盐胁迫下选择性剪接可调控丝氨酸/精氨酸丰富(SR)蛋白的表达和异构体的形成。前期研究鉴定了木薯SR蛋白家族中的两个亚家族SCL和 SR，这两个亚家族参与调控植物非生物胁迫的响应，然而SR蛋白家族中的其他亚家族是否也在转录后水平上调控植物盐胁迫应答有待探究。本研究通过11个物种RS亚家族的同源性比对找到37个基因，并系统性的分析了RS40 和 RS31基因在非生物胁迫条件下的表达情况。进一步蛋白结构域分析表明植物RS亚家族在非生物胁迫响应中其作用可能是保守的。在拟南芥中过表达MeRS40基因可通过维持活性氧的动态平衡和调控盐胁迫响应基因的表达进而提高植物的耐盐性。然而，在木薯中过表达MeRS40基因则通过负调节自身的pre-mRNA来抑制其内源性基因表达，从而降低转基因木薯的耐盐性。此外，MeRS40蛋白与木薯MeU1-70Ks（MeU1-70Ka 和 MeU1-70Kb）蛋白在体内和体外互作。因此，我们的研究为木薯SR蛋白参与调控盐胁迫应答提供了新的理论基础和探索方向。

microRNAs（miRNAs）是广泛存在于哺乳动物中的一种微小、非编码RNA，可以通过靶向吸附调节下游基因的表达，参与多种生物学过程。虽然关于 miRNAs 调控哺乳动物毛色的研究取得了一定的成果，但其调控网络尚不完善，仍需要不断深入研究。前期测序发现，miR-370-5p在白色绵羊皮肤中的表达水平显著高于黑色绵羊，推测其可能参与绵羊皮肤黑色素生成。本研究以绵羊黑色素细胞为研究对象，探究miR-370-5p在绵羊黑色素细胞中的作用。表型检测发现，高表达的miR-370-5p可以显著抑制（P=0.001）酪氨酸酶活性，从而显著降低（P<0.001）黑色素的产生；CCK 8实验检测发现，黑色素细胞转染miR-370-5p后的第4天至第5天，细胞的增殖速率显著降低（P<0.01）。靶基因预测发现，丝裂原活化蛋白激酶8（Mitogen-activated protein kinases, MAP3K8）的3'非翻译区（Untranslated Region, UTR）存在miR-370-5p的靶向结合位点，推测两者可能存在靶向调控关系。双荧光素酶报告载体实验结果显示，miR-370-5p可以靶向吸附MAP3K8-3’UTR。原位杂交实验显示，MAP3K8广泛表达于黑素细胞的细胞质。定量RT-PCR和Western blot结果显示，miR-370-5p显著抑制（P<0.01）MAP3K8的表达。以上结果表明，miR-370-5p可以靶向结合MAP3K8-3’UTR，抑制其表达。siRNA干扰结果显示，黑素细胞中干扰MAP3K8的表达可以显著抑制（P<0.01）细胞增殖，降低（P<0.001）黑色素生成，影响趋势与过表达miR-370-5p一致。靶基因拯救实验结果显示，黑色素细胞中共转染miR-370-5p和MAP3K8-cDNA（含有miR-370-5p靶向结合位点）载体，可以显著上调（P≤0.001）MAP3K8的表达，显著促进细胞增殖（P<0.001）和黑色素产生（P<0.01）。以上结果表明， miR-370-5p通过靶向抑制MAP3K8表达，抑制绵羊黑色素细胞增殖、降低黑色素产量。本研究通过miRNA过表达探明了miR-370-5p对黑色素细胞增殖、酪氨酸酶活性及黑色素产量的影响；通过靶基因干扰、拯救实验解析了miR-370-5p抑制黑色素细胞增殖、酪氨酸酶活性及黑色素生成的分子机制，有助于丰富miRNAs参与毛色形成的调控机制，为后续毛用动物毛色改良提供参考。

