脂肪沉积是猪最重要的经济性状之一，是猪遗传学研究和育种工作中关注的焦点，其分子调控机制一直被视为猪分子育种重要研究内容。猪的生理结构、器官大小、代谢特征以及脂肪的生理解剖位置与人类更为相似，脂肪易沉积、易解剖和易获取，这使得猪成为研究不同内脏脂肪组织结构与功能的理想选择。长链非编码RNA (long non-coding RNA, lncRNA)是一类具有重要基因调控功能的RNA分子，在多种生物学过程中起着重要作用。随着对lncRNAs研究的深入，人们发现它不仅影响脂肪细胞的合成，还对脂肪过度沉积伴随的肥胖和代谢综合征相关的全身低度炎症具有调节作用。然而，lncRNAs对猪的内脏脂肪组织沉积过程中的调控作用还有待进行进一步研究。因此，本研究以成年雌性巴马猪（2年）为研究对象，分两组进行基础饮食和高脂饮食饲喂后，通过转录组测序技术对两组个体的内脏脂肪（腹膜后脂肪）进行测序。通过分析两组样本的测序数据，筛选了差异表达的lncRNAs，在细胞水平上进行lncRNAs的功能验证。在这里，我们在猪的基因组中发现了一个新的反义转录物，命名为APMAP-AS，由脂肪细胞膜相关蛋白（APMAP）转录而成。与对照组猪相比，APMAP-AS和APMAP在肥胖猪的腹膜后脂肪中高度表达。利用猪骨髓间质干细胞的脂肪分化模型，我们发现APMAP-AS对脂肪形成成分化有积极的调节作用。同时，APMAP-AS促进了脂质代谢并抑制了炎症因子的表达。APMAP-AS有可能与APMAP形成一个RNA-RNA双链，并增加APMAP mRNA的稳定性，从而起到正向调控猪体内APMAP表达的作用。这些结果表明，APMAP-AS通过顺式作用调节APMAP基因的表达，从而影响脂肪沉积、脂质代谢和巴马猪腹膜后脂肪组织的免疫反应。APMAP-AS是一种适应性机制，在肥胖期间促进脂肪组织的健康重塑并维持代谢平衡。这些与脂质合成相关的调控基因的天然反义转录物的发现，可能会进一步加深我们对lncRNAs在驱动适应性脂肪组织重塑和维护代谢健康方面的理解。

蔗糖磷酸合成酶（SPS）是蔗糖合成途径中的限速酶，与磷酸蔗糖磷酸酶（SPP）形成复合体共同催化合成蔗糖，在植物生长发育过程中提供能量并在果实品质提升方面发挥着重要作用。目前，关于苹果SPS基因家族的进化模式及系统性分析的研究较少。本研究从苹果基因组GDDH13 v1.1中鉴定了7个MdSPS基因和4个MdSPP基因，并分析了其基因结构、基因启动子顺式元件、蛋白保守基序、亚细胞定位和生理生化特性。染色体定位和基因组复制分析表明，全基因组复制（WGD）和片段复制是MdSPS基因家族进化的主要方式，MdSPS基因对的Ka/Ks比值分析指出该家族成员在驯化过程中经历了较强的纯化选择。根据系统发育关系将SPS基因划分为3个亚家族，并观察到基因亚家族间古老的基因复制事件和差异显著的进化速率。此外，根据‘金冠’、‘富士’、‘秦冠’和‘蜜脆’四个苹果品种果实发育过程中可溶性糖含量与SPS家族基因表达水平的相关性，鉴定了一个蔗糖积累相关的关键基因MdSPSA2.3。随后通过病毒诱导MdSPSA2.3基因沉默证实了该基因在苹果果实蔗糖积累中的重要功能。本研究为更好地阐明MdSPS基因在苹果果实发育过程中的生物学功能奠定了理论基础。

