不同种源青檀种子的营养成分及种子活力的差异

以采自安徽（ＡＨ）、山东（ＳＤ）及江苏（ＪＳ）的６个青檀（ＰｔｅｒｏｃｅｌｔｉｓｔａｔａｒｉｎｏｗｉＭａｘｉｍ．）种源种子为材料,测定各种源种子营养成分含量及种子活力。６个种源种子的蛋白质、可溶性糖、淀粉及粗脂肪含量存在较大差异。在种子品质上,６个种源的种子千粒重、浸泡液电导率及简化种子活力指数（ＳＶＩＳ）也存在显著差异。种子中各营养成分含量的高低与ＳＶＩＳ的大小密切相关,复相关系数达０８２２３,以蛋白质含量对ＳＶＩＳ的影响最大,淀粉和粗脂肪含量影响次之,可溶性糖含量影响最小。采用模糊聚类分析法,以种子千粒重、电导率及ＳＶＩＳ为评价指标,可将６个种源的种子品质划分为三大类：第一类包括ＳＤ１、ＡＨ１和ＪＳ１３个种源,种子品质较好;第二类仅为ＡＨ３种源,品质中等;第三类包括ＡＨ２和ＳＤ２２个种源,品质较差。     

苦瓜果实发育过程中的主要营养成分变化及种子生活力演进

为明确苦瓜的果实和种子的适宜采收时期,采用"翠中翠"苦瓜为研究对象,对苦瓜果实发育过程中的可溶性蛋白、总可溶性糖、维生素C的含量及种子生活力的变化进行动态监测。结果显示:(1)花后第14天至第26天,随着果实的迅速膨大,可溶性蛋白、总可溶性糖及维生素C含量也迅速增长;(2)种子干物质迅速积累,含水量迅速下降,种子生活力迅速提高,至花后第22天至第26天,种子生活力基本稳定。     

人工老化处理对结球甘蓝种子生理生化特性的影响

以结球甘蓝品种‘冬升’种子为材料,研究高温(40℃)高湿(相对湿度100%)人工老化处理过程中种子的萌发特性、种子浸出液相对电导率和丙二醛、可溶性蛋白、可溶性糖含量以及抗氧化酶活性的变化,以揭示种子劣变的机理。结果表明:(1)人工老化处理甘蓝种子的含水量和不正常苗率均随着老化时间的延长逐渐增加,而种子发芽势、发芽率、发芽指数和活力指数的增加均逐渐降低。(2)随着处理天数的延长,老化处理甘蓝种子的浸出液电导率显著增大,浸出液可溶性糖含量逐渐升高,可溶性蛋白含量表现出显著下降趋势,而种子MDA含量呈先升高后逐渐下降的趋势。(3)在结球甘蓝种子老化进程中,其种子中SOD、POD、CAT活性变化的趋势相似,均随老化程度的加深而逐渐降低;而APX活性在老化处理的最初2d显著增加,第6天显著降低。研究发现,在结球甘蓝种子老化进程中,种子活力和萌发率显著降低,其种子浸出液电导率、可溶性蛋白含量、可溶性糖含量、保护酶活性变化与种子老化及劣变程度密切相关,膜脂过氧化作用可能是引起或加剧种子老化劣变的重要原因之一。     

Regulation of storage lipid metabolism in developing and germinating lupin (<Emphasis Type="Italic">Lupinus</Emphasis> spp.) seeds

