高等植物中的甾类激素

甾类激素（Steroid hormons）一般包括动物性激素、皮质激素和植物油菜素内酯等几类。其中油菜素内酯已在20世纪80年代对其进行了广泛而深入的研究,并确认它能够调节植物的生长发育,是植物重要的生长调节物质。动物中的甾类激素和皮质激素在动物的生长、发育和生殖等方面起着重要作用。早在20世纪30年代,虽然人们就已发现了甾类激素在植物中的存在,但对于它们在高等植物体中功能的研究,一直进展缓慢。近十多年来,随着检测技术的迅猛发展,才使得这一领域的研究取得了长足进展。最初巴特兰德（Butenandt）和杰克比（Jacobi）1933年…     

未成熟油菜种子的子叶和花瓣细胞中BL的分布

BL（油菜素内酯）是从油菜花粉中分离得到的具有自醇内酯结构（Grove等1979）和具有很强生理效应的新型植物生长调节物质（Hewitt等1980）,后被建议为第六大类植物激素（Mandava1988）。近年来的一些研究均表明,它不仅可以促进植物细胞的伸长生长（Katsunu1985）,而且可以明显调节植物内源激素平衡（徐如涓等1990）。但这些研究工作多数侧重于该物质对植物生长的促进作用,而对它在细胞内的分布特点则研究较少。目前由于技术和方法的限制,有关在细胞超微结构水平上对植物体中BL分布的研究尚未见报告。为此,我们以未成熟油菜种子的…     

植物矮化突变体的激素调控

作者主要从赤霉素（GA）、油菜素内酯（BR）和生长素（IAA）三方面介绍了植物矮化突变体的激素水平变化及其调控,其对其他与激素调控有关的植物筹化体研究进展作了介绍。     

白菜型油菜,芥菜型油菜与诸葛菜的属间杂交合子胚的组织培养

TissueCultureofZygoticEmbryosofIntergenericHybridizationAmongBrassicacampestris,B．junceaandOrychophragmusviolaceusWUYan－You,JIANGJiu－Yu（InstituteofGeochemstry,TheAcademyofScience,Guiyang550002）1植物名称白菜型油菜（Brassicacampestris）品种川油8号（2n=20）、芥菜型油菜（B.juncea）品种沪州四棱（2n=36）和诸葛菜（Orychophragmusviolaceus,2n=24）。2材料类别白菜型油菜和芥菜型油菜作母本,诸葛菜作父本,人工授粉22d“萝卜”角果中的未成熟杂种胚。3培养条件分化培养基为MS＋6-BA2mg／L（单…     

细胞因子对卵巢功能的调节作用

细胞因子是一类具有广泛生物学活性的激素样多肽。近年来,细胞因子在生殖活动中的作用日益被人们所认识和关注,而成为一个新的研究领域。肿瘤坏死α（ＴＮＦ－α）、白介素１（ＩＬ－１）、ＩＬ－６、ＩＬ－８、γ－干扰素（ＩＦＮ－γ）、粒－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）等多种细胞因子可参与卵巢功能的调节。本文着重介绍细胞因子在卵泡发育和甾体激素生成、排卵、黄体形成和退化等方面的研究进展。     

生长素与油菜素甾醇相互作用机制的研究进展

植物生长发育是一个复杂、精细的调控过程,涉及细胞、组织和器官间多层次的信息交流,激素在其间发挥了重要调控作用．生长素和油菜素甾醇（BR）都能促进植物伸长,随着对其作用机制研究的深入,人们发现它们协同调控很多生理过程,对二者作用机制和信号转导的相互作用研究也成为激素研究领域的热点之一．对生长素和BR转导途径的揭示及直接下游基因的大规模发掘为二者通过相互作用调控不同生理过程的机制研究提供了重要线索．生长素和BR的相互作用涉及到下游基因转录的调控、信号组分互作以及合成代谢和极性运输等多层次的调控．     

白菜型油菜与蓝花子的属间杂交合子胚组织培养

TissueCultureofZygoticEmbryosofIntergenericHybridizationBetweenBrassicacampestrisandRaphanussativusvar．raphanistroidesWUYan-You,JIANGJiu-Yu（InstituteofGeochemstry,TheChimeseAcademyofScience,Guiyang550002）1植物名称白菜型油菜（Brassicacam－pestris）品种川油8号（2n=20）和蓝花子（Raphanussativusvar．raphanistroidesMakino,2n＝18）。2材料类别白菜型油菜作母本,蓝花子作父本,人工授粉22d“萝卜”角果中的未成熟杂种胚。3培养条件分化培养基为MS＋6－BA2mg／L（单位下同）＋NAA0．1;生根培…     

