TDZ对莴苣(Lactuca sativa L.)器官发生及乙烯形成的影响

为了研究TDZ在植物器官发生中的生理作用，用不同浓度的TDZ替代MS中的BA，发现仅用1／50BA浓度（0．1mg／L）的TDZ处理，已相当于用BA处理所得芽数，可见它具有很强的细胞分裂素活性；但是TDZ又能显著促进乙烯形成，较低浓度时抑制莴苣的器官发生，可能此时乙烯起着主导作用。

Selenium distribution and nitrate metabolism in hydroponic lettuce(Lactuca sativa L.): Effects of selenium forms and light spectra

A deficiency in selenium(Se) in the human diet is a worldwide problem. The intake of Se-rich vegetables can be a safe way to combat Se deficiency for humans. However, most leafy vegetables can accumulate a high content of nitrates, which poses a potential threat to human health. Light is an important environmental factor that regulates the uptake and distribution of mineral elements and nitrogen metabolism in plants. However, the effects of Se forms and light conditions, especially light spectra, on the uptake and translocation of Se and on nitrate reduction are poorly understood. In this study, lettuce(Lactuca sativa L.) was treated with exogenous Se applied as selenate(10 mmol L^-1) and selenite(0.5 mmol L^-1) and grown under five different light spectra: fluorescent light(FL), monochromatic red LED light(R), monochromatic blue LED light(B), and mixed red and blue LED light with a red to blue light ratio at 4(R/B=4), 8(R/B=8), and 12(R/B=12), respectively. The effects of light spectra and Se forms on plant growth, photosynthetic performance, Se accumulation and nitrate reduction were investigated. The results showed that the light spectra and Se forms had significant interactions for plant growth, foliar Se accumulation and nitrate reduction. The Se concentration and nitrate content in the leaves were negatively correlated with the percentage of red light from the light sources. Compared to Se applied as selenite, exogenous Se applied as selenate was more effective in reducing nitrate via promoting nitrate reductase and glutamate synthase activities. The lowest nitrate content and highest plant biomass were observed under R/B=8 for both the selenate and selenite treatments. The significant effect of the light spectra on the root concentration factor and translocation factor of Se resulted in marked variations in the Se concentrations in the roots and leaves. Compared with FL, red and blue LED light led to significant decreases in the foliar Se concentration. The results from this study suggest that the light spectra can contribute to Se distribution and accumulation to produce vegetables with better food quality.

Effects of Priming in Combination with Fungicides on Germination and Infestation of Lettuce (Lactuca sativa L.)

Two seed lots of lettuce (Lactuca sativa L.) cv. Krlowa Majowych were primed in polyethylene glycol (PEG) 8000 at -1.25MPa for 7 days in dark at 20C. Two fungicide treatments combined with PEG were used to control fungi: 1) Funaben T(0.1%) and Apron 35 SD (0.02%) were added to -1.25 MPa PEG solution (PEG+F); 2) After seed priming and drying,Funaben T was mixed at 5 g kg-1 and Apron 35 SD at 1 g kg-1 of seeds (PEG then F dust). PEG, PEG+F and PEG then F dusttreatments reduced significantly thermodormancy and increased the seed germination at 35C in both lots. PEG then Fdust treatment had the best effect on reducing seed thermodormancy at 35C, and increased seed germination to 64.5% inlot 1 and 72.0% in lot 2 compared to 0 in untreated. PEG and PEG then F dust treatments have accelerated germinationspeed at 20 and 15C in both lots. There was a significant reduction in seed infestation in which the seeds were treatedwith PEG+F and PEG then F dust compared to untreated seeds and PEG primed seeds. PEG priming enhanced seedinfestation considerably by Alternaria alternata, Penicillium spp., Rhizopus spp. and Ulocladium spp. Mycologicalanalysis showed higher frequency of Alternaria alternata and Ulocladium spp. in untreated seeds at 20C. Priming incombination with fungicides significantly alleviated the infestation of fungi, especially Alternaria alternata infestation.

