低温胁迫下4种苹果砧木叶片多胺的变化

据《果树学报））2008年第2期报道山东农业大学园艺科学与工程学院／作物生物学国家重点实验室和山东烟台市农业科学研究院的研究人员,以山定子、新疆野苹果、烟台沙果和莱芜难咽等4种苹果砧木为试材,测定了低温胁迫下不同砧木叶片的多胺含量,旨在探讨苹果属植物对低温胁迫的抗性机制,丰富苹果抗寒机理研究。     

外源多胺对低温胁迫下黄瓜幼苗叶绿素荧光参数的影响

应用外源多胺(Polyamines,PAs)腐胺(Putrescine,Put)、亚精胺(Spermidine,Spd)、精胺(Spermine,Spm)处理2叶1心黄瓜幼苗,然后进行8℃/8℃低温及恢复处理,研究Put、Spd、Spm对黄瓜幼苗叶绿素荧光参数的影响。结果表明,在低温胁迫下黄瓜幼苗叶片叶绿素荧光参数最大荧光Fm、最大光化学效率Fv/Fm、PSII(光系统II)潜在活性Fv/F0均下降,初始荧光F0上升,表明PSII受到了伤害,使得PSII原初光能转换效率、PS潜在活性降低;与单纯低温胁迫相比,外源Put、Spd、Spm预处理均可以提高Fm、Fv/Fm、Fv/F0,而使F0降低。这一结果从叶绿素荧光动力学方面说明Put、Spd、Spm对改善黄瓜的耐冷性有一定的作用。     

NaCl胁迫对番茄嫁接苗叶片ABA和多胺含量的影响

 以未经NaCl胁迫的番茄自根苗为对照, 研究了100 mmol·L ^{- 1} NaCl胁迫下番茄嫁接苗的生长、叶片ABA和多胺( PAs) 含量的变化。结果表明, 嫁接苗地上部和根的生物量显著高于对照。嫁接苗ABA含量显著高于对照, 胁迫2 d时比对照增加56.60%。胁迫2 d时嫁接苗多胺总量显著高于对照, 比对照增加14.96% , 腐胺( Put) 含量在胁迫2 d后显著低于对照, 亚精胺( Spd) 含量显著高于对照, 胁迫4～8 d之间两者差异不显著, 胁迫10 d时显著低于对照; 精胺( Spm) 含量显著高于对照, 胁迫10 d时比对照增加102.80%。嫁接苗Put/PAs值显著低于对照, 而( Spd + Spm) /Put值显著高于对照。表明NaCl胁迫下嫁接苗生物量显著高于对照, ABA和多胺含量变化显著, 表现出较强的耐盐特征。     

Ca~(2+)和TFP对NaCl胁迫下黄瓜幼苗多胺含量和抗氧化酶活性的影响

采用营养液栽培方法,研究NaCl胁迫下Ca2+和TFP对"津春2号"黄瓜幼苗叶片中多胺含量和抗氧化酶活性的影响。结果表明:Ca2+预处理能显著提高NaCl胁迫下黄瓜幼苗叶片中亚精胺(Spd)和精胺(Spm)含量,降低腐胺(Put)含量,同时叶片中SOD、POD和CAT活性也相应提高,使得株高相对生长率和干重明显增加;TFP预处理能显著增加Put含量,降低黄瓜幼苗叶片中Spd、Spm含量和(Spd+Spm)/Put比值,加重了NaCl胁迫对黄瓜幼苗生长的抑制。表明TFP阻碍Ca2+.CaM信使功能,从而降低盐胁迫下黄瓜幼苗的抗逆性。     

外源多胺对核桃雌雄花芽分化及叶片内源多胺含量的影响

 以‘辽宁1号’核桃为试材，研究了外源多胺对雌雄花芽分化及叶片内源多胺含量的影响。两年试验结果表明，喷施1×10^-3mol·L^-1和1×10^-4mol·L^-1的腐胺(Put)和亚精胺(Spd)能够显著增加雌花数量，提高雌雄花芽比例。在雌花芽生理分化期，芽内Put、Spd和精胺(Spm)含量升高并达高峰，叶片内Put含量累积并达高峰，而Spd、Spm含量变化不大。1×10^-3mol·L 的Put和Spd处理可提高叶片内源多胺含量，其中内源Put、Spd的含量升高早于内源Spm含量的升高。     

