The effects of seed priming with Fe-Zn-NA chelate (FeSO 4 +ZnSO 4 +niacinamide) and the longevity of the beneficial priming effects were investigated for aged seeds of hybrid rice cv. Lingyouhuazhan (LYHZ) and cv. Longxiangyou 130 (LXY130). As compared with untreated and hydroprimed seeds, Fe-Zn-NA chelate priming significantly enhanced germination energy (GE), germination percentage (GP), germination index (GI), vigour index (VI) and normal seedling rate (NSR), and increased seedling shoot height (SH) and seedling dry weight (DW) in both cultivars. After priming with Fe-Zn-NA chelates, the GP of LYHZ was 96.0%, which was 12.7 and 12.0% higher than hydroprimed and non-primed seeds, respectively. Similarly, the GP of LXY130 was 89.5%, significantly higher than the hydroprimed and non-primed seeds (by 11.5 and 10.0%, respectively). When stored at 25°C, the benefits of Fe-Zn-NA chelate priming on seed vigour and viability was maintained for three months; while after six months storage, the GP of LYHZ and LXY130 was only 48.0 and 34.0%, respectively, which was significantly lower than the non-primed seeds (84.0 and 71.1%). When stored at 15 or 5°C for six months, the germination potential of Fe-Zn-NA chelate-primed seeds was still high. The GP of LYHZ and LXY130 seeds was 94.4% and 77.8%, respectively, after storage at 15°C, and 97.8% and 85.6% after storage at 5°C. In conclusion, the Fe-Zn-NA chelate priming was an effective method to improve the vigour and viability of hybrid rice aged seeds; however, the duration of beneficial priming effects needs to be determined according to the storage temperature.

Polyamines have been reported to be involved in grain filling and they might contribute to the construction of heat resistance of some cereals. In this study, the hybrid rice 'YLY 689' was used to explore the possible effects of exogenous spermidine (Spd) on seed quality under high temperature during the filling stage. Rice spikes were treated with Spd or its synthesis inhibitor cyclohexylamine (CHA) after pollination, and then the rice plants were transferred to 40 °C for 5-day heat treatment. The results showed that, compared with the control under high temperature, Spd pretreatment significantly improved the germination percentage, germination index, vigor index, seedling shoot height, and dry weight of seeds harvested at 35 days after pollination, while the CHA significantly decreased the seed germination and seedling growth. Meanwhile, Spd significantly increased the peroxidase (POD) activity and decreased the malondialdehyde (MDA) content in seeds. In addition, after spraying with Spd, the endogenous content of spermidine and spermine and the expression of their synthetic genes, spermidine synthase (SPDSYN) and spermine synthase (SPMS1 and SPMS2), significantly increased, whereas the accumulation of amylose and total starch and the expression of their related synthase genes, soluble starch synthase II-3 (SS II-3) and granules bound starch synthase I (GBSSI), also increased to some extent. The data suggests that exogenous Spd pretreatment could alleviate the negative impacts of high temperature stress on rice seed grain filling and improve the rice seed quality to some extent, which might be partly caused by up-regulating endogenous polyamines and starch metabolism.

The preservation of seed viability and quality in storage is an important trait both for commercial and germplasm usage. To better explore potential mechanisms of tobacco seed deterioration, seed packed in cloth bag (C) and vacuum bag (V) were stored under room temperature (RT) and low temperature (LT, 18°C), and sampled periodically for laboratory testing. Seed stored in low temperature with vacuum bag (LT/V) owned the highest seed vigour after 25 months of storage and in room temperature with cloth bag (RT/C) lost seed vigour and germination ability after 20-month storage. Meanwhile, seed in RT/C notably increased about 5-fold endogenous hydrogen peroxide (H2O2), 4-fold malondialdehyde (MDA) contents, 12-fold Lipoxygenases (LOX) activity and 2-fold the expression of NtLOX3 comparing with LT/V at the end of 15-month storage. In addition, regression analysis indicated that LOX activity was strongly negatively correlated with seed vigour as the R 2 value reached 0.970 in RT/C. Furthermore, caffeic acid and catechin, the inhibitors of LOX activity, were applied to tobacco seeds pre-treatment and followed with artificial accelerated aging. Seeds pretreated with inhibitors, especially caffeic acid, reduced LOX activity by 50%, MDA and H2O2 contents by 40% and 20%, respectively, and increased more than 1.2-fold seed vigour and seedling quality comparing with seeds pretreated with H2O after 6-day artificial aging, indicating a better seed storability after artificial accelerated aging. These results suggest that LOX accelerated seed aging, and suppression of LOX activity enhanced seed vigour and viability in accelerated aging tobacco seed, opening new opportunities for effective management of seed germplasm under long-term storage and conservation.

