水稻幼穗响应盐胁迫的转录组分析

盐胁迫是影响作物生长发育的重要环境因素之一.鉴定水稻耐盐新基因以及揭示其可能的机制并应用于新种质创制和新品种选育,是提高水稻耐盐性的重要途径之一.本研究以实验室自主选育的耐盐性不同的水稻品系58M和58L为材料,用0.6％NaCl处理0、6、24 h后收集水稻的幼穗,并进行转录组测序研究.结果发现,以0 h的幼穗为对照...     

热胁迫下水仙花叶片的转录组分析

为研究水仙响应高温胁迫过程中相关基因的表达及响应热应激的分子机制,本研究以漳州水仙花为材料,使用BGISEQ-500测序技术,对高温（30、35 ℃）处理及正常生长条件（15 ℃）的水仙叶片进行转录组学的测序分析。使用Trinity软件对15（对照）、30、35 ℃（高温胁迫）处理24 h的水仙叶片测序数据进行从头组装,利用BLAST软件进行基因比对注释,通过DEGseq和PossionDis检测差异表达基因,并对差异表达基因进行GO和KEGG富集分析。结果表明：本次水仙花叶片测序共获得112 160条总长度为128 733 815 bp、平均长度为1147 bp的Unigene,其N50以及GC含量分别为1770 bp和42.33%。Nr比对注释匹配度最高的物种为石刁柏,利用KOG数据库进行比对,5560条Unigene序列分布于25个功能区域。差异表达基因GO富集显示与光合系统及膜系统相关的GO term被显著富集,KEGG分析显示次生代谢物的生物合成、苯丙烷类生物合成、代谢途径、光合作用、糖胺聚糖降解、乙醛酸和二羧酸代谢、光合作用-天线蛋白、单萜类生物合成等8条代谢途径在3个比较组中均显著性富集,硫胺素代谢途径是唯一在高温胁迫条件下均显著富集的代谢途径。本研究注释了大量相关基因序列,通过本研究为改善水仙花植物的耐热性及耐热性品种的培育提供了丰富的数据资源和分子基础。     

Comprehensive Characteristics of MicroRNA Expression Profile Conferring to Rhizoctonia solani in Rice

MicroRNAs(miRNAs) are about 22 nucleotides regulatory non-coding RNAs that play versatile roles in reprogramming plant responses to biotic and abiotic stresses. However, it remains unknown whether miRNAs confer the resistance to necrotrophic fungus Rhizoctonia solani in rice. To investigate whether miRNAs regulate the resistance to R. solani, we constructed 12 small RNA libraries from susceptible and resistant rice cultivars treated with water/pathogen at 5 h post inoculation(hpi), 10 hpi and 20 hpi, respectively. By taking the advantage of next-generation sequencing, we totally collected 400–450 known mi RNAs and 450–620 novel miRNAs from the libraries. Expression analysis of mi RNAs demonstrated different patterns for known and novel miRNAs upon R. solani challenge. Thirty-four mi RNA families were identified to be expressed specifically in rice, and most of them were involved in plant disease resistance. A particular Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis result revealed that a great majority of target genes of regulated miRNAs belonged to the pathway of plant-pathogen interaction. Moreover, miR444 b.2, miR531 a, mir1861 i, novel_miR1956 and novel_miR135 conferred response to R. solani infection confirmed by Northern blot. Our global understanding of miRNA profiling revealed that the regulation of mi RNAs may be implicated in the control of rice immunity to R. solani. Analysis of the expression of miRNAs will offer the community with a direction to generate appropriate strategies for controlling rice sheath blight disease.     

花后高温胁迫下匀播春小麦旗叶的转录组分析

为研究不同播种模式下花后高温胁迫对春小麦旗叶转录组的影响,以宁春50号为试验材料,采用人工模拟高温的方法,设条播和匀播两种播种方式,灌水施肥方式均为水肥一体化,对高温处理后的春小麦旗叶分别构建转录组测序文库,采用FPKM法计算基因的相对表达量,并对差异表达基因进行KEGG通路分析。结果表明,相较于常温处理,高温胁迫下条播和匀播滴灌处理分别有199和1 819个基因上调表达,55和1 335个基因下调表达,说明高温胁迫下匀播滴灌处理对春小麦旗叶转录组的表达影响明显。KEGG通路富集分析结果显示,高温胁迫下与条播滴灌处理对比,匀播滴灌处理的春小麦光合作用-天线蛋白通路注释到的差异表达基因最多,有52个,其次为淀粉和蔗糖通路(注释到50个差异表达基因);而常温条件下与条播滴灌处理对比,匀播滴灌处理的春小麦淀粉和蔗糖代谢通路注释到的差异表达基因最多,有49个,其次为光合作用-天线蛋白通路(注释到41个差异表达基因)。因此,高温胁迫下匀播滴灌技术可以更好地改善植物的光合系统,有效缓解高温引起的小麦植株早衰。     

