Thermal-Stable Proteins of Fruit of Long-Living Sacred Lotus Nelumbo nucifera Gaertn var. China Antique

Single-seeded fruit of the sacred lotus Nelumbo nucifera Gaertn var. China Antique from NE China have been shown to remain viable for as long as ~1,300 years, determined by direct radiocarbon-dating, and to have a germination rate of 84 %. The pericarp, a fruit tissue that encloses the single seeds of Nelumbo, is one of the major factors contributing to fruit longevity. Proteins that are heat stable and have a protective function are equally important to such centuries-long seed viability. We document proteins of Nelumbo fruit that are able to withstand heating, 32 % of which remained soluble in the 110 °C-treated embryo axis of a 549-year-old fruit and 76 % retained fluidity in its cotyledons. The genome of Nelumbo has recently been published and annotated. The amino-acid sequences of 11 “thermal proteins” (soluble at 100 °C) of modern Nelumbo embryo axes and cotyledons, identified by mass spectrometry, Western blot and bioassay, are assembled and aligned with those of an archaeal hyperthermophile Methancaldococcus jannaschii (“Mj,” an anaerobic methanogen having a growth optimum of 85 °C) and with those of five mesophile angiosperms. These thermal proteins have roles in protection and repair under stress. More than half (55 %) of the durable Nelumbo thermal proteins are present in the archaean Mj, indicating their ancient history. One Nelumbo protein-repair enzyme exhibits activity at 100 °C, having a heat-tolerance higher than the comparable enzyme of Arabidopsis. A list of 30 sequenced but unassembled thermal proteins of Nelumbo is appended.     

Secretome Prediction and Analysis in Sacred Lotus (Nelumbo nucifera Gaertn.)

Sacred lotus, Nelumbo nucifera (Gaertn.), is a basal eudicot with agricultural and medicinal importance. The secretome and proteins in some other subcellular locations including endoplasmic reticulum (ER), mitochondrion, chloroplast, and membrane of sacred lotus were predicted using a set of computational tools. The distribution of proteins in each subcellular location in sacred lotus was compared with proteins in five other plant species. Plant proteomes contained approximately 6–9 % of secreted proteins, 13–15 % membrane proteins, 12–20 % mitochondrial or chloroplast proteins, respectively. Plant secreted proteins consist of a large number of hydrolases and peroxidases which may contribute to cell wall formation, rhizome development and seed germination regulation. The information of secretome and other protein subcellular locations in sacred lotus and other species can be accessed at the PlantSecKB website (http://proteomics.ysu.edu/secretomes/plant.php).     

花莲种质资源形态性状多样性研究(英文)

对从国家种质资源圃中选取的40份花莲种质资源的19个形态性状进行了观察。结果发现花型、花瓣数、雌蕊是否瓣化、雌蕊瓣化程度和根茎颜色与花蕾形状呈显著正相关,其中花型、花瓣数和根茎颜色与花蕾形状呈极显著高度相关。通径分析表明现蕾期对花型有显著正向效应(0.552),其次是花瓣数(0.516)和根茎颜色(0.368)。与花型呈显著负相关的性状有花瓣长(-0.801)、现花期(-0.558)和叶宽(-0.451)。主成分分析显示前四个成分累计贡献率达65.68%。聚类分析将所有材料分为四组。     

The Phloem of Nelumbo nucifera Gaertn

In common with other aquatic angiosperms, Nelumbo nucifera Gaertn.has a relatively strongly developed phloem tissue. The vascularsystem consists of discrete collateral bundles in which no cambiumdevelops and the phloem and xylem are separated by a narrowlayer of parenchyma cells. The phloem consists of sieve elements,companion cells, and phloem parenchyma cells. The sieve elementshave transverse end walls with simple sieve plates. The cellsattain considerable width in the late phloem (metaphloem). Thecompanion cells are in vertical strands. In the early phloem(protophloem) of large bundles the sieve tubes and companioncells are eventually obliterated. The parenchyma cells alsoform vertical strands which may contain tannin cells. Some parenchymacells and companion cells are binucleate. The sieve elementsshow ultrastructural features common for these cells in dicotyledons.At maturity, they lack nuclei, ribosomes, and tonoplasts, butretain a plasmalemma, mitochondria, and plastids. The latterare poorly differentiated and form starch. The endoplasmic reticulumis in part stacked, in part it forms a network next to the plasmalemma.The P-protein occurs in two forms. One consists of tubules notassembled in any specific type of array. The other, possiblycomposed of much extended tubules, is assembled in crystallineaggregates which are retained as such in mature cells. The sieveplate pores are lined with callose and plasmalemma. The lateralwalls are relatively thin and the nacreous layer varies in degreeof distinctness.     

