新疆2种盐生补血草营养器官的解剖学研究

采用叶片离析法和石蜡切片法,对生长在新疆盐渍环境中的大叶补血草[Limonium gmelinii(Willd.) Kuntze]和耳叶补血草[Limoniumotolepis(Schrenk) Kuntze]的营养器官解剖学特征进行了观察研究.结果显示,2种补血草属典型泌盐植物,茎和叶片表皮上分布有多细胞组成的盐腺;叶表皮细胞排列紧密,其外切向壁增厚,表皮外还被有厚的角质层;上下表皮都有气孔,气孔与表皮细胞平齐,为不等型气孔;其中大叶补血草为异面叶,而耳叶补血草为等面叶.2种补血草茎中都散生有多轮维管束;大叶补血草根中还有大量通气组织等.研究结果表明,2种补血草的解剖结构表现出与其生境相适应的特征.     

烟台补血草盐腺结构及发育过程观察

利用叶表皮离析、扫描电镜以及常规石蜡切片法对烟台补血草[ Limonium franchetii( Debx.) Kuntze]叶片盐腺的分布和结构特征及其发育过程进行了观察.结果表明:烟台补血草叶片上、下表皮均有盐腺分布,上、下表皮的盐腺密度分别为7.57和8.09 mm-2,同一时期叶片上表皮盐腺密度略小于下表皮.烟台补血草的成熟盐腺是由20个细胞构成的复合结构,其中,中央有4个分泌细胞,每个分泌细胞外侧均伴有1个长方形的毗邻细胞,再向外依次包围着4个内杯状细胞和4个外杯状细胞,靠近叶肉细胞处还有4个收集细胞,收集细胞与盐腺的其他细胞同源;在4个分泌细胞顶端的角质层中央各有1个小孔,称为泌盐孔.烟台补血草盐腺发育过程依次经历原表皮细胞期、2细胞期、4细胞期、8细胞期、16细胞期和20细胞期6个阶段,由1个单独的原表皮细胞发育而成,发育过程中细胞均进行垂周分裂;另外,同一时期的叶片存在盐腺发育不同步的现象.根据观察结果推测烟台补血草主要通过泌盐孔L向外泌盐.     

耳叶补血草的组织培养与快速繁殖

1植物名称 耳叶补血草（Limonium otolepis Kuntze）。 2材料类别花茎。     

二色补血草叶片泌盐结构的扫描电镜观察

对二色补血草盐泉结构进行比较研究,发现二色补血草叶下表皮具有花型盐腺,这些盐腺是由基细胞和帽细胞构成,植物体靠盐腺的泌盐孔和基细胞破碎释盐,表明二色补血草具有演化较高级的双重泌盐结构,是二色补血草能在盐碱地生长而不受盐害的主要原因。     

新疆四种补血草属植物叶片的解剖学研究

利用叶片离析法和石蜡切片法研究了补血草属4种植物叶片的形态结构。结果表明:(1)4种植物的叶片有许多共同的结构适应特征,表皮细胞排列紧密,表面有厚的角质层;气孔类型均为不等型,气孔位置为平置或略微下陷;上下表皮还具有多细胞构成的盐腺;栅栏组织发达,多为等面叶;存在粘液细胞和单宁细胞;机械组织和维管组织都不发达等。(2)不同种间有不同的结构适应特征,如表皮细胞的形状、大小、垂周壁饰样,气孔密度,盐腺密度,叶片厚度和栅栏组织厚度等。通过叶的结构特征反映出盐生植物与旱生植物的不同。     

四种野生盐生植物解剖结构与抗旱耐盐性

为了解盐生植物的解剖结构与抗盐性和抗旱性的关系,以二色补血草、草木樨,艾蒿、猪毛菜为材料,通过徒手切片和显微观察了植物的叶、茎、腺毛、分泌腔、气孔、表皮毛分布和结构。结果显示:猪毛菜的气孔密度低、气孔器小,表皮毛密集,叶面积小,抗旱能力最强;艾蒿的表皮毛长、浓密,气孔密度较低、气孔较小,抗旱性较强;二色补血草表皮毛短、密集,但气孔密度较高、气孔器较大,抗旱性较差;草木樨表皮毛短、稀疏,气孔密度较高、气孔也较大,抗旱性最差;二色补血草有发达的内分泌和外分泌组织,根系吸收的大量盐份积累在分泌腔中,并通过盐腺排出叶片,是排盐植物,耐盐性强;猪毛菜具有发达的内分泌组织,有大量分泌腔,且有粘液细胞和大量薄壁细胞,是耐盐植物,耐盐性强;草木樨具有较多的盐腺,是泌盐植物,耐盐性较强;艾蒿无盐腺等分泌组织。猪毛菜可以作为盐碱地"生物脱盐器"。     