The main storage compound in lupin seeds is protein, whose content can reach up to 45–50 % of dry matter. However, seeds of some lupin species can also contain quite a large amount of storage lipid. The range of lipid content in lupin seeds is from about 6 to about 20 % of dry matter. Storage lipid in developing seeds is synthesized mainly from sugars delivered by mother plants. During seed germination, one of the main end-products of storage lipid breakdown is also sugars. Thus, the sugar level in tissues is considered an important regulatory agent, during both lipid accumulation and lipid breakdown. Generally, in developing legume seeds, there is a strong negative relation between accumulation of storage protein and storage lipid. Results obtained in developing lupin cotyledons cultured in vitro pointed to the possibility of a positive relation between protein and lipid accumulation. Such a positive effect could be caused by nitrate. During lupin seed germination and seedling development, the utilization of storage lipid is enhanced under sugar deficiency conditions in tissues and is controlled at the gene expression level. However, under sugar starvation conditions, autophagy is significantly enhanced, and it can cause disturbances in storage lipid breakdown. The hypothesis of pexophagy, i.e., autophagic degradation of peroxisomes under sugar starvation conditions during lupin seed germination, has been taken into consideration. The flow of lipid-derived carbon skeletons to amino acids was discovered in germinating lupin seeds, and this process is clearly more intense in sucrose-fed embryo axes. At least four alternative or mutually complementary pathways of carbon flow from storage lipid to amino acids in germinating lupin seeds are postulated. The different strategies of storage compound breakdown during lupin seed germination are also discussed.     

水引发对油松种子和幼苗的生理效应及其作用机理

为了解决油松种子在直播造林中发芽率低、幼苗抗旱性差的问题,研究了油松种子水引发的方法及引发对其种子和幼苗的生理效应,并对水引发后幼苗的抗旱机理进行了探索。结果表明:油松种子水引发的最佳条件为10℃,闭光条件下分批给种子加水,加水总量为种子初始质量的30%,引发10 d。水引发可显著(P0.05)降低种子的半数发芽天数和硬实率,显著提高种子的发芽指数、最终发芽率和活力指数;水引发种子的可溶性糖及可溶性蛋白含量相比对照也得到提高。水引发可增加油松幼苗的茎粗、鲜重及根长,降低其相对苗高;并极显著(P0.01)提高了幼苗过氧化氢酶、过氧化物酶和根内脱氢酶活性,降低了游离氨基酸含量。干旱胁迫下,引发种子的幼苗脯氨酸和可溶性糖含量分别高于对照39.6%、118.9%,丙二醛含量低于对照93.4%,均达极显著水平。综合分析认为,水引发提高了种子可溶性糖及可溶性蛋白含量为种子萌发提供了保障,从而提高了种子发芽率,并通过增强幼苗抗氧化酶活性、降低丙二醛含量,进而增强幼苗抗氧化系统的功能,最终明显提高其抗旱性。     

贵州苏铁种子钙形态特性分析

通过测定贵州苏铁新鲜成熟种子中不同组织中总钙和不同形态类型钙物质含量,探索贵州苏铁种子发育过程中对钙的储存形式和分布规律。结果表明贵州苏铁新鲜成熟种子中总钙含量为外种皮>中种皮>胚;钙主要集中在外种皮并且主要以HCl钙形态存在,其含量高达470.8 mg/kg,占外种皮钙形态的56.3%,以及组织和整个种子的24.6%和11.4%,HCl钙形态在种子胚的发育过程中主要起到源和库的作用;中果皮和胚主要积累的是水溶性的有机钙,含量分别为70.2 mg/kg和70.6 mg/kg,对参与种子的结构和胚的发育起到积极作用。另外,贵州苏铁种子中可溶性蛋白质和可溶性糖含量与外种皮高钙含量和高钙形态含量密切相关,而大分子物质的积累对促进贵州苏铁适应高钙质环境具有积极意义。     

AAP1 regulates import of amino acids into developing Arabidopsis embryos

The embryo of Arabidopsis seeds is symplasmically isolated from the surrounding seed coat and endosperm, and uptake of nutrients from the seed apoplast is required for embryo growth and storage reserve accumulation. With the aim of understanding the importance of nitrogen (N) uptake into developing embryos, we analysed two mutants of AAP1 (At1g58360), an amino acid transporter that was localized to Arabidopsis embryos. In mature and desiccated aap1 seeds the total N and carbon content was reduced while the total free amino acid levels were strongly increased. Separately analysed embryos and seed coats/endosperm of mature seeds showed that the elevated amounts in amino acids were caused by an accumulation in the seed coat/endosperm, demonstrating that a decrease in uptake of amino acids by the aap1 embryo affects the N pool in the seed coat/endosperm. Also, the number of protein bodies was increased in the aap1 endosperm, suggesting that the accumulation of free amino acids triggered protein synthesis. Analysis of seed storage compounds revealed that the total fatty acid content was unchanged in aap1 seeds, but storage protein levels were decreased. Expression analysis of genes of seed N transport, metabolism and storage was in agreement with the biochemical data. In addition, seed weight, as well as total silique and seed number, was reduced in the mutants. Together, these results demonstrate that seed protein synthesis and seed weight is dependent on N availability and that AAP1-mediated uptake of amino acids by the embryo is important for storage protein synthesis and seed yield.     