发掘稳定的数量性状位点（Quantitative trait loci，QTL），并开发其紧密连锁分子标记，是进一步提高小麦产量的重要途径。本研究以中麦578/济麦22重组自交系（Recombinant inbreed lines，RIL）群体262个家系为材料，通过调查两年五个环境千粒重、粒长、粒宽、平均灌浆速率、穗粒数和株高共六个产量相关性状，利用50K SNP芯片基因型分析数据，构建了含有1501个bin标记的遗传连锁图谱，图谱总长度2384.95 cM。利用完备区间作图法，在1D（2）、2A（9）、2B（6）、2D、3A（2）、3B（2）、4A（5）、4D、5B（8）、5D（2）、7A（7）、7B（3）和7D（5）染色体上共定位到53个产量相关QTL，可解释表型变异的2.7–25.5%，其中23个QTL可在3个以上环境定位到，表现稳定；QKl.caas-2A.1、QKl.caas-7D、QKw.caas-7D、QGfr.caas-2B.1、QGfr.caas-4A、QGfr.caas-7A和QPh.caas-2A.1等7个QTL可能是新的位点。定位到的一因多效QTL共形成六个富集区段（R1–R6），分别包含2–6个QTL，位于2A、2B、4A、5B、7A和7D染色体；TaSus2-2B和WAPO-A1分别是位于2B和7A染色体上一因多效QTL的候选基因。7D染色体上的QTL富集区段内含有4个稳定QTL，分别控制千粒重、粒长、粒宽和株高，利用与其紧密连锁的侧翼标记，开发了KASP标记，在自然群体中对其效应进行了验证。本研究结果为小麦的高产育种和中麦578的进一步改良提供了基因和分子标记。

本研究将XANES技术与化学连续浸提法相结合，探究土壤磷的形态和转化。10年的定位试验包括4个处理：100%化肥处理（4CN）、50%猪粪（2CN+2MN）、50%秸秆（2CN+2SN）、50%猪粪配合秸秆替代化肥处理（2CN+2MSN）。与单施化肥相比，有机替代施肥处理提高0−40 cm土层的活性磷含量，增幅为13.7-54.2%，主要组分是MgHPO₄·₃H₂O和CaHPO₄。有机替代施肥处理降低稳定性磷含量，羟基磷灰石（Ca5(PO₄)3OH）是主要组分，其比例随着土壤深度的增加呈增加的趋势。秸秆施用（2CN+2SN和2CN+2MSN处理）提高中等活性磷含量，降低底土（60−100 cm）活性磷的含量。此外，施用秸秆显著降低总磷、可溶性无机磷（DIP）和颗粒磷的淋失量和浓度。可溶性无机磷是磷淋溶流失的主要形态，其与可溶性有机碳和NO₃^--N存在共迁移现象。偏最小二乘路径模型表明，施用秸秆通过增加中等活性磷和降低底土中的活性磷来减少磷的浸出。总体而言，施用秸秆有利于制定可持续的磷管理措施，因为其增加了上层土壤中的活性磷可供植物吸收利用，并减少磷的迁移和淋失。

本研究制备了在骨骼肌组织中特异表达人FST基因的转基因（TG）猪，并进行了表型鉴定。相较于野生型（WT）猪，TG猪骨骼肌重量显著增加(P<0.05)，脂肪沉积显著减少(P<0.05)，代谢状态显著改善(P<0.05)。根据表型变化，利用RNA-seq技术对WT猪和TG猪的骨骼肌（酵解型：背最长肌，氧化型：腰大肌）、白色脂肪（皮下脂肪：背部皮下脂肪，内脏脂肪：腹膜后脂肪）和肝脏共6个组织进行了转录组比较分析。结果表明，PIK3-AKT信号通路、钙离子信号通路及氨基酸代谢通路在FST诱导的骨骼肌肥大中具有重要作用；MYH7基因（决定I型肌纤维）表达量的相对比例在TG猪腰大肌中显著减低，氧化磷酸化和脂肪酸代谢等相关信号通路也在TG猪腰大肌中显著下调；相较于WT猪，TG猪脂肪中的AMPK信号通路、脂代谢相关通路发生显著变化，脂质合成、脂质分解及脂质储存相关基因表达量在皮下脂肪中显著降低，脂质分解相关基因表达量在腹膜后脂肪组织中显著升高。肝脏组织中，TGF-β信号通路相关基因在TG猪中显著下调。这些结果将有助于理解卵泡抑素引起猪表型变化的分子机制，为该候选靶点进一步在分子育种中的应用提供了基础数据。

