Effects of Salt Stress on Root Vitality of Limonium bicolor (Bunge) Kuntze

[Objective] This study aimed to investigate the effects of different salt concentrations on the root vitality of Limonium bicolor （Bunge） Kuntze. [Method] Limonium bicolor （Bunge） Kuntze was treated with 0, 100, 200 and 400 mmol/L NaCl, respectively. After two weeks, root vitality, biomass and other physiological indicators were measured. [Result] Salt stress had significant influences on the growth of roots. Root vitality of Limonium bicolor increased firstly and reduced gradually with the increase of salt concentration. [Conclusion] The results indicate that Limonium bicolor has certain salt tolerance ability at low salt concentrations; under relatively high salt concentrations, Limonium bicolor roots can maintain high vitality; however, with the continuous increase of salt concentration, Limonium bicolor roots are damaged, with decreasing vitality.

Cloning of Syntaxin Gene in Limonium sinense Kuntzet

[Objective] The aim was to clone Syntaxin genes in Limonium sinense Kuntze. [Method] Limonium sinense Kuntze leaves were used as materials and total RNA was extracted and transcribed reversely. Nested primers were designed based on EST sequences at 5’ region of Syntaxin, and cDNA obtained through reverse reaction was taken as the template. Sequences of Syntaxin gene at 3’ region were obtained through two rounds of PCR amplifications. [Result] DNA fragments （1 096 bp） were obtained. For LsSyntaxin, open reading frame （ORF） was 816 bp and the encoded amino acids were 271. The relative molecular weight of Syntaxin was 30 254.3 Da and isoelectric point in theory was 5.55. [Conclusion] Syntaxin genes from Limonium sinense Kuntze were cloned. The research laid foundation for the study on Syntaxin gene function in Limonium sinense Kuntze and salt-secreted process.

二色补血草(Limonium bicolor)高频再生体系的建立

以二色补血草的种子和无菌苗的叶片作为外植体,建立其高频再生体系,并对其再生植株过程进行系统研究,研究不同浓度的生长素对试管苗成活率的影响,确定其最适宜的初代、继代增殖、诱导生根培养基。

The RING zinc finger protein LbRZF1 promotes salt gland development and salt tolerance in Limonium bicolor

The recretohalophyte Limonium bicolor thrives in high-salinity environments because salt glands on the above-ground parts of the plant help to expel excess salt.Here,we characterize a nucleus-localized C3HC4(RING-HC)-type zinc finger protein of L.bicolor named RING ZINC FINGER PROTEIN 1(LbRZF1).LbRZF1 was expressed in salt glands and in response to NaCl treatment.LbRZF1 showed no E3 ubiquitin ligase activity.The phenotypes of overexpression and knockout lines for LbRZF1 indicated that LbRZF1 positively regulated salt gland development and salt tolerance in L.bicolor.lbrzf1 mutants had fewer salt glands and secreted less salt than did the wild-type,whereas LbRZF1-overexpressing lines had opposite phenotypes,in keeping with the overall salt tolerance of these plants.A yeast two-hybrid screen revealed that LbRZF1 interacted with LbCATALASE2(LbCAT2)and the transcription factor LbMYB113,leading to their stabilization.Silencing of LbCAT2 or LbMYB113 decreased salt gland density and salt tolerance.The heterologous expression of LbRZF1 in Arabidopsis thaliana conferred salt tolerance to this non-halophyte.We also identified the transcription factor LbMYB48 as an upstream regulator of LbRZF1 transcription.The study of LbRZF1 in the regulation network of salt gland development also provides a good foundation for transforming crops and improving their salt resistance.

