in plant growth and mediation of root development.  However, the role of auxin in root growth in response to different NH₄⁺/NO₃^– ratios remains unclear.  Two tobacco cultivars (Nicotiana tabacum L.) were adopted in this study, which displayed variant growth features under the situations with sole NO₃^– nutrition ratio (NH₄⁺/NO₃^– ratio: 0/100), low NO₃^– nutrition ratio (NH₄⁺/NO₃^– ratio: 97/3), and optimal NH₄⁺/NO₃^– ratio (50/50).  We investigated the effects of the different NH₄⁺/NO₃^– ratios on the formation and elongation of lateral roots (LRs), auxin concentration, DR5::GUS expression, 3H-labeled indole acetic acid ([3H]IAA) transport, and the expression of six PIN genes in tobacco roots.  We also examined the effects of exogenous auxin and a transport inhibitor on LRs growth.  The results are shown as follows, compared to optimal N nutrition conditions, the biomass and nitrogen (N) accumulation were largely reduced by sole and low NO₃^– nutrition treatment in NC89, but no difference was observed in Zhongyan 100.  In most cases, sole and low NO₃^– nutrition impaired the elongation and formation of first-order lateral roots (1° LRs), only in NC89, thus reducing the root growth.  IAA concentration and DR5::GUS expression levels decreased in roots when NC89 was subjected to sole and low NO₃^– nutrition media, suggesting that different NH₄⁺/NO₃^– ratios affect the transport of auxin from leaves to roots.  Results were similar following exogenous NAA application to low NO₃^– nutrition treated seedlings.  Based on direct [3H]IAA transport measurement, the transport of polar auxin from shoots to roots decreased due to low NO₃^– nutrition.  PIN4 expression levels were markedly decreased in roots of NC89 by sole and low NO₃^– nutrition, while they were unaffected in Zhongyan 100 roots.  Overall, our findings suggest that LRs formation in tobacco seedlings is regulated by NH₄⁺/NO₃^– ratios via modifying polar transport of auxin.

To optimize the spatial distribution of cotton bolls and to increase the yield, the relationship between yield components and boll spatial distribution was investigated among different Bt (Bacillus thuringensis) cotton varieties.  A five-year field experiment was conducted to reveal the reasons for the differences in lint yield and fiber quality across three Bt cotton varieties with different yield formations from 2013 to 2017.  The lint yield of Jiman 169 (the average yield from 2013–2017 was 42.2 g/plant) was the highest, i.e., 16.3 and 36.9% higher than Lumianyan 21 (L21) and Daizimian 99B (99B), respectively.  And the differences in boll weight among the three cultivars were similar to the lint yield, while the others yield components were not.  So the increase in lint yield was mainly attributed to the enlargement in boll weight.  However, the change in fiber quality was inconsistent with the lint yield, and the quality of L21 was significantly better than that of Jimian 169 (J169) and 99B, which was caused by the diversity of boll spatial distribution.  Compared with 99B, the loose-type J169 had the highest number of large bolls in inner positions; the tight-type L21 had a few large bolls and the highest number of lower and middle bolls.  And approximately 80.72% of the lint yield was concentrated on the inner nodes in Jiman 169, compared with 77.44% of L21 and 66.73% of 99B during the five-year experiment.  Although lint yield was significantly affected by the interannual changes, the lint yield of J169 was the highest and the most stable, as well as its yield components.  These observations demonstrated the increase in lint yield was due to the increase in boll weight, and the large bolls and high fiber quality were attributed to the optimal distribution of bolls within the canopies.

Tree peony seeds are rich in α-linolenic acid (ALA), and the peony seed oil is now being produced in China. Paeonia ostii is the most widely used tree peony species for oil extraction, which is commercially called Fengdan and treated as a single cultivar. Here, 50 P. ostii individuals from the same population in northern China were randomly selected for fatty acids (FAs) analysis. Thirteen FAs were isolated, and the most abundant five were palmitic acid (5.31–6.99%), stearic acid (1.22–2.76%), oleic acid (18.78–28.15%), linoleic acid (11.86–26.10%), and ALA (41.11–57.51%). There were significant individual differences of plants in FA quality and quantity and the linoleic acid content in Plant No. 48 even exceeded the scope of 1–99%. Further statistical analysis indicated that most of the individual FAs, saturated FAs, unsaturated FAs, and total FAs levels showed significant positive correlations to each other, whereas the seed yield per plant was independent and not correlated to the factors mentioned above. Ward’s hierarchical clustering results grouped the 50 plants into four clusters based on FA contents and seed yield, and the seven plants in Cluster IV were identified as good candidates for oil production. Our results confirmed that the individual differences did occur in P. ostii and Fengdan cannot be simply treated as one uniform cultivar. Also, these results may help simplify the selection of plants for oil peony breeding and accelerate the development of the oil peony industry.

