ACC处理对不同基因型玉米幼苗响应氮素供给的调控效应

乙烯对玉米生长发育与形态建成具有重要调控作用,但乙烯对玉米氮素吸收与积累调控效应缺乏深入研究,局限了乙烯在玉米丰产高效栽培中的应用。本研究以郑单958、瑞福尔1号和德美亚3号3个玉米品种为试验材料,比较研究不同基因型玉米植株对氮素供给的响应差异,结合外源添加乙烯合成前体1-氨基环丙烷-1-羧酸(1-aminocyclopropane-1-carboxylicacid,ACC),分析乙烯对不同基因型玉米氮素吸收的调控效应。研究结果表明,在低氮条件下,氮素敏感型品种(德美亚3号和瑞福尔1号)比郑单958叶片缺氮表型明显,对ACC处理敏感,而且ACC处理抑制玉米植株地上和地下部的生长和干物质积累;ACC处理抑制了低氮下叶片叶绿素合成,降低叶片可溶性蛋白积累,促进玉米叶片早衰,其中ACC处理郑单958叶片叶绿素和可溶性蛋白含量均显著高于德美亚3号和瑞福尔1号;进一步研究发现,低氮处理抑制乙烯合成关键酶基因ZmACS7和ZmACO15的表达,降低乙烯含量,ACC处理促进低氮条件下ZmACS7和ZmACO15基因的表达,提高乙烯含量;低氮处理抑制玉米根系中ZmNRT2.1表达,但ACC处理促进低氮下玉米根系中ZmNRT2.1表达,其中郑单958根中ZmNRT2.1表达在低氮条件下显著高于德美亚3号和瑞福尔1号。研究结果表明乙烯通过调控玉米植株乙烯合成关键酶基因和ZmNRT2.1表达,调节了氮素吸收与分配,影响了植株生长,其中氮素敏感性品种比持绿型品种对乙烯更为敏感。     

两个低谷蛋白基因插入缺失标记的设计与验证

低谷蛋白稻米是肾脏病人极有效的食疗辅助品,培育低谷蛋白功能性水稻品种具有重大意义。低谷蛋白基因Lgc1作为培育低谷蛋白功能性水稻品种的优质资源,受到了育种家的青睐。为提高低谷蛋白基因Lgc1分子标记辅助选择的准确性,我们根据其突变体在两个谷蛋白基因GluB4和GluB5间的碱基缺失,设计出了Lgc1基因的插入缺失标记InDel-Lgc1-A和InDel-Lgc1-B。利用InDel标记对W3660(Lgc1低谷蛋白品种)/南粳46(谷蛋白正常品种)的F2分离群体和13份水稻品种进行检测验证。依据其PCR扩增产物的电泳带型,可准确地区分出低谷蛋白纯合基因、谷蛋白正常纯合基因和杂合基因型3种带型,且3种带型与其植株或品种相应的蛋白性状表现完全一致,表明这两对InDel标记可用于Lgc1低谷蛋白基因资源的鉴定以及分子辅助育种。     

1-MCP处理对贮前预熟南果梨货架期间果实衰老的影响

以南果梨为试材,研究1-MCP处理对贮后14d货架期的不同预熟度南果梨衰老指标的影响。结果表明:1-MCP处理显著地抑制了果实总酚含量的降低幅度及PPO、POD活性的升高,延缓果实中MDA含量和相对膜透性的增加,推迟果实的衰老进程,且未出现果皮褐变现象。结果还发现,1-MCP处理对贮前预熟5d果实防褐保鲜效果较好。     

鸡传染性支气管炎病毒地方分离株S1、N和M基因的克隆与表达

摘要：将IBVSX16株的S1、N和M基因克隆入真核表达载体pVAX1,构建IBV真核表达载体pVAX1-16S1、pVAX1-16N和pVAX1-16M。体外转染BHK-21细胞,用间接ELISA检测到目的蛋白表达,用构建的3个表达载体免疫小鼠,从小鼠血清中检测到了抗IBV抗体,初步证实用IBVS1、N和M基因作为核酸疫苗免疫动物,可以激活机体免疫应答。     

不同种类绿茶提取物抗氧化活性研究

测定了三种绿茶的总多酚、黄酮和花青素含量,利用亚铁离子螯合能力、DPPH清除能力和铁还原力法对三种绿茶提取物的抗氧化活性进行分析,结果表明绿茶中以黄山毛峰的总酚含量最高。黄酮含量基没有显著性差异。花青素的含量由大到小依次是信阳毛尖、黄山毛峰和营州芽峰。亚铁离子螯合能力,黄山毛峰>信阳毛尖>营州芽峰。在稀释倍数为2时,黄山毛峰的亚铁离子螯合能力分别是信阳毛尖和营州芽峰的1.32倍和1.38倍。在0.25-1mgDW/mL的浓度下,黄山毛峰的对DPPH的清除能力要显著高于信阳毛尖和营州芽峰,而信阳毛尖和营州芽峰之间无显著性差异。在稀释倍数为2时,黄山毛峰的铁还原力分别是信阳毛尖和营州芽峰的1.35和1.4倍。     