Physiological Responses of Limonium aureum Seeds to Ultra-drying

The seeds of Limonium aureum （L.） Hill. were dried from 8.92% to 2.88% moisture content in a desiccating container with silica gel. After ultra-drying the seeds were accelerated aged （50 ℃, 1 month）, and some physiological indices, including the electrical conductivity, dehydrogenase activity, superoxide dismutase （SOD）, peroxidase （POD）, glutathione reductase （GR）, ascorbate peroxidase （APX）, catalase （CAT）, volatile aldehydes and malondialdehyde （MDA） were tested. The results indicated that dehydrogenase, POD, SOD, GR, APX and CAT activities of the ultra-dry seeds were higher than the control seeds, while volatile aldehydes and malondialdehyde were lower than the control group. The results suggest that ultra-drying is beneficial for maintaining the vigor of L. aureum seeds at a high level. Thus, L. aureum seeds could be stored under ultra-dry conditions.

The genome of the recretohalophyte Limonium bicolor provides insights into salt gland development and salinity adaptation during terrestrial evolution

Halophytes have evolved specialized strategies to cope with high salinity.The extreme halophyte sea lavender(Limonium bicolor)lacks trichomes but possesses salt glands on its epidermis that can excrete harmful ions,such as sodium,to avoid salt damage.Here,we report a high-quality,2.92-Gb,chromosome-scale L.bicolor genome assembly based on a combination of Illumina short reads,single-molecule,real-time long reads,chromosome conformation capture(Hi-C)data,and Bionano genome maps,greatly enriching the genomic information on recretohalophytes with multicellular salt glands.Although the L.bicolor genome contains genes that show similarity to trichome fate genes from Arabidopsis thaliana,it lacks homologs of the decision fate genes GLABRA3,ENHANCER OF GLABRA3,GLABRA2,TRANSPARENT TESTA GLABRA2,and SIAMESE,providing a molecular explanation for the absence of trichomes in this species.We identified key genes(LbHLH and LbTTG1)controlling salt gland development among classical trichome homologous genes and confirmed their roles by showing that their mutations markedly disrupted salt gland initiation,salt secretion,and salt tolerance,thus offering genetic support for the long-standing hypothesis that salt glands and trichomes may share a common origin.In addition,a whole-genome duplication event occurred in the L.bicolor genome after its divergence from Tartary buckwheat and may have contributed to its adaptation to high salinity.The L.bicolor genome resource and genetic evidence reported in this study provide profound insights into plant salt tolerance mechanisms that may facilitate the engineering of salt-tolerant crops.

Does persistence of showy calyces in Limonium leptolobum enhance pollinator attraction?

Aims The calyx,the outermost whorl of a flower(usually green),has been considered to function to protect flowers.in some species,how-ever,calyces are colorful and retained during seed development.Limonium species have been exploited as cut flower crops because the calyces persist for several months after the corolla has closed.To explore the adaptive significance of the persistent calyx in a desert plant Limonium leptolobum,we ask whether persistence of caly-ces can enhance pollinator attraction by enlarging floral displays,increasing reproductive success in this self-incompatible species.Methods The yellow flower of L.leptolobum lasted 1-2 days but its white,membranous calyx extended fully after the corolla closed,and per-sisted for over 2 months in the field,making hundreds of‘showy flowers’on one individual.To examine the ecological function of calyces,we test the pollinator attraction hypothesis.in an experi-mental population,we compared the difference in visit frequency and visitor behavior between intact inflorescences and inflores-cences with their calyces removed on the same individual plants.Important findingsin four experimental plots four types of floral visitors were observed including bees,butterflies,syrphid flies and day-flying moths.No significant preference was observed between calyx-free and intact inflorescences for both first arrivals and total visit frequency of all types of floral visitors,indicating that the persistence of calyces did not make plants more attractive to potential pollinators.The pollina-tor attraction hypothesis for the showy calyces was not supported by the current data.Whether the calyx in this desert plant helps seed development or has other functions needs further study.

