Saffron(Crocus sativus L.) stigmas as a potential natural additive to improve oxidative stability attributes of sunflower(Helianthus annuus L.) oil stored under different conditions

The aim of our study was to explore the antioxidant potential of Moroccan saffron stigmas(SS) and examine their performance as a natural antioxidant in enhancing the stability and quality properties of edible sunflower oil(SO), with a focus on understanding the critical importance of edible oil stability for predicting quality deterioration during storage. Bearing this in mind, our research was designed to compare the efficacy of three concentrations of dried SS(at 0.2%, 0.3%, and 0.6%) against tocobiol(a synthetic antioxidant) as a positive control(at 0.3% concentration). This comparison was conducted under three distinct storage conditions namely accelerated ageing(60 ℃), exposure to light at ambient temperature, and darkness, to evaluate their impact on preventing severe oxidation and extending oil shelf-life. Oxidation state evolution was evaluated through peroxide value(PV), free fatty acid(FFA), anisidine value(p-AV), K_(270)value(conjugated trienes), total oxidation index(TOTOX), iodine value(IV), and fatty acid composition(FA). Our results revealed notable differences in stability tracking parameters. Specifically, these parameters were higher in samples stored under accelerated conditions, followed by the samples stored in ambient light, while those stored in darkness showed the highest stability among the three storage conditions. Supplementation of sunflower oil with SS and tocobiol significantly enhanced its oxidation stability. Notably, SS exhibited exceptional effectiveness in stabilizing sunflower oil regardless of SS dose, with the highest efficacy observed at 0.6%. This was evidenced by the slower rate of oxidation parameters under various storage conditions, highlighting a superior antioxidant activity compared to both the non-enriched oil and tocobiol-enriched oil. Furthermore, saffron stigmas, used as a natural supplement,contributed to the preservation of polyunsaturated fatty acids, indicating its potential as a robust source of natural antioxidants in sunflower oil. These attributes position SS as a promising alternative to synthetic antioxidants, offering opportunities to enhance the nutritional quality and extend edible oil shelf-life.

Assessment of Sunflower (Helianthus annuus L.) for Phytoremediation of Heavy Metal Polluted Mine Tailings—A Case Study of Nampundwe Mine Tailings Dam, Zambia

Mining activities have led to a generation of large quantities of heavy metals laden wastes which are released into the environment in an unsustainable way causing the contamination of the ecosystems and posing a risk to human health. Most mining companies have not employed any rehabilitation or remediation program of the heavy metal laden waste. The aim of this study was to assess the potential of sunflower for phytoremediation of heavy metal polluted mine tailings. Phytoremediation is an emerging technology in the remediation of mine tailings that uses tolerant plant species to clean up contaminated sites. It uses plants with high biomass and sunflower has been identified as such. These plants can extract, transfer, sequester and stabilize a variety of metals through mechanisms such as phytoextraction, phytostabilization, phytoaccumulation and phytovolatilization. Pot experiments were conducted by growing sunflower (Helianthus annuus L.) in pyrite mine tailings and in agricultural soil as a control. The study showed that the concentration of Cu reduced from 40.76 mg/kg to 36.59 mg/kg, Zn reduced from 3.58 mg/kg to 3.49 mg/kg and Fe reduced from 23.70 mg/kg to 10 mg/kg respectively in the mine tailings after 6 weeks. Analysis of harvested sunflower (roots, stems, leaves) showed that sunflower could remove heavy metals from the tailings and the highest removal efficiency was 53.7% and the highest translocation factor was 0.25. It was concluded that sunflower has the potential to remediate contaminated mine tailings and that phytoremediation is a viable and efficient technology to treat soils contaminated with heavy metals.

向日葵(Helianthus annuus L.)对^(133)Cs、^(88)Sr的吸收和分布(英文)

通过盆栽试验研究了向日葵(Helianthus annuusL.)对土壤中不同处理浓度133Cs和88Sr的吸收,以及133Cs和88Sr在向日葵不同部位的分布。结果表明:随着处理浓度的增加,植物中133Cs或88Sr的含量增加。同一处理浓度下,88Sr含量约比133Cs含量高一个数量级1。33Cs和88Sr在植物不同部位分布不同。根部中133Cs含量高于植物的其他部位(茎、叶、花)。不同于133Cs在植物中的分布,88Sr除在根中的分布外,主要转运到了叶片1。33Cs和88Sr在向日葵体内的分布与目前对放射性137Cs和90Sr的研究结果相似,所以133Cs和88Sr可分别预测137Cs和90Sr的运转。向日葵是治理大面积低放核素污染土壤的较佳植物种类。

Effect of chromium on growth attributes in sunflower(Helianthus annuus L.)

