共查询到18条相似文献，搜索用时 218 毫秒
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为了研究韭菜叶绿体积累淀粉特性及其超微结构特性,以西瓜叶片作为对照进行组织化学方法和透射电子显微技术鉴定。结果表明:韭菜叶片叶肉细胞叶绿体虽具有大量类囊体并形成大量基粒,但均不积累淀粉;以辅助运输光合产物为主要功能的维管薄壁细胞和以保护为主要功能的表皮细胞中的质体未分化为叶绿体,这些质体也不积累淀粉。显然,韭菜叶绿体与其他植物叶绿体不同,不具有合成、积累淀粉的能力,这是韭菜叶绿体的一个显著细胞生物学特征。此外,快速生长的幼叶叶绿体的类囊体膜电子染色浅,成熟叶叶绿体的类囊体膜电子染色深,是韭菜叶绿体的另一特征。 相似文献
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叶衰老引起大分子和细胞器组分降解,质体小球是源于类囊体、由膜脂单分子层包围中性脂所组成的细胞器,然而目前对衰老叶中质体小球降解的亚细胞途径还了解甚少,因此采用超微技术对番茄叶衰老诱导的质体小球降解亚细胞途径进行了研究。结果发现,番茄叶衰老诱导质体小球体积增大之后以两种方式降解:一是质体小球离开叶绿体并向液泡内转移,在液泡中发生降解;二是质体小球不离开叶绿体,在叶绿体内发生降解,降解始于小球表面某一点,伴随小泡发生。因此,番茄叶衰老诱导质体小球通过两种亚细胞途径降解。 相似文献
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为揭示蚜虫取食对杏叶片细胞分化、果枝节间伸长和花芽形成量的影响,对‘金太阳’杏被桃蚜取食与未被取食同龄幼叶超微结构、果枝节间长度和每节花芽数进行比较,结果表明：（1）被取食幼叶叶肉细胞比未被取食同龄幼叶叶肉细胞明显小,显示其生长较慢。（2）被取食与未被取食同龄幼叶叶肉细胞的质体差异显著,未被取食幼叶中质体凸透镜形,含丰富类囊体和发达基粒,表现叶绿体形态结构;被取食幼叶中质体球形或椭球形,含少量类囊体,不具叶绿体形态结构。（3）被取食果枝节间长度显著短于未被取食果枝,相反,被取食果枝每节花芽数显著多于未被取食果枝。因此认为,蚜虫取食阻碍杏叶细胞生长和分化,抑制果枝节间伸长,每节花芽数增加。 相似文献
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采用透射电子显微镜、组织化学和荧光显微镜相结合的方法对华南忍冬（Lonicera confusa DC.）不同发育阶段的花结构差异及其绿原酸积累规律进行系统分析。结果显示：随着花的发育,花冠筒叶绿体结构逐渐完善并积累淀粉粒,幼蕾期叶绿体已有基粒和基粒片层出现,但没有明显的淀粉粒出现;绿蕾期叶绿体结构完整,积累有一至数个淀粉粒;白蕾期叶绿体数量少,含有丰富的淀粉粒;银花期和金花期叶绿体极少;花冠筒木质部导管细胞壁逐渐木质化加厚。在花冠筒中,幼蕾期和绿蕾期绿原酸含量丰富;白蕾期薄壁细胞内绿原酸含量开始减少,维管束仍积累较多的绿原酸;银花期和金花期薄壁细胞绿原酸含量进一步减少且分散分布,维管束累积的绿原酸也减少,主要分布在木射线中。在花萼筒-子房中,不同发育阶段,其薄壁细胞、维管束、中轴胎座和胚珠都有绿原酸分布。表明绿原酸可能在叶绿体内合成,然后转至细胞液中聚合,最后在液泡内积累;叶绿体中淀粉粒数量与绿原酸合成呈负相关。 相似文献
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为了解辣椒果实成熟过程中果皮内贮藏物质的变化模式,用光学和透射电子显微技术对绿色和成熟变红果皮进行显微化学和超微结构观察。结果表明,果实充分膨大并且仍呈绿色时,中果皮的薄壁组织和内果皮含大量淀粉粒,中果皮的厚角组织及外果皮无淀粉。果实成熟变红后,淀粉粒消失,果皮积累两种脂滴,外果皮积累质体脂滴,中果皮及内果皮积累质体脂滴和胞质脂滴;胞质脂滴椭球形,存在于细胞质中,沿质膜内表面排列,质体脂滴球形和棒状,存在于有色体中;外果皮中质体脂滴以球形为主,中果皮和内果皮中质体脂滴以棒状为主;胞质脂滴和质体脂滴都与四氧化锇反应,显示脂肪酸链含有双键。归纳起来,果实成熟前,果皮中的贮藏物质是淀粉粒,淀粉积累有组织特异性,只在中果皮的薄壁组织和内果皮中积累;果实成熟变红后,贮藏物质转化成胞质脂滴和质体脂滴,质体脂滴存在于所有组织,而胞质脂滴不存在于外果皮;辣椒油富含不饱脂肪酸。 相似文献
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《果树学报》2015,(4)
【目的】探索枇杷在果实成熟过程中其果肉细胞质体的发育与果肉颜色变化的关系。【方法】以不同颜色的枇杷品种‘黄金块’(橙红)、‘解放钟’(黄色)、‘白玉’(白色)不同发育阶段的果肉为试材,应用光学和电子显微镜观察果肉细胞质体的大小,颜色和超微结构。【结果】通过光学显微镜观察,在果实成熟过程中发现‘黄金块’、‘解放钟’果肉细胞中的质体由叶绿体转变为有色体,而‘白玉’的果肉中没有形成相应的有色体。此外,在对质体的超微结构进行观察时,发现在果实成熟过程中‘黄金块’、‘解放钟’果肉细胞质体中的质体小球逐渐发育,到成熟期有大量的质体小球出现;而‘白玉’果肉细胞质体在成熟过程中没有大量的质体小球出现。【结论】‘黄金块’、‘解放钟’、‘白玉’果肉的不同颜色可能与有色体的形成有关,而质体小球的发育影响有色体的的形成,最终表现为果肉颜色上的差异。 相似文献
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苹果果实发育过程中淀粉代谢和淀粉粒超微结构研究 总被引：3，自引：1，他引：3
苹果果实发育过程中,伴随果糖、葡萄糖和蔗糖的积累,淀粉含量经历了从低到高,又从高到低的变化。发育中后期,果实淀粉与可溶性糖呈现互为消长的变化。淀粉粒超微结构的变化表明,幼果期果肉细胞代谢旺盛,可观察到发育初期的造粉质体和大量的线粒体;发育中期是果实淀粉的主要累积期,整个造粉质体内充满淀粉;成熟期的果肉细胞呈现降解特征,淀粉粒大部分被降解,但淀粉粒表膜依然保持完整。还研究了淀粉代谢及淀粉粒超微结构变化与果实发育的关系。 相似文献