干旱和盐胁迫对华山新麦草种子萌发及幼苗生理特性的影响

模拟华山新麦草野生土壤生境特点,分别采用聚乙二醇(PEG-6000)、钙(CaCl2)以及二者混合液3种方式浸种,研究PEG-6000和Ca2+浸种对华山新麦草种子萌发及幼苗生长的影响.结果表明:3种处理下华山新麦草的种子发芽率、发芽势和发芽指数均无显著变化;但PEG-6000浸种后,华山新麦草幼苗可溶性糖和可溶性蛋白含量增加,蛋白酶、SOD和POD活性增强;CaCl2浸种后,华山新麦草幼苗可溶性糖含量增加,蛋白酶、SOD和CAT活性增强,淀粉酶活性降低;而PEG-6000和CaCl2混合液浸种后,华山新麦草幼苗可溶性糖含量下降,SOD活性降低,华山新麦草生长受阻.据此推测华山干旱和钙离子含量高的生境特点可能是华山新麦草种群濒危的原因之一.     

Cytological and physiological changes related to cryotolerance in recalcitrant <Emphasis Type="Italic">Livistona chinensis</Emphasis> embryos during seed development

Cytological and biochemical changes in recalcitrant Livistona chinensis embryos following the acquisition and loss of cryotolerance to liquid nitrogen during seed development were studied. The embryonic cells were always hydrated and contained fully functional organelles throughout seed development. However, the central cells in the root-epicotyl end of the embryo exhibited partial dedifferentiation during the middle developmental stages, although extensive reduction of mitochondria and vacuolation and intensive accumulation of starch grains, lipid, and protein bodies were not observed. Total soluble sugar content rose then decreased on a fresh weight and water weight basis, while soluble and heat-stable proteins increased in number and content then decreased, as seeds matured. These cytological and biochemical features differ from those of orthodox seeds, providing a physiological basis for the recalcitrant behavior of L. chinensis seeds. The changes were closely correlated with acquisition and loss of cryotolerance in L. chinensis embryos and are presumed to contribute to cryotolerance, which would account for the cryotolerance variation in L. chinensis embryos. Cryotolerance is suggested to be a complex, multifaceted process, and accumulation of soluble sugars and soluble and heat-stable proteins alone is not enough to increase cryotolerance per se without acting in combination with a decrease of cellular metabolic activity.     

麻楝种子形态和营养特征遗传变异分析

为系统揭示麻楝种源间种子形态和营养成分的变异程度和变异规律,以8个国家26个种源麻楝种子为试验材料,对不同种源麻楝种子的形态特征和营养成分进行比较分析。多重比较结果表明,麻楝种源间种子的长、宽、厚、长宽比、百粒重以及可溶性蛋白质、可溶性糖和淀粉含量差异极显著;相关分析表明,种子百粒重与种子长、种子宽呈极显著正相关,可溶性蛋白质、可溶性糖和淀粉含量与百粒重均呈极显著正相关;主成分分析结果显示,影响麻楝种子品质的第1主成分主要是种子形态性状,即种子长、百粒重和种子宽,第2主成分是种子营养成分;通过分析麻楝种子形态特征及营养成分变异系数可知,麻楝种子形态变异系数大于营养成分变异系数,表明种子形态受外界环境影响较大。通过主成分聚类分析,将26个种源分为2个集群,第1集群包括澳大利亚和马来西亚2个种源,其特点是种子形态较大、百粒较重、养分含量较高;第2集群包括其余24个种源。结合聚类分析和种子形态与地理气候因子相关分析结果可知,麻楝种子形态变异具有一定的地理区域特征,与分布区的自然地理因素有一定的相关性,麻楝分布区南部种子较大而北部种子较小。     