Heavy metal soil pollution takes place when the metal concentration of soil exceeds natural background level and causes ecological destruction and deterioration of the environment.In the present study,a pot experiment was conducted to evaluate the effect of chromium-contaminated soil in sunflower(Helianthus annuus L.)growth attributes.Three different levels of chromium(Cr)i.e.,20, 40,and 60 mg/kg were applied to three varieties of sunflower(G-3,G-9,and G-59).The results of morphological,chemical,and yield p...

Evaluation of Three Sunflower （Helianthus annuus L.） Hybrids for Salt Tolerance in Vitro

This study aimed to induce callus from three sunflower （Helianthus annulus L.） hybrids, namely Anna, Alhaja and Kuds, and to evaluate their callus for salt stress tolerance. Cotyledons and hypocotyl were taken from seedling of these hybrids and cultured on MS media contained 2,4-D （0,0, 0.5, 1.0, 1.5 and 2.0 mg/L） and kinetin （0.0, 0.5, and 1.0 mg/L）. The cultures incubated at 25 ＋ I^C under light condition （1,000 Lux） for 16 h/day. After 6 weeks observations were taken on the response of cotyledons and hypocotyl to callus induction. The induced callus were cultured on the same MS media that contained appropriate concentrations of 2,4-D and kinetin for callus induction as well as contained various concentration of sodium chloride NaCI （0.0, 0.05, 0.1, 0.15 and 0.2%）. After six weeks callus fresh and dry weights, proline and total carbohydrates concentrations were measured. The results showed significant differences among the hybrids, explants, 2,4-D and kinetin concentration and significant interaction between them in their percentage response for callus induction. The results also revealed that fresh and dry weights were significantly reduced with increased NaCI concentration in the medium, hybrids showed significant differences in their response to salt stress. Proline and total carbohydrate concentration increased in callus as NaCI increased in the media. Significant interaction was showed between hybrids and NaCI concentration in these parameters.

Influences of Genotype and Explant on Callus Induction and Shoot Regeneration in Sunflower （Helianthus annuus L.）

In vitro regeneration was performed with the aim of developing efficient callus and shoot regeneration from different explants of sunflower （Helianthus annuus L.）. The 6 genotypes （RHAI0, RHA 14, RHA15, PR6404, N Record 109/Sanay 3-5, N Record 109/Sera） were used as plant materials. The roots, hypocotyls and cotyledons were excised from 4 day-old seedlings and cultured on embryo induction medium （EIM） supplemented with Benzylaminopurine （BAP）, Naphthaleneacetic acid （NAA） and Gibberellic acid （GA3）. The experiments were kept in 18/6 hour light/dark photoperiod at 26± 2 ℃for four weeks. The rates of callus and root organ formation on explants were 67%-100% and 7%-31% respectively, depending on the genotype. Root explants produced statistically high callus formation （2.6 score） compared to cotyledon （2.0 score） and hypocotyl explants （2.5 score） at all sunflower genotypes used. The highest shoot regeneration was obtained from RHAI 5 （7%） while PR6404 （100%） produced the highest callus formation.

Two New Diterpenes from Helianthus annuus L.

Two new diterpenes, 2β, 16β-ent-kaurane diol, 15α, 16α-epoxy-17β-al-ent-kaurane- 19-oic acid were isolated from Helianthus annuus L. Their structures were determined by spectroscopic evidences.

Identification, characterization and full-length sequence analysis of a novel endornavirus in common sunflower (Helianthus annuus L.)