建立一种同时鉴别诊断猪瘟病毒（classical swine fever virus, CSFV)、非洲猪瘟病毒（African swine fever virus, ASF）和猪非典型瘟病毒（atypical porcine pestivirus, APPV）的快速、灵敏、有效的检测方法。依据GenBank中登录的CSFV (5¢ UTR)、ASFV (B646L) 和 APPV (5¢ UTR) 的高度保守基因序列分别设计和优化了多对特异性引物和Taq-man探针，以保守区基因序列分别制备三种阳性质粒，用矩阵法优化单重/多重荧光PCR的反应体系和条件，为避免荧光通道的交叉干扰多重荧光PCR扩增，结合所标记的荧光报告基团做颜色补偿试验，构建标准曲线的扩增图和对应的线性方程，并进行特异性、敏感性、重复性、符合性以及临床样本的检测等试验。三种病毒的标准曲线相关系数均达到0.995以上，具有良好的线性关系；与其它常见猪病无交叉扩增反应，具有很好的特异性；多重荧光PCR的最低检测量均为1 copy/mL，具有较高的敏感性；组内和组间的变异系数均小于1%，具有很好的重复性。该方法与CSF的国标(GB/T 27540-2011), ASF的国标 (GB/T 18648-2020)，APPV的发明专利 (CN108611442A)检测样本盘的22个毒株样本符合率为100%。本研究建立的多重荧光PCR检测方法具有快速、高效、通量高、特异性好、灵敏度高等特点，可以对CSFV、ASFV和APPV病毒进行鉴别检测，为动物疫病的流行病学调查、疫情的检测提供一种新型的检测手段。本研究结合荧光PCR仪不同荧光通道设计CSFV、ASFV和APPV探针荧光信号强度较高且干扰较小的FAM、CY5和HEX报告基团，建立多重荧光PCR检测方法，用于同时鉴别诊断3种主要猪病毒的检测方法，在临床诊断中具有重要的应用价值。

之前研究表明活性氧（reactive oxygen species，ROS）在棉铃虫滞育蛹脑中通过调节独特的胰岛素信号通路转导机制来促进滞育。然而，滞育蛹脑中ROS的来源及调控滞育的机制尚不清楚。本研究的结果显示，滞育蛹脑中积累了高水平的线粒体ROS和总ROS，说明线粒体是滞育蛹脑中ROS的主要来源。另外，注射葡萄糖代谢抑制剂2-脱氧-D-葡萄糖可通过提高非滞育蛹脑中线粒体ROS的水平进而延迟蛹的发育。注射代谢物混合物到滞育蛹中可以降低线粒体ROS的水平进而逆转滞育的进程。进一步的研究显示，线粒体ROS可以激活HSP60的表达和活性，进而促进HSP60/Lon复合物的稳定性，从而降解线粒体转录因子A和降低线粒体活性或生成。因此，本研究阐明了ROS通过降低线粒体活性而促进滞育或寿命延长的有益作用。

本研究通过设置不同浓度的脱氢乙酸钠（SD）（0即对照、0.01、0.1和1.0 mmol L^-1），研究SD延长‘巨峰’葡萄货架期的效果。结果表明0.01 mmol L^-1的SD对于延长‘巨峰’葡萄的货架期效果最好。与对照相比，0.01 mmol L^-1 SD处理的‘巨峰’葡萄果实失重率、褐变指数、过氧化氢（H₂O₂）和丙二醛含量（MDA）显著降低，且好果率、果实硬度、总可溶性固形物含量、抗坏血酸含量和超氧化物歧化酶（SOD）活性均显著升高。此外，甲基化敏感扩增多态性（MSAP）检测结果表明，0.01 mmol L^-1 SD处理后，‘巨峰’葡萄的DNA甲基化水平显著高于对照。综上，0.01 mmol L^-1 SD可用于延长‘巨峰’葡萄的货架期。本研究结果还揭示了葡萄贮藏过程中活性氧（ROS）代谢与DNA甲基化水平变化之间的密切联系。

小麦的高产主要通过增施氮肥和增加灌水实现，但过量的氮肥和灌水投入增加了倒伏的风险。本研究的主要目的是明确高产小麦抗倒伏能力对氮肥和灌水的响应以及探索提高小麦抗倒伏性的有效途径。试验于2015-2016和2016-2017生长季在山东农业大学农学实验站进行，供试品种为济麦22，设置3个施氮量和4个灌水处理，主要研究结果如下：随施氮量增加，倒伏指数和倒伏率增加，倒伏风险上升。增加氮肥用量，与倒伏指数呈正相关的株高、基部节间长度和重心高度显著增加，与倒伏指数呈负相关的基部第二节间（茎秆和叶鞘）充实度及其细胞壁组分含量显著降低。适度增加灌水可增加基部第二节间壁厚、茎秆抗折力和叶鞘的充实度，增加了茎秆强度。在本实验条件下，施氮量240 kg hm^-2 并配合在拔节期和开花期各灌水600 m³ hm^-2在获得最高产量的同时茎秆强度最大。结果表明，适宜的株高保证高产所需的足够的生物量，较厚的壁厚、较高的茎秆和叶鞘充实度以及细胞壁组分含量保证了较大的茎秆强度，以上特征可作为创建小麦高产抗倒群体的参考指标。