干旱胁迫对盆栽“川丹参1号”生理指标及主要活性成分含量的影响

采用聚乙二醇（PEG-6000）对盆栽“川丹参1号”（CDS-1）模拟长期干旱胁迫,研究干旱胁迫对其生长情况、生理指标及主要活性成分积累的影响。结果表明,干旱胁迫显著降低CDS-1叶片中叶绿素含量,可溶性蛋白、可溶性糖和脯氨酸含量随干旱程度增加呈上升趋势,干旱胁迫下丙二醛含量显著增加,抗氧化酶（SOD、POD和CAT）活性随干旱胁迫程度增加而增加。活性成分分析表明,干旱胁迫后CDS-1根中酚酸和丹参酮类含量均有所上升,迷迭香酸和丹酚酸A含量在PEG-6000浓度为150g/L时最高,分别为CK的145%和175%,丹参酮类含量在PEG-6000浓度为50g/L时最高,增幅超60%。CDS-1在干旱胁迫下表现出适应性变化,轻度和中度干旱胁迫（PEG-6000浓度为50~100g/L）有利于CDS-1中酚酸和丹参酮类活性成分的积累,在实际生产中可通过科学控水保证和提高丹参药材的品质。     

大豆KTI1基因表达方式分析及其启动子预测

为明确大豆胰蛋白酶抑制剂基因(KTI1)在不同逆境、ABA条件下及大豆不同组织中的表达方式,本研究采用实时荧光定量PCR技术检测,结果表明KTI1基因受低温、盐、干旱和ABA诱导,分别在处理10、5、24和lh时获得诱导最高值,相对表达量分别是未处理的288.65,274.35,136.04和56.48倍;KTI1基因...     

1-Methylcyclopropene (1-MCP)-induced protein expression associated with changes in Tsai Tai (Brassica chinensis) leaves during low temperature storage

Leaf yellowing is an early symptom of senescence and greatly affects the commercial value of leafy vegetable products. The ethylene action inhibitor 1-methylcyclopropene (1-MCP) has been widely studied regarding its effects on senescence, but little is known on how it influences the protein expression profile of leafy vegetables in storage. In this study, by using a proteomic approach, changes in proteomic profile induced by 1-MCP in Tsai Tai (Brassica chinensis) leaves during storage under low but non-freezing temperature were investigated. Compared with the control, 1-MCP treatment inhibited leaf etiolation and reduced weight loss of Tsai Tai stored at 1 °C, indicating that it delayed senescence. Two dimensional electrophoresis revealed 16 differentially accumulated protein spots, 12 of which were successfully identified by mass spectrometry. A comparison between the control and the 1-MCP-treated Tsai Tai showed that 1-MCP enhanced levels of four proteins involved in photosynthesis, i.e. photosystem II protein, oxygen-evolving enhancer protein 2, chloroplast ribulose 1,5-bisphosphate carboxylase/oxygenase activase and high molecular weight RuBisCO, inhibited malate dehydrogenase, a key enzyme involved in the tricarboxylic acid cycle, downregulated gibberellin 2-beta-dioxygenase expression, a key enzyme involved in biosynthesis of active gibberellins, and suppressed glutathione s-transferase, an important scavenger for reactive oxygen species. These results imply that 1-MCP could maintain leaf capacity for carbon assimilation, inhibit the tricarboxylic acid cycle, induce biosynthesis of GAs and reduce levels of reactive oxygen species, which together may have contributed to inhibition of leaf yellowing and delay of senescence.     

Cultivar differences in gaseous 1-methylcyclopropene accumulation in whole and fresh-cut apple fruit

A number of studies have shown that responses of apple fruit to 1-methylcyclopropene (1-MCP) vary considerably among cultivars. This study was designed to determine if cultivars show differences in accumulation of gaseous 1-MCP. Apple fruit were placed in 1.76 L jars that were sealed and injected with 20 μL L⁻¹ 1-MCP. After 12 h, samples of intercellular atmosphere were removed and analyzed for 1-MCP concentration. Accumulation of internal gaseous 1-MCP varied markedly among cultivars, ranging from 0.14 ± 0.06, 0.22 ± 0.03, and 0.77 ± 0.30 in ‘Redcort’, ‘McIntosh’, and ‘Empire’, respectively, to 2.10 ± 0.28, 3.33 ± 0.13, and 6.93 ± 0.35 μL L⁻¹ in ‘Gala’, ‘Cameo’, and ‘Honeycrisp’, respectively. Accumulation of gaseous 1-MCP was reduced an average of 51% in fruit treated with Sta-Fresh 8711 fruit wax. The role of the epidermis in modulating 1-MCP ingress was determined by measuring gaseous 1-MCP accumulation in fresh-cut tissue. Fresh-cut cortical tissue rapidly depleted headspace 1-MCP (>95%) over a 1-h exposure yet accumulated negligible quantities of internal gaseous 1-MCP. By contrast, cortical tissue treated with ascorbic acid or hypotaurine, or aged for several hours prior to exposure to 1-MCP, showed reduced consumption of headspace 1-MCP and high accumulation of internal gaseous 1-MCP. Levels of internal 1-MCP in cortical tissue from the cultivars generally paralleled those for intact fruit, ranging from 0.23 ± 0.07, 0.37 ± 0.18 and 1.09 ± 0.14 μL L⁻¹ in ‘Empire’, ‘McIntosh’ and ‘Redcort’, respectively, to 2.40 ± 0.71, 4.55 ± 0.15, and 6.24 ± 0.85 in Gala’, ‘Cameo’, and ‘Honeycrisp’, respectively. Although commercial fruit wax influences gaseous 1-MCP accumulation, the comparable accumulation patterns in unwaxed whole and fresh-cut apple fruit suggest that epidermal tissue/native waxes alone do not account for cultivar differences.