茉莉花和勿忘我花瓣在沐浴露中的应用

为了找到合适的悬浮剂和防腐剂,在适当的条件下对花瓣进行处理,从而让花瓣在加入到沐浴露产品后,能够长期保持良好的形态,使用高效液相色谱仪(HPLC)和场发射扫描电子显微镜(FESEM)对茉莉花和勿忘我花瓣在预处理前后,以及置于沐浴露5年后的情况进行研究。结果表明,干花瓣采用沸水和强氧化剂处理后,脱去了色素和易挥发的成分;置于沐浴露中5年,依然能够保持花瓣形状完好且均匀悬浮,同时未发现微生物超标现象;由于花瓣中非挥发性物质减少,导致花瓣颜色变淡,质地变薄,但有利于花瓣形态在沐浴露配方中保持稳定。

新疆地区民族药补血草生态适宜性研究

目的通过对新疆地区繁枝补血草、耳叶补血草和大叶补血草等道地药材的生态适宜性分析,预测其适宜生长区域。方法通过近年来对该属植物的实地调查及文献报道,获得184份样本信息,利用最大熵(MaxEnt)模型和ArcGIS软件进行分析。结果影响新疆补血草分布的主要生态因子是8月份平均雨量、温度季节性变化标准差、12月份平均雨量、年降水量、降水量变异系数、土壤湿度指数、6月平均最低温度,最湿月降水量,最暖季度平均温度;最适宜分布区域主要有乌鲁木齐、昌吉、石河子、哈密、博乐、伊犁、塔城、阿勒泰等地等天山北坡前沿地区和伊犁盆地戈壁荒漠盐碱地带。结论本研究所生成生态适宜性区划图,可为新疆地区曲柯尔属植物的野生资源的保护和栽培选址提供理论依据。

黄花补血草个体差异对生殖分配的影响

以平沙地黄花补血草种群为研究对象,以生殖枝冠幅和高度为依据标定植株大小,研究了其个体生长差异对各生殖构件的生物量、生殖配置的影响以及其相关性。结果表明:各生殖构件生物量分别与生殖枝冠幅和高度之间存在显著或极显著的线性相关,其中生殖枝生物量增加最为显著,花生物量次之,二者占绝对优势,种子生物量增加较小,其增加比值约为6.7∶5.3∶1。其各生殖构件的生殖分配与生殖枝冠幅和高度之间存在显著的对数相关,其中与生殖枝分配呈负的对数相关,而与花和种子分配呈正的对数相关,生殖枝与花和种子在生殖资源分配方面存在相互制约的关系。其生殖生长(冠幅、株高)、各生殖构件(生殖枝、花、种子)生物量以及其生殖分配各要素之间均呈显著或极显著相关(除生殖枝高与各生殖构件分配之间相关性不显著),其中生殖枝分配与其它各要素之间呈显著或极显著的负相关,说明生殖枝配置与其它各要素之间存在相互制约关系。

哈萨克药繁枝补血草总黄酮提取分离纯化工艺及抗氧化活性研究

目的建立繁枝补血草总黄酮的最佳提取工艺,利用大孔树脂确定总黄酮最佳纯化工艺,测定其抗氧化活性。方法以繁枝补血草总黄酮含量为指标,选取最适宜繁枝补血草总黄酮的提取方法。根据单因素实验,正交实验选取最优提取工艺。筛选最适宜大孔树脂,确定最佳纯化工艺。利用体外抗氧化能力实验,研究总黄酮的抗氧化能力。结果料液比1∶50 g/ml,50%乙醇加热回流60 min,提取3次,最高提取率13.77%。选用X-5型大孔树脂,样品浓度1.270 mg/ml,70%乙醇洗脱,径高比1∶10,流速2 BV/h,总黄酮纯度80.3%。DPPH清除实验显示,繁枝补血草总黄酮提取物抗氧化能力强,DPPH自由基清除率IC_(50)值为0.8492 mg/ml。结论提取纯化工艺可行,且提取物具有很好的抗氧化活性。