Effects of Different Concentrations of Photosynthetic Bacteria Solutions on Yield and Quality of Lactuca sativa L.

The effects of different concentrations of photosynthetic bacteria solutions （CK, 0 ml photosynthetic bacteria agent＋4 000 ml nutrient solution; T1, 200 ml pho- tosynthetic bacteria agent＋3 800 ml nutrient solution; T2, 400 ml photosynthetic bacteria agent＋3 600 ml nutrient solution; T3, 600 ml photosynthetic bacteria agent＋ 3 400 ml nutrient solution; T4, 800 ml photosynthetic bacteria agent＋3 200 ml nutrient solution; and T5, 1 000 ml photosynthetic bacteria agent＋3 000 ml nutrient solu- tion） on the leaf number, fresh mass, root vigor, vitamin C content, soluble sugar content, soluble protein content and nitrate content of hydroponic Lactuca sativa L. were investigated. The results showed that the leaf number was increased by 62.66%, the fresh mass was increased by 139.7%, the root vigor was increased by 132.04%, the vitamin C content was increased by 18.34%, the soluble protein content was increased by 16.60%, the soluble sugar content was increased by 192.37%, and the nitrate content was reduced by 69.44% in the T3 group com- pared with those in the control group. The photosynthetic bacteria solution in the T3 group reduced the content of nitrate and improved the yield and quality of hydroponic L. sativa.

生菜(Lactuca sativa var ro mana Hort.)下胚轴愈伤组织的诱导与植株再生

通过对生菜下胚轴的愈伤诱导和植株再生的研究 ,发现诱导愈伤组织时 ,MS培养基中加 0 .5mg/L 6 BA + 1mg/L 2 ,4 D + 0 .1mg/LNAA效果最好 ,其出愈率达 94 %;愈伤组织分化为芽时 ,在MS + 1.0mg/L 6 BA + 0 .0 5mg/L NAA中分化频率最高 ,达 10 0 %.再生苗可在 1/ 2MS+ 0 .5mg/L NAA中诱导生根成完整植株 .

Environmantal Risk Phytoaccumulation of Arsenic in Spinacea Olaracea L, and Lactuca Sativa L

Pollution of the environment, particularly the soil, appears to be one of the major contemporary issues. In addition, many studies point to the involvement of ecological risk of heavy metals into the food chain through edible plants like Spinaceae oleraceae L. and Lactuca sativa L.. This paper presents the results of the ＂ex-situ＂ application of phytoacumulation on the soils of contaminated terrain using the plant species of spinach （Spinacea oleracea L.） and lettuce （Lactuca sativa L.）. Sequestration of arsen from the soil by these plant species was observed through phytoaccumulation factor--PF and limit values （mg/kg）. The main task and objective of this research was to establish the level of accumulation of toxic element As from the soil by plants and to calculate the PF factor of transfer. The experiment was set up in the control conditions where the soil from eight contaminated locations was placed in the experimental containers. The AAS method was used to analyze heavy metal in plant material and soil. PF factor values ranged from 0.1 to 1.0 which indicates that the spinach and lettuce plants rechargeable moderate compared to arsenic.

Irrigation regimes modulate non-structural carbohydrate remobilization and improve grain filling in rice(Oryza sativa L.)by regulating starch metabolism