Even though the impact of Bacillus thuringiensis (Bt) cotton on pesticide use has been well documented, all previous studies focus on the mean value of pesticide use.  Using seven unique waves of panel data collected between 1999 and 2012 in China, we show that Bt cotton adoption has not only caused a reduction of the mean value of pesticide use, but also a reduction of the standard deviation of pesticide use.  We conclude that Bt technology adoption has also contributed to the stability of pesticide use in cotton production.  We believe that this contribution is theoretically and practically relevant because of the long length of our unique dataset.

    Reference genes, stably expressing in different tissues and cells, are commonly used as the references in expression analysis. Selecting the optimum reference gene is crucial to the success of experiments. In this study, the expression stabilities of nine common reference genes, including ACT2, 18S rRNA, APRT, EF-1α, RNA POL II, TUBα, TUBβ, GAPDH and TLF of Agropyron mongolicum, were studied under drought condition. Among them, 18S rRNA was found to be the most optimum reference gene under drought stress by the analyzing of geNorm and NormFinder software. Quantitative expression levels of P5CS using 18S rRNA as the reference gene, and proline contents under drought stress in A. mongolicum were further operated, and we found the expression level of P5CS gene and proline content had a significantly positive relationship (R2=0.7763, P<0.05). This study established and validated 18S rRNA as the reference genes in A. mongolicum under drought stress, providing a powerful tool for the quantitative expression analysis of drought genes in A. mongolicum.

   Stomatal density and size affect plant water use efficiency, photosynthsis rate and yield. The objective of this study was to gain insights into the variation and genetic basis of stomatal density and size during grain filling under drought stress (DS) and well-watered (WW) conditions. The doubled haploid population derived from a cross of wheat cultivars Hanxuan 10 (H10), a female parent, and Lumai 14 (L14), a male parent, was used for phenotyping at the heading, flowering, and mid- and late grain filling stages along with established amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. The stomatal density of doubled haploid (DH) lines was gradually increased, while the stomatal lengths and widths were gradually decreased during grain filling stage. Twenty additive QTLs and 19 pairs of epistatic QTLs for the 3 traits were identified under DS. The other 20 QTLs and 25 pairs epistatic QTLs were obtained under WW. Most QTLs made more than 10% contributions to the total phenotypic variations at one growth stage under DS or WW. Furthermore, QTLs for stomatal density near Xwmc74 and Xgwm291 located on chromosome 5A were tightly linked to previously reported QTLs regulating total number of spikelets per spike, number of sterile spikelets per spike and proportion of fertile spikelets per spike. Qsw-2D-1 was detected across stages, and was in the same marker region as a major QTL for plant height, QPH.cgb-2D.1. These indicate that these QTLs on chromosomes 5A and 2D are involved in regulating these agronomic traits and are valuable for molecular breeding.

Collapsing gully erosion is a specific form of soil erosion types in the hilly granitic region of tropical and subtropical South China, and can result in extremely rapid water and soil loss. Knowledge of the soil physical and chemical properties of farmland influenced by collapsing gully erosion is important in understanding the development of soil quality. This study was conducted at the Wuli Watershed of the Tongcheng County, south of Hubei Province, China. The aim is to investigate soil physical and chemical properties of three soil layers (0–20, 20–40 and 40–60 cm) for two farmland types (paddy field and upland field) in three regions influenced by collapsing gully erosion. The three regions are described as follows: strongly influenced region (SIR), weakly influenced region (WIR) and non-influenced region (NIR). The results show that collapsing gully erosion significantly increased the soil gravel and sand content in paddy and upland fields, especially the surface soil in the SIR and WIR. In the 0–20 cm layer of the paddy field, the highest gravel content (250.94 g kg^–1) was in the SIR and the lowest (78.67 g kg^–1) was in the NIR, but in the upland filed, the surface soil (0–20 cm) of the SIR and the 40–60 cm soil layer for the NIR had the highest (177.13 g kg^–1) and the lowest (59.96 g kg^–1) values of gravel content, respectively. The distribution of gravel and sand decreased with depth in the three influenced regions, but silt and clay showed the inverse change. In the paddy field, the average of sand content decreased from 58.6 (in the SIR) to 49.0% (in the NIR), but the silt content was in a reverse order, increasing from 27.9 to 36.9%, and the average of the clay content of three regions showed no significant variation (P<0.05). But in the upland filed, the sand, silt and clay fluctuated in the NIR and the WIR. Soils in the paddy and upland field were highly acidic (pH<5.2) in the SIR and WIR; moreover lower nutrient contents (soil organic matter (SOM), total N and available N, P, K) existed in the SIR. In the 0–20 cm soil layer of the paddy field, compared with the NIR and the WIR, collapsing gully erosion caused a very sharp decrease in the SOM and total N of the SIR (5.23 and 0.56 g kg^–1, respectively). But in the surface soil (0–20 cm) of the upland field, the highest SOM, total N, available N, available P and available K occurred in the NIR, and the lowest ones were in the SIR. Compared with the NIR, the cation exchange capacity (CEC) in the SIR and WIR was found to be relatively lower. These results suggest that collapsing gully erosion seriously affect the soil physical and chemical properties of farmland, lead to coarse particles accumulation in the field and decrease pH and nutrient levels.