NaCl胁迫对中华补血草活性氧清除能力的影响

[目的]探讨NaCl胁迫对中华补血草活性氧清除能力的影响。[方法]用500 mmol/L NaCl对中华补血草进行处理,分别测定叶片渗透势,MDA含量以及过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)的活性。[结果]MDA含量能维持较低水平,但在处理5 d时达到最高点,而3种抗氧化酶活性呈先升高后下降的趋势,在处理的第5天降至最低,与MDA含量测定结果一致。[结论]补血草在短时间NaCl处理时能依靠抗氧化酶系统及时清除活性氧,减少氧化损伤,维持生长。

黄花补血草形态结构及其生育期研究

通过研究黄花补血草形态结构及物候期表现,掌握其在河西地区的生长发育情况,为黄花补血草人工栽培提供依据。采用显微观察、发芽试验和人工种植的方法对黄花补血草形态结构及其生育期进行了研究。结果表明,黄花补血草花序轴单生或丛出,顶端着生穗状花序。穗状花序上着生小穗3~5个,小穗由3朵小花组成。小花由花柄和花冠组成,1朵小花内有1粒种子,种子位于漏斗状花冠内部。黄花补血草种子千粒重为0.687 g,种子由胚、胚乳和种皮组成,为有胚乳双子叶种子;种子吸水量为干种子重量的69.0%,1~2 h内吸水最快;种子发芽率为96.0%,发芽势为57.7%。种植当年即能开花结实,但营养生长期长于第2年。表明黄花补血草种子为有胚乳双子叶种子,种子8 h吸水饱和,吸水后即萌动,无休眠,当年种植即能开花结实。

干旱胁迫对德国补血草色素含量及光合特性的影响

以德国补血草(Limonium tataticum)为试材,研究干旱胁迫(土壤相对含水量SRW分别为50%、35%、25%)对其色素及光合特性的影响,探讨其抗旱能力。结果表明:随着干旱胁迫程度增加,德国补血草受害症状明显,复水后恢复生长所需时间延长,但各胁迫处理下植株均可以恢复生长;叶绿素含量基本呈下降趋势,但各处理差异不显著;类胡萝卜素含量呈现增加趋势,干旱胁迫处理显著高于对照;可溶性糖含量基本呈先升后降趋势,SRW降至35%时极显著上升,达到最高值。随着干旱胁迫程程度的加深,净光合速率(P_n)和气孔导度(G_s)均呈显著下降趋势;蒸腾速率(T_r)和胞间CO_2浓度(C_i)均呈现先升后降趋势。综合各项指标及观察结果认为,德国补血草有较强的耐旱能力。

水肥耦合对二色补血草生长的影响

二色补血草(Limonium bicolor)是我国北方较为常见的野生植物资源,具有易繁殖、管理简单粗放、花期较长、耐盐碱、耐干旱等特点,在鄂尔多斯市园林绿化中具有广泛的应用前景。文章对二色补血草在不同水肥条件下的生长量和生长状态进行研究,通过盆栽试验条件,设置不同灌水和施肥处理,研究水肥耦合对二色补血草生长的影响,以进一步掌握二色补血草生长习性,为今后鄂尔多斯市园林绿化引种提供管理数据。结果表明:水分和施肥量的增加有利于二色补血草的生长,当土壤含水率为28%、N施肥量为42 ppm时,二色补血草生长状态最佳。