两种品质类型花生品质形成与子叶细胞超微结构的关系

在大田条件下研究了两种品质类型花生(Arachis hypogaea)品质形成的动态差异及其子叶细胞超微结构的差异。结果表明, 高蛋白品种‘XB023’的蛋白质含量在籽仁发育前期较高油品种‘鲁花9号’低, 后期显著高于‘鲁花9号’, 且成熟期籽仁8种必需氨基酸组分含量均高于‘鲁花9号’, 其中谷氨酸、赖氨酸和亮氨酸含量差异极显著; ‘XB023’脂肪含量在籽仁发育期一直低于‘鲁花9号’。‘XB023’各时期的籽仁可溶性糖含量和油酸/亚油酸(O/L)值均显著低于‘鲁花9号’。两品种在果针入土10天时子叶细胞即形成淀粉粒、脂体和蛋白体, 随后脂体、蛋白体的数量不断增加, 淀粉粒先增大后逐渐缩小解体。‘XB023’的脂体达到最大的时间早于‘鲁花9号’, 而‘鲁花9号’的脂体快速积累的时间比‘XB023’长。两品种蛋白体大小都在果针入土40天时达到最大值, ‘XB023’的蛋白体在籽仁发育后期数量增加较快。高蛋白品种较高的蛋白质含量由其子叶细胞中较大蛋白体的大小和较多的蛋白体数量决定, 而高油品种较高的脂肪含量是由其较多的脂体数量决定。     

油菜（Brassica napus L.）种子脱水耐性获得过程中肌醇半乳糖苷合成酶活性与可溶性糖含量的变化

在这个研究中测量不同发育时期的油菜种子中可溶性糖含量与肌醇半乳糖苷合成酶（galactinol synthase,GOLS）活性,将二者的变化趋势与种子脱水耐性获得的过程相比较并对结果进行相关性分析。结果显示油菜种子脱水耐性获得过程中,葡萄糖和果糖含量均随着发育期的延长而下降,蔗糖则保持较高水平;肌醇含量下降而肌醇半乳糖苷含量上升;棉子糖系列寡糖（raffinose familyolig osaccharides,RFO）含量随着种子发育而上升,特别是水苏糖,在成熟种子中可以达到相当高的浓度。油菜种子发育中期,细胞内GOLS活性开始上升,至贮藏物积累完成时达到最大。GOLS活性变化与种子肌醇半乳糖苷积累速度、RFO含量及种子的脱水耐性呈一定的正相关关系。我们认为GOLS促使RFO积累,从而对种子脱水耐性的获得产生重要影响。     

银杏种实发育过程中营养成分的动态变化研究

以银杏良种桂 G86 - 1为试材 ,对种实发育过程中种仁和种皮的维生素 C、 N、 P、 K、灰分、粗蛋白、粗脂肪、蔗糖、还原糖、粗纤维、淀粉等 11种营养成分的含量和积累的变化动态进行系统研究。结果表明 ,在种仁发育过程中 ,蔗糖、粗纤维、淀粉的含量和积累均随生长发育期的变化而递增 ,呈极显著相关关系 ;还原糖、粗脂肪、 N、 P、 K、灰分等养分在幼果期含量较高 ,但随发育期的变化而降低 ,呈显著相关关系 ,除还原糖外 ,这些养分的积累逐渐增加 ,呈极显著相关关系 ,还原糖的积累在盛花后 110 d前明显增加 ,随后逐渐下降 ;维生素 C在种实发育初期含量较高 ,至盛花后 80 d达到最高 ,随后逐渐下降。在种皮发育过程中 ,除还原糖、维生素 C外 ,其它营养成分的含量和积累的变化动态规律与种仁相一致 ;维生素 C在种皮的含量和积累均逐渐上升 ,呈显著相关关系 ;还原糖的含量变化没有明显的规律 ,呈上升趋势 ,积累逐渐增加 ,呈极显著相关关系。     