油菜素内酯对水稻根系发育的调控作用

在油菜素甾醇(brassinosteroids,BRs)化合物中,油菜素内酯(brassinolide,BL)具有活性最高、广谱和无毒等显著特点,而且具有改良植物株型、提高抗逆性等功效。根系是植物吸收水分和矿质元素的主要器官,因此阐明油菜素内酯调控根系发育的遗传、生理和生化机制,有利于更有效地利用BRs激素,实现株型的定向设计。该研究利用叶面喷施的方法分析油菜素内酯对根系侧根、根毛发育的影响;利用植物显微技术分析油菜素内酯对根系侧根结构及发育的作用;利用高压液相色谱法检测油菜素内酯对根系内其他植物激素含量的影响;利用蛋白质组学技术鉴定受油菜素内酯调控的蛋白质,分析油菜素内酯调控根系发育的生化机制。研究表明,一定浓度的油菜素内酯促进种子根、侧根、根毛的发生;提高根系细胞分裂素和赤霉素含量;可能通过调控逆境相关蛋白质来提高植物的抗逆性。     

油菜素内酯生物合成与功能的研究进展

植物激素油菜素内酯广泛调节植物的生长发育及对外界环境因子变化的反应,在作物上的应用也已引起人们的广泛兴趣。通过遗传学等手段对相关突变体及功能基因的研究为其生物合成与功能研究提供了基础。本文总结了油菜素内酯在植物各组织内的分布、生物合成、相关合成突变体及其编码基因的性质、生理功能以及与其它激素间的相互作用等。     

油菜素内酯生物合成与功能的研究进展

植物激素油菜素内酯广泛调节植物的生长发育及对外界环境因子变化的反应, 在作物上的应用也已引起人们的广泛兴趣。通过遗传学等手段对相关突变体及功能基因的研究为其生物合成与功能研究提供了基础。本文总结了油菜素内酯在植物各组织内的分布、生物合成、相关合成突变体及其编码基因的性质、生理功能以及与其它激素间的相互作用等。     

水稻突变体M-20的耐盐生理特性

不同盐（NaCl）浓度的水培条件下,水稻耐盐突变体M－20幼苗生长及生存能力优于其原始品系77－170,膜透性测定表明盐胁迫对M－20质膜的损伤较小;同时,外界盐浓度小于100mmol／L时,M－20幼苗根、地上部的钠离子含量低于其原始品系。土培幼苗浇灌盐水（10mmol／L）时,M－20成熟及生长叶片的内源ABA水平增加时期晚于原始品系,增幅也小;而游离脯氨酸的增加时期虽晚,但增幅远高于原始品系。     

Changes in soluble amino-N,soluble proteins and free amino acids in leaves and roots of salt-stressed maize genotypes

Abstract

The effects of salt stress on the contents of organic solutes and on the pattern of free amino acids were studied in leaves and roots of two maize genotypes, BR5033 (salt-tolerant) and BR5011 (salt-sensitive). In leaves and roots of salt-stressed plants, soluble amino-N increased with time when compared to the controls. Salt stress increased the soluble protein content only in leaves of BR5011. Salinity increased the content of the majority of the free amino acids in leaves and roots of genotypes studied. Results suggest the hypothesis of disturbances in translocation of N-containing compounds from shoot to root in the salt-sensitive genotype. Results also suggest that the accumulation of organic solutes, mainly in roots of BR5033, may have an important role in the tolerance of this genotype to salt stress.     

Phytotoxic effects of trichothecenes on the growth and morphology of Arabidopsis thaliana