本研究的目的是利用我们在先前研究中构建的F₁杂交群体的高密度遗传连锁图谱定位与春季再生相关的数量性状位点（quantitative trait loci, QTL）。该群体包含392个子代，且亲本在春季再生性状上表现出明显的差异。在两个地点连续统计了两年的表型数据，并利用IciMapping软件进行QTL定位分析。利用单个环境中表型的平均值和最佳线性无偏预测（Best Linear Unbiased Prediction，BLUP）作为QTL定位的表型，总共鉴定到36个与春季再生性状显著关联的加性QTL。其中，有十个QTL分别解释了超过10％的表型变异（phenotypic variation, PVE），在P1亲本（父本）中有四个，P2亲本（母本）中有六个。在这些加性QTL中共有六个重叠的QTL区间，在P1和P2中分别有两个和四个。在P1中，两个重叠的区间都位于连锁群7D上。在P2中，PVE >10％的四个QTL在连锁群6D上定位到相同区间。此外，在P2中鉴定出六对显著的上位性QTL，而在P1中没有定位到上位性QTL。在四个重叠的QTL（qCP2019-8，qLF2019-5，qLF2020-4和qBLUP-3）所处区间内筛选到一个候选基因，该基因被注释为MAIL1，拟南芥中的同源基因在植株的生长中起重要作用。本研究定位到的QTLs是利用标记辅助选择对紫花苜蓿春季再生性状进行遗传改良的宝贵资源，鉴定的相关基因为深入了解紫花苜蓿春季再生的遗传特性提供依据。

Sucrose synthases (SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development.  A total of 11 SUS genes have been identified in the genome of Malus domestica (MdSUSs), and phylogenetic analysis revealed that the MdSUS genes were divided into three groups, named as SUS I, SUS II and SUS III, respectively.  The SUS I and SUS III groups included four homologs each, whereas the SUS II group contained three homologs.  SUS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution.  After assessing four different tissues, MdSUS1s and MdSUS2.1 showed the highest expression in fruit, whereas MdSUS2.2/2.3 and MdSUS3s exhibit the highest expression in shoot tips.  Most MdSUSs showed decreased expression during fruit development, similar to SUS enzyme activity, but both MdSUS2.1 and MdSUS1.4 displayed opposite expression profiles.  These results suggest that different MdSUS genes might play distinct roles in the sink-source sugar cycle and sugar utilization in apple sink tissues.

The aim of this research was to study the influence of chlorsulfuron residue and cadmium on the enzymatic activity and photosynthetic apparatus of maize (Zea mays L.) plants.  Chlorsulfuron and cadmium at 0.001 and 5.0 mg kg^–1, respectively, were mixed and applied to soil prior to planting.  The levels of chlorsulfuron- and cadmium-induced stress to plants were estimated by growth, chlorophyll content, lipid peroxide content, enzyme activities, and major fluorescence parameters of chlorophyll (revealed by the fluorescence imaging system FluorCam).  Chlorsulfuron negatively affected the chlorophyll content, photochemical efficiency of photosystem II in the dark-adapted state, the maximum efficiency of photosystem II, photochemical quenching coefficient, and steady-state fluorescence decline ratio in the leaves of maize seedlings.  However, cadmium did not produce noticeable changes.  Plants that were exposed to both chlorsulfuron and cadmium showed an obvious increase in the steady-state fluorescence decline ratio.  These results implied that the seedlings possessed more resistance to cadmium than to chlorsulfuron and their resistance to chlorsulfuron toxicity was enhanced by the presence of cadmium.  The results also suggested that chlorophyll fluorescence imaging reveals overall alterations within the leaves but may not reflect small-scale effects on tissues, as numeric values of specific parameters are averages of the data collected from the whole leaf.