为明确不同生育时期受灾对棉花恢复生长及产量的影响，本研究于2018-2019年，以鲁棉研24号为供试材料，采用自制工具拍打法从棉花五叶期至吐絮期每隔约15天（同一地块只进行一次损害处理）进行4种程度（0%、30%、60%和90%），共计六次（Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ）的雹灾模拟试验，获取受灾后植株叶面积指数、光合势、干物质积累与分配、产量及吐絮铃空间分布图。研究结果表明，棉花籽棉产量随受灾程度的增加而下降，降幅随受灾时期的推迟而增大，其中在花后（第Ⅳ、Ⅴ、Ⅵ时期），30%、60%和90%受灾程度的产量比0%受灾程度分别减少9%-17%、22%-37%和48%-71%。这是由于棉花受雹灾损害后植株叶面积指数和光合势下降，导致干物质积累量减少，但由于棉花的无限生长习性，花前（第Ⅰ、Ⅱ、Ⅲ时期）受灾后营养器官产生较强的补偿能力进而促使蕾铃发育，仅植株中上部及外围果节的吐絮铃受到影响，造成较少的产量损失；花后受灾后营养器官补偿能力下降、恢复时间短，不足以促进新生铃发育、成熟，导致有效果枝数及各果节吐絮铃数下降，造成较大的产量损失。因此，花前受灾后补救措施应以促蕾铃发育为主，促叶片发育为辅；花后受灾后补救应以保铃、促叶片发育为主。本文从灾后植株叶面积指数、光合势、地上生物量积累与分配等方面研究棉花受雹灾损害后的恢复生长及其对最终产量的影响，该研究结果可为减灾、制定灾后管理方案及产量预测提供理论依据。

本研究基于10年（2009-2019）的定位试验，探究有机肥/秸秆替代化肥模式对土壤磷库、磷酸酶和微生物活性的影响，并明确调节土壤磷转化特征的因素。4个施肥处理包括：100%化肥（4CN），50%的猪粪（2CN+2MN）、秸秆（2CN+2SN）、猪粪配合秸秆替代化肥（2CN+1MN+1SN）。有机替代处理显著提高芹菜和番茄的产量，较单施化肥处理分别提高6.9-13.8%和8.6-18.1%，其中，2CN+1MN+1SN处理的产量最高。有机肥/秸秆替代化肥模式持续10年后，与4CN处理相比，有机替代处理减少总磷和无机磷的累积；显著提高土壤速效磷、有机磷和微生物量磷；促进酸性和碱性磷酸单酯酶、磷酸二酯酶、植酸酶和微生物的活性。此外，偏最小二乘路径模型（PLS-PM）分析表明，土壤的C/P比显著并直接影响磷酸酶活性和微生物群落结构，进而对蔬菜产量和土壤磷库产生积极的影响。偏最小二乘（PLS）回归表明，丛枝菌根真菌对磷酸酶活性有积极影响。该研究结果表明，有机肥部分替代化肥施肥模式能够提高微生物活性，促进土壤磷的转化和有效性。综合考虑土壤磷库，微生物活动和蔬菜产量，猪粪与秸秆配合施用对于开发可持续的磷管理措施更为有效。