Seed germination is a complex process controlled by various mechanisms. To examine the potential contribution of reactive oxygen species (ROS) and gibberellin acid (GA) in regulating seed germination, diphenylene iodonium chloride (DPI) and uniconazole (Uni), as hydrogen peroxide (H2O2) and GA synthesis inhibitor, respectively, were exogenously applied on tobacco seeds using the seed priming method. Seed priming with DPI or Uni decreased germination percentage as compared with priming with H2O, especially the DPI + Uni combination. H2O2 and GA completely reversed the inhibition caused by DPI or Uni. The germination percentages with H2O2 + Uni and GA + DPI combinations kept the same level as with H2O. Meanwhile, GA or H2O2 increased GA content and deceased ABA content through corresponding gene expressions involving homeostasis and signal transduction. In addition, the activation of storage reserve mobilization and the enhancement of soluble sugar content and isocitrate lyase (ICL) activity were also induced by GA or H2O2. These results strongly suggested that H2O2 and GA were essential for tobacco seed germination and by downregulating the ABA/GA ratio and inducing reserve composition mobilization mutually promoted seed germination. Meanwhile, ICL activity was jointly enhanced by a lower ABA/GA ratio and a higher ROS concentration.

Single counts of radicle emergence (RE) have revealed vigour differences between different maize seed lots, but has not been applied to test seed vigour of rice. The present study compared the RE counts for 11 indica rice seed lots after 54 hours at 25 degrees C and 102 hours at 18 degrees C with the results for mean germination time at 25 degrees C (MGT1), mean germination time at 18 degrees C (MGT2), cold test (CT) and field emergence (FE). The RE counts at each temperature was highly significantly related to the MGT at that temperature and also to field emergence (R-2 = 0.82, 25 degrees C; R-2 = 0.92, 18 degrees C). The application of single counts of radicle emergence as a test of the seed vigour of indica rice seed is discussed.

The delayed seed germination and poor seedling growth caused by imbibitional chilling injury was common phenomenon in maize seedling establishment. In this study, RNA sequencing technology was used to comprehensively investigate the gene expressions in chilling-imbibed maize embryo and to reveal the underlying mechanism of chilling injury at molecular level. Imbibed seeds for 2 h at 5°C (LT2) were selected and transcriptomic comparative analysis was performed. Among 327 DEGs indentified between dry seed (CK0) and LT2, 15 specific genes with plasma membrane (PM) relevant functions belonging to lipid metabolism, stress, signaling and transport were characterized, and most of them showed down-regulation pattern under chilling stress. When transferred to 25°C for recovery (LT3), remarkable changes occurred in maize embryo. There were 873 DEGs including many PM related genes being identified between LT2 and LT3, some of which showing significant increase after 1 h recovery. Moreover, 15 genes encoding intracellular vesicular trafficking proteins were found to be exclusively differential expressed at recovery stage. It suggested that the intracellular vesicle trafficking might be essential for PM recovery through PM turnover. Furthermore, transcriptome analyses on imbibed embryos under normal condition (25°C) were also made as a contrast. A total of 651 DEGs were identified to mainly involved in protein metabolism, transcriptional regulation, signaling, and energy productions. Overall, the RNA-Seq results provided us a deep knowledge of imbibitional chilling injury on plasma membrane and a new view on PM repaired mechanism during early seed imbibition at transcriptional level. The DEGs identified in this work would be useful references in future seed germination research.

Pre-harvest sprouting (PHS) is a constrain problem in hybrid rice production. The present study was conducted to investigate the inhibitory effect of eugenol on seed germination and PHS of hybrid rice variety (Qian You 1). The results showed that seed germination speed and the activities of α-amylase were inhibited by eugenol pre-soaking and these effects enhanced with the increasing of eugenol concentrations; while seedling growth was not negatively affected. In field trials, eugenol application caused a significant decline in PHS as compared with control, whereas no sustained inhibition in post-harvested seed germination was observed. The HPLC analysis indicated that eugenol raised the internal ABA content by 1–4 times more than control, and seeds treated with eugenol had relatively lower OsABA8OH2 and higher transcript levels of OsNCED2 expression during early stages of seed imbibitions. In addition, seed germinated faster after GA3 application than eugenol alone, and seed endogenous ABA content decreased obviously. It suggested that eugenol strongly delayed seed germination and the PHS in the field, which might be mainly due to the increased ABA contents caused by eugenol. However, the phenomenon of delayed germination and high ABA content caused by eugenol could be effectively recovered by exogenous GA3.

