多胺对甜瓜幼苗抗冷性的影响机理研究

本文研究了外源多胺对在低温胁迫下甜瓜幼苗体内DNA、RNA、可溶性蛋白质、超氧物歧化酶(SOD)及细胞质膜透性的影响.结果表明,多胺处理的甜瓜幼苗在低温(2±1℃)下处理10h后,RNA和DNA含量明显增多,蛋白质的图谱发生显著变化,SOD活性增强,细胞膜的破损渗漏较少,尤以0.4mmol的腐胺处理最为显著.多胺与核酸的相互作用调节了植物体内的代谢过程,与膜的相互作用增强了机体的抗冷性.     

Effect of exogenous putrescine on post-harvest life of strawberry (Fragaria ananassa Duch.) fruit,cultivar Selva

Effect of different concentrations of putrescine on post-harvest life of strawberry (Fragaria ananassa Duch.) fruit, cultivar Selva at 5 °C was studied. Fruits were immerged in 0.3, 0.5, 1 and 2 mM putrescine as well as distilled water (control) for 5 min, then transferred into the fridge (5 °C) together with untreated fruits (dry treatment). The rate of weight loss, ethylene production, flesh firmness, soluble solids content, titratable acidity and pH of fruits were determined 5, 9 and 13 days after the beginning of storage. Flesh firmness, appearance, color change and taste of fruits were also determined in the same intervals using a taste panel. Storage life of the strawberry fruits was significantly increased by the use of putrescine, so that the untreated and control fruits had 6 and 8 days storage life, respectively, while the immerged fruits in 1 and 2 mM putrescine were still suitable to be exposed in the market 12 and 14 days after the beginning of storage, respectively. No significant weight losses were observed in treated fruits compared to controls and dry treatment at all determination times. Ethylene production was decreased significantly by the use of putrescine. Untreated fruits (dry treatment) had the highest rate of ethylene production and the lowest rate was occurred in 2 mM putrescine treatment at all determination times (5, 9 and 13 days after the beginning of storage). The use of putrescine also prevented the softening of fruit flesh during the storage and kept their firmness, so that, the 2 mM putrescine treatment caused the highest fruit firmness at all determination times. Distilled water treatment (control) had the lowest fruit firmness 5 and 9 days after storage, while this occurred for the dry treatment 13 days after storage. Soluble solids content, pH and titratable acidity of the fruits were not significantly affected by the use of putrescine, but the highest and lowest rate of titratable acidity were related to the 2 mM putrescine and dry treatment, respectively, at the three determination times. Overall, the quality of fruits was improved by the use of 2 mM putrescine in terms of properties evaluated by the taste panel.     

腐胺对香蕉果实后熟进程的影响

[目的]研究外源腐胺对香蕉后熟进程的影响.[方法]以顺德中把大蕉为试验材料,研究腐胺对香蕉后熟进程的影响,并对其机理进行了初步分析.[结果]试验表明,5 mmol/L腐胺显著廷缓采后香蕉的后熟进程,果皮褪绿转黄推迟3d,有效维持果皮细胞膜的完整性,显著抑制果实软化,降低果肉可溶性固形物的上升,初步分析其作用机理之一是降低了呼吸强度,对呼吸高峰的到来时机没有显著影响.[结论]研究可为香蕉的采后保鲜提供参考.     

PUT、SPD对辣椒果实中辣椒素及相关物质的影响

以沈椒四号麻辣椒为试材,在辣椒花期喷施不同浓度的PUT、SPD、SPM,研究了外源多胺处理的辣椒果实中辣椒素及其代谢相关物质的变化。结果表明,PUT0.1(1×10-4mol.L-1)和SPD1(1×10-3mol.L-1)能够促进辣椒素的积累,PUT0.1处理促进作用最强。PUT0.1和SPD1均能促进PAL和POD的活性。PUT0.1能够降低PPO的活性和抑制木质素的合成。所有多胺处理均能促进类黄酮和单宁的积累,但PUT0.1对单宁的促进作用较大,对类黄酮的促进作用较小。PUT0.1为促进辣椒素积累的最佳处理。     

A real-time polymerase chain reaction (PCR) method for the identification of Nicotiana tabacum in tobacco products