Non-volatile sesquiterpenoids, a trichothecene family of phytotoxins such as deoxynivalenol (DON) and T-2 toxin, contain numerous molecular species and are synthesized by phytopathogenic Fusarium species. Although trichothecene chemotypes might play a role in the virulence of individual Fusarium strains, the phytotoxic action of individual trichothecenes has not been systematically studied. To perform a comparative analysis of the phytotoxic action of representative trichothecenes, the growth and morphology of Arabidopsis thaliana growing on media containing these compounds was investigated. Both DON and diacetoxyscirpenol (DAS) preferentially inhibited root elongation. DON-treated roots were less organized compared with control roots. Moreover, preferential inhibition of root growth by DON was also observed in wheat plants. In addition, T-2 toxin-treated seedlings exhibited dwarfism with aberrant morphological changes (e.g. petiole shortening, curled dark-green leaves, and reduced cell size). These results imply that the phytotoxic action of trichothecenes differed among their molecular species. Cycloheximide (CHX)-treated seedlings displayed neither feature, although it is known that trichothecenes inhibit translation in eukaryotic ribosomes. Microarray analyses suggested that T-2 toxin caused a defence response, the inactivation of brassinosteroid (BR), and the generation of reactive oxygen species in Arabidopsis. This observation is in agreement with our previous reports in which trichothecenes such as T-2 toxin have an elicitor-like activity when infiltrated into the leaves of Arabidopsis. Since it has been reported that BR plays an important role in a broad range of disease resistance in tobacco and rice, inactivation of BR might affect pathogenicity during the infection of host plants by trichothecene-producing fungi.     

杨树人工林根际古菌群落随细根生长的演变

研究细根不同生长时期根际土壤古菌群落组成结构差异,对深入了解林木细根与土壤微生物互作关系具有重要理论意义.依据细根表面颜色,采集杨树一级细根不同生长时期(白色新生根、黄色成熟根、褐色衰老根)根际土壤并提取微生物总DNA,采用特异性引物对古菌16S rDNA V4-V5区进行扩增,利用Illumina MiSeq平台进行古菌高通量测序分析.结果表明: 新生根和衰老根根际土壤古菌群落操作分类单元(OTU)丰富度相似,而成熟根根际土壤古菌群落OTU数量较少.新生根和成熟根根际土壤共同含有134个OTU;成熟根和衰老根根际土壤共同含有87个OTU,新生根和衰老根根际土壤共同拥有90个OTU.α多样性分析表明,成熟根根际土壤古菌群落Chao1指数和ACE指数显著低于新生根和衰老根根际土壤,而衰老根根际土壤古菌群落Simpson指数和Shannon指数显著低于新生根和成熟根根际土壤.PERMANOVA分析表明,新生根和衰老根根际土壤古菌群落组成有显著差异.物种注释显示,杨树根际土壤共包含12个古菌属,其中新生根5个、成熟根10个、衰老根6个.β多样性指数表明,杨树根际土壤古菌群落相似度随着细根的生长逐渐下降,不同生长阶段细根根际土壤的古菌群落结构有较大差异.其中,占绝对优势的古菌为氨氧化古菌Candidatus_Nitrososphaera,其相对丰度超过70%.且随细根生长发育,该类古菌在根际土壤中的丰度呈现上升趋势,表明其可能与细根的生长发育关系密切.     

小麦突变体返白系生长后期某些生理变化

返白过程之后,返白系随着叶色的复绿,植株的代谢机能开始恢复,叶绿素含量上升,光合作用增强,叶片内可溶性糖含量上升,呼吸速率高于其祖先矮变１号;复绿初期返白系气孔阻力高于矮交１号,蒸腾速率则低于矮变１号。复绿后,以上各项指标都逐渐变化,达到矮变１号的水平。之后,返白系的蒸腾速率高于矮变１号,气孔阻力低于矮变１号,叶绿素含量及光合速率均高于矮变１号,近白系和矮变互号的呼吸速率在５月９～２５日间有上升趋势,但近白系呼吸速率较高。在生长后期,返白系的根系有向土壤深层分布的趋势。分析认为返白系在生长后期有一个补偿性生长阶段,通过改善植株水分状况,提高同化能力,降低消耗来保证生长和结实的需要。     

Isolation and identification of a potent allelopathic substance in Bangladesh rice

Aqueous methanol extracts of Bangladesh rice (Oryza sativa L. cv. BR17) inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), timothy (Phleum pratense), Digitaria sanguinalis, Echinochloa crus-galli and Echinochloa colonum. Increasing the extract concentration increased the inhibition, suggesting that the BR17 may have growth inhibitory substances and possess allelopathic potential. The aqueous methanol extract of the BR17 was purified and a main inhibitory substance was isolated and determined by spectral data as 2,9-dihydroxy-4-megastigmen-3-one. This substance inhibited root and shoot growth of cress and E. crus-galli seedlings at concentrations greater than 0.03 and 3 μM, respectively. The concentrations required for 50% growth inhibition on cress roots and shoots were 0.22 and 0.47 μM, respectively, and on E. crus-galli roots and shoots were 36 and 133 μM, respectively. These results suggest that 2,9-dihydroxy-4-megastigmen-3-one may contribute to the growth inhibitory effect of BR17 and may play an important role in the allelopathy of BR17. Thus, Bangladesh rice BR17 may be potentially useful for weed management in a field setting. An erratum to this article can be found at     