Recently developed ‘super’ rice cultivars with greater yield potentials often suffer from the problem of poor grain filling, especially in inferior spikelets. Here, we studied the activities of enzymes related to starch metabolism in rice stems and grains, and the microstructures related to carbohydrate accumulation and transportation to investigate the effects of different water regimes on grain filling. Two ‘super’ rice cultivars were grown under two irrigation regimes of well-watered(WW) and alternate wetting and moderate soil drying(AWMD). Compared with the WW treatment,the activities of ADP glucose pyrophosphorylase(AGPase), starch synthase(StSase) and starch branching enzyme(SBE), and the accumulation of non-structural carbohydrates(NSCs) in the stems before heading were significantly improved, and more starch granules were stored in the stems in the AWMD treatment. After heading, the activities of α-amylase, β-amylase, sucrose phosphate synthase(SPS) and sucrose synthase in the synthetic direction(SSs)were increased in the stems to promote the remobilization of NSCs for grain filling under AWMD. During grain filling, the enzymatic activities of sucrose synthase in the cleavage direction(SSc), AGPase, StSase and SBE in the inferior spikelets were increased, which promoted grain filling, especially for the inferior spikelets under AWMD.However, there were no significant differences in vascular microstructures. The grain yield and grain weight could be improved by 13.1 and 7.5%, respectively, by optimizing of the irrigation regime. We concluded that the low activities of key enzymes in carbon metabolism is the key limitation for the poor grain filling, as opposed to the vascular microstructures, and AWMD can increase the amount of NSC accumulation in the stems before heading, improve the utilization rate of NSCs after heading, and increase the grain filling, especially in the inferior spikelets, by altering the activities of key enzymes in carbon metabolism.

Two new eudesmane sesquiterpenes from Lactuca sativa var.anagustata L

Two new eudesmane sesquiterpene lactones were isolated from the stalk of Lactuca sativa vat anagustata L and their structures were elucidated by means of spectroscopic methods, including 2D NMR （1H-1H COSY, HMBC and NOESY） as 1β-O-β-D- glucopyranosyl-4α-hydroxyl-5α, 6β, 11βH-eudesma-12, 6α-olide （1） and 1β-hydroxyl-15-O-（p-methoxyphenylacetyl）-5α, 6β, 11 βH-eudesma-3-en- 12, 6a-olide （2）.

Anxiolytic property of hydro-alcohol extract of Lactuca sativa and its effect on behavioral activities of mice

Lactuca sativa, belonging to the Asteraceae family, is a leafy vegetable known for its medicinal properties. This study aimed to understand the mechanism of Lactuca sativa extract with respect to pharmacological action. We investigated the anxiolytic effects of hydro-alcoholic extract of leaves of Lactuca sativa on mice. The behav- ioral tests performed on mice models to assess anti-anxiety properties were： open field test （OFT）, elevated plus maze test （EPM）, elevated T maze test, and marble burying test. Increased locomotor activity and time spent in the ＂open-ann＂ were observed in extract fed group. Malondialdehyde （MDA） and nitrite levels were decreased, cata- lase and glutathione levels were increased in Lactuca sativa treated mice. The data obtained in the present study suggests that the extract of Lactuca sativa can afford significant protection against anxiolytic activity.

The auxin transporter OsAUX1 regulates tillering in rice(Oryza sativa)

Tillering is an important agronomic trait of rice(Oryza sativa)that affects the number of effective panicles,thereby affecting yields.The phytohormone auxin plays a key role in tillering.Here we identified the high tillering and semi-dwarf 1(htsd1)mutant with auxin-deficiency root characteristics,such as shortened lateral roots,reduced lateral root density,and enlarged root angles.htsd1 showed reduced sensitivity to auxin,but the external application of indole-3-acetic acid(IAA)inhibited its tillering.We identified the mutated gene in htsd1 as AUXIN1(OsAUX1,LOC_Os01g63770),which encodes an auxin influx transporter.The promoter sequence of OsAUX1 contains many SQUAMOSA PROMOTER BINDING PROTEIN-LIKE(SPL)binding sites,and we demonstrated that SPL7 binds to the OsAUX1 promoter.TEOSINTE BRANCHED1(OsTB1),a key gene that negatively regulates tillering,was significantly downregulated in htsd1.Tillering was enhanced in the OsTB1 knockout mutant,and the external application of IAA inhibited tiller elongation in this mutant.Overexpressing OsTB1 restored the multi-tiller phenotype of htsd1.These results suggest that SPL7 directly binds to the OsAUX1 promoter and regulates tillering in rice by altering OsTB1 expression to modulate auxin signaling.