玉米自交系苗期冷胁迫miRNA表达谱研究

以冷敏感自交系B73和耐冷自交系W9816为材料,分析供试材料在冷胁迫条件下的miRNA表达谱。冷处理后,有10种miRNA上调表达,包括miR156、miR166b/c/d、miR171d/e、miR398a/b、miR399e和miR408等;有21个miRNA下调表达,包括miR159a、miR166h、miR167a/b/c/d/h/i、miR319b/d、miR393a/c和miR399a/b/c/h等。对部分miRNA的荧光定量检测与测序结果基本一致。基于生物信息学的预测,差异表达的miRNA共有84个靶基因,GO分析表明,这些靶基因参与了基因转录和能量代谢过程,并响应胁迫刺激。结果表明,冷处理差异表达miRNA及其靶基因在玉米冷胁迫响应中具有重要的生理作用。     

Inheritance of Rice Seed Germination Ability under Salt Stress

A population of recombinant inbred lines(RILs,F2:9),derived from a cross between IR26(Oryza sativa subsp.indica)and Jiucaiqing(Oryza sativa subsp.japonica),was used to identify seed germination ability of rice under 100 mmol/L NaCl for 10 days.Six germination traits including imbibition rate,germination rate,germination index,root length,shoot length and vigor index were investigated.A mixed major gene and polygene inheritance model was applied to conduct genetic analysis for germination ability.Significant...     

低温胁迫对水稻幼苗耐冷性的鉴定

以14个耐冷性不同的水稻品种为材料,经对照(20℃)和低温(10℃)处理后,测定分析幼苗叶片的耐冷指数以及对过氧化物酶同工酶凝胶电泳的分析。结果表明,经低温处理后,各品种差异较明显。低温与对照相比,大部分水稻品种多出1～2酶带。     

干旱胁迫下过表达TaER小麦的转录组及光合特性分析

为探究小麦TaER基因调控蒸腾效率及抗旱性的分子机制,以2个T_3代转TaER基因株系及其野生型为材料,对其正常灌溉和干旱胁迫处理下的灌浆期旗叶进行转录组(RNA-seq)测序,分析其差异表达基因并进行GO和KEGG富集分析,探究其功能及可能参与的调控通路,同时测定光合及蒸腾参数。结果表明,与野生型相比,TaER过表达株系在正常灌溉和干旱胁迫下分别获得1 439和607个共同的差异表达基因;GO富集分析发现,光合作用、脂质和膜脂代谢基因响应干旱胁迫;KEGG富集分析表明,亚油酸和α-亚麻酸代谢中的酯氧合酶、甘油脂代谢中的糖基转移酶基因均上调表达,光合作用相关基因响应干旱胁迫;干旱胁迫下,TaER过表达株系的净光合速率和水分利用效率较高,蒸腾速率较低。综上所述,TaER过表达株系可能是通过调控脂类代谢及光合作用等生物过程,提高光合速率及水分利用效率,从而适应干旱胁迫的。     

Impeded Carbohydrate Metabolism in Rice Plants under Submergence Stress

The detrimental effects of submergence on physiological performances of some rice varieties with special references to carbohydrate metabolisms and their allied enzymes during post-flowering stages have been documented and clarified in the present investigation. It was found that photosynthetic rate and concomitant translocation of sugars into the panicles were both related to the yield. The detrimental effects of the complete submergence were recorded in generation of sucrose, starch, sucrose phosphate synthase and phosphorylase activity in the developing panicles of the plants as compared to those under normal or control (i.e. non-submerged) condition. The accumulation of starch was significantly lower in plants under submergence and that was correlated with ADP-glucose pyrophosphorylase activity. Photosynthetic rate was most affected under submergence in varying days of post-flowering and was also related to the down regulation of Ribulose bisphosphate carboxylase activity. However, under normal or control condition, there recorded a steady maintenance of photosynthetic rate at the post-flowering stages and significantly higher values of Ribulose bisphosphate carboxylase activity. Still, photosynthetic rate of the plants under both control and submerged conditions had hardly any significant correlation with sugar accumulation and other enzymes of carbohydrate metabolism like invertase with grain yield. Finally, plants under submergence suffered significant loss of yield by poor grain filling which was related to impeded carbohydrate metabolism in the tissues. It is evident that loss of yield under submergence is attributed both by lower sink size or sink capacity (number of panicles, in this case) as well as subdued carbohydrate metabolism in plants and its subsequent partitioning into the grains.     