表油菜素内酯对拟南芥细胞分化的影响

研究了表油菜素内酯（ｅｐｉ－ＢＲ）对拟南芥细胞体外分化的影响．表明ｅｐｉ－ＢＲ不仅能促进愈伤组织的增殖,而且还能有效地诱导愈伤组织转绿,继而分化绿芽和长成小植株,其诱导频率高达７０％以上。电镜观察表明,ｅｐｉ－ＢＲ诱导的转绿细胞中的叶绿体发育正常。     

Physiological integration for salinity stress alleviation in stoloniferous turfgrass,Zoysia matrella in heterogeneous saline environments

To clarify physiological integration for salinity stress alleviation in Zoysia matrella, interconnected clonal stolon ramets were grown in three separate pots [basal (BR), intermediate (IR), and apical ramets (AR)]. Once ramets were well established, two experimental groups were set up: stolons connected with other ramets (Intact) and stolons cut between ramets (Severed). NaCl solution was used for IR, while tap water was used for BR and AR for 49 days. For BR and AR, there was no significant difference in NaCl content in any plant part (green leaves, brown leaves, stolons, and roots) in both groups. Therefore, we concluded that no NaCl translocation in interconnected ramets occurred for both basal and apical directions. For the IR in Intact group, water content in stolons was 1.2 times higher, and NaCl content in green and brown leaves was 16 and 29% lower, respectively than in Severed group. Dry weight of both above ground and below ground parts in Intact groups were 1.3 times higher as compared to that in Severed group. It was considered that tap water treated ramets (BR or AR) translocated water to IR and decreased the amount of NaCl in the body, thereby alleviating salt stress. For the IR in both groups, NaCl content in brown leaves was 2–3 times higher than in other parts. We conclude that Zoysia matrella does not translocate toxic component, such as NaCl between ramets, and does not distribute it to other ramets; however, ramet accumulates NaCl in brown leaves under salt stress condition.

     

Effects of a brassinosteroid on growth and on H+-extrusion in isolated radish cotyledons: comparison with the effects of benzyladenine

We investigated the effect of 24-epibrassinolide (BR) on the cytokinin-bioassay based on growth of isolated radish ( Raphanus sativus L. cv. Tondo Rosso Quarantino) cotyledons. BR stimulated growth of the cotyledons by about 50% when applied at saturating concentrations (3 μ M ). This effect was much lower than that of saturating concentrations of benzyladenine (BA) which was about 150% at 10 μ M BA. The effects of saturating concentrations of BR and BA were additive. BR, but not BA, stimulated H⁺-secretion by the cotyledons (measured as acidification of the incubation medium) slightly but reproducibly. These results indicate that the modes of action of the two phytoregulators are at least partially different.
BR-induced stimulation of H⁺-secretion was of similar amplitude to that induced by a concentration of fusicoccin (30 n M ) such as to stimulate growth to the same extent as BR. These results suggest that BR-induced stimulation of radish cotyledon growth might depend, at least in part, on BR-induced acidification of the wall space, similar to that observed on Azuki bean epicotyls and maize roots.     

在条锈菌侵染早期小麦初生叶内多聚核糖体水平与蛋白质合成能力的变化

小麦初生叶接种条锈菌毒性生理小种（ＣＹ２９）及其弱毒突变菌系（ＣＹ２９－ｍｕｔ３）后,呈不亲和反应的寄主叶片可溶性蛋白质合成能力在接种后２４ｈ显著高于未接种对照,但其后逐渐降低,直至接近对照;而呈亲和性反应的寄主叶片可溶性蛋白质合成在侵染早期与对照相近,但与膜结合蛋白质在９６ｈ时大大高于对照。对接种叶中核糖体的密度梯度分析证实：呈不亲和反应寄主叶片游离多聚核糖体及亲和反应的寄主内与膜结合多聚核糖体均有特异性增加。上述结果表明寄主的抗病和感病反应均与蛋白质合成能力的变化有关。