    Starch is the major component of wheat flour and serves as a multifunctional ingredient in food industry. The objective of the present study was to investigate starch granule size distribution of Chinese wheat cultivars, and to compare structure and functionality of starches in four leading cultivars Zhongmai 175, CA12092, Lunxuan 987, and Zhongyou 206. A wide variation in volume percentages of A- and B-type starch granules among genotypes was observed. Volume percentages of A- and B-type granules had ranges of 68.4–88.9% and 9.7–27.9% in the first cropping seasons, 74.1–90.1% and 7.2–25.3% in the second. Wheat cultivars with higher volume percentages of A- and B-type granules could serve as parents in breeding program for selecting high and low amylose wheat cultivars, respectively. In comparison with the B-type starch granules, the A-type granules starch showed difference in three aspects: (1) higher amount of ordered short-range structure and a lower relative crystallinity, (2) higher gelatinization onset (T_o) temperatures and enthalpies (ΔH), and lower gelatinization conclusion temperatures (T_c), (3) greater peak, though, and final viscosity, and lower breakdown viscosity and pasting temperature. It provides important information for breeders to develop potentially useful cultivars with particular functional properties of their starches suited to specific applications.

Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Leaves, especially the flag leaves, as CHA initial recipients play a decisive role in inducing male sterility. To investigate effects of different treatment times of CHA-SQ-1 used, morphological, biochemical and physiological responses of wheat flag leaves were detected in this study. CHA induced programmed cell death (PCD) as shown in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) and DNA laddering analysis. In the early phase, CHA-SQ-1 triggered organelle changes and PCD in wheat leaves accompanied by excess production of reactive oxygen species (O2 -. and H2O2) and down-regulation of the activities of superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD). Meanwhile, leaf cell DNAs showed ladder-like patterns on agarose gel, indicating that CHA-SQ-1 led to the activation of the responsible endonuclease. The oxidative stress assays showed that lipid peroxidation was strongly activated and photosynthesis was obviously inhibited in SQ-1-induced leaves. However, CHA contents in wheat leaves gradually reduced along with the time CHA-SQ-1 applied. Young flags returned to an oxidative/antioxidative balance and ultimately developed into mature green leaves. These results provide explanation of the relations between PCD and anther abortion and practical application of CHA for hybrid breeding.

Drought stress is a major abiotic stress of common bean (Phaseolus vulgaris L.) throughout the world. Increasing the proline accumulation contributes to enhance crop drought tolerance. A cDNA for δ-ornithine aminotransferase (δ-OAT), an enzyme involved in the biosynthesis of proline, was isolated from Phaseolus vulgaris (PvOAT). PvOAT exhibits 87.4 and 39.8% similarity of the deduced amino acid sequences with δ-OAT from Glycine max and Vigna aconitifolia, respectively. The transcriptional analysis revealed that PvOAT was strongly induced by drought stress. And the expression of PvOAT was higher in leaves than that in the root and stem of common bean by drought stress. Similar increase of the proline accumulation was observed in leaves and roots of common bean by drought stress. Furthermore, the proline content, the PvOAT expression and the PvOAT enzyme activity in cultivar F5575 was significantly (P<0.01) higher than that in cultivar F4851 under drought-stress conditions. Interestingly, it had been observed that, in the later stage of drought stress, the proline steadily maintained at the maximum level maybe result from the PvOAT enzyme activity increasing steadily. These results indicated that the expression of PvOAT and the accumulation of proline induced by drought stress treatment were related to the degree of common bean drought tolerance. So our results support the view that δ-OAT is associated with proline synthesis under drought stress conditions.