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。

2015-2017年连续2个生长季，选择西南地区广泛使用的小麦品种9个进行源库关系分析，其中3个具有不同株型品种进行花后源库操作处理：对照（Ct）、去除旗叶和倒二叶（Lr）和去除一侧小穗（Sr），设置2个施氮水平（N+, 150 kg ha^-1; N-, 60 kg ha^-1），研究两种氮水平下不同品种在冠层水平和单株水平上的源库关系。结果表明，Lr显著降低了3个品种的单粒重，而Sr使单粒重显著增加，表明小麦产量潜力在灌浆期受源限制较大，但源库平衡明显受气候变化和氮素亏缺的影响。籽粒产量与库容量（SICA）、粒数、生物量、SPAD值和叶面积指数呈显著正相关关系，表明源限制程度随着SICA的增加而增加。因此，当SICA增加时，育种家应更加关注源限制的影响，尤其在环境较好的条件下。川麦104属半紧凑型品种，穗子大小适中、上部叶片狭长，在源库平衡关系中表现较好，因为川麦104在Lr后籽粒重降幅小、Sr后籽粒重增幅大；花后干物质积累减少幅度最低、源库操作后灌浆期的光合产物向籽粒转移最多。

我国华北地区萝卜生产中施肥过量导致了较低的养分利用率，并造成了严重的环境问题。养分专家系统（Nutrient Expert, NE）是一个基于科学的、实地的施肥决策支持系统，但对于萝卜养分专家系统田间适用性的评价鲜有报道。本研究旨在从农学、经济和环境效益方面验证萝卜养分专家系统的可行性。于2018年4月-2019年11月在我国华北萝卜主产区共实施了46个田间试验。结果表明，与农民习惯施肥（FP）处理相比，NE处理显著降低了氮、磷和钾肥施用量分别为98 kg N/ha、110 kg P₂O₅/ha和47 kg K₂O/ha；与土壤测试（ST）相比，NE处理显著降低了氮肥和磷肥施用量分别为48 kg P₂O₅/ha和44 kg K₂O/ha，而钾肥施用量无显著性差异。与FP和ST处理相比，NE处理显著提高了萝卜产量分别为2.7和2.6 t/ha，提高了经济效益分别达5951和3071元/ha。就全部试验的平均值而言，与FP和ST处理相比，NE处理显著提高了氮、磷和钾肥的农学效率分别为42.4和31.0、67.4和50.9以及20.3和12.3 kg/kg，显著提高了氮、磷和钾肥的回收利用率分别为11.4和7.0、14.1和7.5以及11.3和6.3个百分点，显著提高了氮、磷和钾肥的偏生产力分别为162.9和96.8、488.0和327.3以及86.9和22.4 kg/kg。此外，与FP处理相比，NE处理显著降低了氮肥和磷肥盈余量分别为105.1 kg N/ha和115.1 kg P₂O₅/ha，降低表观氮素损失达110.8 kg N/ha。综上所述，养分专家系统是一种有效的、可行的推荐施肥方法，可提高我国华北地区萝卜养分利用率和降低环境风险。

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。

生长素（吲哚-3-乙酸，IAA）对调节植物碳水化合物水平和生长具有较大的影响，但是它调节植物体内糖分水平的机制却很少受到关注。本研究中，我们发现外源IAA主要通过调节MdSUSY1、MdFRK2、MdHxK1和MdSDH2的转录水平进而改变茎尖中果糖（Fru）、葡萄糖（Glc）和蔗糖（Suc）浓度。此外，我们利用五年生的“Royal Gala”苹果树进一步验证这些基因在调控库强方面的主要作用。结果表明，MdSUSY1、MdFRK2、MdHxK1/3和MdSDH2可能是库强调节的主要贡献基因。综上所述，这些结果为碳水化合物代谢机制的调控提供了新的视角，这将有助于调节库强和产量。