Heat stress seriously affects wheat production in many regions of the world.  At present, heat tolerance research remains one of the least understood fields in wheat genetics and breeding and there is a lack of effective methods to quantify heat stress and heat tolerance in different wheat cultivars.  The objective of this study was to use various wheat cultivars to evaluate stress intensity (δ) and a new method for quantification of heat tolerance and compare this technique with three other currently utilized methods.  This new parameter for heat tolerance quantification is referred to as the heat tolerance index (HTI) and is an indicator of both yield potential and yield stability.  Heat treatments were applied in a controlled setting when anthesis had been reached for 80% of the wheat.  The stress intensity evaluation indicated heat shock was the main factor associated with kernel weight reduction while grain yield reduction was mainly associated with chronic high temperature.  The methods evaluation showed that a temperature difference of 5°C from natural temperatures was a suitable heat treatment to compare to the untreated controls.  HTI was positively correlated with yield under heat stress (r=0.8657, δ₂₀₁₀=0.15, in 2009–2010; r=0.8418, δ₂₀₁₁=0.20, in 2010–2011; P<0.01), and negatively correlated with yield reduction rate (r=–0.8344, in 2009–2010; r=–0.7158, in 2010–2011; P<0.01).  The results of this study validated the use of HTI and temperature difference control for quantifying wheat heat tolerance that included the yield potential and the stability of different wheat cultivars under heat stress.  Additionally, 10 wheat cultivars showed high HTI and should be further tested for their heat confirming characteristics for use in wheat heat tolerance breeding.

Ovine bones are the major by-products after slaughtered.  The present study was conducted to extract and characterize acid soluble collagens (ASC) and pepsin soluble collagens (PSC) from ovine bones (Ujumuqin sheep).  Ovine bones collagen were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) as type I collagen.  The results of Fourier transform infrared (FTIR) spectra analysis testified the existence of triple superhelical structure in both ASC and PSC, showing pepsin did not disrupt the triple helical structure of ovine bones collagen.  Glycine, accounting for one-third of total amino acids, was the major amino acid for ovine bones collagen.  Higher imino acid content was responsible for higher thermal denaturation temperature of ovine bones collagen compared to fish collagens.  The isoelectric point of ASC was lower than PSC due to the higher content of acidic amino acids.  Therefore, this study provides the potential reference for collagen extraction and application of ovine bones by-procduct.

Carex rigescens (Franch.) V. Krecz is a wild turfgrass perennial species in the Carex genus that is widely distributed in salinised areas of northern China.  To investigate genome-wide salt-response gene networks in C. rigescens, transcriptome analysis using high-throughput RNA sequencing on C. rigescens exposed to a 0.4% salt treatment (Cr_Salt) was compared to a non-salt control (Cr_Ctrl).  In total, 57 742 546 and 47 063 488 clean reads were obtained from the Cr_Ctrl and Cr_Salt treatments, respectively.  Additionally, 21 954 unigenes were found and annotated using multiple databases.  Among these unigenes, 34 were found to respond to salt stress at a statistically significant level with 6 genes up-regulated and 28 down-regulated.  Specifically, genes encoding an EF-hand domain, ZFP and AP2 were responsive to salt stress, highlighting their roles in future research regarding salt tolerance in C. rigescens and other plants.  According to our quantitative RT-PCR results, the expression pattern of all detected differentially expressed genes were consistent with the RNA-seq results.  Furthermore, we identified 11 643 simple sequence repeats (SSRs) from the unigenes.  A total of 144 amplified successfully in the C. rigescens cultivar Lüping 1, and 69 of them reflected polymorphisms between the two genotypes tested.  This is the first genome-wide transcriptome study of C. rigescens in both salt-responsive gene investigation and SSR marker exploration.  Our results provide further insights into genome annotation, novel gene discovery, molecular breeding and comparative genomics in C. rigescens and related grass species.