Assessment of Heavy Metals and Microbial Pollution of Lettuce (<i>Lactuca sativa</i>) Cultivated in Two Sites (Paspanga and Tanghin) of Ouagadougou, Burkina Faso

Environmental pollution can have detrimental effects on crop yield and its consumers. The current study was designed to investigate the potential human health risks associated with the consumption of lettuce crop contaminated with toxic heavy metals and microbiological status. Irrigated water, soil and lettuce were analyzed by AAS technics for heavy metals including Cd, Cr, Cu, Mn, Ni, Pb and Zn. Transfer factor (TF), daily intake of metals (DIM) and health risk index (HRI) were also calculated. Microbial analysis was carried out for the presence foodborne pathogens. The results showed that the heavy metals contents were higher in the soil than wastewater and the vegetables. Heavy metals ranged (mg·Kg-1) for Cd (1.27 to 2.93), Cr (7.28 to 7.38), Cu (0.91 to 1.70), Mn (0.29 to 6.60), Ni (1.74 to 2.16), Pb (1.32 to 1.69), Zn (3.08 to 3.79);and were higher than the WHO maximum limit permissible (ML) in vegetables. HRI TF values designated an enhanced bio-contamination. Microbial numeration revealed the presence of spoiler and pathogenic microorganisms. The lettuce tested was not safe for human use, especially for direct consumption by human beings.

Anxiolytic property of Lactuca sativa,effect on anxiety behaviour induced by novel food and height

Objective:To study anxiolytic property of hydro alchohol extract and to estimate polyphenols present in the extract by HPLC.Methods:To evaluate anxiolytic properly two animal models were used viz.Elevated T maze and hyponeophagia.Diazepam(1 mg/kg body wt.) served as the standard anxiolvtic agent for all the tests.The dried extract of the plant leaf in doses of 100.200 and 400 mg/kg body weight was administered orally to mice for duration of 1? or 30 days and locomotor and anxiolytic activities were performed.Polyphenols was estimated using HPLC. Results:The HPLC analysis of the polyphenols revealed the presence chlorogenic acid,vanillin, epicatechin,caffeic acid,rutin hydrate,sinapic acid,quercetin-3-rhamnoside.p-coumeric acid and quercitin.Time spent and number of entries into the open arm was improved in 30 days treated animals than that of 15 days treated groups,200 and 400 mg/kg body weight treated group showed significant results when comparing with the control group.Conclusions:Te hydro alcohol extract rich in Polyphenols and other secondary metabolites is a potent anxiolytic agent.

Construction of Lactuca sativa Plastid Transformation Vector and High-level Expression of gfp Gene in Escherichia coli

Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragments of exogenous gene were integrated to construct lettuce plastid expression vector p Brpo AGFP,which harbored the expression cassette Prrn-gfp-aad A-Tpsb A. The results showed that the amplified flanking fragments were 1.2 and 1.1 kb in size. After sequencing,restriction digestion,ligation and transformation,lettuce plastid expression vector containing expression cassette Prrn-gfp-aad A-Tpsb A was constructed and confirmed by SDS-PAGE electrophoresis. The results of SDS-PAGE electrophoresis indicated that gfp gene was efficiently expressed under the regulation of plasmid specific promoter Prrn and terminator Tpsb A. GFP accounted for 45. 6% of total soluble proteins; inclusion bodies accounted for 47.5 % of bacterial proteins,which reached relatively high expression levels. The construction of lettuce plastid expression vector p Brpo A-GFP laid a solid foundation for establishment of subsequent lettuce plastid transformation system and genetic improvement of lettuce using various functional genes.