To identify the possible quarantine viruses in seven common sunflower varieties imported from the United States of America and the Netherlands, we tested total RNAs extracted from the leaf tissues using next-generation sequencing of small RNAs. After analysis of small RNA sequencing data, no any quarantine virus was found, but a double-stranded RNA（dsRNA） molecule showing typical genomic features of endornavirus was detected in two varieties, X3939 and SH1108. Full-length sequence and phylogenetic analysis showed that it is a novel endornavirus, temporarily named as Helianthus annuus alphaendornavirus（HaEV）. Its full genome corresponds to a 14 662-bp dsRNA segment, including a 21-nt 5′ untranslated region（UTR）, 3＇ UTR ending with the unique sequence CCCCCCCC and lacking a poly（A） tail. An open reading frame（ORF） that encodes a deduced 4 867 amino acids（aa） polyprotein with three domains： RdRP, Hel and UGT（UDP-glycosyltransferase）. HaEV mainly distributed in the cytoplasm but less in the nucleus of leaf cells by fluorescence in situ hybridization（FISH） experiment. This virus has a high seed infection rate in the five varieties, X3907, X3939, A231, SH1108 and SR1320. To our knowledge, this is the first report about the virus of the family Endornaviridae in the common sunflower.

Phosphorus Use Efficiency of Safflower （Carthamus tinctorius L.） and Sunflower （Helianthus annuus L.） Studied in Nutrient Solution

Safflower represents an important oil crop internationally and may have a production potential under low input conditions, but its putatively high phosphorous use efficiency is not sustained. This study aims to directly compare safflower with sunflower in terms of phosphorus use efficiency in nutrient solution under controlled conditions. Growth of both species responded strongly to increasing P supply. Safflower recovers less proportion of added P than sunflower. External P requirement （（g P supply （100 g dry matter （DM） produced）~） was higher in safflower than sunflower. The efficiency of the crops for DM production based on accumulated P （mg P potl, efficiency ratio）, and P concentration in DM （（mg P （g DM）＇I）, utilization index） were interpreted using Michaelis-Menten kinetics as growth response curves. Accordingly, Km constant was lower in sunflower compared to safflower in terms of utilization index, but both were similar in terms of efficiency ratio. High Km constant in safflower in terms of utilization index indicates the high P concentration in tissues to produce 50% of potential maximum DM, consequently less efficient crop. Utilization efficiency contributed more than uptake efficiency in overall PUE in the efficient cultivar and could be the cause of its superiority in PUE. It can be concluded that safflower has a high requirement for P with respect to growth, sunflower is more efficient in terms of uptake and utilization of P at optimal and sub-optimal P supplies indicating that safflower can not be considered a low nutrient input crop compared to sunflower with respect to phosphorus.

Effects of Exogenous Vc on Seed Germination and Physiological Properties of Oil Sunflower(Helianthus annuus) under Salt Stress

[Objective] This study aimed to provide the theoretical and technical basis for alleviating salt damages in production practice of oil sunflower （Helianthus annuus）. [Method] Seeds of oil sunflower were used as experimental materials and treated with 120 mmol/L NaCI solution and 0-200 mg/L Vc solution during the germina- tion process, to investigate the effects of exogenous Vc on seed germination and physiological properties of oil sunflower under salt stress. [Result] Under salt stress, with the increase of Vc concentration, germination potential and germination rate of oil sunflower seeds, superoxide dismutase （SOD） and peroxidase （POD） activities and proline （Pro） content of oil sunflower seedlings increased first and then declined, which reached the maixmum in 80 mg/L Vc treatment, 120 mg/L Vc treatment and 80 mg/L Vc treatment, respectively; malondialdehyde （MDA） content of oil sunflower seedlings declined first and then increased, which reached the minimum in 160 mg/L Vc treatment. [Conclusion] To varying degrees, Vc could improve germination potential and germination rate of oil sunflower seeds and promote seedling growth under salt stress, thus alleviating the damages of salt stress to seed germination and seedling growth of oil sunflower.

向日葵[Helianthus annuus(L.)]白花粉突变体遗传研究初报

向日葵[IIelianlhus anuus (L.)]是我国的重要经济作物。其花粉通常呈深浅程度不同的黄颜色。据我们掌握和查新资料,目前世界上尚未见有关白花粉方面的报道。1989年7月下旬至8月上旬,我们在吉林农业大学向日葵育种试验田的恢复系C8711群体中,先后发现4株白花粉突变体。暂分别定名为C8711—1、C8711—2、C8711—3和C8711—4。在进行人工套袋之前,此4株突变体已经在一定程度上发生了开放授粉,其中C8711—4开放授粉程度较轻。成熟时单独收获这4株突变体的种子,以进行有关遗传学研究,本文拟对白花粉突变的遗传学机理进行初步的探讨。