藕莲种质资源形态与农艺性状的遗传变异分析

藕莲是莲（Nelumbo nucifera Gaertn.ssp.nucifera）的3种类型之一,在我国作为水生蔬菜栽培的历史愈两千年。对国家种质资源圃中来自17个省和直辖市的68份藕莲资源的19个形态和农艺性状进行了观察,并对其遗传变异进行了分析。结果发现整藕重与主藕重、主藕长和第三节粗成极显著正相关。通径分析结果表明主藕重对整藕重的正向效应最高（0.982）。主成分分析结果显示前4个成分占总变异的77.33%。结果还显示对整藕重负效应最高的是主藕重/整藕重（-0.296）。聚类分析发现所有藕莲资源可分为5组。     

试管藕诱导技术研究

莲藕 ( Nelumbo nucifera Gaertn.)在我国有着悠久的栽培历史 ,分布极为广泛 ,是一种重要的水生蔬菜和水生观赏植物 ,但其繁殖系数较低 ( 1∶ 1 0 ) ,远途运输费用高。为此 ,我们已进行了快繁技术研究 [1 ] ,但试管苗的成活率较低 ,因此我们开展了试管藕的诱导工作。试管藕作为一种休眠和繁殖器官 ,利于成活 ,便于运输。此外 ,还可以进行离体保存及其他的生理、生化方面的研究工作 ,为这些研究提供一个可操作的简单系统。1 　材料与方法1 .1 　材料取国家种质水生蔬菜资源圃试验田的鄂莲一号和鄂莲四号的茎尖。1 .2 　方法将取回的鄂莲一号…     

藕莲种质资源形态与农艺性状的遗传变异分析(英文)

藕莲是莲(Nelumbo nucifera Gaertn.ssp.nucifera)的3种类型之一,在我国作为水生蔬菜栽培的历史愈两千年。对国家种质资源圃中来自17个省和直辖市的68份藕莲资源的19个形态和农艺性状进行了观察,并对其遗传变异进行了分析。结果发现整藕重与主藕重、主藕长和第三节粗成极显著正相关。通径分析结果表明主藕重对整藕重的正向效应最高(0.982)。主成分分析结果显示前4个成分占总变异的77.33%。结果还显示对整藕重负效应最高的是主藕重/整藕重(-0.296)。聚类分析发现所有藕莲资源可分为5组。     

Laticifers in Nelumbo nucifera Gaertn.: Distribution and Structure

The laticifers of Nelumbo nucifera Gaertn. (Nelumbonaceae) occurin vascular bundles and separately from these in the groundparenchyma. In common with laticifers in some other plants,they pass through a stage when they contain numerous small vacuoles,or vesicles, which later merge with the central vacuole. Osmiophilicglobules are formed in the small vacuoles and later releasedinto the central one. Partial disintegration of protoplaststakes place in the central vacuole, apparently by autophagy.The globules are retained. The laticifers are long thin-walledcells. Many show single perforations in the end walls.     

Management and use of Nelumbo nucifera Gaertn. in Thai wetlands

Management and use of Nelumbo nucifera Gaertn.—the lotus plant—was studied in 58 wetlands distributed throughout Thailand. Although traditionally harvested in extractive systems depending on natural wetlands, N. nucifera is now increasingly being managed. Two hundred eighty informants mentioned 20 different uses, mainly for food, medicine, and religious rites, in both subsistence and cash economies. The uses of N. nucifera appeared to be rather generalized throughout the country even if informants in the northern and central regions knew of more uses and ways of commercializing its products, possibly related to the abundance of wetlands and natural stand in those regions, and maybe also cultural differences.     