Alfalfa (Medicago sativa L.) is an important forage crop and is also a target of many fungal diseases including Fusarium spp.  As of today, very little information is available about molecular mechanisms that contribute to pathogenesis and defense responses in alfalfa against Fusarium spp. and specifically against Fusarium proliferatum, the causal agent of alfalfa root rot.  In this study, we used a proteomic approach to identify inducible proteins in alfalfa during a compatible interaction with F. proliferatum strain YQC-L1.  Samples used for the two-dimensional gel electrophoresis (2-DE) and MALDI-TOF/TOF mass spectrometry were from roots and leaves of alfalfa cultivar AmeriGraze 401+Z and WL656HQ.  Plants were grown in hydroponic conditions and at 4 days post inoculation with YQC-L1.  Our disease symptom assays indicated that AmeriGraze 401+Z  was tolerant to YQC-L1 infection while WL656HQ was highly susceptible.  Analysis of differentially expressed proteins found in the 2-DE was further characterized using the MASCOT MS/MS ion search software and associated databases to identify multiple proteins that might be involved in F. proliferatum resistance.  A total of 66 and 27 differentially expressed proteins were found in the roots and leaves of the plants inoculated with YQC-L1, respectively.  These identified proteins were placed in various categories including defense and stress response related metabolism, photosynthesis and protein synthesis.  Thirteen identified proteins were validated for their expressions by quantitative reverse transcription (qRT)-PCR.  Our results suggested that some of the identified proteins might play important roles in alfalfa resistance against Fusarium spp.  These finding could facilitate further dissections of molecular mechanisms controlling root rot disease in alfalfa and potentially other legume crops.   

   Straw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing and rotary tillage practices are widespread in the region, only few studies have focused on rotation tillage. To determine the effects of maize straw return on the nitrogen (N) efficiency and grain yield of winter wheat (Triticum aestivum L.), we conducted experiments in this region for 3 years. Five treatments were tested: (i) rotary tillage without straw return (RT); (ii) deep plowing tillage without straw return (DT); (iii) rotary tillage with total straw return (RS); (iv) deep plowing tillage with total straw return (DS); (v) rotary tillage of 2 years and deep plowing tillage in the 3rd year with total straw return (TS). Treatments with straw return increased kernels no. ear^–1, thousand-kernel weight (TKW), grain yields, ratio of dry matter accumulation post-anthesis, and nitrogen (N) efficiency whereas reduced the ears no. ha^–1 in the 2011–2012 and 2012–2013 growing seasons. Compared with the rotary tillage, deep plowing tillage significantly increased the grain yield, yield components, total dry matter accumulation, and N efficiency in 2013–2014. RS had significantly higher straw N distribution, soil inorganic nitrogen content, and soil enzymes activities in the 0–10 cm soil layer compared with the DS and TS. However, significantly lower values were observed in the 10–20 and 20–30 cm soil layers. TS obtained approximately equal grain yield as DS, and it also reduced the resource costs. Therefore, we conclude that TS is the most economical method for increasing grain yield and N efficiency of winter wheat in Huang-Huai-Hai Plain.

    A survey of the population densities of rice planthoppers is important for forecasting decisions and efficient control. Traditional manual surveying of rice planthoppers is time-consuming, fatiguing, and subjective. A new three-layer detection method was proposed to detect and identify white-backed planthoppers (WBPHs, Sogatella furcifera (Horváth)) and their developmental stages using image processing. In the first two detection layers, we used an AdaBoost classifier that was trained on a histogram of oriented gradient (HOG) features and a support vector machine (SVM) classifier that was trained on Gabor and Local Binary Pattern (LBP) features to detect WBPHs and remove impurities. We achieved a detection rate of 85.6% and a false detection rate of 10.2%. In the third detection layer, a SVM classifier that was trained on the HOG features was used to identify the different developmental stages of the WBPHs, and we achieved an identification rate of 73.1%, a false identification rate of 23.3%, and a 5.6% false detection rate for the images without WBPHs. The proposed three-layer detection method is feasible and effective for the identification of different developmental stages of planthoppers on rice plants in paddy fields.

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most severe wheat diseases.  Mining powdery mildew resistance genes in wheat cultivars and their appliance in breeding program is a promising way to control this disease.  Genetic analysis revealed that a single dominant resistance gene named PmTm4 originated from Chinese wheat line Tangmai 4 confers resistance to prevailing isolates of B. graminis f. sp. tritici isolate E09.  Detailed comparative genomics analyses helped to develop closely linked markers to PmTm4 and a fine genetic map was constructed using large F₂ population, in which PmTm4 was located into a 0.66-cM genetic interval.  The orthologous subgenome region of PmTm4 in Aegilops tauschii was identified, and two resistance gene analogs (RGA) were characterized from the corresponding sequence scaffolds of Ae. tauschii draft assembly.  The closely linked markers and identified Ae. tauschii orthologs in the mapping interval provide an entry point for chromosome landing and map-based cloning of PmTm4.