特早熟温州蜜柑‘胁山’果实浮皮过程中内源游离多胺含量的变化

以特早熟温州蜜柑‘胁山’为试材,研究了内源游离多胺含量与果实浮皮的关系。结果表明:‘胁山’果实浮皮过程中内源游离多胺总量减少,腐胺(Put)迅速积累,亚精胺(Spd)和精胺(Spm)含量持续降低,Put/(Spd+Spm)值逐渐增大,证明柑橘果实浮皮可能是果实的过早衰老引起的。外源Spd能有效地降低Put/(Spd+Spm)值,增加内源多胺总量,从而延缓果实衰老,推迟浮皮的发生。     

根际低氧胁迫下外源亚精胺对黄瓜幼苗多胺和抗氧化系统的影响

采用营养液水培,研究了根际低氧胁迫下不同浓度外源亚精胺（Spd）处理对黄瓜幼苗根系和叶片中多胺含量、抗氧化酶活性、O₂^ˉ 产生速率、H₂O₂和MDA含量的影响。结果表明,营养液中添加0.05 mm ol·L^-1 Spd,可促进低氧胁迫下黄瓜幼苗的生长,缓解低氧胁迫的伤害;低氧胁迫下黄瓜幼苗体内抗氧化酶活性和多胺含量之间存在着密切的关系,0.05 mmol·L^-1外源Spd可明显提高植株体内Spd和Spm含量,降低Put含量,提高（Spd + Spm）/ Put比值,增强抗氧化酶活性,降低O₂^ˉ 产生速率、H₂O₂和MDA含量,从而促进植株的生长,提高植株对低氧胁迫的耐性。     

外源多胺对薄皮甜瓜花芽分化及花发育的影响

为了明确外源多胺对薄皮甜瓜花芽分化和花发育的影响,以薄皮甜瓜永甜3号为试材,子叶刚出土时外源喷施腐胺（Put）和亚精胺（Spd）,采用石蜡切片法观察花芽分化和花发育情况,测定花芽和叶片中内源激素及多胺含量。结果表明：外源喷施Put和Spd均提高了甜瓜子蔓第1节位结实花率,促进了花芽分化,使结实花花期提前|喷施高浓度Put和低浓度Spd后,叶片中IAA含量升高、ZT含量降低、ABA含量提前达到峰值|花芽中Spd含量较早达到峰值,精胺（Spm）含量较低,变化不规律。花芽中3种内源多胺的含量远高于叶片中。外源喷施1×10-3 mol•L-1的Put和1×10-4 mol•L-1的Spd效果最好。     

多胺对黄瓜生长和雌花分化的影响

应用6、12、24 mg/L的亚精胺(Spd)、精胺(Spm)、腐胺(Put)溶液喷施2～3叶期黄瓜幼苗,发现Spd、Spm处理均能明显地促进黄瓜植株的营养生长、雌花分化,其中12 mg/L Spd、24 mg/L Spm处理的雌花数和结瓜数分别高于其它处理,其雌花始花节位分别低于其它处理.Put处理的雌花数和结瓜数低于CK,但6、12 mg/L的Put处理明显地促进黄瓜植株的营养生长.     

施肥水平对马铃薯块茎发育过程中PAs、GA3和JAs含量的影响

 为探讨肥力水平对马铃薯块茎发育影响的机理,以‘台湾红皮’（Cardinal）马铃薯为试验材料,采用反相高效液相色谱（HPLC）技术,研究了低、中、高肥力水平对块茎发育过程中多胺（PAs）、赤霉素（GA₃）和茉莉酸（JAs）含量的影响。研究结果表明：（1）腐胺（Put）、精胺（Spm）和亚精胺（Spd）含量在块茎发育过程中呈降低-升高-降低的变化趋势,但对不同肥力水平的响应有差异,中肥力水平下块茎发育中期（播种后60 ~ 68 d）PAs含量高于低肥力和高肥力水平含量,高肥力水平使Put含量降低,含量峰值出现时间提前,而使Spd和Spm峰值出现时间延后。Put/Spd呈现随肥力水平的提高,峰值不断降低,峰值出现时间提前的趋势。（2）低肥力水平下GA₃含量在中期高,中肥力水平下在中期含量最低。低肥力水平下JAs含量在块茎发育的各阶段都比较低,中肥力水平下在中期含量高于低肥力和高肥力水平。低、高肥力水平下GA₃/JAs有先升高后降低的变化趋势,与中肥力水平变化相反。（3）JAs与PAs的相关性较大,其中与Put为正相关,与Spm、Spd显著负相关,Spm和Spd极显著正相关。合理的肥力水平提高了块茎发育中期PAs、JAs的含量,降低了GA₃的含量,有利于块茎的发育和膨大。     

