氮素和红蓝复合光配比对苋菜幼苗亚硝酸还原酶活性及其基因表达的影响

为了研究苋菜亚硝酸还原酶基因NiR对不同铵硝配比及红蓝复合光配比调控氮代谢的响应,采用RT-PCR结合qRT-PCR的方法从大红苋菜中克隆出一个NiR基因,命名为AtrNiR (GenBank登录号:MT374155),对其相对表达量进行分析,并测定材料NiR酶活性。结果表明:1)苋菜AtrNiR基因含一个1 785bp开放阅读框,编码594个氨基酸;2)生物信息学分析表明,苋菜AtrNiR的蛋白分子式为C_(2937)H_(4692)N_(828)O_(873)S_(28),相对分子质量为66.47ku,AtrNiR为亲水性较强的蛋白;3)系统进化树分析表明,苋菜AtrNiR蛋白序列与甜菜、藜麦和菠菜的NiR蛋白同源性最高,具有类似的功能;4)苋菜幼苗NiR酶含量分析表明,不同铵硝配比处理3d时,硝态氮(NH_4~+-N)与铵态氮(NO_3~--N)摩尔比值为10∶0时NiR酶活性最高,处理6d时,NH_4~+-N与NO_3~--N摩尔比值为3∶7时NiR酶活性最高;不同红蓝光配比处理3d时,红光(Red)∶蓝光(Blue)=2∶8处理下NiR酶活性最高,可见,NO_3~--N和蓝光能提高苋菜幼苗NiR酶活性;5)qRT-PCR分析结果表明,不同铵硝配比处理3d时,NH_4~+-N与NO_3~--N摩尔比值为5∶5时AtrNiR表达量最高;不同红蓝复合光配比处理3d时,R∶B=2∶8处理下AtrNiR表达量最高。研究表明,适宜比例的氮素和红蓝复合光能提高AtrNiR转录水平,改善苋菜幼苗的氮代谢,为优质苋菜工厂化生产提供理论支撑。     

雪樱子低极性成分的GC-MS对比分析

[目的]研究雪樱子低极性成分。[方法]经水蒸气蒸馏或石油醚提取,以GC-MS分离鉴定,并用面积归一化法计算各组分含量。[结果]在雪樱子挥发油中鉴定的28个化合物占总检出峰的80.32%,芳香烃类含量较多,占已鉴定化合物含量的42.82%;雪樱子石油醚提取物中鉴定了21个成分,其含量占总检出峰的71.67%,脂肪烃及酯为主要成分,占总检出峰的57.43%。[结论]通过对雪樱子低极性化合物的GC-MS对比分析,证实该植物有进一步研究的价值。     

Broadening weed control with imazamethabenz combinations

Broad-spectrum weed control by use of imazamethabenz (AC 222 293) in herbicide combinations was investigated in the greenhouse. Imazamethabenz at rates ranging from 0·1 to 0·4 kg a.i./ha effectively controlled wild oats (Avena fatua L.). Additional control of redroot pigweed (Amaranthus retroflexus L.) was achieved when imazamethabenz, plus octoxynol surfactant, was applied in combination with MCPA (amine or ester) or commercial MCPA mixtures (bromoxynil/MCPA and cyanazine/MCPA). Only inclusion of propanil/MCPA in the combination reduced wild-oat control by imazamethabenz at the lower rate (0·1 kg/ha). Control of green foxtail (Setaria viridis (L.) Beauv.) was also obtained by use of fenoxaprop-ethyl in combination with imazamethabenz (plus octoxynol). Three-way mixtures of imazamethabenz (or plus octoxynol), MCPA alone or mixture, and fenoxaprop-ethyl may provide practical control of grass and broad-leaved weeds in the field.     

Seed priming improves germination in saline conditions for Chenopodium quinoa and Amaranthus caudatus

Seed priming has proved to be an effective method in imparting stress tolerance to plants using natural and/or synthetic compounds to treat the seeds before germination. The present work aimed to evaluate the effectiveness of priming treatments in seeds of Chenopodium quinoa and Amaranthus caudatus to improve germination under NaCl. Species‐specific protocols for seed hydropriming and osmopriming were established by germinating seeds under different water potentials and creating seed imbibition curves. Primed seeds were then germinated under different concentrations of NaCl, and the effect of priming was analysed based on the parameters, such as final germination percentage (FGP), germination index (GI) and mean germination time (MGT). Seed hydropriming and osmopriming caused significant improvements in germination velocity and uniformity, reflected in high FGP, high GI and reduced MGT under salinity. C. quinoa had a higher tolerance to salinity than A. caudatus during seed germination. Improved germination in salinity resulted from osmopriming seeds with solutions of low water potential for A. caudatus, while for C. quinoa, this effect was achieved from hydropriming and osmopriming seeds with solutions of high water potential. Primed tolerance to moderate salinity was achieved for A. caudatus, and for both species, the salinity threshold for germination to occur was slightly broadened.     

Characterization of Amaranthus hypochondriacus seed protein fractions,and their antioxidant activity after hydrolysis with lactic acid bacteria

The objective of this work was to obtain and characterize five Amaranthus hypochondriacus seed protein fractions followed by the determination of antioxidant activities of hydrolysates produced with two Lactobacillus species. Molecular weights of polypeptides (SDS-PAGE) in fractions were 14–97 kDa and those identified by LC-MS/MS include agglutinin, trypsin inhibitor, and cystatin. Each fraction was hydrolyzed with Lactobacillus helveticus and Lactobacillus plantarum at their exponential (4 and 8 h) and stationary (14 and 24 h) growth phases. The free amino group content in hydrolysates produced with L. helveticus was up to 5.15% compared to 4.79% in those obtained with L. plantarum. In the antioxidant tests, higher ROO• scavenging activities were obtained for hydrolysates from albumins (1037 ± 80 μM TE/mL) and glutelins (1793 ± 168 μM TE/mL) fractions produced with L. helveticus and L. plantarum, respectively. Scavenging activities of •OH radicals were higher for 11S-G hydrolysates with both Lactobacillus at the stationary phase.     