Pre-harvest sprouting (PHS) occurs frequently in most of the wheat cultivation area worldwide, which severely reduces yield and end-use quality, resulting in substantial economic loss.  In this study, quantitative trait loci (QTL) for PHS resistance were mapped using an available high-density single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) genetic linkage map developed from a 269 recombinant inbred lines (RILs) population of Yanda 1817×Beinong 6.  Using phenotypic data on two locations (Beijing and Shijiazhuang, China) in two years (2012 and 2013 harvesting seasons), five QTLs, designated as QPhs.cau-3A.1, QPhs.cau-3A.2, QPhs.cau-5B, QPhs.cau-4A, and QPhs.cau-6A, for PHS (GP) were detected by inclusive composite interval mapping (ICIM) (LOD≥2.5).  Two major QTLs, QPhs.cau-3A.2 and QPhs.cau-5B, were mapped on 3AL and 5BS chromosome arms, explaining 6.29–21.65% and 4.36–5.94% of the phenotypic variance, respectively.  Precise mapping and comparative genomic analysis revealed that the TaVp-1A flanking region on 3AL is responsible for QPhs.cau-3A.2.  SNP markers flanking QPhs.cau-3A.2 genomic region were developed and could be used for introgression of PHS tolerance into high yielding wheat varieties through marker-assisted selection (MAS).

Grain size is a major determinant of grain weight and a trait having important impact on grain quality in rice. The objective of this study is to detect QTLs for grain size in rice and identify important QTLs that have not been well characterized before. The QTL mapping was first performed using three recombinant inbred line populations derived from indica rice crosses Teqing/IRBB lines, Zhenshan 97/Milyang 46, Xieqingzao/Milyang 46. Fourteen QTLs for grain length and 10 QTLs for grain width were detected, including seven shared by two populations and 17 found in one population. Three of the seven common QTLs were found to coincide in position with those that have been cloned and the four others remained to be clarified. One of them, qGS10 located in the interval RM6100–RM228 on the long arm of chromosome 10, was validated using F2:3 populations and near isogenic lines derived from residual heterozygotes for the interval RM6100–RM228. The QTL was found to have a considerable effect on grain size and grain weight, and a small effect on grain number. This region was also previously detected for quality traits in rice in a number of studies, providing a good candidate for functional analysis and breeding utilization.

    Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide (H₂S) has been proven to function in physiological responses to various stresses. The present study evaluated the effect of foliar application of wheat seedlings with a H₂S donor, sodium hydrosulfide (NaHS), on the response to acute heat stress. The results showed that pretreatment with NaHS could promote heat tolerance of wheat seedlings in a dose-dependent manner. Again, it was verified that H₂S, rather than other sulfur-containing components or sodion derived from NaHS solution, should contribute to the positive role in promoting wheat seedlings against heat stress. To further study antioxidant mechanisms of NaHS-induced heat tolerance, superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11) activities, and H₂S, hydrogen peroxide (H₂O₂), malonaldehyde (MDA), and soluble sugar contents in wheat seedlings were determined. The results showed that, under heat stress, the activities of SOD, CAT, and APX, H₂S, H₂O₂, MDA, and soluble sugar contents in NaHS-pretreated seedlings and its control all increased. Meanwhile, NaHS-pretreated seedlings showed higher antioxidant enzymes activities and gene expression levels as well as the H₂S and soluble sugar levels, and lower H₂O₂, MDA contents induced by heat stress. While little effect was detected in antioxidant enzymes activities and soluble substances contents in pretreated wheat seedlings compared with its control under normal culture conditions (data not shown). All of our results suggested that exogenous NaHS could alleviate oxidative damage and improve heat tolerance by regulating the antioxidant system in wheat seedlings under heat stress.

    To speed up the degradation of corn stover directly returned to soil at low temperature, the corn stover-degrading microbial consortium GF-20, acclimated to biological decomposition in the frigid region, was successfully constructed under a long-term limiting substrate. To evaluate its potential in accelerating the decomposition of un-pretreated corn stover, the decomposing property, fermentation dynamic and the microbial diversity were analyzed. GF-20 degraded corn stover by 32% after 15-day fermentation at 10°C. Peak activities of filter paperlyase (FPA), β-glucosidases (CB), endoglucanases (Cx), and cellobiohydrolases (C1) were 1.15, 1.67, 1.73, and 1.42 U mL^–1, appearing at the 6th, 3rd, 11th, and 9th d, respectively. The pH averaged at 6.73–8.42, and the optical density (OD) value peaked at 1.87 at the 120 h of the degradation process. Cellulase, hemicellulase and lignin in corn stover were persistently degraded by 44.85, 43.85 and 25.29% at the end of incubation. Result of denaturing gradient gel electrophoresis (DGGE) profiles demonstrated that GF-20 had a stable component structure under switching the temperature and pH. The composition of the GF-20 was also analyzed by constructing bacterial 16S rDNA clone library and fungal 18SrDNA-PCR-DGGE. Twenty-two bacterial clones and four fungal bands were detected and identified dominant bacteria represented by Cellvibrio mixtus subsp., Azospira oryzae, Arcobacter defluyii, and Clostridium populeti and the fungi were mainly identified as related to Trichosporon sp.