莲子食用价值研究进展

莲（Nelumbo nucifera Gaertn.）为莲科莲属多年生水生双子叶被子植物,在世界上具有广泛的分布。莲的用途广泛,其各个组织器官都可以食用或药用。莲的种子即莲子是一种广受欢迎的食物,既可鲜食也可加工成各种莲子产品后食用。莲子中含有丰富的淀粉、蛋白质、多糖、氨基酸、矿质元素、酚类、生物碱等成分,既能食用,也具有保健价值。前人对莲子的生长发育及营养价值已经开展了较多的研究,在此基础上,该文主要针对莲子的营养成分、保健功效和加工工艺进行综述,并对莲子的开发应用前景和限制因素进行总结和展望。     

珍稀濒危植物野生莲的适生分布区预测

基于野生莲（Nelumbo nucifera Gaertn.）136个分布点的数据和14个环境因子参数,运用规则集遗传算法（GARP）和最大熵（MaxEnt）两个生态位模型对他们在我国的适生分布区进行预测。结果显示：根据GARP和MaxEnt模型计算得到的ROC曲线下面积的AUC均值分别为0.861和0.964,其中MaxEnt模型的AUC值更大,预测结果更精准。MaxEnt模型预测结果表明,莲的最适分布区主要集中在四川、湖北、湖南等地的大部分地区,江西北部,以及黑龙江、辽宁、浙江、广东等地的小部分地区。刀切法（Jackknife）检测结果表明,影响莲适生分布区的主要环境因子包括：水汽压、海拔、年平均气温、多年平均降水量、最热季节平均温度、最冷季节平均温度、最干月降水量、最冷月最低温和最热月最高温等。适生区环境因子的统计分析结果显示,野生莲最适宜生长在海拔1~2216 m、年降水量丰富（1202.50 mm）、年均温约为16.19℃、最热月温度范围在24.60℃~35.10℃、最冷月均温不低于-0.53℃的地区。研究结果可为有效保护中国野生莲资源提供有利依据。     

The Development of Embryo and Endosperm of Nelumbo nucifera Gaertn

The development of the embryo and endosperm of Nelumbo nucifera Gaertn can be summarized as follows: 1. Embryogenesis of N. nucifera belongs to Solanad type; the 1st mitotic division of the zygote takes place later than that of the primary endosperm nucleus. 2. The development of endosperm basically conforms to the Helobial endosperm. After fertilization, the primary endosperm nucleus divides first transversely. This division results in the formation of two cells. The wall of this division is a little oblique to the longitudinal axis of the embryo sac. In accordance with the character of the endospermic development, it can be divided into, three stages: (1) two-celled endosperm stage, (2) multicellular endosperm stage, and (3) the stage of the endospermic nutrition being absorbed and cells atrophy. The developments of the embryo and endosperm are well correlated. This relation is relatively stable. 3. The cotyledons of the mature embryo are comparatively developed, but the radicle is extremely reduced. 4. As the seed is ripening, a thin membrane remains outside the plumule, which is the remainder of the endosperm. Therefore, the seed of N. nucifera is exalbuminous.     

Genome of the long-living sacred lotus (Nelumbo nucifera Gaertn.)

Background

Sacred lotus is a basal eudicot with agricultural, medicinal, cultural and religious importance. It was domesticated in Asia about 7,000 years ago, and cultivated for its rhizomes and seeds as a food crop. It is particularly noted for its 1,300-year seed longevity and exceptional water repellency, known as the lotus effect. The latter property is due to the nanoscopic closely packed protuberances of its self-cleaning leaf surface, which have been adapted for the manufacture of a self-cleaning industrial paint, Lotusan.

Results

The genome of the China Antique variety of the sacred lotus was sequenced with Illumina and 454 technologies, at respective depths of 101× and 5.2×. The final assembly has a contig N50 of 38.8 kbp and a scaffold N50 of 3.4 Mbp, and covers 86.5% of the estimated 929 Mbp total genome size. The genome notably lacks the paleo-triplication observed in other eudicots, but reveals a lineage-specific duplication. The genome has evidence of slow evolution, with a 30% slower nucleotide mutation rate than observed in grape. Comparisons of the available sequenced genomes suggest a minimum gene set for vascular plants of 4,223 genes. Strikingly, the sacred lotus has 16 COG2132 multi-copper oxidase family proteins with root-specific expression; these are involved in root meristem phosphate starvation, reflecting adaptation to limited nutrient availability in an aquatic environment.

