水杨苷异羟肟酸和茉莉酸甲酯对唐菖蒲试管结球的影响

为探讨水杨苷异羟肟酸(SHAM)和茉莉酸甲酯(MJ)对唐菖蒲试管结球的影响,以'Rose Supreme'的籽球为外植体,研究了不同处理球茎内可溶性蛋白、内源MJ、碳水化合物(蔗糖、淀粉和纤维素)含量、脂氧合酶(LOX-1)、抗氧化酶(SOD、CAT、POD和APX)活性和LOX同工酶变化与试管结球之间的关系。结果表明：与对照相比,SHAM处理使结球时间明显推迟,结球率、球茎鲜样质量和直径降低;可溶性蛋白含量、LOX-1活性和MJ含量显著降低,LOX同工酶谱带变弱,并有2条同工酶带逐渐消失;抗氧化酶活性和碳水化合物含量降低。而MJ处理后上述指标均不同程度上调,0.5mmol·L^-1为测试浓度范围内促进唐菖蒲试管结球的最佳浓度。以上试验结果说明SHAM对唐菖蒲试管结球起抑制作用,而MJ有明显的促进作用,可能通过外施MJ提高了LOX活性及内源MJ含量,调动碳水化合物的积累,增加抗氧化酶的活性,从而对球茎的发生和生长进行调控。     

异源表达唐菖蒲GhOPR3 提高了拟南芥的抗逆性

 通过RT-PCR 与RACE 技术从唐菖蒲（Gladiolus hybridus）品种‘Rose Supreme’球茎中克 隆茉莉酸生物合成途径中的关键酶——12–氧–植物二烯酸还原酶（12-oxo-phytodienoic acid reductase， OPR）基因的1 489 bp 全长cDNA 序列，quantitative RT-PCR 结果表明，GhOPR3 在唐菖蒲叶、花、根、 匍匐茎、新球茎和籽球中都表达，其中在籽球和匍匐茎中相对表达量较高；0.1 ~ 0.5 mmol · L-1 的茉莉酸 甲酯（Methyl jasmonate，MJ）处理后，提高了GhOPR3 在球茎中的表达量和内源MJ 含量；采用农杆菌 介导侵染拟南芥花粉，进行GhOPR3 基因的过表达分析，过表达拟南芥株系较野生型提高了耐盐性和抗 旱性；提高了机械损伤后相关基因的表达水平和内源MJ 含量。     

玉米秸秆型基质对唐菖蒲子球生理生化指标的影响

以唐菖蒲栽培品种"粉友谊"为试材,研究不同配比的玉米秸秆型基质对唐菖蒲种球在生长发育过程中可溶性糖、可溶性蛋白质、淀粉、蔗糖含量及地下鲜重的影响。结果表明:腐熟玉米秸秆∶蛭石=6∶4的处理最适合唐菖蒲子球的膨大。     

NAA和6-BA在唐菖蒲切花花期提早和新球品质提高上的作用

以唐菖蒲切花品种"超级红"为试材,通过比较2013年及2014年NAA和6-BA不同浓度不同处理时间下叶片宽度、花茎长度、切花采收期、新球鲜重和直径,以及新球蔗糖和淀粉含量,发现与蒸馏水处理下最早的切花采收期相比,0.05mg/L NAA-2h、0.20mg/L NAA-2h、0.05mg/L NAA-4h、0.10mg/L NAA-4h、0.05mg/L 6-BA-2h和0.05mg/L 6-BA-4h均有提早作用;与蒸馏水处理下最大新球鲜重和直径相比,0.05mg/L NAA-4h和0.10mg/L NAA-6h有增大作用;与蒸馏水处理下最大新球蔗糖和淀粉含量相比,3个浓度的NAA处理2h以及0.05mg/L NAA-4h、0.10mg/L NAA-4h对蔗糖含量有增大作用,对淀粉含量有显著增加作用。其中0.05mg/L NAA-4h对叶片宽度、花茎长度、新球鲜重和直径、蔗糖含量均具有提高作用,对新球中淀粉含量有显著提高,并可提早切花采收期。相关分析表明,唐菖蒲2~7叶宽与切花采收期存在显著负相关,相关系数均大于0.76。因此在今后的切花生产中可采用0.05mg/L NAA浸泡种球4h来提早花期、提高新球品质。     