苹果砧木生长及吸收利用硝态氮和铵态氮特性比较

 以一年生平邑甜茶（Malus hupehensis Rehd.）、八棱海棠（M. micromalus Makino）、楸子［M.  prunifolia（Willd）Borkh.］、新疆野苹果［M. sievesii（Ledeb.）Roemer］、东北山荆子（M. baccata Borkh.）实生苗为试材,采用¹⁵NH₄NO₃和NH₄¹⁵NO₃分别标记的方法,研究5种砧木的生长特性及其对NH₄NO₃中硝态氮和铵态氮的吸收、分配和利用特性。结果表明：幼苗生物量顺序为楸子 > 平邑甜茶 > 八棱海棠 > 新疆野苹果 > 东北山荆子;根系总表面积、总根长、根尖数均以楸子最大,东北山荆子最小。5种砧木对硝态氮和铵态氮的利用率顺序为楸子 > 新疆野苹果 > 平邑甜茶 > 八棱海棠 > 东北山荆子,5种砧木对硝态氮的利用率均高于铵态氮利用率,并且硝态氮利用率与根尖数呈显著正相关。5种砧木植株各器官从硝态氮中吸收分配到的¹⁵N量对该器官全氮量的贡献（Ndff）均高于从铵态氮中吸收分配到的;标记硝态氮时,楸子叶、茎和根的Ndff均最高,平邑甜茶最低;标记铵态氮时,东北山荆子叶、茎和根的Ndff均最高,新疆野苹果叶、楸子茎、平邑甜茶根最低。标记的硝态氮和铵态氮在器官中的分配均为叶 > 根 > 茎。     

锰胁迫对不同砧木苹果幼树锰吸收分配及抗氧化系统的影响

 研究山荆子、八棱海棠和辽砧2号/山荆子3种砧木富士苹果在400 mg · kg^-1锰胁迫条件下树体的生理响应和锰积累特征。结果表明,400 mg · kg^-1锰胁迫下,3种砧木的富士苹果幼树叶片先后出现中毒症状,其中山荆子砧的幼树中毒最重,辽砧2号/山荆子砧次之,八棱海棠砧的最轻。400 mg · kg^-1锰显著抑制了山荆子和辽砧2号/山荆子砧富士苹果幼树的生长,增加了锰在地上部的积累,却促进了八棱海棠富士苹果幼树地下生物量增加和锰在地下部的积累。过量锰导致山荆子和辽砧2号/山荆子苹果叶片自由基和丙二醛含量大量增加,超氧化物歧化酶活性和抗坏血酸含量增加较小,抗氧化物酶活性变化不明显。八棱海棠砧富士苹果幼树受锰胁迫后叶片抗氧化酶超氧化物歧化酶、抗氧化物酶、过氧化氢酶和抗氧化物质AsA活性显著提高,与锰胁迫前相比叶片自由基含量没有显著差异,丙二醛含量增加幅度较小。     

不同苹果砧木对连作土壤微生物及酶活性的影响

为了更好地利用砧木抗性来综合防控苹果连作障碍,以平邑甜茶（Malus hupehensis Rehd.）、富平楸子 [M. prunifolia（Willd）Borkh.]、八棱海棠（M. micromalus Makino）、新疆野苹果 [M. sieversii （Le deb.）Roem.]、山荆子 [M. baccata（Linn.）Borkh.] 为试材,探讨了不同苹果砧木对连作土壤中的酶活性、微生物以及酚酸类物质的影响。结果表明：以平邑甜茶为砧木的土壤磷酸酶活性最高,八棱海棠为砧木的土壤蔗糖酶活性最高,富平楸子为砧木的土壤脲酶活性最高;平邑甜茶为砧木的土壤真菌数量最低,富平楸子和平邑甜茶为砧木的土壤细菌数量较高,平邑甜茶为砧木的土壤细菌/真菌比值最高。从总酚酸含量来看,平邑甜茶为砧木的土壤酚酸含量最低,八棱海棠为砧木的土壤酚酸含量最高。综上,平邑甜茶为砧木的土壤真菌数量最少,土壤总酚酸含量最低,且相关土壤酶活性较高,说明其对连作土壤环境的改善效果最佳,更适合作为砧木综合防控苹果连作障碍。     