中华补血草盐腺发育的解剖学研究

采用叶表皮印痕、扫描电镜以及石蜡切片法对中华补血草的叶片进行解剖研究,观察其成熟盐腺的结构、盐腺的发育与盐腺的密度。结果表明:(1)上表皮的盐腺密度比下表皮的略小。(2)成熟的盐腺由20个细胞构成,中央有4个分泌细胞,每一个分泌细胞外侧又伴有一个长方形的毗邻细胞;向外由2层杯状细胞包围,每一层分别有4个杯状细胞,使盐腺呈近似圆形;盐腺内部靠近叶肉细胞处有4个收集细胞;中央4个分泌细胞顶端的角质层各有一小孔,是盐分泌出的通道。(3)中华补血草盐腺是由一个单独的表皮细胞发育而成,分别经历单细胞时期、2细胞时期、4细胞时期、8细胞时期、16细胞时期和20细胞时期的不同发育阶段。     

黄花补血草叶片盐腺的发育解剖学研究

利用扫描电镜和石蜡切片法对黄花补血草叶片进行解剖学研究,观察叶片营养器官中盐腺的分布、密度、结构及发育过程。结果表明:黄花补血草叶片上、下表皮有大量的盐腺分布,且下表皮的盐腺密度比上表皮的多,盐腺周围有7～9个表皮细胞呈辐射状排列;盐腺的成熟结构由12个细胞构成,中央有4个分泌细胞,每个分泌细胞都有一个明显的分泌孔,是盐分泌出的通道;分泌细胞外侧伴有4个弧形的毗邻细胞围成一圈;盐腺内部靠近叶肉细胞处有4个收集细胞。研究认为,黄花补血草盐腺由一个表皮原始细胞发育而成,分别经历单细胞时期、2细胞时期、4细胞时期、8细胞时期和12细胞时期的不同发育阶段。     

运城盐湖4种藜科盐生植物叶的比较解剖研究

应用扫描电镜和光学显微镜对山西运城盐湖周围盐渍环境中4种藜科（Chenopodiaceae）盐生植物叶的结构进行了比较解剖研究。结果表明,碱蓬（Suaeda glauca Bunge）和盐地碱蓬（Suaedasalsa（Linn．）Pall．）属真盐生植物,结构特征相似：叶线形、肉质化,表皮上气孔器密集,叶肉具有发达的储水组织细胞和栅栏组织。灰绿藜（Chenopodium glaucum Linn．）和西伯利亚滨藜（Atriplex sibirica Linn．）为泌盐盐生植物,其中,灰绿藜具有双细胞构成的盐腺,西伯利亚滨藜则具有盐囊泡,此外,两种泌盐盐生植物中存在的异细胞和含晶细胞,对适应盐生环境有积极意义。从表皮细胞来看,4种植物的叶都有相同的适盐特征。总之,4种藜科盐生植物的叶片结构具有适盐的共同性和个体的多样性特征。     

中国蓼属分叉蓼组和冰岛蓼属植物叶下表皮微形态研究

采用光学显微镜对中国蓼属分叉蓼组(Polygonum section Aconogonon)和冰岛蓼属(Koenigia)的21种植物的叶下表皮微形态进行了观察研究。结果表明,其叶下表皮微形态特征可分为三种类型：（1）气孔器类型为无规则型,表皮细胞多边形,垂周壁为波状;（2）气孔器类型为无规则型兼有非典型不等型,表皮细胞为多边形或不规则形,垂周壁为平直弓形或波状;（3）气孔器类型为不等细胞型,表皮细胞多边形,垂周壁为平直弓形。分叉蓼组（西伯利亚蓼除外）植物的叶表皮气孔器类型具有高度一致性,说明该组是一个自然类群。本文研究结果不支持将大铜钱叶蓼(Polygonum forrestii Diels)、铜钱叶蓼(P. nummularifolium Meissner)划归于冰岛蓼属的处理意见;支持将西伯利亚蓼(P. sibiricum Laxm.)独立成属,即西伯利亚蓼属(Knorringia Tzvel.)的观点;同时也支持仍将多穗蓼(P. polystachyum Wall.ex Meissner)和松林蓼(P. pinetorum Hemsl.)归在分叉蓼组的处理意见。     