唐菖蒲脂氧合酶基因GhLOX1 对球茎膨大的影响

 以唐菖蒲（Gladiolus hybridus）品种‘Rose Supreme’的球茎为试材，应用Real time RT-PCR技术，分析唐菖蒲球茎在不同浓度的茉莉酸甲酯（methyl jasmonate，MJ）0.1、0.2、0.5 mmol · L^-1和水杨酸异羟肟酸（salicylhydroxamic acid，SHAM）0.5、0.75、1.0 mmol · L^-1处理后脂氧合酶（LOX）基因的的表达水平，并且对LOX活性、内源MJ含量以及球茎鲜样质量与体积进行测定。分析结果表明，GhLOX1表达水平、脂氧合酶活性、内源MJ含量以及球茎的鲜样质量与体积均随着MJ浓度的增加而逐渐提高。与此相反，经过不同浓度的LOX抑制剂SHAM处理后，以上各项指标随着SHAM浓度的增加而逐渐降低。同时，构建35S-GhLOX1过表达载体，利用根癌农杆菌介导法将GhLOX1导入马铃薯栽培品种‘中薯3号’的试管薯薄片中，转基因马铃薯植株块茎的数量、体积和鲜样质量分别得到了不同程度的提高。     

纽荷尔脐橙果肉糖分积累和蔗糖代谢相关酶活性的变化

在纽荷尔脐橙果实不同发育时期测定了果肉中的蔗糖、葡萄糖和果糖含量以及蔗糖代谢相关酶的活性。结果表明:在果实膨大期,可溶性糖积累以蔗糖积累为主,3种可溶性糖含量积累同步上升,果实膨大期结束时是可溶性糖积累的关键时期;在成熟期,3种可溶性糖含量维持膨大期时的最高含量。9月前,果肉蔗糖转化酶(Ivr)活性明显下降,9月后,活性差异不显著;蔗糖磷酸合成酶(SPS)活性在8月最高,然后下降,成熟期又明显上升;蔗糖合成酶(SS)在果实膨大初期和成熟期分解活性高于合成活性,在果实膨大中、后期反之;蔗糖代谢酶类总活性和净活性变化与果实生长发育进程和果肉蔗糖含量的变化特点一致。     

唐菖蒲种球种植期对匍匐茎和子球生长发育的影响

 研究了唐菖蒲栽培品种‘Traderhorn’和‘Advanced Red’露地栽培条件下, 不同种植期匍匐茎和子球的生长发育规律。结果表明: 匍匐茎由新球基部鞘叶叶腋间的腋芽发育而来, 在植株4～6 叶期花序抽出前形成, 新球中部茎节匍匐茎生长最佳; 种植90～110 d 后匍匐茎顶端膨大形成子球。5 月底种植有利于子球数量和质量的增加。     

亚洲百合糖代谢相关基因的表达与代谢分析

以亚洲百合‘蜂鸣’为试材,采用转录组测序、荧光定量PCR技术以及测量种球的表型和生理指标的方法,研究了亚洲百合种球膨大过程中的生理变化及种球膨大前后共11个与种球膨大相关基因的表达量,以期了解亚洲百合糖代谢相关基因及糖代谢途径。结果表明：亚洲百合种球膨大过程中过氧化氢酶(CAT)活性和过氧化物酶(POD)活性显著提高,尤其在根系发育中起重要作用的POD,活性也明显高于CAT;参与蔗糖代谢的可溶性酸性转化酶(SAI)、己糖激酶(HK)、蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SS),负责淀粉合成的结合态淀粉合成酶(GBSS)和可溶性淀粉合成酶(SSS)活性均有显著增长且变化幅度相似。同时发掘到了与百合种球膨大相关酶8个,分别为CAT、POD、GBSS、SSS、SAI、HK、SPS、SS;相关基因11个,分别为LaSPS、LaSS、LaGBSS、LaGBE1、LaUGP、LaAGPase、LaGSK-3β、LaCAT、LaPOD、LaSAI、LaHK基因;相关代谢物4个,α-D-甘露糖1-磷酸、2-异丙基苹果酸、熊果苷和L-丝氨酸。     

抑制脂氧合酶对马铃薯试管块茎形成及膨大的影响

 采用LOX活性抑制剂对马铃薯试管苗进行处理，探讨LOX对块茎发生的影响。结果显示，经抑制剂处理的试管苗，其植株及块茎内的LOX活性以及内源JA含量明显下降，同时块茎形成株率、单株块茎形成数及平均块茎质量等皆明显降低。试验分析显示，匍匐茎中的LOX活性及内源JA含量最高，证明LOX在马铃薯块茎形成及膨大中起着重要作用，其作用途径可能是通过影响JA的生物合成来对块茎的发生及生长进行调控。     