旨在基于简化基因组测序（Genotyping-by-sequencing，GBS）技术进一步挖掘与大白猪初生重（Birth weight，BW）和达百公斤日龄（Days to 100 kg，D100）性状相关的分子遗传标记，并挖掘同时影响两个性状的多效基因。简化基因组测序数据相较于SNP芯片分型数据能够获得更多的SNP位点信息，能够有效的提高全基因组关联分析的检测力。本研究采集600头大白猪的耳组织样品，提取基因组DNA，并利用GBS测序技术进行测序，测序共获得487.34Gb Clean data，测序结果经质量控制和基因型填充后，利用全基因组关联分析（Genome-wide association study，GWAS）鉴定影响大白猪BW和D100的SNP位点和候选基因，采用GEMMA软件对大白猪BW和D100性状进行全基因组关联分析。结果显示，通过GATK软件初步检测共获得10 445 924个SNPs，经过严格的质量控制后共获得279 787个高质量的SNPs位点，并利用Beagle 5.1软件对该基因型数据进行基因型填充。基于填充后的GBS数据采用全基因组关联分析，在基因组显著水平上鉴定到30个SNPs（P<1.79E-07）与D100相关；在建议显著水平上鉴定到22和2个SNPs（P<3.57E-06）分别与D100和BW相关。通过全基因组关联分析筛选到一个显著的SNPs（SSC12: 46,226,512 bp）同时影响BW和D100，暗示了基因在不同性状间具有的一因多效性。本文依据候选基因的相关分子生物学功能，最终确定了2个基因（NSRP1和DOCK7）作为影响猪生长性状的最有希望的候选基因。本研究结果为猪BW和D100性状提供了重要的遗传变异位点和候选基因，可以为猪生长性状基因组选择提供重要遗传信息。

己糖激酶（HXK）是糖酵解途径中第一个不可逆的催化酶，不仅为植物的生长和发育提供能量，而且还作为响应环境变化的信号分子。但是，HXK基因家族在苹果中的进化模式仍然未知。本研究中，在苹果（Malus×domestica）基因组GDDH13 v1.1中共鉴定出9个HXKs基因，分析了MdHXKs基因的生理和生化特性，外显子-内含子结构，保守基序和顺式元件，亚细胞定位预测结果表明MdHXKs基因主要分布在线粒体、细胞质和细胞核中。基因复制结果显示，全基因组复制（WGD）和片段复制在MdHXKs基因家族扩展中起着至关重要的作用。成对MdHXKs基因的ω值表明，该家族在苹果驯化过程中经历了强烈的纯化选择。此外，对五个亚家族进行了分类，并根据系统进化树分析确定了最近和最老的重复事件，并评估了不同HXKs亚家族之间的进化速率。此外，MdHXKs基因在四个源/库组织和五个苹果果实发育不同阶段的表达模式表明，MdHXKs基因在苹果果实发育和糖积累中起着至关重要的作用。本研究为今后阐明苹果果实发育过程中MdHXKs基因的生物学功能提供了理论基础。

长白猪和大白猪是重要的商品猪品种。在长期的育种过程中，由于两种猪的育种目标不同，经过强烈的人工选择，长白猪和大白猪在猪基因组上有不同的选择信号，这些选择信号反映了它们特定的表型特征。因此本研究旨在通过全基因组选择信号扫描检测长白猪和大白猪之间的选择痕迹差异，从而为长白猪和大白猪的育种历史提供基础数据支持。在本研究中我们使用了Z转换的FST（Z(FST)）和Z转换的杂合度（ZHp）两种方法对长白猪和大白猪进行全基因组扫描。在扫描过程中我们使用滑动窗口（40-kb窗口和20-kb步长）来检验FST值和杂合度，然后对FST值和杂合度进行Z转换，当滑动窗口的Z(FST)>5或ZHp<-2.8时，我们将该窗口确定为显著窗口，然后基于该窗口的基因组范围搜索候选基因。我们使用Z(FST)的方法找到了17个显著窗口，基于这些窗口找到15个注释元件，其中包括13个基因，比如UGP2基因, RAB3C基因和TLL1基因；我们使用ZHp的方法鉴别了363个显著窗口，基于这些窗口找到208个注释元件，其中包括140个基因，比如PPP3CA基因，PTPN13基因和MAPK10基因。功能分析和相关研究结果表明，大部分候选基因与基础代谢、抗病、细胞过程和生化信号有关，有几个与机体形态和器官有关。研究结果表明由于长期的人工选择，长白猪和大白猪在猪基因组上有明显不同的选择足迹。本研究基于全基因组重测序数据对长白猪和大白猪进行全基因组选择信号扫描，与其他研究相比，我们鉴别出了两个品种特定的差异基因组区域和候选基因，这些结果可以帮助研究者更好的了解人工选择对长白猪和大白猪的选择作用以及为这两个品种的现代育种提供新的方向。