苋菜试管开花过程中相关microRNA表达的qPCR分析

以苋菜无菌试管苗及其试管开花过程中各阶段培养物为材料,利用qPCR技术进行苋菜试管开花过程相关microRNA的表达分析。研究结果表明:由NormFinder软件计算出最适合的内参基因为ama-miR159a;在苋菜试管开花过程中,ama-miR156c、ama-miR156d、ama-miR156g相对表达量在幼苗期向壮苗期转变过程中呈下降趋势,并在整个发育过程中一直保持较低水平;ama-miR156h、ama-miR157b、ama-miR157c、ama-miR157d、ama-miR3和ama-miR10相对表达量在幼苗期向花芽期转变过程中呈下降趋势,并在花芽期达到最低;ama-miR172d的表达模式与miR156/miR157表达模式相反;苋菜试管苗幼苗期到花芽期形成时ama-miR319b相对表达量呈上升趋势,ama-miR164b在花芽期时相对表达量比较高,花芽期向开花期转变时,其相对表达量降低;ama-miR166a/miR166g表达在苋菜开花过程中始终呈上调表达;ama-miR167b/miR167d和ama-miR4相对表达量先略有升高然后降低,在花芽期降到最低,随后又升高。由此可见,microRNA在调控苋菜试管苗由幼苗期向壮苗期转变、营养生长向生殖生长转变以及花器官的形成等过程中起重要的调控作用。     

刺苋总多酚提取工艺及其抗氧化性研究

为给刺苋的研究与开发提供理论基础,对刺苋总多酚提取工艺条件进行了优化,并考察了其对羟基自由基的清除效果.结果表明:刺苋中总多酚最佳提取工艺条件为:乙醇浓度60%,浸提时间1 h,料液比为1:10,提取温度40℃.在最佳工艺条件下,刺苋中总多酚提取量可达4.89mg/g.从刺苋中提取的总多酚对羟基自由基有很强的清除能力,...     

籽粒苋AhNAD-ME的序列特征与表达

NAD(P)-苹果酸酶催化苹果酸氧化脱羧,产生丙酮酸和CO₂,伴随NAD(P)的还原。在C₄植物中,苹果酸酶参与了C₄光合作用。本研究对克隆的双子叶C₄植物籽粒苋NAD-苹果酸酶基因(AhNAD-ME)编码的氨基酸序列进行了生物信息学分析,结果表明, AhNAD-ME具有苹果酸酶的完整功能域,包括苹果酸N端结构域和苹果酸酶的NAD结合结构域;进化树表明, 该序列属于NAD-ME的α亚基,该亚基定位于线粒体基质中。半定量RT-PCR分析表明,该基因主要在叶片和茎中表达,表达量随光照时间延长而增加。将AhNAD-ME基因重组到原核表达载体pEASY-E1中,电击法转化到大肠杆菌Transette (DE3)菌株中,IPTG诱导其高效表达,表达的融合蛋白的分子量与预期相符,主要以包涵体形式存在。     

A rapid and reliable PCR-restriction fragment length polymorphism (RFLP) marker for the identification of Amaranthus cruentus species

A rapid and reliable PCR-restriction fragment length polymorphism (RFLP) marker was developed to identify the Amaranthus cruentus species by comparing sequences of the starch branching enzyme (SBE) locus among the three cultivated grain amaranths. We determined the partial SBE genomic sequence in 72 accessions collected from diverse locations around the world by direct sequence analysis. Then, we aligned the gene sequences and searched for restriction enzyme cleavage sites specific to each species for use in the PCR-RFLP analysis. The result indicated that MseI would recognize the sequence 5′-T/TAA-3′ in intron 11 from A. cruentus SBE. A restriction analysis of the amplified 278-bp portion of the SBE gene using the MseI restriction enzyme resulted in species-specific RFLP patterns among A. cruentus, Amaranthus caudatus and Amaranthus hypochondriacus. Two different bands, 174-bp and 104-bp, were generated in A. cruentus, while A. caudatus and A. hypochondriacus remained undigested (278-bp). Thus, we propose that the PCR-RFLP analysis of the amaranth SBE gene provides a sensitive, rapid, simple and useful technique for identifying the A. cruentus species among the cultivated grain amaranths.     

进境粮谷中携带苋属检疫性杂草籽风传播扩散距离的预测

风媒传播是外来杂草传播扩散的主要途径之一。我国进口粮谷中经常携带大量苋属杂草种子,这些种子质量轻,在卸货、运输等过程中存在风传播扩散风险。本文以3种重要苋属检疫性杂草,即长芒苋、西部苋和糙果苋种子为材料,通过测定其在可能撒漏高度范围和撒漏点风速范围内的垂直沉降速度和水平扩散距离,预测苋属3种检疫性杂草在装卸及运输过程中风传播扩散范围。结果表明在风速为35 m/s,种子释放高度为35 m时,长芒苋、西部苋和糙果苋3种杂草种子的最远扩散距离分别为57.75 m、111.68 m和114.33 m。