外源褪黑素对NaCl胁迫下向日葵种子萌发的影响

盐胁迫是影响作物产量和质量的非生物胁迫之一,褪黑素能有效提高植物应对盐胁迫的水平。本文以矮生向日葵为研究对象,以筛选出的0.25mol/LNaCl为胁迫浓度,通过测定种子萌发指标、膜脂过氧化程度、渗透调节物质含量和抗氧化酶活性等,研究外源褪黑素对盐胁迫下向日葵种子萌发的生理调控机制。结果表明:随着褪黑素浓度的增加,种子的发芽势、发芽率、发芽指数、可溶性蛋白质含量均呈先升后降趋势,其中25μmol/L的效果最佳。脯氨酸含量较对照不断增长,以100μmol/L的效果最佳。MDA含量较对照减少,以25μmol/L的抑制作用最为显著。不同浓度外源褪黑素对种子SOD、POD和CAT活力均有明显的增加,以25μmol/L的效果最为显著。综上所述,25μmol/L褪黑素可以作为向日葵种子萌发期对抗NaCl胁迫的有效预处理措施,本研究为褪黑素的利用和向日葵栽培调控提供依据。

Effect of Nitrogen on Yield and Oil Quality of Sunflower (<i>Helianthus Annuus</i>L.) Hybrids under Sub Humid Conditions of Pakistan

Sunflower (Helianthus annuus L.) has emerged as an economically important crop in Pakistan due to its significant share in vegetable oil production. The plant metabolic processes require protein to increase the vegetative, reproductive growth and yield of the crop. The protein is wholly dependent upon the amount of nitrogen fertilization available for plant use. A two-year field study was conducted in 2008 and 2009. The objective was to determine the effect of different nitrogen (N) levels (N1 = 0 kg·ha–1, N2 = 60 kg·ha–1, N3 = 120 kg·ha–1, N4 = 180 kg·ha–1 and N5 = 240 kg·ha–1) on three sunflower hybrids (Hysun-33, Hysun-38 and Poineer-64A93) in agro-climatic conditions of Gujranwala, a sub-humid region in the centre of the Punjab province of Pakistan. A randomized complete block design split plot experiment was set-up with cultivars in the main plots and N levels in the subplots. Results showed that Hysun-38 gave maximum TDM (15815 kg·ha–1) and maximum grain yield (3389 kg·ha–1), while minimum TDM (14640 kg·ha–1) and grain yield (3125 kg·ha–1) was observed in Hysun-33. Among different N rates evaluated, N4 gave maximum TDM (17890 kg·ha–1) and grain yield (3809 kg·ha–1) compared to the other N rates. The maximum oil content (46.2%) was observed in Hysun-38 without application of N fertilizer (N1), while the minimum oil content (40.6%) was observed from N5 treatment. In conclusion, the application of 180 kg·ha–1 N to Hysun-38 provided the best combination for good yield in sunflower crop under the prevailing sub-humid conditions of Pakistan.

In-Silico Identification and Differential Analysis of Mitochondrial RNA Editing Events in Helianthus Genotypes/Species and Powdery Mildew Infected Variants

Sunflower is one of the most used commercial oilseed crops and suffers due to Powdery mildew. RNA sequence alteration occurs due to RNA editing which is a post transcriptional modification. It causes a deviation from the genomic DNA sequence resulting in RNA-DNA differences. Accurate study of RNA editing events in diverse species is possible by NGS based methods. Here, we performed RNA sequencing of 12 leaf transcriptomes, which include three genotypes of Helianthus annuus (2023B, TX16R and ID25), H. debilis, H. niveus, and H. praecox along with their respective powdery mildew pathogen infected variants and systematically analysed the mitochondrial RNA editing events using computational reference-based mapping approach. We discovered 687 editing sites, 220 editing events in the protein-coding regions, among all species and genotypes considered in this study. These included “C to U” and “U to C” RNA editing events. On further analysis, we observed that these editing events include 14 different types of amino acid changes that involve the creation of two stop codon events. The conserved editing sites identified were 247 accounting for ~36% of all the editing sites identified. This study provides a detailed picture of the Helianthus species’ mitochondrial RNA editing status. We have identified and characterized for the first time, genotype-specific, species-specific, and stress-specific RNA editing events which may be useful as a potential source for stress-responsive studies in the future.