南北样带温带区栎属树种种子化学组成与气候因子的关系

选取南北样带温带区8个核心分布区的7种优势栎属树种作为对象,通过检测种子的化学组成,包括淀粉、蛋白质、油脂、可溶性总糖、单宁和脯氨酸,分析其化学组成与气候因子之间的关系,结果发现:在气候因子中,温度是影响种子化学组成的主要因素,日照时数次之,而降水没有明显影响.在南北样带温带区,随纬度的增加,温度降低,年日照时数增加,生长积温减少,生长季缩短,淀粉含量积累下降,并趋向于水解为可溶性糖类;同时,从南到北,为适应低温的环境条件,栎属树种通过增加种子蛋白质、可溶性总糖和脯氨酸的含量,以提高种子的抗寒性.栎属树种种子的化学组成之间存在一定的相互关系,可溶性总糖、蛋白质和脯氨酸之间呈正相关关系,它们三者与淀粉均为负相关,种子化学组成之间的这种相互关系是植物对环境适应的生态策略.     

Protein Disulfide Isomerase-Like Protein 1-1 Controls Endosperm Development through Regulation of the Amount and Composition of Seed Proteins in Rice

Protein disulfide isomerase (PDI) is a chaperone protein involved in oxidative protein folding by acting as a catalyst and assisting folding in the endoplasmic reticulum (ER). A genome database search showed that rice contains 19 PDI-like genes. However, their functions are not clearly identified. This paper shows possible functions of rice PDI-like protein 1-1 (PDIL1-1) during seed development. Seeds of the T-DNA insertion PDIL1-1 mutant, PDIL1-1Δ, identified by genomic DNA PCR and western blot analysis, display a chalky phenotype and a thick aleurone layer. Protein content per seed was significantly lower and free sugar content higher in PDIL1-1Δ mutant seeds than in the wild type. Proteomic analysis of PDIL1-1Δ mutant seeds showed that PDIL1-1 is post-translationally regulated, and its loss causes accumulation of many types of seed proteins including glucose/starch metabolism- and ROS (reactive oxygen species) scavenging-related proteins. In addition, PDIL1-1 strongly interacts with the cysteine protease OsCP1. Our data indicate that the opaque phenotype of PDIL1-1Δ mutant seeds results from production of irregular starch granules and protein body through loss of regulatory activity for various proteins involved in the synthesis of seed components.     

壳聚糖包衣对油菜种子萌发及幼苗耐盐性影响

以不同浓度的壳聚糖对油菜种子进行包衣处理,考察其对油菜种子萌发及幼苗耐盐性的影响,并在不同盐浓度胁迫条件下对种子萌发时的发芽势、发芽率、生物量（鲜重、干重、根长、芽长）等指标进行测定,同时分析油菜幼苗叶绿素含量、可溶性蛋白及可溶性糖含量的变化。结果表明,一定浓度的壳聚糖包衣处理可提高油菜种子发芽率、发芽势、生物量、幼苗的耐盐指数、叶绿素含量、可溶性蛋白及可溶性糖的含量,其中浓度为0.25 g·L^-1壳聚糖包衣处理对油菜种子萌发的促进效果较好,而浓度为0.50 g·L^-1壳聚糖包衣处理对提高油菜幼苗耐盐性具有较好的促进作用。     

The effect of soil drought on the composition of carbohydrates in yellow lupin seeds and triticale kernels

Carbohydrate analysis was made of yellow lupin seeds (cv. Juno) and triticale kernels (cv. Dagro), produced by plants exposed to drought stress for 21 days after the initial flowering of the first node of lupin and initial earing of triticale. The seeds of all experimental variants were harvest at full maturity, dried and stored in linen bags at 18–20 °C. Soluble carbohydrates were extracted and analysed as described by Horbowicz and Obendorf (1994). Gas chromatographic separation of carbohydrates showed that raffinose family oligosaccharides (RFO) were dominant in lupin seeds. The other carbohydrates present were sucrose (10 %), cyclitols and galactosyl cyclitols (12–13 %). Soil drought resulted in higher levels of verbascose, but decreased the quantities of the other carbohydrates in lupine seeds. In triticale kernels, over 50 % of soluble sugars were composed of sucrose and maltose, while 17.7 % were raffinose and stachyose. In response to drought the content of mono- and oligosaccharides declined. The decrease of soluble carbohydrates content in seeds of lupin and triticale kernels has no effect on the seed germination and vigour. It is assumed that the changes in the concentration of soluble sugars observed under drought may impair the storability of triticale kernels, but improve it for lupine seeds.     