弱光胁迫对不同基因型水稻稻米淀粉RVA谱特征值及直链淀粉含量的影响

以Ⅱ优498、冈优188、冈优527、川香9838、冈优906为材料,研究了弱光胁迫对稻米淀粉RVA谱特征值及直链淀粉含量的影响。结果表明,返青分蘖期和孕穗期遮荫均影响了淀粉RVA谱特征值及直链淀粉含量,孕穗期遮荫影响程度高于返青分蘖期。随着光照强度的减弱,最高黏度、最终黏度、崩解值降低,而消减值增加,直链淀粉含量在弱光下表现为返青分蘖期增加,孕穗期减少的趋势。不同基因型稻米淀粉RVA谱特征值对弱光的反应不同,Ⅱ优498、冈优906经遮荫处理后RVA谱特征值与对照差异不显著,而其余3个品种遮荫处理的RVA谱特征值与对照差异显著。冈优527、冈优188和川香9838的直链淀粉含量对弱光较敏感。综合淀粉RVA谱特征值和直链淀粉含量,Ⅱ优498和冈优906受弱光影响较小,较适应四川弱光寡照环境条件。     

Genetic Control of Germination Ability under Cold Stress in Rice

An F₉ recombinant inbred lines (RIL) population, derived from a cross between IR28 (Oryza sativa L. spp. indica) and Daguandao (O. sativa L. spp. japonica), was used to construct a molecular linkage map and to identify germination ability including the traits of imbibition rate, germination rate, germination index, root length, shoot length and seed vigor at 14°C for 23 d. A composite interval mapping approach was applied to conduct genetic analysis for germination ability. The frequency distributions of the germination ability traits under the cold stress in the RIL population showed continuous segregation, suggesting they were quantitative traits controlled by several genes. A total of seven QTLs were identified on chromosomes 4, 6 and 9, including two for imbibition rate (qIR-6, qIR-9), one for germination rate (qGR-4), two for germination index (qGI-4-1, qGI-4-2) and two for root length (qRL-4-1, qRL-4-2). There were no detected QTLs controlling shoot length and seed vigor. The phenotypic variance explained by a single QTL ranged from 9.1% to 37.0%, and two major QTLs, qIR-6 and qGI-4-2, accounted for over 30% of the phenotypic variance. The expressions of QTLs were developmentally regulated and growth stage-specific. Most of the QTLs observed here were located in the regions similar to the QTLs for rice cold tolerance reported previously, indicating that these QTLs were reliable. However, qRL-4-2 is not reported before.     

高温胁迫下油菜素内酯对水稻幼苗的保护作用

以两个籼稻材料082（耐热型）和协青早B（热敏型）为研究对象探讨高温胁迫下油菜素内酯（BR）对水稻秧苗的保护作用。在苗期进行高温和喷施BR处理,观察高温胁迫下BR对叶绿素、蛋白质和MDA含量、电解质外渗率和保护酶（SOD、POD）活性及其同工酶表达等的影响。结果表明,高温胁迫下,喷施BR能明显提高热敏型材料协青早B的叶片叶绿素和蛋白质含量,增加SOD和POD活性,降低叶片MDA含量和电解质外渗率,但对耐热型材料082的影响相对较小。经BR处理后两个材料的POD同工酶谱带表达均明显增强。在高温胁迫下,BR处理减弱了耐热材料082的4条SOD同工酶谱带的表达,但明显增强了热敏感材料协青早B的A、B两同工酶谱带的表达,表明BR能够增强稻苗内活性氧保护酶系统的活性或诱导其表达,能有效减轻高温对秧苗的伤害。BR处理后稻苗对高温的应答机制,在温敏性不同的材料间存在差异。     

‘赣南早'脐橙在干旱胁迫下的生理及转录组研究

我国脐橙产区的季节性干旱对脐橙产量和品质影响较大。‘赣南早'脐橙作为一个新品种脐橙,目前在我国脐橙产区已大面积推广。为深入了解这个新品种的耐旱性,探究早熟品种‘赣南早'脐橙应对干旱胁迫的调控机制,以‘赣南早'脐橙与‘纽荷尔'脐橙（对照）为材料,测定比较不同干旱胁迫程度下二者光合作用、干旱相关生理指标等差异,并通过RNA-Seq分析比较转录水平差异及抗氧化物酶基因表达调控。结果表明：干旱胁迫下‘赣南早'脐橙净光合速率（P_n）、蒸腾速率（T_r）、气孔导度（G_s）均显著高于‘纽荷尔'脐橙;随着干旱胁迫程度增加,‘赣南早'脐橙叶片较‘纽荷尔'脐橙更舒展,‘赣南早'脐橙相对电导率和丙二醛含量显著低于‘纽荷尔'脐橙,而保护酶超氧化物歧化酶（SOD）和过氧化物歧化酶（POD）活性变化幅度更大;‘赣南早'脐橙和‘纽荷尔'脐橙叶片可溶性糖含量无显著性差异,复水后,‘纽荷尔'脐橙叶片中可溶性糖含量极显著高于‘赣南早'脐橙。转录组测序分析表明,干旱胁迫0、10、20 d时,‘赣南早'脐橙和‘纽荷尔'脐橙间DEGs数量分别为1266、683、658个。GO富集分析显示,在干旱胁迫过程中‘赣南早'脐橙差异基因主要集中在细胞蛋白修饰过程、高分子修饰作用、含磷化合物代谢过程、蛋白修饰过程等通路,而‘纽荷尔'脐橙未见明显富集。KEGG富集分析显示,除了富集于淀粉及蔗糖通路和氨基酸及核苷酸糖代谢途径,‘赣南早'脐橙其他差异基因富集途径与‘纽荷尔'脐橙基本一致。差异基因转录因子分析显示二者在ERF家族、MYB家族、NAC家族、MYB_related家族、WRKY家族、bHLH家族、HB-other家族、HSF家族、B3家族和bZIP家族均有分布,此外,‘赣南早'脐橙特异分布于GRAS家族。根据转录组分析筛选出抗氧化酶相关基因30个,其中上调表达48%,下调表达52%。本研究结果为‘赣南早'响应干旱胁迫的生理变化提供理论依据,并为其抗旱性研究提供分子基础。     