Study on pathway and characteristics of ion secretion of salt glands of Limonium bicolor

Recretohalophytes with specialized salt-secreting structures, including salt glands and salt bladders, can secrete excess salts from plant tissues and enhance salinity tolerance of plants. However, the pathway and property of salt secretion by the salt gland has not been elucidated. In the article, Limonium bicolor Kuntze was used to investigate the pathway and characteristics of salt secretion of salt gland. Scanning electron microscope micrographs showed that each of the secretory cells had a pore in the center of the cuticle, and the rice grain-like secretions were observed above the pore. The chemical composition of secretions from secretory pores was mainly NaCl using environmental scanning electron microscope technique. Non-invasive micro-test technology was used to directly measure ion secretion rate of salt gland, and secretion rates of Na⁺ and Cl^? were greatly enhanced by a 200-mmol/L NaCl treatment. However, epidermal cells and stoma showed little secretion of ions. In conclusion, our results provide evidence that the salt glands of L. bicolor have four secretory pores and that NaCl is secreted through these pores of salt gland.     

耳叶补血草大、小孢子发生与雌、雄配子体的发育

本文较系统地报道了耳叶补血草(Limonium otolepis(Schrenk.)Kuntze.)的大、小孢子发生和雌、雄配子体形成过程.主要结果:(1)小孢子母细胞减数分裂过程中的胞质分裂为同时型,小孢子四分体多为正四面体形,少数左右对称形;(2)成熟的花粉为三细胞型,具3个萌发孔;(3)花药壁由5层细胞组成,最外层为表皮,其内分别为药室内壁、中层、绒毡层,绒毡层为变形型,花药壁的发育属于基本型;(4)耳叶补血草的雌蕊由5心皮组成,柱头、花柱分离,子房合生,1室,基生胎座,胚珠1个,拳卷型,双珠被,厚珠心,珠孔由内珠被形成;(5)孢原细胞发生于珠心表皮下,经1次平周分裂,形成造孢细胞,由造孢细胞直接发育成大孢子母细胞,大孢子母细胞减数分裂形成4个大孢子呈直线排列,合点端大孢子具功能,属于典型的蓼型胚囊发育.     

Ovexpression of a Vacuolar H<Superscript>+</Superscript>-ATPase c Subunit Gene Mediates Physiological Changes Leading to Enhanced Salt Tolerance in Transgenic Tobacco

H⁺-ATPase subunit c (VHA-c) is involved in the adaptation to environmental stresses, including salt, drought, and heavy metals. However, it remains unclear whether VHA-c can induce a physiological response related to stress tolerance. To investigate this possibility, we generated transgenic tobacco lines overexpressing a V-ATPase subunit c (LbVHA-c1) gene from Limonium bicolor (Bunge) Kuntze. Compared with wild-type (WT) tobacco, superoxide dismutase (SOD) and peroxidase (POD) activities in the transgenic plants were significantly enhanced under salt stress conditions. The level of malondialdehyde (MDA) in the transgenic plants was significantly lower than that in WT plants grown under salt stress conditions. Moreover, the transgenic plants displayed obviously better growth than the WT plants under salt stress. These results suggest that LbVHA-c1 may confer stress tolerance through enhancing POD and SOD activities, and by protecting membranes from damage by decreasing lipid peroxidation under salt stress.     

补血草愈伤组织中渗透调节物对NaCl胁迫的响应

用不同浓度的NaCl处理盐生植物黄花补血草和大叶补血草愈伤组织,研究其中H2O2、MDA及渗透性调节物质等生理指标含量的变化,从细胞水平分析比较2种补血草愈伤组织对盐环境的适应机制.结果表明:随NaCl胁迫浓度的升高,2种补血草愈伤组织的H2O2和MDA含量逐渐显著增加;愈伤组织中脯氨酸含量增加幅度在75和150mmol/LNaCl下明显表现为黄花补血草大于大叶补血草,而其中的可溶性糖含量增加程度于相同NaCl浓度下明显呈现出黄花补血草小于大叶补血草的趋势;可溶性蛋白含量在黄花补血草中随NaCl浓度升高而逐渐增加,但在大叶补血草中却表现为低浓度(75mmol/L)比对照升高,而高浓度(150和300mmol/L)比对照明显减少的趋势.研究发现,2种补血草愈伤组织中脯氨酸、可溶性糖和可溶性蛋白这些有机渗透性调节物质对盐胁迫的反应特性存在差异,并与其耐盐性有关.     