Soil alkalinity is a major factor that restricts the growth of apple roots. To analyze the response of apple roots to alkali stress, the root structure and endogenous hormones of two apple rootstocks, Malus prunifolia (alkali-tolerant) and Malus hupehensis (alkali-sensitive), were compared. To understand alkali tolerance of M. prunifolia at the molecular level, transcriptome analysis was performed. When plants were cultured in alkaline conditions for 15 d, the root growth of M. hupehensis with weak alkali tolerance decreased significantly. Analysis of endogenous hormone levels showed that the concentrations of indole-3-acetic acid (IAA) and zeatin riboside (ZR) in M. hupehensis under alkali stress were lower than those in the control. However, the trend for IAA and ZR in M. prunifolia was the opposite. The concentration of abscisic acid (ABA) in the roots of the two apple rootstocks under alkali stress increased, but the concentration of ABA in the roots of M. prunifolia was higher than that in M. hupehensis. The expression of IAA-related genes ARF5, GH3.6, SAUR36, and SAUR32 and the Cytokinin (CTK)-related gene IPT5 in M. prunifolia was higher than those in the control, but the expression of these genes in M. hupehensis was lower than those in the control. The expression of ABA-related genes CIPK1 and AHK1 increased in the two apple rootstocks under alkali stress, but the expression of CIPK1 and AHK1 in M. prunifolia was higher than in M. hupehensis. These results demonstrated that under alkali stress, the increase of IAA, ZR, and ABA in roots and the increase of the expression of related genes promoted the growth of roots and improved the alkali tolerance of apple rootstocks.

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 NAC (NAM, ATAF1/2 and CUC2) transcription factor family plays a key role in plant development and responses to abiotic stress.  GmNAC15 (Glyma15g40510.1), a member of the NAC transcription factor family in soybean, was functionally characterized, especially with regard to its role in salt tolerance.  In the present study, qRT-PCR (quantitative reverse transcription PCR) analysis indicated that GmNAC15 was induced by salt, drought, low temperature stress, and ABA treatment in roots and leaves.  GmNAC15 overexpression in soybean (Glycine max) hairy roots enhanced salt tolerance.  Transgenic hairy roots improved the survival of wild leaves; however, overexpression of GmNAC15 in hairy root couldn’t influnce the expression level of GmNAC15 in leaf.  GmNAC15 regulates the expression levels of genes responsive to salt stress.  Altogether, these results provide experimental evidence of the positive effect of GmNAC15 on salt tolerance in soybean and the potential application of genetic manipulation to enhance the salt tolerance of important crops. 

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.   

DNA methyltransferases (Dnmts) comprise a family of proteins which involved in the establishment and maintenance of DNA methylation patterns.  In pig, the molecular characterization and tissue expression profile of Dnmt gene family are not clear.  To solve this problem, reverse transcriptase PCR and rapid amplification of cDNA ends were used to clone the sequences of the porcine Dnmt2 and Dnmt3b genes.  Furthermore, the mRNA expression profiles of Dnmt1, Dnmt2, Dnmt3a and Dnmt3b genes from 54 adult tissues and 2 entire fetuses of Rongchang pig were analyzed by quantitative real-time PCR (qRT-PCR).  As a result, the lengths of porcine Dnmt2 and Dnmt3b gene cDNAs were 1 227 and 2 559 bp with cytosine-C5 specific DNA methylase domain, respectively.  The four Dnmt genes were highly expressed in longissimus dorsi muscle (P<0.01).  Dnmt1 is highly expressed in heart (P<0.01) and Dnmt 2 shows its preference in liver and seminal vesicle tissue (P<0.01).  Dnmt3a and Dnmt3b are highly expressed in the two fetus stages (P<0.01).  All these results suggested that each gene has its specific expression profile, and deeper study is required to dig more details between the methylation level and Dnmt family mRNA expressions in different tissues.