A simple and specific real-time PCR assay based on TaqMan^® technology has been developed for the identification of cultured tobacco (Nicotiana tabacum) in various commodities such as cigars, cigarettes and reconstituted tobacco. The TaqMan^® assay targets a sequence of the putrescine N-methyltransferase gene family encoding an enzyme that plays a crucial role in the biosynthesis of nicotine. To reduce the possibility of false negatives, universal plant chloroplast primers were also used in a separate real-time PCR reaction to give indication if DNA is amplifiable in the matrix. The TaqMan^® assay successfully identified tobacco in over 40 commercial tobacco products, while negative results were obtained from the assay for DNA extracted from a variety of other botanical products. In our study, two commercial DNA isolation kits were used, namely, the Qiagen DNeasy^® Plant Mini kit and the Qiagen Gentra^® Puregene^® kit. They produced good quality DNAs in sufficient quantities for real-time PCR analysis. In a few cases, an additional purification step with the Promega DNA IQ™ system had to be implemented to obtain amplifiable DNA.     

外源腐胺对糯米糍荔枝座果的影响

试验研究了腐胺（Put）在不同时期、不同浓度和不同次数喷施对糯米糍荔枝座果的影响。结果表明，以盛花期喷施30－40mg/L的座腐胺1次，对提高糯米糍荔枝的座果率效果最好，而对果实体积和单果重没有明显影响。     

Putrescine and carnauba wax pretreatments alleviate chilling injury,enhance shelf life and preserve pomegranate fruit quality during cold storage

Keeping in mind to reduce chilling injury and retain quality; pomegranate (Punica granatum L., cv. Mridula) fruits were treated with putrescine, carnauba wax and putrescine + carnauba wax prior to cold storage at 2 °C. Before analyzing physical, physiological and biochemical parameters fruits were subjected to post cold storage exposure at 20 °C for 3 days. Untreated fruits developed rapidly chilling injury, with main symptoms being brown discolouration of the skin, surface pitting, weight and firmness loss during storage. All these undesirable changes were significantly delayed by putrescine + carnauba wax application. Respiration and ethylene evolution rate were also brought down by combined application of putrescine and carnauba wax treatment. The superiority of combine treatment over other applications seems arises due to additive benefit of antisenescence and barrier properties of putrescine and carnauba wax, respectively.     

Effect of various polyamines on production of protocorm-like bodies in orchid—Dendrobium ‘Sonia’

Polyamines, putrescine, spermidine and spermine all at three concentrations viz., 0.2, 0.4 and 1.0 mM were tested, by supplementing to MS basal+4.44 μm BAP medium. The explant used was fractionated plb. Ethylene and methane was measured at 20 and 40 days after inoculation (DAI). Among various polyamines tested, maximum number of plb’s (protocorm-like bodies) were produced in putrescine 0.4 mM treatment. Increase (1.0 mM) or decrease (0.2 mM) in concentration caused a decrease in the production of plb’s. All spermidine and spermine treatments resulted in the production of less number of plb’s than control. No ethylene evolution was observed in any of the polyamine treatments. However, methane evolution was observed in all the polyamine treatments. The absolute amounts, of methane evolved could not be related to the observed plb’s production response. However, when the evolution of methane was more than 1 nmol per gram FW h⁻¹, poor plb’s production was observed.     

香蕉果实贮藏冷害与PAL活性及可溶性蛋白的关系

研究了200μmol/L脱落酸(ABA)和5mmol/L腐胺(Put)处理对贮藏于8℃下条件的香蕉果实耐冷性的影响及其与PAL活性及可溶性蛋白的关系。结果表明:与对照果实相比较,ABA和Put两种处理都不同程度地减轻香蕉果实贮于8℃条件下的冷害。具体表现在,两种处理均延缓了果皮颜色变暗与细胞膜透性的升高,提高了果皮可溶性蛋白含量,维持果实果皮较高的PAL活性。本文还讨论了香蕉果实耐冷性与果皮PAL活性的关系。     

酸胁迫对林木内源多胺及活性氧代谢的影响

多胺（ＰＡｓ）广泛存在于原核生物及真核生物中,在高等植物中,ＰＡｓ以阳离子状态存在于细胞中,它们能与ＤＮＡ、ＲＮＡ等大分子阴离子相结合,从而促进细胞分裂;ＰＡｓ也能促进体细胞胚的形成,不定芽的发生,根的形成和发生,子房和果实的发育,花原基的形成和分化...