油葵(Helianthus annuus L.)HaFAD2-9基因的克隆与表达分析

FAD2基因在植物脂肪酸的生物合成、发育和对非生物胁迫的响应中发挥重要作用。为探究油葵FAD2-9基因具体的生物学功能,本研究从油葵中克隆得到HaFAD2-9基因,对其生物信息学和表达模式进行分析。结果表明,HaFAD2-9基因的ORF全长为1 146 bp,编码381个氨基酸,转录后蛋白的相对分子量为43.9 kD,等电点为6.69,有5个跨膜结构域,亚细胞定位显示其定位在内质网。HaFAD2-9蛋白含有三个保守的组氨酸簇[HECGHH, HRRHH和HV(A/L)HH]。分子系统进化分析显示,HaFAD2-9与红花(Carthamus tinctorius)和黄花蒿(Artemisia annua)的亲缘关系较近。该基因在根、茎、叶、子叶及授粉后不同时期的种子中均有表达,在17 DAF表达量最高,低温、盐、干旱和ABA均能诱导HaFAD2-9基因的表达。本研究为油葵应对非生物胁迫提供参考,为作物遗传改良提供候选基因。

Acute and chronic toxicity studies of hydromethanol leaf extract of Helianthus annuus Linn.in rats

Objective:To investigate the safety levels of hydromethanol leaf extract of Helianthus annuus Linn.(H.annuus) in rat.Methods:Acute oral toxicity test of hydromethanol leaf extract of H.annuus was conducted through up and down method at 2.00 g/kg dose limit in rats.The chronic toxicity study was conducted by administering different concentrations(0.25,0.50 and 1.00 g/kg) of hydromethanol extract of H.annuus in feed,for 90 consecutive days.On days 30,60 and 90,blood samples were collected from the retro-orbital plexus of the rats for determination of serum biochemical parameters.Histopathological examination of the pancreas,livers,kidneys and testis were also conducted.Results:The LD_(50) of the hydromethanol extract of H.annuuswas greater than 2.00 g/kg and it significantly(P < 0.05) reduced serum cholesterol.On days 60 and 90,the serum urea and creatinine levels of hydromethanol extract of H.annuustreated groups were elevated when compared with the control group.There were fibrosis in the kidneys and livers;degeneration and necrosis in the testis and significant dose-dependent increases in number and size of pancreatic islet of langerhans.Conclusions:The findings suggest that hydromethanol extract of H.annuus is tolerated in short term administration,but long term(up to 90 days) administration at high doses,may elicit hepatic,testicular and nephrotic disorder.

Study on Petal-Sepal Mutant of Sunflower (Helianthus annuus) after Space Mutation

In this paper, we studied the morphological, histological and photosynthetic characteristics of the stably inherited sunflower petal-sepal mutant, and it was obtained by the space radiation-induced mutagenesis. Afterwards, we got following results: 1) The morphological characteristics represented that the inflorescence of petal-sepal mutant maintained the appearance and structure of capitulum, whereas no explicit tubular flower or ligulate flower was differentiated. 2) The histological characteristics revealed that the petal-sepal mutant only completed the inflorescence development and the differentiation of sepal primordia and inflorescence primordia, without entering the differentiation stage of tubular flower primordia, ligulate flower primordia, stamen primordia or pistil primordia. 3) The photosynthetic characteristics showed that the photosynthetic rate, transpiration and stomatal conductance of petal-sepal mutant were relatively weaker than the control plants. In the end, we concluded that the petal-sepal mutant of sunflower had only inflorescence differentiation, while several mutant genes were caused by radiation-induced mutation, which entered an infinitely recurrent development process rather than the floral differentiation stage. We also observed a few chloroplast structures in the paraffin section, combined with the results of photosynthetic characteristics of petal-sepal mutant, and then we believed that the inflorescence of petal-sepal mutant was involved in photosynthesis to accumulate energy for plant growth.