BACKGROUND:The low seed vigor and poor field emergence are main factors that restricting the extension of sweet corn in China. Spermidine (Spd) plays an important role in plant growth and development, but little is known about the effect of Spd on sweet corn seed germination. Therefore the effect of exogenous Spd on seed germination and physiological and biochemical changes during seed imbibition of Xiantian No.5 were investigated in this study.RESULTS:Spd soaking treatment not only improved seed germination percentage but also significantly enhanced seed vigor which was indicated by higher germination index, vigor index, shoot heights and dry weights of shoot and root compared with the control; while exogenous CHA, the biosynthesis inhibitor of Spd, significantly inhibited seed germination and declined seed vigor. Spd application significantly increased endogenous Spd, gibberellins and ethylene contents and simultaneously reduced ABA concentration in embryos during seed imbibition. In addition, the effects of exogenous Spd on H2O2 and MDA productions were also analyzed. Enhanced H2O2 concentration was observed in Spd-treated seed embryo, while no significant difference of MDA level in seed embryo was observed between Spd treatment and control. However, the lower H2O2 and significantly higher MDA contents than control were detected in CHA-treated seed embryos.CONCLUSIONS:The results suggested that Spd contributing to fast seed germination and high seed vigor of sweet corn might be closely related with the metabolism of hormones including gibberellins, ABA and ethylene, and with the increase of H2O2 in the radical produced partly from Spd oxidation. In addition, Spd might play an important role in cell membrane integrity maintaining.

The present study was designed to study the effects of storage conditions on hybrid rice seeds 'Y Li-ang-you 689'. The seeds with 11.0%, 13.0% and 14.5% moisture content (MC) were packed by both paper and plastic bags, then stored at room temperature and 5°C, respectively. The changes of seed vigor, viability, en-zyme activity, contents of abscisic acid (ABA), gibberellins (GA3) and their related genes expression were mea-sured after storage 12 months. The seeds stored at 5°C had higher seed vigor and viability than those stored at room temperature under different MCs and packing methods. When storage at room temperature, seeds with 11.0% MC significantly higher than those of 13.0% MC in seed vigor and viability, then 13.0% MC seeds sig-nificantly higher than those of 14.5% MC, however, was significantly lower than those of non-storage control. Seeds stored in paper bags recorded higher seed vigor and viability when seed moisture content keep at 13.0%and 14.5% levels than those in plastic bags. On the other hand, seeds stored in plastic bags recorded higher seed vigor and viability when seed moisture content keep at 11.0% level. The seeds kept high seed vigor and viabili-ty when storage at 5°C, the germination of the seeds with different seed moisture contents packed by different packing methods kept above 80.0%, the highest germination was about 94.0%. The activities of α-amylase, per-oxidase (POD), catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were consistent with vigor index after storage. The lower of seed vigor, the lower of the activities of α-amylase, POD, CAT, APX and SOD. These parameters could reflect the degree of the seed quality. The higher of the seed moisture content, the lower of seed vigor, the higher of the ABA content, while the content of GA3 was in lower lever. In addition, the seeds with higher rate of ABA/GA3 had lower ability of germination. Further studies showed that the expression of OsABAox2 related ABA synthesis and OsNCED2 related ABA resolving was lower in higher vigor seeds after storage in two packing methods and three kinds of MCs, so the content of ABA was in lower level, the expression of related GA3 OsGA20ox1 synthesis was higher, the expression of OsGA2ox5 related GA3 resolving was lower, so the content of GA3 was in higher level, therefore there was more GA3 and less ABA ac-cumulation that promoted the seed germination.