Effect of Cadmium on <i>Lactuca sativa</i>Grown in Hydroponic Culture Enriched with Phosphate Fertilizer

Cadmium (Cd), one of the most toxic heavy metals added to soil after phosphate fertilizer treatment, was investigated. The effects of this metal on morphological and physiological changes of Lactuca sativa were studied in addition to its partitioning in different parts of the crop. In parallel, Lactuca sativa was allowed to grow under hydroponic conditions with modifications of the Hoagland nutrient solution. This solution was submitted to five Cd concentrations, 0, 0.093, 0.186, 0.279 and 0.372 mg Cd/L and three P concentrations, 0, 299 and 1420 mg P/L. The study showed a positive effect of phosphorus on root elongation, surface area while cadmium inhibited plant growth and sometimes the death of the plants. Cadmium was found to be accumulated in roots while zinc was preferably accumulated in the leaves and stems. The increase of performance of Lactuca sativa under hydroponic condition and Hoagland contaminated solution with cadmium was found to be better than the ones grown in Cd amended soil with or without phosphorus.

亚热带地区水稻(Oryza sativa L.)气孔臭氧通量和产量的响应关系

基于开放式臭氧浓度升高O_3-FACE(Free-Air Concentration Elevation of O_3)实验平台,利用前期水稻O_3-FACE试验的基础数据,通过建立水稻产量与不同评价指标(累积气孔O_3吸收通量PODY和O_3浓度指标AOTX)的响应关系,比较了水稻产量损失与各评价指标的相关性差异,通过对暴露剂量、吸收通量相关参数取值与产量损失的观察和分析结果的比较,找出更为合理的农作物臭氧风险评估阈值。结果表明:随着通量阈值Y[0~11 nmol O_3·m^(-2)PLA·s^(-1)(PLA:projected leaf area,投影叶面积)]和暴露浓度阈值X(0~50 n L·L^(-1))的增加,回归分析R^2值逐渐增加,当Y为11 nmol O_3m^(-2)PLA·s^(-1)和X为50 n L·L^(-1)时,气孔臭氧吸收通量POD11和累积暴露剂量AOT50与水稻相对产量的相关性最大,当通量阈值Y为8~13 nmol O_3·m^(-2)PLA·s^(-1)和暴露阈值X为46~58 n L·L^(-1)时,可获得较高的R^2值取值范围,分别为0.70~0.75和0.70~0.745。参考文献发现,目前地表臭氧污染可能引起的水稻产量损失范围为5%~8%,对照圈中POD9~10和AOT40~45产量损失的预测值亦在这区间,但前者R^2值(0.73~0.74)明显高于后者R^2值(0.64~0.69),表明基于气孔臭氧通量的评价指标能更好地反映水稻产量的变化。通过进一步分析发现,当通量阈值Y为9 nmol O_3·m^(-2)PLA·s^(-1)时,能更准确地评估水稻产量损失,且其R^2值(0.73)高于通量指标POD6(0.57)。以上研究结果表明,通量指标POD9更适合评估亚热带地区O_3污染对水稻作物的影响。

水稻(Oryza sativa L·)捕光叶绿素a/b结合蛋白基因全长cDNA的克隆和特性分析

根据捕光叶绿素a／b结合蛋白基因（cab）家族中的保守序列设计PCR引物，扩增出的约310bpcDNA小片段为分子杂交探针，对构建的水稻cDNA文库进行杂交筛选，并结合PCR分析确定阳性克隆中cDNA片段的大小。通过对插入的cDNA片段最长的阳性克隆进行测序分析验证，克隆了水稻中1个cab基因全长cDNA，命名为cab-n8（GenBank登记号：AY445626）。cab-n8长为1128bp，从第55bp开始至789bp含有1个开放阅读框和1个终止密码子，编码244个氨基酸（GenBank登记号为AAR19267．1）；在3’端含有330bp的非编码区和Poly（A）18；在5’端有45bp的非编码区，在转录起始位点附近有TCA序列。通过序列分析，cab-n8编码的蛋白质在第54—216位包括典型的捕光叶绿素a／b结合蛋白功能域（chlorophll a／b binding domain）；在第141—158位含有无名指结构功能域（ring finger structure domain），该位点可能与捕光叶绿素结合蛋白与叶绿素a／b的结合有关；在第194—231位含有甘油醛-3-磷酸脱氢酶C端功能域（C-terminal domain of glyceraldehyde-3-phosphate dehydrogenase-like）。cab-n8编码的蛋白质预测的等电点和分子量分别为6．52和26955．80 Da。通过比较分析，cab-n8DNA序列（AY445626）和编码的氨基酸序列（AAR19267．1）与cab27DNA序列（AF094775．1）和编码的氨基酸序列（AAC67557．1）相似性最高，均为97％，显示cab家族基因在进化过程中是相当保守的。Northern blot分析表明，该基因在水稻叶和茎中表达没有差异，但光对其表达有明显的诱导促进作用。