    The vacuolar proton pump ATPase (V-H⁺-ATPase), which is a multi-subunit membrane protein complex, plays a major role in the activation of ion and nutrient transport and has been suggested to be involved in several physiological processes, such as cell expansion and salt tolerance. In this study, three genes encoding V-H⁺-ATPase subunits B (ScVHA-B, GenBank: JF826506), C (ScVHA-C, GenBank: JF826507) and H (ScVHA-H, GenBank: JF826508) were isolated from the halophyte Suaeda corniculata. The transcript levels of ScVHA-B, ScVHA-C and ScVHA-H were increased by salt, drought and saline-alkali treatments. V-H⁺-ATPase activity was also examined under salt, drought and saline-alkali stresses. The results showed that V-H⁺-ATPase activity was correlated with salt, drought and saline-alkali stress. Furthermore, V-H⁺-ATPase subunits B, C and H (ScVHA-B, ScVHA-C and ScVHA-H) from S. corniculata were introduced separately into the alfalfa genome. The transgenic alfalfa was verified by Southern and Northern blot analysis. During salt and saline-alkali stresses, transgenic linevacuolar proton pump, salt tolerance, saline-alkali tolerance, alfalfa
s carrying the B, C and H subunits had higher germination rates than the wild type (WT). More free proline, higher superoxide dismutase (SOD) activity and lower malondialdehyde (MDA) levels were detected in the transgenic plants under salt and saline-alkali treatments. Moreover, the ScVHA-B transgenic lines showed greater tolerance to salt and saline-alkali stresses than the WT. These results suggest that overexpression of ScVHA-B, ScVHA-C and ScVHA-H improves tolerance to salt and saline-alkali stresses in transgenic alfalfa.

The solar radiation intensity and duration are continuously decreasing in the major wheat planting area of China. As a consequence, leaf senescence, photosynthesis, grain filling and thus wheat yield shall be affected by light deficiency. Therefore, two winter wheat (Triticum aestivum L.) cultivars, Tainong 18 (a large-spike cultivar) and Ji’nan 17 (a multiple-spike cultivar), were subjected to shading during anthesis and maturity under field condition in 2010–2011 and 2011–2012. Under the slight shading treatment (S1, 88% of full sunshine), leaf senescence was delayed, net photosynthesis rate (Pn) and canopy apparent photosynthesis rate (CAP) were improved, and thus thousand-kernel weight (TKW) and grain yield were higher as compared with the control. However, mid and severe shading (S2 and S3, 67 and 35% of full sunshine, respectively) led to negative effects on these traits substantially. Moreover, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in flag leaf were significantly greater under slight shading than those in other treatments, while the malondialdehyde (MDA) content was less than that under other treatments. In addition, the multiple-spike cultivar is more tolerant to shading than large-spike cultivar. In conclusion, slight shading after anthesis delayed leaf senescence, enhanced photosynthesis and grain filling, and thus resulted in higher grain yield.

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most devastating wheat diseases. Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is a promising source of disease resistance for wheat. A powdery mildew resistance gene conferring resistance to B. graminis f. sp. tritici isolate E09, originating from wild emmer wheat, has been transferred into the hexaploid wheat line WE4 through crossing and backcrossing. Genetic analyses indicated that the powdery mildew resistance was controlled by a single dominant gene, temporarily designated MlWE4. By mean of comparative genomics and bulked segregant analysis, a genetic linkage map of MlWE4 was constructed, and MlWE4 was mapped on the distal region of chromosome arm 5BL. Comparative genetic linkage maps showed that genes MlWE4, Pm36 and Ml3D232 were co-segregated with markers XBD37670 and XBD37680, indicating they are likely the same gene or alleles in the same locus. The co-segregated markers provide a starting point for chromosome landing and map-based cloning of MlWE4, Pm36 and Ml3D232.