In vitro Pharmacological Activity of Chromenes in Disk of Helianthus annuus

[Objectives]The anti-tumor,anti-bacterial,anti-acetylcholinesterase and anti-α-glucosidase activity in vitro of five chromenes isolated from Helianthus annuus disk was studied,in order to provide reference for the development and utilization of H.annuus disk resources.[Methods]The effect of different concentrations of chromenes on the survival rate of leukemia HL-60 cells,lung cancer A549 cells,liver cancer SMMC-7721 cells,breast cancer MCF-7 cells and colon cancer SW480 cells was detected by MTS method,and the IC50 was calculated.The inhibitory activity of chromenes against Escherichia coli,Staphylococcus aureus subsp.aureus,Salmonella enterica subsp.enterica,Pseudomonas aeruginosa and Candida albicans was detected by microdilution method.The DTNB substrate method was used to detect the inhibitory activity of chromenes on acetylcholine.The PNPG substrate method was used to detect the inhibitory activity of chromenes onα-glucosidase.[Results]The five chromenes had no obvious in vitro inhibitory activity on the five kinds of tumor cells,with IC50 greater than 40μM.The five chromenes had no obvious in vitro inhibitory activity against the four kinds of bacteria and C.albicans.The five chromenes had certain inhibitory activity on acetylcholinesterase,and among them,6-acetyl-2,2-dimethylchromene and 6-acetyl-7-hydroxy-2,3-dimethylchromene showed strong inhibitory activity on acetylcholinesterase,with IC50 of 28.253 and 16.945μM,respectively,both smaller than that(0.275μM)of the positive control tacrine(P<0.01).The five chromenes showed good inhibitory effect onα-glucosidase,and among them,7-hydroxy-6-hydroxyacetyl-2,2-dimethylchromene and 6-acetyl-7-hydroxy-2,3-dimethylchromene had stronger inhibitory activity,with IC50 of 20.240 and 21.052μM,respectively,significantly better than that(169.780μM)of the positive control acarbose(P<0.01).[Conclusions]The five chromenes in H.annuus disk have certain in vitro inhibitory activity against acetylcholinesterase andα-glucosidase and certain potential in fighting neurodegenerative diseases and diabetes.

Pollination Efficiency of <i>Ceratina cyanea</i>(Hymenoptera: Apidae) on <i>Helianthus annuus</i>(Asteraceae) Flowers at Dang (Ngaoundere, Cameroon)

To evaluate the impact of Ceratina cyanea on fruit and seed yields of sunflower, experimental field was set up from June to July in 2016 and 2017 at Dang. Observations were done on 540 capitula divided in four treatments: two treatments differentiated according to the presence or absence of protection on capitula regarding Ceratina cyanea and other flowering insects’ visits;the third with capitula protected and uncovered when florets were opened, to allow C. cyanea visits and flowers bagged uncovered and rebagged without the visit of insects or any other organisms. Bee’s daily rhythm of activity, its foraging behavior on florets and its pollination efficiency were evaluated. Bee’s daily rhythm of activity, its foraging behavior on flowers and its pollination efficiency were evaluated. Results show that, C. cyanea foraged on Helianthus annuus flowers throughout its whole blooming period. Among 32 insect species recorded on H. annuus capitula, C. cyanea ranked second accounting for 10.79% all visits, after Apis mellifera (76.06%). On florets, individual bees intensely harvested nectar and slightly collected pollen. The mean duration of a visit per floret was 3.62 sec for nectar harvest and 9.58 sec for pollen collection. For the two years, through its pollination efficiency on H. annuus, C. cyanea has increased the fruiting rate by 65.90%, the percentage of fruit with seed by 63.56% and the percentage of normal seeds by 76.11%. Based on these results, we recommend the protection of C. cyanea nests at the vicinity of sunflower fields to increase its fruit and seed yields in the Adamaoua Region of Cameroon.

金属离子和热激处理对菊芋(HelianthustuberosusL.)类金属硫蛋白基因htMT_2表达的影响

使用不同金属离子及热激对菊芋进行了处理 ,并对菊芋不同组织器官中类金属硫蛋白基因 (htMT2 )mRNA水平的变化进行了研究 结果表明 ,htMT2在根中不表达 ,而且其表达不受金属离子的影响 Cu2 + 降低叶中htMT2的表达 ,Cu2 + 浓度与茎中htMT2mRNA水平呈负相关性 在低浓度范围内 ,Zn2 + 浓度与茎、叶中的htMT2mRNA水平呈正相关性 ,而在高浓度范围内 ,Zn2 + 浓度与htMT2mRNA水平呈负相关性 Ca2 + 对叶中htMT2表达的影响与Zn2 + 的作用相似 ,但Ca2 + 诱导茎中htMT2mRNA水平升高 热激处理对不同组织中htMT2的表达无显著影响 研究的结果表明 ,htMT2表达受金属离子影响的特征与植物MT基因一致 ,进一步证实了我们前期工作中分离到的htMT2是一个新的植物MT基因 .