籽用和肉用南瓜品种果实生长发育过程中营养成分的比较分析

以籽用和肉用南瓜品种为试材,分析果实生长发育过程中主要营养成分及其变化规律。结果表明：籽用南瓜品种和肉用南瓜品种的可溶性糖、β-胡萝卜素和干物质含量在果实生长发育过程中呈现相似的变化趋势,随着果实的逐渐成熟,含量逐渐增加,但各营养成分在不同品种中增长速率不同|淀粉、VC、果胶含量在肉用南瓜品种和籽用南瓜品种果实生长发育过程中变化规律不同,其中印度南瓜籽用品种98-2-2和银辉1号淀粉含量在果实发育过程中呈现不断增长的趋势,而美洲南瓜籽用品种金辉2号、0516-2和印度南瓜肉用品种锦元、红栗淀粉含量呈现先升高后下降的变化趋势|不同类型品种VC含量变化趋势不同,其中印度南瓜籽用品种98-2-2、银辉1号和肉用南瓜品种锦元、红栗VC含量的变化趋势相同,均呈现先降后升的变化趋势,美洲南瓜籽用品种金辉2号和0516-2中VC含量变化趋势大致相同,呈现逐渐下降的变化趋势。除了金辉2号果实中果胶含量呈现逐渐增加的趋势外,其余5个品种果实中果胶含量均呈现先升高后下降的变化趋势。     

Effects of lipoxygenase on the corm formation and enlargement in Gladiolus hybridus

To investigate the effects of lipoxygenase (LOX1) on the corm formation and enlargement in Gladiolus hybridus, the field and in vitro researches were conducted to detect the growth and development course, the LOX1 activity, the contents of endogenetic methyl jasmonate (MJ), sucrose, starch and cellulose, as well as LOX isozymes and the expression of its genes in ‘Rose Supreme’ and ‘Advanced Red’. The field investigation showed that the highest activities of LOX1 activity and MJ content in stolons, but not detected in leaves, which were higher in ‘RS’ than in ‘AR’. And the contents of sucrose, starch and cellulose in corm and cormels showed different increase during growth and development of Gladiolus corm. The in vitro investigation showed that the salicylhydroxamic acid (SHAM) treatment caused obviously delayed corm formation, decrease of fresh weight and diameter, and percentage of corm formation; reduced contents of total dissoluble protein, MJ and carbohydrates, and LOX1 activity. Additionally the activity of LOX isozymes became weaker, with two isozyme bands disappeared. In contrast, these physiological and biochemical indexes were increased under MJ treatment. RT-PCR also demonstrated that the expression of LOX1 gene was inhibited under SHAM treatment, induced under MJ treatment. These results suggested that LOX1 might regulate the growth and development of Gladiolus corm through affecting JAs biosynthesis cycles, and then resulting in carbohydrate accumulation. The corm formation could be improved by MJ, but suppressed by SHAM, in which, MJ 0.5 mmol/L was the optimum concentration for promoting corm formation and enlargement in Gladiolus.     

Cloning,characterization and expression analysis of a 9-lipoxygenase gene in Gladiolus hybridus

Plant lipoxygenases (LOXs) is a functionally diverse class of dioxygenases involved in multiple physiological processes such as growth, senescence, and stress-related responses. Previously, based on the analysis of LOX1 activity and corm formation, it was depicted that LOX1 increased jasmonic acid (JA) synthesis and induced enlargement at top of stolon branches, forming cormels in Gladiolus hybridus. Here, LOX gene (GhLOX1) in full length was isolated from developing corms in G. hybridus. Sequence analysis showed that GhLOX1 was a novel LOX1 gene encoding 9-LOX. Transient expression analysis determined GhLOX1 to be a cytoplasm protein. Real time RT-PCR showed that the mRNA level of GhLOX1 gene correlated positively with LOX activity and was highest in cormels. GhLOX1 mRNA level, LOX activity and endogenous methyl jasmonate (MJ) content in corms increased steadily with a MJ gradient from 0.1 mmol/L to 0.5 mmol/L. Conversely, GhLOX1 mRNA level, LOX activity, and endogenous MJ content in corms steadily decreased with the increasing concentration of Salicylhydroxamic acid (SHAM). At the same time, we observed that MJ and SHAM treatments effected both LOX1 mRNA level and LOX activity, leading to promotion and inhibition of corm formation and enlargement, respectively. These data reveal that GhLOX1 is a novel LOX1 gene encoding a cytoplasm 9-LOX protein and its expression would contribute to LOX activity which plays an important role in corm formation and enlargement. In general, GhLOX1 is an ideal candidate for the promotion of corm formation and enlargement by gene manipulation in G. hybridus.     