Characterisation of seeds of a C4 phosphoenolpyruvate carboxylase-deficient mutant of Amaranthus edulis

Seeds from the C(4) plant Amaranthus edulis were studied as part of the characterisation of a mutant (designated LaC(4) 2.16), which contains reduced amounts (5% of wild type) of the photosynthetic leaf form of phosphoenolpyruvate carboxylase (PEPC). On a per seed basis, the amount of PEPC activity was not significantly altered, while the weight and protein content of the mutant seeds were 34% lower than that of the wild type. Western gel blot analysis detected two PEPC polypeptides with molecular masses of 105 kDa (minor) and 100 kDa (major). The determination of in vitro phosphorylation in reconstituted assays revealed the presence of both calcium-dependent and calcium-independent PEPC-kinase activities in protein extracts of wild-type and mutant seeds. However, PEPC proteins were phosphorylated in dry seeds, and PEPC phosphorylation did not occur in vivo during seed imbibition in the presence of (32) P-phosphate. In contrast, (32) P-phosphate was incorporated into a range of proteins in wild-type seeds, but not in mutant seeds. In addition, ATP content was much reduced in germinating mutant seeds and this did not increase following the supply of phosphate. Collectively, these data suggest that the deficiency in C(4) PEPC in mutant A. edulis leaves has no effect on C(3) -type PEPC content and phosphorylation state in seeds, but causes impairment of energy production, thereby accounting for the reduced germination of the mutant.     

成熟度与烘干温度对结球甘蓝种子质量的影响

以结球甘蓝品种冬升种子为材料,研究了不同成熟度和烘干温度下种子秕粒率、千粒重、发芽率、生理活性情况以及不同烘干温度下种子的含水量.结果表明,结球甘蓝冬升开花后45～55 d采收的种子,发芽率均达到了95%以上;随着种子成熟度提高,其种子质量、发芽活力及其超氧化物歧化酶(SOD)、过氧化物酶(POD)、脱氢酶活性显著上升,而相对电导率显著下降.与对照(自然风干)相比,30～50℃的烘干温度对种子千粒重和秕粒率无显著性影响,也仅在50℃下可使种子的发芽活力显著降低;随着烘干温度的升高,种子的SOD、POD和脱氢酶活性逐渐显著下降,相对电导率则逐渐显著上升;30～50℃烘干6 h种子的含水量由13.3%降至5.4%左右.研究发现,结球甘蓝冬升开花授粉后45 d种子已达到了采收程度,30～50℃烘干6 h种子含水量已达到储藏要求,并且愈接近自然干燥温度(30～40℃)的处理,种子发芽能力愈好;甘蓝种子活力与其SOD、POD和脱氢酶活性呈正相关,而与其相对电导率呈负相关.     

The Maillard reaction and oxidative stress during aging of soybean seeds

The chemical reactions that may lead to the loss of seed viability were investigated both during the accelerated aging and natural aging of soybeans ( Glycine max Merrill cv. Chippewa 64). Under conditions of accelerated aging (36°C and 75% RH), fluorescence of soluble proteins accumulated, which was closely correlated with the loss of seed germinability and vigor. We were able to show this correlation by using partially purified proteins for the assay. Fluorescence also increased in seeds under good storage conditions (5°C for up to 21 years), although there was a less significant correlation between seed viability and the accumulation of fluorescent products during the time of natural aging. The rise in protein fluorescence is interpreted as an increase of Maillard products. The carbonyl content of soluble proteins (a measure of the oxidative damage) did not change significantly during either accelerated aging or natural aging: however the elimination of carbonyls during germination seemed to be hindered in seeds that had poor germination. The Maillard reaction may be a consequence of the formation of reducing sugars through a gradual hydrolysis of oligosaccharides during aging. Preliminary evidence from the natural aging study showed that, when seeds were in the glassy state, the sugar hydrolysis was inhibited. These results suggest that the Maillard reaction and oxidative reaction may play an important role in seed deterioration.