Relationship between changes in endogenous polyamines and seed quality during development of sh2 sweet corn (Zea mays L.) seed

Polyamines putatively affect tolerance to abiotic stresses and are believed to be important in organogenesis. Present experiments investigate the relationship between polyamines (PAs) and seed quality. Therefore, during seed development, the changes in free putrescine (Put), spermidine (Spd) and spermine (Spm) and physiological and biochemical parameters in F₁ seeds of sh₂ sweet corn were compared. Concentrations of Put, Spd and Spm increased from 14 to 30 days after pollination (DAP). After 30 DAP Put concentration declined with an opposite trend to that of Spd and Spm. The regression analysis between PAs and seed quality described by physiological and biochemical parameters including germination percentage, germination energy, germination index, seed size, seed fresh and dry weight, total soluble sugar, total soluble protein, Malondialdehyde (MDA) concentration, electrolyte leakage, peroxidase (POD) and catalase (CAT) activity were conducted. Spd was observed to have a closer relation with the comprehensive physiological changes of seeds during their development than that of Put and Spm. Moreover, the Spm concentration might be more suitable to forecast seed germinability during seed maturation period than Spd and Put. It indicated that endogenous Spd and Spm in dissociated form had more effect than Put during seed development progress of sweet corn.     

苹果5种砧木幼苗对连作土壤的适应性差异研究

 以苹果砧木新疆野苹果[Malus sieversii（Ledeb.）Roem.]、莱芜难咽（M. micromalus Makino）、平邑甜茶（M. hupehensis Rehd.）、山荆子[M. baccata（L.）Borkh.]和八棱海棠（M. micromalus）为试验材料,应用盆栽方法研究其对连作土壤的适应性差异。结果表明：连作条件下各砧木叶片光合速率和光合色素含量均低于非连作。平邑甜茶叶片光合速率降幅最小,仅为7.06%,其叶绿素a和类胡萝卜素含量降幅亦较小,分别为9.15%和8.17%。5种砧木根系抗氧化物酶活性及丙二醛（MDA）含量较各自对照升高。与对照相比,连作处理平邑甜茶根系超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性增幅均最小,分别为3.72%、26.60%和23.78%;平邑甜茶根系MDA含量增幅最小,为15.24%,莱芜难咽增幅最大,为54.56%。最终连作对5种苹果砧木的外在影响表现为生物量、株高和地径的下降,其中平邑甜茶适应性较强。     

水分胁迫条件下10种苹果砧木抗旱性评价

在盆栽条件下对10种苹果砧木进行了水分胁迫下的抗性鉴定,对旱害指数和相对生长量进行了聚类分析,结果表明,新培育的砧木品系Luo-6、Luo-2是抗旱性强的砧木,在土壤相对含水量40%～45%的中度水分胁迫下,新梢相对生长量分别可以达到92.13%和88.56%,其中,Luo-6在30%～35%的重度水分胁迫下24d才出现1级旱害症状,新梢相对生长量可达78.40%,Luo-2能忍受10d以下短时间的重度水分胁迫;莱芜茶果、黄海棠、海棠果、莱芜难咽、八棱海棠是中等耐旱,可以忍受20d以上的中度干旱,新梢相对生长量保持在66.13%～88.56%;平邑甜茶、六蜜海棠、山定子对水分胁迫非常敏感,在相对含水量55%～60%的轻度水分胁迫下17～31d即出现1级旱害症状,新梢相对生长量下降到70%以下。     

低氧胁迫对无土栽培网纹甜瓜幼苗多胺含量的影响

 研究了低氧胁迫处理对无土栽培网纹甜瓜幼苗叶片生长及游离态、结合态、束缚态多胺(腐胺、亚精胺和精胺) 含量的影响。结果表明, 低氧胁迫显著抑制了植株叶片的生长, 幼苗3种形态的腐胺、亚精胺和精胺含量显著提高; 但耐低氧性强的‘星光’比耐低氧性较弱的‘西域一号’幼苗生长较快, 而且游离态、结合态、束缚态的3种多胺含量较高, 表明较高多胺可能参与了网纹甜瓜耐低氧能力的调节。     