Conclusions

The slow nucleotide substitution rate makes the sacred lotus a better resource than the current standard, grape, for reconstructing the pan-eudicot genome, and should therefore accelerate comparative analysis between eudicots and monocots.     

Cloning and Characterization of the Wx Gene Encoding a Granule-Bound Starch Synthase in Lotus (Nelumbo nucifera Gaertn)

The granule-bound starch synthase (GBSS) proteins were widely considered as one of the most important enzymes in plant amylose synthesis. However, understanding of the molecular basis of the GBSS protein in lotus remains fragmented. In this work, a lotus Wx gene, encoding a GBSS (GenBank accession no. EU938541), was isolated and characterized. This gene comprises 13 exons and 12 introns and covers 4152?bp (GenBank accession no. FJ602702). The exons of Wx gene have similar lengths, while the introns vary greatly. Phylogenetic tree indicated that the lotus GBSS protein belongs to a GBSS I subgroup. The expression of the Wx gene varies in different organs of the lotus during its development process and is also expressed differently in different cultivars. The Wx gene is expressed at a higher level in the rhizomes of cultivar Meirenhong than in those of cultivar Elian 4. This study elucidates more molecular information about the Wx gene in lotus and provides a theoretical foundation for the genes regulation and the modification of starch quality.     

莲胚芽暗萌发过程中的光合系统发育研究

被子植物在黑暗中萌发生长不能合成叶绿素和建成光合系统,但是将莲（Nelumbo nucifera Geartn.)胚芽置于黑暗中萌发生长时,却可以清楚地观察到它的光合系统进行发育;首先,在原位低温荧光光谱上,LHCⅡ的荧光发射逐步红移变成典型的PSⅡ荧光发射,同时随着萌蝗延长,PSⅠ的荧光发射也从无到有,逐渐增强;其次,对暗萌发10d莲苗的叶绿体进行部分变性凝胶电泳分析也得到了PSⅠ的叶绿素蛋白复合物条带。通过Western blots的蛋白免疫检测,在暗萌发莲苗中也证实了LHCⅠ组分中有Lhca1的存在;最后,对暗萌发莲苗叶绿体的PSⅡ和PSⅠ电子传递活性测量结果表明,在暗中发育形成的PSⅡ和PSⅠ核心都是有光化学活性的。章讨论了莲胚芽暗萌发过程中进行光合系统发育的原因。     

Short photoperiod induces dormancy in Lotus (Nelumbo nucifera)

BACKGROUND AND AIMS: Lotus (Nelumbo nucifera) has been cultivated as an ornamental and food plant in Japan for more than 1000 years. As large areas are required for its cultivation (approximately 2 m2 per plant), physiological research, such as into the effect of environmental factors on dormancy, has not been well studied until recently. In this paper, seedlings were used to examine environmental factors affecting dormancy induction. METHODS: In a first experiment, seeds were sown from 6 April to 6 October at 2-month intervals, and cultivated for 2 months in an unheated greenhouse. In a second experiment, seeds were prepared for germination on 16 November and 16 May and the seedlings were grown at 25 or 30 degrees C under natural daylength in phytotron growth rooms. After 1 month, the seedlings were cultivated at 20, 25 or 30 degrees C for a further month. The number of leaves and rhizome branches on the main stem were counted, and growth of rhizomes on the main stem was calculated using a rhizome enlargement index (= maximum internode diameter/internode length) after 2 months of culture in both experiments. KEY RESULTS: Rhizomes elongated without enlargement when the seeds were sown in April and June. Sowing the seeds in August and October resulted in rhizome enlargement from the tenth and fifth internodes, respectively. Rhizomes enlarged in the November-sowing but elongated in the May-sowing irrespective of temperature treatments under natural daylength in the phytotron rooms. The seedlings cultivated from May at 25-30 degrees C for 2 months had more leaves, and more rhizome branches and nodes than those cultivated from November. CONCLUSIONS: Short days led to induced dormancy in lotus.