We have had little understanding on the effects of different types and quantities of biochar amendment on soil N transformation process and the microbial properties. In this study, various biochars were produced from straw residues and wood chips, and then added separately to a paddy soil at rates of 0.5, 1 and 2% (w/w). The effects of biochar application on soil net N mineralization and nitrification processes, chemical and microbial properties were examined in the laboratory experiment. After 135 d of incubation, addition of straw biochars increased soil pH to larger extent than wood biochars. The biochar-amended soils had 37.7, 7.3 and 227.6% more soil organic carbon (SOC), available P and K contents, respectively, than the control soil. The rates of net N mineralization and nitrification increased significantly as biochars quantity rose, and straw biochars had greater effect on N transformation rate than wood biochars. Soil microbial biomass carbon increased by 14.8, 45.5 and 62.5% relative to the control when 0.5, 1 and 2% biochars (both straw- and wood-derived biochars), respectively, were added. Moreover, biochars amendments significantly enhanced the concentrations of phospholipid fatty acids (PLFAs), as the general bacteria abundance increased by 161.0% on average. Multivariate analysis suggested that the three rice straw biochar (RB) application levels induced different changes in soil microbial community structure, but there was no significant difference between RB and masson pine biochar (MB) until the application rate reached 2%. Our results showed that biochars amendment can increase soil nutrient content, affect the N transformation process, and alter soil microbial properties, all of which are biochar type and quantity dependent. Therefore, addition of biochars to soil may be an appropriate way to disposal waste and improve soil quality, while the biochar type and addition rate should be taken into consideration before its large-scale application in agro-ecosystem.

Water erosion is the major reason for the loss of soil organic carbon in the Northeast China, which leads to the soil quality deterioration and adjacent water pollution. In this study, the effect of extraction temperature, pH value, and salt on the water extractable organic matter (WEOM) was determined by means of the UV absorbance, fluorescence excitationemission matrix, and derived fluorescence indexes. In general, the carbon content and aromaticity of WEOM increased with the increasing of extraction temperature, with the exception that there was no significant difference in the amount at 0 and 20°C. More fluorophores, especially microbially-derived organic matter were extracted at high temperature. The pH values of extractant, including 5, 7, and 10, showed no effect on the carbon amount of WEOM, whereas the aromaticity and microbially-derived component gradually increased with the increasing of pH values. The fluorescence intensity of humic acid-like fluorophore was stronger in neutral and alkali condition than that in acidic condition. The addition of 10 mmol L-1 CaCl2 significantly decreased the carbon amount of recovered WEOM. Moreover, it significantly decreased the aromaticity of WEOM and the quantity of fulvic acid-like and humic acid-like fluorophores, whereas increased the percentage of tyrosine-like and tryptophan-like fluorophores in the total fluorophores and the amount of microbially-derived organic matter. Generally, 10 mmol L-1 KCl showed the same influence trend, but with low influence degree.

Studies have demonstrated that regulation of GDNF on male germline stem cells (mGSCs) mainly through Ras/Erk1/2, Src family kinase and PI3K/Akt signaling pathways, but the signaling pathways GDNF-mediated are different when the species and cell lines varied. Whether GDNF regulates self-renewal of mGSCs isolated from livestock has not been reported. Here, we purified mGSCs from dairy goat testis using mixed enzymes and fibronectin. Immunofluoresce staining revealed the cultured dairy mGSCs expressed Vasa, Nanos2, Ngn3, Tert, Dazl, Lin28, Oct4, CD49f, Stra8 and GFRa1, reflecting that these cells were mGSCs phenotype. Then we cultured these dairy goat mGSCs in different concentrations of GDNF (0, 5, 10, or 20 ng mL-1) to optimize the best concentration of GDNF to sustain the dairy goat mGSCs self-renewal, after that the inhibitor of PI3K (LY294002, 10 μmol L-1) was added to the medium which contains the optimal concentration of GDNF we obtained by experiments. The mGSCs cultured in different media were compared through the population doubling time (PDT), capacity of cell proliferation evaluated by PCNA and BrdU immunofluorescence staining, RT-PCR, QRT-PCR, Western blotting and flow cytometry. Results showed that 10 ng mL-1 was the optimal concentration of GDNF to maintain goat mGSCs self-renewal and GDNF up-regulates c-Myc transcription via the PI3K/Akt pathway to promote goat mGSCs proliferation. This study provides us an efficient model to study the mechanism in mGSCs proliferation and differentiation in goat, and has important implications in unveiling signaling pathways in livestock GSCs.