盐胁迫对盐生植物黄花补血草种子萌发和幼苗生长的影响

盐生植物黄花补血草广泛分布于我国西北地区、东北西部以及华北北部,对改良盐碱土壤具有重要的生态作用。以黄花补血草(Limonium aureum(L.)Hill)为材料,研究分析了不同浓度NaCl胁迫对其种子萌发和幼苗生长产生的抑制效应及作用机制。结果表明:低浓度NaCl(25 mmol/L和50 mmol/L)处理不影响黄花补血草种子萌发和幼苗生长,25 mmol/L NaCl甚至促进了根生长,而高浓度NaCl(100 mmol/L和150 mmol/L)处理明显抑制种子萌发及幼苗生长。利用荧光探针的检测结果表明,NaCl处理的幼苗根中过氧化氢(H2O2)和一氧化氮(NO)含量明显高于对照水平。碘化丙啶(PI)染色结合激光共聚焦显微镜观察及检测相对电导率结果显示,高浓度NaCl处理抑制了幼苗根尖伸长区细胞的伸长生长,增加了细胞膜的通透性,对根细胞造成了明显的伤害。此外,高浓度NaCl处理诱导叶片丙二醛(MDA)含量显著升高。以上结果说明,黄花补血草对低浓度的盐具有一定的耐盐性,但高浓度盐降低了种子的萌发率,使幼苗根中H2O2产生增加,抑制根尖伸长区细胞的伸长生长,对根、叶造成明显氧化损伤,从而抑制黄花补血草幼苗的生长。

FAAS法测定二色补血草中不同部位的金属元素

采用浓硝酸-高氯酸（4＋1）溶解消化方法进行样品处理,用火焰原子吸收光谱法对二色补血草花、茎、叶、根中K,Mg,Ca,Na,Fe,Zn,Cu和Co八种微量金属元素进行了分析测定,获得了测定仪器的最佳工作条件、方法的准确性和精密度。结果表明,各元素平均回收率（n=7）在99.3%-105.3%之间,平均RSD值（n=7）为0.34%-1.04%。二色补血草不同部位各金属元素含量有一定差异,花中Na〉K〉Mg〉Ca〉Fe〉Zn〉Co〉Cu,茎中K〉Mg〉Ca〉Na〉Fe〉Zn〉Cu〉Co,叶中K〉Mg〉Ca〉Na〉Fe〉Zn〉Co〉Cu,根中K〉Mg〉Na〉Fe〉Ca〉Zn〉Cu〉Co。各部位均含有丰富的Ca,Mg,K,Na和Fe元素。测定方法快速、简单,准确度和精密度均较好,能达到分析要求。

二色补血草多糖的结构表征及其对Hela细胞的抑制作用

从中药二色补血草中分离提取到一种水溶性多糖 ( LP) . 1 H NMR,1 3C NMR,IR,HPLC和 GC-MS等方法分析表明 ,LP是以α-D-[Glc A( 1→ 6) Glc]二糖为结构单位 ,每个重复的二糖单位彼此以α-( 1→ 4)糖苷键连接成直链多糖 .荧光光谱显示 LP的荧光谱峰出现在 460 nm附近 ,Zn2 + ,Ca2 + 通过与 LP络合 ,其荧光强度增加 .MTT实验表明 ,LP具有抑制肿瘤细胞活性 ,对 Hela细胞抑制的 IC50 为 62 .2 μg/m L.

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.

NaCl处理下两种补血草种子萌发和幼苗抗性的比较

用不同浓度的NaCl处理盐生植物黄花补血草和大叶补血草,研究其种子萌发和幼苗叶片中叶绿素和可溶性蛋白等各项生理指标的变化,分析比较这两种植物的耐盐性。结果表明,NaCl处理抑制两种补血草种子的萌发,此效应具有浓度依赖性,低浓度的NaCl促进黄花补血草根和大叶补血草茎叶的生长,高浓度的NaCl抑制两种补血草幼苗的生长;与对照比,50、150和300 mmol.L-1NaCl处理后,两种补血草幼苗叶片的叶绿素a(Chla)、叶绿素b(Chlb)和叶绿素总量均减少,而H2O2和MDA含量却增加;低浓度的NaCl处理使两种补血草幼苗叶片可溶性蛋白含量增加,而高浓度的NaCl处理使其可溶性蛋白的含量降低。此外,相同浓度的NaCl处理对大叶补血草种子萌发、叶绿素含量等指标的抑制作用明显强于黄花补血草,且其MDA产生明显强于黄花补血草,这些表明黄花补血草可能比大叶补血草具有较强的耐盐性。