Progress in mechanism of salt excretion in recretohalopytes

The recretohalophyte with specialized salt-secreting structures including salt glands and salt bladders can secrete salt from their bodies and easily adapt themselves to many kinds of salt habitats. Salt glands and salt bladders, arose from dermatogen cells, are excretory organs specially adapted for dealing with ionic homeostasis in the cells of recretohalophytes. The main function of salt glands or salt bladders is to secrete excess ions that invade the plant. The structures of salt glands or salt bladders differ among plant species. In addition to structural differences, salt glands also differ in their secretion abilities. In this review, we mainly focus on recent progress in the mechanism of salt excretion of salt glands and salt bladders, and in particular, emphasize the vesicle-mediated secretion systems from the vacuole to the plasmalemma and the possibly involved membrane-bound translocating proteins for salt secretion of plant gland secretory cell.     

Modification of plant architecture in Limonium spp. induced by rol genes

An Agrobacterium-mediated transformation system for Limonium has been developed. The leaf explants of the sterile hybrid L116 (Limonium otolepis, Kuntze × Limonium latifolium, Kuntze) were inoculated with A. tumefaciens LBA4404 harboring the binary vector pBin19 containing a T-DNA fragment encompassing rol A,B and C genes of A. rhizogenes Ri plasmid (pRi1855). Transgenic shoots, regenerated on selection medium, were micropropagated, rooted, and transferred to soil. Southern analysis confirmed the insertion of rol genes into the plant genome. Three transgenic clones were selected and based on their phenotypic characteristics were named super-compact, compact and semi-compact types. In general the transformed plants showed ornamental traits such as dwarfness and early flowering which are highly desirable. This revised version was published online in June 2006 with corrections to the Cover Date.     

Isolation of ACC deaminase-producing habitat-adapted symbiotic bacteria associated with halophyte Limonium sinense (Girard) Kuntze and evaluating their plant growth-promoting activity under salt stress

Background and aims

Many plant growth-promoting endophytes (PGPE) possessing 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity can reduce the level of stress ethylene and assist their host plants cope with various biotic and abiotic stresses. However, information about the endophytic bacteria colonizing in the coastal halophytes is still very scarce. This study aims at isolating efficient ACC deaminase-producing plant growth-promoting (PGP) bacterial strains from the inner tissues of a traditional Chinese folk medicine Limonium sinense (Girard) Kuntze, a halophyte which has high economic and medicinal values grown in the coastal saline soils. Their PGP activity and effects on host seed germination and seedling growth under salinity stress were also evaluated.

Methods

A total of 126 isolates were obtained from the surface sterilized roots, stems and leaves of L. sinense (Girard) Kuntze. They were initially selected for their ability to produce ACC deaminase as well as other PGP properties such as production of indole-3-acetic acid (IAA), N₂-fixation, and phosphate-solubilizing activities and subsequently identified by the 16S rRNA gene sequencing. For selected strains, seed germination, seedling growth, and flavonoids production in axenically growth L. sinense (Girard) Kuntze seedlings at different NaCl concentrations (0–500 mM) were quantified.

Results

Thirteen isolates possessing ACC deaminase activity were obtained. The 16S rRNA gene sequencing analysis showed them to belong to eight genera: Bacillus, Pseudomonas, Klebsiella, Serratia, Arthrobacter, Streptomyces, Isoptericola, and Microbacterium. Inoculation with four of the selected ACC deaminase-producing strains not only stimulated the growth of the host plant but also influenced the flavonoids accumulation. All four strains could colonize and can be re-isolated from the host plant interior tissues.

Conclusions

These results demonstrate that ACC deaminase-producing habitat-adapted symbiotic bacteria isolated from halophyte could enhance plant growth under saline stress conditions and the PGPE strains could be appropriate as bioinoculants to enhance soil fertility and protect the plants against salt stress.