Analysis of Genetic Relationship among Medicago sativa,Medicago falcate and Trigonella foenum-graecum Using ISSR

[Objective] This study aimed to analyze the genetic relationships among Medicago sativa,Medicago falcata and Trigonella foenum-graecum.[Method] ISSR technique was adopted to determine their genetic relationships.[Result] M.sativa,M.falcate and T.foenum-graecum had a broad genetic base.T.foenum-graecum shared closer relationship with M.falcata rather than M.sativa.The study on relationship between M.sativa and T.foenum-graecum was advantageous to identify disputable transition types.But a boundary should be found to identify species to be M.sativa or T.foenum-graecum.[Conclusion] This study will provide reference for identifying some disputable transition types.

逆境下水稻(Dryza sativa L.)rHsp90基因的克隆及功能分析

本研究中,利用差异显示法,在碳酸盐逆境下,从水稻(OryzasativaL.)根的cDNA文库中克隆得到了水稻热激蛋白90基因(rHsp90,GenBankAccessionNo.AB037681)。Northern杂交结果表明,在水稻根中,rHsp90基因的转录水平在包括盐(NaCl,NaHCO3和Na2CO3),PEG,高pH(pH8.0和pH11.0)以及热激(50℃)逆境下,都受到了不同程度的诱导。同时,适量表达rHsp90基因的酵母(Saccharomycescerevisiae)在各种盐逆境以及热激逆境中,生长状态要好于对照。对转水稻rHsp90基因烟草的抗盐(NaCl,NaHCO3)分析表明,转基因烟草的生长势要好于野生型烟草。通过以上研究表明,水稻rHsp90基因与逆境之间具有一定的应答关系,并在植物适应环境逆境过程中起着重要的作用。

不同遗传背景及环境中水稻(Oryza sativa L.)穗长的QTLs和上位性分析

以粳稻Azucena为父本与舢稻IR64杂交发展的一双单倍体（DH）群体，与籼稻IR1552杂交发展的一重组自交系（RI）群体为材料，应用分子标记图谱对2个群体在大田和盆栽2个环境下的穗长进行QTLs及上位性效应分析。DH群体中共检测到6个穗长QTLs，位于第1、4条染色体上的3个QTLs，在2个环境中稳定表达，未检测到上位性效应，加性效应为穗长遗传主效应。R1群体中，共检测到3个穗长QTLs及6对互作效应位点，位于策4条染色体上的1个QTL及位于第1、12条染色体上的2个互作位点在2个环境中稳定表达，上位性效应表现为遗传主效应。在2个群体中均检测到的与穗长相关的1个QTL位于第4条染色体RG163～RZ23区间内，遗传正效应等位基因来源于Azucena；位于第1条染色体与RG323连锁的位点在DH群体中表现为1个QTL，但在RI群体中表现为互作位点。

Advances in Physiological-biochemical and Genetic Mechanisms of Seed Aging in Rice(Oryza sativa L.)

Reasons causing or accelerating seed aging are mainly damage of mem- branes, DNA and proteins, decline of protein synthesis capacity and excessive ac- cumulation of reactive oxygen species. With the application of natural aging or artifi- cial aging methods, it was reported that quantitative trait loci （QTLs） of seed stora- bility in rice were widely distributed on the chromosomes except the 10th chromo- some. In this paper, we reviewed the progresses in the research on physiological- biochemical and genetic mechanisms of seed aging, and analyzed the existing problems and developing prospect in molecular breeding of rice with improved seed storability, in order to provide reference for the basic research and genetic improve- ment of rice seed storabUity.