Seed dehydration is very important in hybrid rice seed production. For seed production safety, dehydrating agents are used in this process because natural dehydration is slow and easily affected by rainy weather, which often results in seed late ma-ture of and pre-harvest sprouting. In this study, the effects of different dehydrating agents on seed dehydration and quality were compared using hybrid rice variety "Y Liangyou 689". The eleven dehydrating agents tested all accelerated seed dehydration. Particularly, agents No.7 and No.9 resulted in seed moisture content at five days after spray decreased by 4.6% and 3.6%, respec-tively, and had no negative effects on 1000-grain weight, seed germination and seedling growth. Moreover, both agents signifi-cantly increased the contents of soluble protein, soluble sugar, ABA and GA3 in seeds. After storage at room temperature for six months, agents No.7, No.8, and No.9 had no negative effects on seed germination and seedling growth as compared to the control. There were no significant differences in soluble protein content,α-amylase activity and ABA content among agents No.7, No.9 and the control. Agent No.7 was better in lowering seed moisture content than No.9, suggesting its potential use in Y Liangyou 689 seed production. Interestingly, agents No.7, No.8, and No.9 inducedOsNECD1andOsNCED2 expressions and reduced OsGA2ox1 expression in seeds before storage. After six-month storage, the expressions ofOsNECD1 andOsNCED2 decreased and the expression ofOsCYP707A5 andOsGA2ox1 increased in seeds treated with agents No.7, No.8, and No.9. This result indi-cate that the effects of dehydrating agents on ABA biosynthesis genes and GA3 catabolism genes in seeds weakened during stor- age and the high expression level ofOsCYP707A5 resulted in the decline of ABA content, which might be a main reason for better seed germination.

为探索豌豆种皮的结构和成分对种子透水性的影响,借助扫描电镜对种皮表面和横断面结构进行观察,并采用显微化学鉴别法、红外光谱分析法以及能量色散型x射线荧光分析仪对种皮成分进行了定性和定量测定.结果表明,豌豆种脐是水分进入种子的主要通道,而种皮结构中的角质层、栅栏层是水分和其他外源物质进入的主要障碍.种皮成分中纤维素、木质素、角质、含碳化合物和Sr元素等的积累增加了种皮的机械强度,从而降低种子的透水性,而种皮中K、Fe、Ca元素的积累可能有利于种皮透水.此外,研究还发现,皮壳率越高,种子透水性越好,且保持种子种皮完整性对种子吸水和保水具有重要作用.

Effects of three priming methods (hydropriming, sand priming, and KNO3+KH2PO4 solution prim-ing) on the germination and seedling growth of normal corn (‘Nongda 108’), waxy corn (‘Meiyu 3’) and sweet corn (‘Xiangtian 1’) under 5°C low-temperature stress were studied at three stages (before low-temperature stress, after low-temperature stress for 3 d, and after recovering growth at 25°C for 3 d). The results show that the three priming methods had no significant effect on germination percentage, however, significantly improved germination energy, germination index, shoot height and shoot dry and fresh weights, and shortened mean ger-mination time in the three types of corns. The relative conductivity of three types of corns was decreased by hy-dropriming and sand priming, and the relative conductivity of sweet corn was significantly declined by solution priming. The three priming methods increased chlorophyll content of normal corn in 3 stages and sweet corn before low-temperature stress and after recovering growth at 25°C for 3 d, while chlorophyll content of waxy corn was improved only after recovering growth at 25°C for 3 d. Before low-temperature stress and after low-temperature stress, hydropriming enhanced the peroxidase (POD) activity of three types of corn. After low-temperature stress for 3 d, sand priming promoted the catalase (CAT) activity of three types of corn. After recovering growth at 25°C for 3 d, sand priming raised the POD, CAT and ascorbate peroxidase (APX) activi-ties of three types of corns, and solution priming increased APX activity of three types of corn. Three priming methods significantly reduced the malondialdehyde (MDA) content of waxy maize and sweet corn after low-temperature stress for 3 d. It suggests that three priming methods could increase seed vigor and improve the chilling tolerant of normal, waxy and sweet corns. Sand priming had advantage in improving seed vigor of waxy corn, and hydropriming showed better improvement for sweet corn. However, there was no significant difference among the three priming methods for normal corn.