漏斗孢球囊霉菌根真菌对苹果属植物幼苗生长的影响

对冷海棠、八楞海棠和新疆野苹果接种漏斗孢球囊霉(GM)的试验结果表明,GM菌根真菌有显著促进冷海棠、八楞海棠和新疆野苹果生长的效果,生长量一般为对照的2倍以上。八楞海棠试验表明,根系侵染率与其生长量一致,即根系侵染率高的幼苗生长也快。在盐碱条件下,新疆野苹果接种GM菌根真菌比冷海棠、八楞海棠生长快,无缺铁失绿现象,冷海棠和八楞海棠有不同程度缺铁失绿现象。     

Nitrogenous compounds enhance the growth of petunia and reprogram biochemical changes against the adverse effect of salinity

This study aimed to determine ways to improve the growth and salt tolerance of petunia. Effects of polyamines (PAs; spermidine [Spd], spermine [Spm], and putrescine [Put]) and a nitric oxide (NO) donor (sodium nitroprusside [SNP]) were investigated. Initially, we screened petunia cultivars against sodium chloride (0–125 mM). The petunia cultivar Hurrah Red was identified as salt-sensitive cultivar in the basis of salt-effect on seed germination, fresh weight, and root length of seedlings. Treatment of Hurrah Red shoots with nitrogenous compounds improved the number, length, and fresh weight of roots, as well as the length and fresh weight of shoots over those of the control. Furthermore, plantlets rooted in an optimal concentration of Spd (34.5 µM), Spm (24.8 µM), Put (62.1 µM), and SNP (3.9 µM) were treated with 200 mM NaCl for 3 days to assess their tolerance level. Salt-affected plantlets showed higher level of lipid peroxidation, reduced catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) activities and decreased contents of photosynthetic pigments and polyphenol than those of the control. PAs and SNP treatments significantly elevated photosynthetic pigments, enhanced antioxidant enzymes, and decreased lipid peroxidation in salt-stressed plantlets. Moreover, the growth and salt-tolerance response of petunia was highest when plantlets were exposed to SNP, followed by levels on treatment with Put, Spm, and Spd. Thus, the findings of this study suggested that treatment with exogenous SNP, Put, Spm, and Spd could protect petunia plants against soil salinity and improve their commercial production.     

Polyamines enhance chilling tolerance of cucumber (Cucumis sativus L.) through modulating antioxidative system

Cucumber chilling-resistant cultivar Changchun mici and -sensitive cultivar Beijing jietou were used in this study to investigate the effects of exogenous PAs on protection against chilling injury as well as on changes of physiological features, and the fluctuation of free PAs content in the leaves under chilling stress. Upon chilling treatment, free spermidine (Spd), spermine (Spm) and putrescine (Put) were remarkably induced in the leaves of cv. Changchun mici 1 day after treatment. The induction of Put declined thereafter, whereas Spd and Spm levels increased steadily. In the leaves of cv. Beijing jietou, Put content was increased only at 1 day after chilling while Spd content decreased significantly upon chilling treatment. Chilling reduced soluble protein content, and decreased the activities of antioxidant enzymes, including superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) only in Beijing jietou. However, these changes could be renovated by exogenous application of Put and Spd. It was also found that pretreatment with Put and Spd diminished the increased electrolyte leakage and malondialdehyde (MDA) content caused by chilling in the leaves of both cultivars. Pretreatment of methyglyoxal-bis-(guanylhydrazone) (MGBG), the PAs biosynthetic inhibitor cancelled the effects of PAs in most of the treatments. Moreover, histochemical staining and quantitative measurements showed that exogenous application of Put and Spd eliminated but MGBG exaggerated the hydrogen peroxide (H₂O₂) accumulation caused by chilling stress, especially in leaves of Beijing jietou. Interestingly, Changchun mici was found to contain higher endogenous free PAs contents compared to Beijing jietou. While no significant difference of SOD, POD and CAT activities was found between non-chilling Changchun mici and Beijing jietou seedlings, the former exhibited higher APX activity than the latter. These results suggest that PAs play important roles in the tolerance of cucumber against chilling stress, which is most likely achieved by acting as oxidative machinery against chilling injury.