Microsporidia are highly specialized obligate intracellular parasites that can infect a wide variety of animals ranging from protists to mammals. The classical concept of the parasite invasion into a host cell involves its polar tube acting as a needle-syringe system. However, recent studies show microsporidian spores can also gain access to host cells by phagocytosis. The present study investigated the phagocytic uptake process of causative agent of the pebrine disease, Nosema bombycis, in several insect cell lines. We observed KOH-treated spores and cold-storaged spores can be easily uptaken by all the studied cell types 4 h post inoculation. In contrast, large numbers of freshly recovered spores remained in the culture medium. To further investigate the intracellular fates of KOH-treated spores and cold-storaged spores, electron and fluorescence microscopy were performed. No intracellular germination or subsequent parasite development were observed. Intracellular spores can be detected in host cells by polyclonal antibody 7 d post inoculation, suggesting phagocytized N. bombycis could not be digested by these non-professional phagocytes. Our results suggest that, phagocytic uptake of N. bombycis spores might represent a defense mechanism of the host cells and the intact spore wall barrier enable freshly recovered spores to keep resistance to this mechanism.

Cuscuta campestris, a dodder, can parasitize and suppress a scrambling herbaceous to semi-woody perennial vine, Mikania micrantha, one of the most destructive weeds in the world. To assess the effects of the mixed residue of C. campestris and M. micrantha on the subsequent plant community, we conducted a one-year experiment on the germination and seedling growth of subsequent plant community after the application of C. campestris. Seven treatments of varying proportions of C. campestris and M. micrantha residue on 21 subject trees and shrubs, which were commonly found in South China, resulted in a germination rate of 35.3% for all 8715 seeds from 18 species, ranging from 5.7 to 81.9%; the remaining 3 species failed to germinate. ANOVA analysis showed that the residue did not affect the germination, growth, or mortality of the trees and shrubs. The germinated C. campestris seeds from the residue coiled the seedlings of most of the species, but less than 4% host death caused by C. campestris. In addition, the residue did not affect the germination of the herbaceous seedlings originating from the loam, and the similarity coefficients of the germinated seedlings between the treatments were very high. These results suggested that the residue had no negative impact on the germination and early seedling stages of the tree, shrub and grass species of the subsequent plant community. The use of C. campestris residue had a positive effect on the growth of M. micrantha, but it did not change the trend of M. micrantha being suppressed because re-parasitization occurred soon after the growth restarted. No negative effect was detected on the other species as a result of the parasitization of C. campestris or by the use of the mixed residue. This suggests that C. campestris is likely to be an effective and promising ecologically safe native herbaceous agent for controlling M. micrantha.

The H19 gene, which is imprinted with preferential expression from the maternal allele, was one of the first identified imprinting genes in mammals. Recent studies revealed that correct imprinting of the H19 gene plays a vital role in human spermatogenesis. To investigate whether imprinting defects were associated with the hybrid sterility of male cattle-yak, the methylation patterns of the H19 imprinting control region (ICR) and H19 mRNA expression in the testes of cattle-yak, yak, and cattle were examined. The results showed that the 3rd CCCTC-binding factor (CTCF) site of the H19 ICR was significantly hypomethylated in the testes of cattle-yak compared with yak or cattle. As expected, H19 was expressed at a significantly higher level in cattle-yak than in yak or cattle. These results suggest that imprinting defects of the CTCFbinding site in the H19 ICR were possibly associated with disturbed spermatogenesis of male cattle-yak. Thus, we propose that disorders in H19 imprinting, resulting in an increased H19 mRNA expression, might contribute to the sterility of F1 male hybrids between cattle and yak.