Cationic emulsified asphalt (CEA) and poly(vinyl alcohol) (PVA) polymer binding agents may affect the combustion characteristics and pollutant emissions of coal logs shaped for transportation in hydraulic pipelines. Therefore, these characteristics were investigated using thermal analysis as well as a lab-scale fixed-bed combustor, together with those of raw coals. Three raw coals, anthracite, bitumite, and lignite, were selected to produce coal logs. The results of thermal analysis were compared to those of raw coals. Binders made the three coals more prone to be ignited. Binders improved the combustion of coal logs made of anthracite yet worsened the combustion performance of bitumite coal logs. CEA binder ameliorated the combustion performance of coal logs made of lignite. PVA binder slightly worsened the combustion performance of coal logs made of lignite. Different binders had dissimilar effects on the pollutant emissions when burning coal logs made of different coals.

In order to discuss the feasibility of repeated utilization of colchicines in chromosome doubling experiment for tobacco seedling,the haploid aseptic seedlings,cultivated from anthers of F1 generation of burley tobacco,were taken as materials and the colchicines solvent with initial concentration of 4 g/L was taken as doubling reagent to conduct six repeated utilization experiments,and the chromosome doubling indicators were determined,including dead seedling rate,haploid rate,haploid-diploid mixoploid rate,dihaploid rate,tetraploid rate and dihaploid-tetraploid mixoploid rate.The results showed that the doubling efficiency of dihaploid,which mainly be focused,showed a tendency of increasing fist and then decreasing;it was 21.3% after the sixth repeated utilization,only decreased by 1.5 percentage points in comparison with the doubling efficiency of the first utilization(22.8%),and it was the highest in the third repeated utilization by 36.1%.

Activated sludge is widely used to treat industrial wastewater, but its efficiency is affected by a variety of factors, including toxic substances such as tetrahydrofuran (THF). In this study, we examined the toxicity of THF at different concentrations (0–320mM) on the microbial community in activated sludge. A remarkable dose-dependent decrease in the total organic compound removal rate and culturable bacteria and fungi was observed. At THF concentrations higher than 160mM, a decrease in pH to 3.0 was observed. The activities of five enzymes (catalase, dehydrogenase, urease, phosphatase and protease) analyzed were all significantly inhibited (p<0.01) at THF concentrations higher than 160mM, especially dehydrogenase activity, which lost 95.4% of its activity at 320mM THF. Microbial community analysis by PCR-DGGE revealed a substantial shift in the community structure and a reduction in diversity at a low THF concentration (20mM). These results suggest that THF is much more toxic than reported in the literature, indicating its acute toxicity to microorganisms.

Polyamines play an important role in plant response to abiotic stress. S-adenosyl-l-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the tolerance of high-temperature stress in tomato, SAMDC cDNA isolated from Saccharomyces cerevisiae was introduced into tomato genome by means of Agrobacterium tumefaciens through leaf disc transformation. Transgene and expression was confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing yeast SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wild-type plants under high temperature stress, and enhanced antioxidant enzyme activity and the protection of membrane lipid peroxidation was also observed. This subsequently improved the efficiency of CO(2) assimilation and protected the plants from high temperature stress, which indicated that the transgenic tomato presented an enhanced tolerance to high temperature stress (38 degrees C) compared with wild-type plants. Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating high temperature-tolerant germplasm.

Abstract 3 Polyamines play an important,role in plant response to abiotic stress. S-adenosyl-l-methionine 4 decarboxylase,(SAMDC) is one ,of the ,key ,regulatory enzymes ,in the ,biosynthesis ,of 5 polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on 6 the tolerance of high-temperature stress in tomato, SAMDC cDNA isolated from 7

The crude ethanol extract of Pulsatilla chinensis (Bunge) Regel roots was extracted successively with light petroleum, dichloromethane and n -butanol. The light petroleum fraction (PEF) exhibited potent anti-proliferation activity on HL60 cells with an IC 50 value of 14 μg/mL. As a result, ICR mice transplanted with tumor strain S180 were employed for testing the effectiveness of drug administration of PEF. The tumor inhibitory rate was 36.7% at a dose of 20 mg/kg/d, which was higher than the positive control, which produced 31.5% inhibition. However, an unusual phenomenon was observed in that the tumor inhibitory response was reverse dose-dependent since tumor inhibition was only 19.5% at a dose of 180 mg/kg/d. GC-MS revealed that the main components of the PEF were C-19 and C-22 polyunsaturated fatty acids. Previous studies had revealed that polyunsaturated fatty acids exhibit either anti-tumor or tumor promoting activities, and so it is proposed that the effects of PEF on tumor growth is dependent on dosage.