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Sugar and starch levels were determined in leaves, fruits, bark and roots of the ‘Navelate’ variety (low yield) and compared with those of ‘Washington Navel’ (standard yield). Old leaves had the lowest sugar content in May, while young leaves had a decreasing content from spring to summer in both varieties. ‘Navelate’ had lower sugar content in leaves, bark and roots than ‘Washington Navel’. Starch levels in the leaves showed a maximum towards the end of May. In winter, ‘Navelate’ had a higher starch content, mainly in the roots and bark, due to its low yield. 相似文献
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以超表达平邑甜茶（Malus hupehensis Rehd. var. pingyiensis Jiang）SnRK1（蔗糖非发酵–1–型相关蛋白激酶–1）基因MhSnRK1的番茄株系O-7及野生型番茄（Solanum lycopersicum）为试材,研究MhSnRK1对番茄植株碳代谢的影响。结果表明,与野生型番茄相比,超表达MhSnRK1番茄数字基因表达谱分析显示,光合途径中差异表达的10个基因中7个基因转录被上调;功能叶片的净光合速率日变化平均值提高20.3%;嫩叶及功能叶SnRK1酶活性比野生型功能叶提高20.6%和25.0%,可溶性糖提高57.7%和27.0%;超表达MhSnRK1番茄嫩叶SnRK1酶活性明显高于功能叶,淀粉含量提高了近1倍,而野生型番茄嫩叶及功能叶差异不明显。海藻糖处理后,超表达MhSnRK1番茄和野生型番茄净光合速率都下降,且野生型下降幅度大于超表达MhSnRK1番茄;超表达MhSnRK1及野生型番茄嫩叶和功能叶SnRK1酶活性都降低,但超表达MhSnRK1番茄仍高于野生型。 相似文献
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萝卜花芽分化过程中茎尖和叶片碳水化合物含量的变化 总被引：9，自引：0，他引：9
以萝卜冬性品种‘一点红’和春性品种‘短叶13’为材料，研究花芽分化过程中茎尖和叶片以及萌动种子碳水化合物含量的变化。萌动种子在5℃下处理20 d，然后在温暖(>15℃)、长日照(16h)下生长，于不同花芽分化时期测定可溶性总糖、蔗糖和淀粉含量。结果表明：在花芽分化期间，无论是茎尖或是叶片，可溶性总糖、蔗糖和淀粉含量的变化趋势在两个品种之间较为接近。随着花芽分化的继续，可溶性总糖含量呈先上升后下降的趋势；蔗糖和淀粉含量则一直呈现上升趋势，在花芽分化完成后再下降。叶片中可溶性总糖、蔗糖和淀粉含量始终低于茎尖。冬性品种的蔗糖和淀粉含量在整个花芽分化期间始终较低，但在花芽分化初期的可溶性总糖含量则高于春性品种。 相似文献
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Container-grown Ligustrum ovalifolium L. plants were used to determine the influence of nutrient availability on the mobilisation of carbon (C), nitrogen (N) and phosphorus (P) during spring growth. During the spring of the second growing season, plants either received no fertiliser, or were fertilised early (starting 17 days after bud break) or late (starting 3 months after bud break). Nutrient composition of different plant tissues was determined at several times during the second growing season from bud break to the end of elongation. Time of fertilisation did not influence aerial dry weight until flowering was completed. Plants that received no fertiliser or were fertilised late had greater root dry weight than plants that received fertiliser early. Fertilised plants had a second flush of growth after flowering completed. Nitrogen and phosphorus mobilisation occurred from bud break to the end of elongation (3 months). Nutrient mobilisation was effective in each perennial organ: root, trunk, ligneous stems and old leaves. However, the role of old leaves as storage organ was minor compared to evergreen tree leaves. Carbon mobilisation only occurred on the 1st month following bud break, before elongation. C-starch accumulation was observed in unfertilised plants even when the C-starch quantities in early fertilised plants were very low at the end of elongation, mainly in roots. In spite of fertilisation supplies, N and P quantities did not increase after elongation in the early fertilised plants, probably in relation to C insufficiency in roots