Effects of chlorocholine chloride and prohexadione-Ca on rhizome growth and lateral bud production in Iris germanica L.

Iris germanica L. is a popular perennial flower worldwide, but its use is limited in China due to an inadequate availability of propagules. To accelerate rhizome growth and lateral bud production using plant growth retardants (PGRs), chlorocholine chloride (CCC; at 1,500 or 3,000 mg l^?1) or prohexadione-Ca (at 700 or 1,500 mg l^?1) were applied to uniform plants of I. germanica. Time-course measurements of changes in morphogenesis, carbohydrate metabolism, total soluble protein (TSP) concentrations, and endogenous phytohormone concentrations in rhizomes were conducted to test the efficacy of CCC or prohexadione-Ca for increasing rhizome growth and lateral bud production. The results showed that both PGRs increased the fresh weights of rhizomes at 2, 4, and 6 weeks after treatment (WAT). Overall, 700 mg l^?1 prohexadione-Ca was most effective at promoting the formation of lateral buds which increased by 183.5% at 12 WAT relative to untreated control plants. Concentrations of sucrose and starch in PGR-treated rhizomes increased at 2, 4, and 6 WAT, while a decline was observed by 12 WAT. TSP concentrations increased during rhizome enlargement, then decreased during lateral bud germination after prohexadione-Ca treatment. In general, concentrations of endogenous phytohormones, such as gibberellins, indole-3-acetic acid, jasmonic acid, and zeatin riboside, decreased significantly in rhizomes at 4 WAT, then increased at 12 WAT. Our study indicated that prohexadione-Ca promoted rhizome growth and the accumulation of sucrose and starch before summer dormancy, then significantly accelerated the production of lateral buds.     

光周期对野生卷丹试管苗鳞茎形成及糖代谢的影响

为了探索光周期对百合试管鳞茎生长发育的诱导效应,寻求试管鳞茎生产的最佳光照参数,以秦巴山区野生卷丹（Lilium lancifolium）试管苗为材料,采用5种不同光周期处理（每天分别暗处理0、8、12、16和24 h）,对试管小鳞茎的发生和膨大、糖含量、淀粉酶活性及其对培养基糖源利用情况进行了测定。研究结果表明：不同光周期处理对试管小苗的形态建成和生长发育影响显著,以16 h暗处理对小鳞茎的发生和膨大最为有利;不同培养时期测定表明,经不同光周期处理的小鳞茎可溶性总糖含量、淀粉含量及淀粉酶活性等呈现一定差异;经60 d培养,短光照和黑暗处理（黑暗12、16和24 h）的小鳞茎淀粉含量比全光照和长光照（0和8 h）处理的高;不同光周期处理下试管鳞茎对培养基蔗糖利用率不同,以短光照（黑暗16 h · d-1）处理的利用效率最高。     

Sucrose synthase dominates carbohydrate metabolism and relative growth rate in growing kiwifruit (Actinidia deliciosa, cv Hayward)

Changes in fruit growth rate, carbohydrate content (glucose, fructose, sucrose and starch) and enzyme activity (sucrose synthase, UDPglucose pyrophosphorylase, fructokinase, glucokinase, sucrose phosphate synthase, ADPglucose pyrophosphorylase and invertases), in the external pericarp of kiwifruit, were measured throughout the growing season. Sucrose synthase showed the highest activity among the sucrose cleaving enzymes during large part of the growing season. The activity of invertases were much lower than that of sucrose synthase until ripening started. Sucrose synthase showed a tight although not linear relationship with the fruit RGR. Furthermore, sucrose synthase showed linear and significant correlations with the activities of both fructokinase and UDPglucose pyrophosphorylase indicating a strong co-regulation of the activities of these three enzymes involved in sucrose cleavage and sink strength, in kiwifruit. Sucrose synthase is suggested to be the dominating enzyme in the cleavage of imported carbon in kiwifruit, in tight coordination with fructokinase and UDPglucose pyrophosphorylase.