水稻根表铁膜对磷的富集作用及其与水稻磷吸收的关系

采用溶液培养方法,使铁毒耐性不同的两个基因型水稻根表分别形成有铁膜和无铁膜的根系,研究水稻根表铁膜对磷的富集作用及其与水稻磷吸收的关系。不同基因型水稻根表形成的铁膜厚度存在显著差异,对介质中磷的富集能力也有显著差异。根表形成的铁膜越厚,对介质中磷的富集作用也越大,即根表铁膜数量与铁膜对磷的富集量呈显著正相关。铁膜对磷的富集作用是一个化学过程,吸附可在0.5~1.0 h内达到饱和。根表铁膜明显促进水稻对磷的吸收,表明在淹水降低土壤磷有效性时,水稻根表铁膜富集的磷可作为磷库,保证水稻能正常吸收利用磷。     

Protective Roles of Brassinolide on Rice Seedlings under High Temperature Stress

Two indica rice(Oryza sativa L.)materials,Xieqingzao B(sensitive to heat stress)and 082(tolerant to heat stress),were used to study the role of brassinolide(BR)in protection of rice seedlings from heat stress.Young seedlings were subjected to high temperature(38℃/30℃)and sprayed with 0.005 mg/L of BR.Analysis was conducted on the contents of chlorophyll,protein and malondialdehyde(MDA),the leakage of electrolyte,the activities of peroxidase(POD)and superoxide dismutase(SOD)and their isozymes expression levels in leaves.Under the high temperature treatment,application of BR significantly increased the contents of chlorophyll and protein,and the activities of POD and SOD,and reduced the content of MDA and the leakage of electrolyte in the leaves of the heat-sensitive material Xieqingzao B,whereas BR had less effect on those of the heal-tolerant material 082 relatively.The BR treatment enhanced the expression of POD isozymes in the Ieaves of both materials.Under the high temperature stress and BR treatment.the expression of four SOD isozymes reduced in 082,but the expression of two SOD isozymes increased in Xieqingzao B.This suggests that BR plays an important role in protection of rice seedlings from heat stress by enhancing the activities or expression level of protective enzymes in the leaves.The materials with various heat-tolerance might differ in the mechanism of response to heat stress with BR application.     

缺磷胁迫下小麦叶片中磷脂酰甘油含量降低的机理

为了揭示缺磷胁迫下小麦叶片磷脂酰甘油(GP)含量降低的机理,比较分析了小麦不同发育阶段叶片中的PG含量与PG水解酶活性的变化,结果表明,当小麦第一叶刚刚展开时,缺磷处理与对照间PG含量、PG水解酶活性相似;随着叶片逐渐衰老,缺磷叶片中PG含量迅速下降,PG水解酶活性大幅度上升.这一结果表明,缺磷条件下衰老叶片中的PG水解酶活性增强是导致PG含量下降的一个重要原因.另外,通过比较不同叶位叶片刚刚展开时的PG含量与PG水解酶活性,探讨了缺磷条件下PG生物合成受阻对植物体内PG含量的影响.     

孕穗期低温胁迫下不同磷营养对水稻生长发育影响的研究

以不同耐冷性品种吉粳81和长白9为供试材料,进行不同的磷肥施用量处理（施入磷酸二铵分别为0、40、80、120和160 kg/hm2）,对孕穗期低温胁迫下不同磷营养对水稻株高、穗抽出度、穗长、结实率以及单穴产量进行研究。结果表明,低温胁迫会抑制吉粳81和长白9植株生长,导致穗抽出度、穗长、结实率以及产量下降,且对非耐冷...