The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV) and porcine circovirus type 2 (PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/ municipalities of China during the period from February 2011 to November 2012 were assayed for T. gondii antigens and antibodies using enzyme linked immunosorbent assay (ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of T. gondii, PRSSV, CSFV and PCV-2 was 9.14% (34/372), 50.00% (186/372), 37.10% (138/372) and 3.23% (12/372), respectively. Among the 34 T. gondii positive samples, 26 samples were simultaneously infected with T. gondii and viruses, while the remaining eight samples were infected with T. gondii alone. In addition, the co-infection rate of T. gondii with PRSSV, T. gondii with PRSSV and CSFV, T. gondii with PRSSV and PCV-2, T. gondii with CSFV and PCV-2, T. gondii with PRSSV, CSFV and PCV-2 was 1.61% (6/372), 4.03% (15/372), 0.27% (1/372), 0.27% (1/372) and 0.81% (3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of T. gondii infection in pig. This is the first report of T. gondii co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of T. gondii and viruses in pigs.

In this study, four strains of Toxoplasma gondii with the same genetic type (Type I) originated from chicken, human, cat and swine were used to compare the immune responses in resistant chicken host to investigate the relationships between the parasite origins and the pathogenicity in certain host. A total of 300, 10-day-old chickens were allocated randomly into five groups which named JS (from chicken), CAT (from cat), CN (from swine), RH (from human) and a negative control group (–Ve) with 60 birds in each group. Tachyzoites of four different T. gondii strains (JS, CAT, CN and RH) were inoculated intraperitoneally with the dose of 1×107 in the four designed groups, respectively. The negative control (–Ve) group was mockly inoculated with phosphate-buffered saline (PBS) alone. Blood and spleen samples were obtained on the day of inoculation (day 0) and at days 4, 11, 25, 39 and 53 post-infection to screen the immunopathological changes. The results demonstrated some different immune characters of T. gondii infected chickens with that of mice or swine previous reported. These differences included up-regulation of major histocompatibility complex class II (MHC II) molecules in the early stage of infection, early peak expressions of interleukin (IL)-12 (IL-12) and -10 (IL-10) and long keep of IL-17. These might partially contribute to the resistance of chicken to T. gondii infection. Comparisons to chickens infected with strains from human, cat and swine, chickens infected with strain from chicken showed significant high levels of CD4+ and CD8+ T cells, interferon gamma (IFN-γ), IL-12 and IL-10. It suggested that the strain from chicken had different ability to stimulate cellular immunity in chicken.

Genetic transformation is an important technique for functional genomics study and genetic improvement of plants. Until now, Agrobacterium-mediated transformation methods using cotyledon as explants has been the major approach for cucumber, and its frequency has been up to 23%. For example, significantly enhancement of the transformation efficiency of this plant species was achieved from the cotyledon explants of the cultivar Poinsett 76 infected by Agrobacterium strains EHA105 with efficient positive selection system in lots of experiments. This review is to summarize some key factors influencing cucumber regeneration and genetic transformation, including target genes, selection systems and the ways of transgene introduction, and then to put forward some strategies for the increasing of cucumber transformation efficiency. In the future, it is high possible for cucumber to be potential bioreactor to produce vaccine and biomaterials for human beings.