to sustain N and P absorption and assimilation. By contrast, in late fertilised plants, high C quantities in roots were mobilised for N and P uptake and assimilation, which allowed both second growth flush and storage of N and P in perennial organs. The mobilisation of nutrients before and during elongation revealed the nutritional autonomy of shrubs, which could allow fertiliser use efficiency to be increased and environmental impacts to be minimised by delaying spring fertilisation. Nevertheless, the shrub ability to valorise fertilisation supplies for sustaining growth or nutrient storage restoration required sufficient C-starch quantities in roots. The starch accumulated in roots before late nutrient supply can be used for these objectives. 相似文献
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E.E. Goldschmidt N. Aschkenazi Y. Herzano A.A. Schaffer S.P. Monselise 《Scientia Horticulturae》1985,26(2):159-166
Girdling in October of small or large fruitless branches increased 2–3-fold both starch content of leaves and flower numbers as compared with ungirdled ‘Murcott’ mandarin trees. Autumn girdling and GA3 treatments were both effective and additive in increasing starch contents of leaves and twigs of ‘Shamouti’ orange trees. GA3, however, had the expected effect of depressing the reproductive inflorescences in both girdled and ungirdled branches, while girdling had the opposite effect. Girdling and fruit removal in October also additively and dramatically increased flower production in ‘Murcott’. Lowtemperature regimes in a phytotron caused young ‘Minneola’ budlings to flower earlier in the season and more profusely, while having no effect on starch content of leaves and twigs. The interactions of increased carbohydrate content and gibberellin in the control of flower formation in citrus are discussed. 相似文献
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《Scientia Horticulturae》2004,102(4):433-440
Carbohydrate partitioning was investigated in different plant organs of Lachenalia cv. Ronina during bulb production under a low temperature regime. At 4-week intervals, data were collected on bulb, roots, leaves, inflorescence and carbohydrate composition. The roots and especially the bulb were found to be the main starch sinks of the plant, whilst the leaves and the inflorescence were the main source for soluble sugars. Changes in the starch concentration closely followed dry weight changes in the bulb during the growing season. When bulbs were initially exposed to a low temperature, starch was converted to soluble sugars, but thereafter sugars were low, indicating continued export and conversion to starch. Low sugar levels in the leaves and high levels in the inflorescence, with continuous starch increase in the bulb and roots, probably indicate that the inflorescence, but especially the leaves, produced ample photosynthates during the growing season. 相似文献