The adsorption of Cu(II) from aqueous solution onto humic acid (HA) which was isolated from cattle manure (CHA), peat (PHA), and leaf litter (LHA) as a function of contact time, pH, ion strength, and initial concentration was studied using the batch method. X-ray absorption spectroscopy (XAS) was used to examine the coordination environment of the Cu(II) adsorbed by HA at a molecular level. Moreover, the chemical compositions of the isolated HA were characterized by elemental analysis and solid-state 13C nuclear magnetic resonance spectroscopy (NMR). The kinetic data showed that the adsorption equilibrium can be achieved within 8 h. The adsorption kinetics followed the pseudo-second-order equation. The adsorption isotherms could be well fitted by the Langmuir model, and the maximum adsorption capacities of Cu(II) on CHA, PHA, and LHA were 229.4, 210.4, and 197.7 mg g–1, respectively. The adsorption of Cu(II) on HA increased with the increase in pH from 2 to 7, and maintained a high level at pH>7. The adsorption of Cu(II) was also strongly influenced by the low ionic strength of 0.01 to 0.2 mol L–1 NaNO3, but was weakly influenced by high ionic strength of 0.4 to 1 mol L–1 NaNO3. The Cu(II) adsorption on HA may be mainly attributed to ion exchange and surface complexation. XAS results revealed that the binding site and oxidation state of Cu adsorbed on HA surface did not change at the initial Cu(II) concentrations of 15 to 40 mg L–1. For all the Cu(II) adsorption samples, each Cu atom was surrounded by 4 O/N atoms at a bond distance of 1.95 Å in the first coordination shell. The presence of the higher Cu coordination shells proved that Cu(II) was adsorbed via an inner-sphere covalent bond onto the HA surface. Among the three HA samples, the adsorption capacity and affinity of CHA for Cu(II) was the greatest, followed by that of PHA and LHA. All the three HA samples exhibited similar types of elemental and functional groups, but different contents of elemental and functional groups. CHA contained larger proportions of methoxyl C, phenolic C and carbonyl C, and smaller proportions of alkyl C and carbohydrate C than PHA and LHA. The structural differences of the three HA samples are responsible for their distinct adsorption capacity and affinity toward Cu(II). These results are important to achieve better understanding of the behavior of Cu(II) in soil and water bodies in the presence of organic materials.

Mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases widely conserved in all eukaryotes and involved in responses to biotic and abiotic stresses. In this study, two over-expressing BnMAPK1 oilseed rape lines, ov3 and ov11, were used to study the drought-resistant mechanism of BnMAPK1 under natural drought and simulation drought through spraying 10% PEG 8000 in seedlings. Zhongyou 821 (WT) was used as control. Compared with wild type, transgenic seedlings had higher leaf water content, higher root activity, slightly higher peroxidase (POD) and superoxide dismutase (SOD) activity, higher proline content and lower malondialdehyde (MDA) content. The expression of drought-resistant related genes, including P5CSB, PLC, LEA4 and SCE1, have been up-regulated in some degree and the expressed time of transgenic lines were earlier than that of wild type. These results suggested that over-expression of BnMAPK1 can enhance the resistance to drought in oilseed rape (Brassica napus).

The western flower thrips, Frankliniella occidentalis (Pergande) is a highly invasive pest that is able to exploit many crops across a wide range of environmental conditions. Five full-length cDNAs of heat shock protein (HSP) genes (Fo-HSP90, Fo-HSP70, Fo-HSP60, Fo-HSP40 and Fo-HSP28.9) were cloned from F. occidentalis, and their expression profiles were investigated under conditions of thermal stress and insecticide exposure, and at different stages during development, using real-time quantitative PCR. All five gene sequences showed high similarity to homologs in other species, indicating the conserved function of this gene family. HSP60 represents an informative phylogenetic marker at the ordinal taxonomic level within Insecta, but HSP90, which has two homologous copies in Hymenoptera, was not informative. The expression of Fo-HSPs under thermal stress suggests that Fo-HSP90, Fo-HSP70, and Fo-HSP28.9 are inducible by both cold and heat stress, Fo-HSP40 is only heat-inducible, and Fo-HSP60 is thermally insensitive. There were two patterns of cold induction of Fo-HSPs: one is from 0 to 4°C and the other is around -8°C. All five Fo-HSPs genes were induced by exposure to sublethal concentrations of the insecticide avermectin. The expression of the five Fo-HSPs during different developmental stages suggests that they all play a role in development of F. occidentalis.

Pregnancy toxemia is a metabolic disorder of lipid and glucose. Recent investigations have found that angiopoietin-like protein 3 (ANGPTL3) can contribute to disorder of carbohydrate and lipid metabolism. The present study was conducted to investigate the change of ANGPTL3 expression during pregnancy toxemia. We firstly cloned the full-length cDNA of ANGPTL3 in Liuyang Black goats, revealing that goat ANGPTL3 had the typical structure of the angiopoietin-like family, and its mRNA was exclusively expressed in liver. Pregnancy toxemia of pregnant goat does with twins during late gestation was induced by being fasted for 72 h, and then they were recovered after 5 d of refeeding. Hepatic ANGPTL3 gene expression was significantly down-regulated concomitantly with decreased serum glucose concentration, elevated serum β-hydroxybutyrate and free fatty acid levels in pregnant toxemic goats, and these changes were reversed after refeeding. These results suggest ANGPTL3 may play a certain role in the development of pregnancy toxemia in goats.