烟草细胞乙醇分解代谢能力的离体调控

报告了一些重要因子对培养在含有乙醇的培养基上的烟草细胞的乙醇分解代谢能力（ＥＣＡ）的调控效果。在供试的５种生长毒和２种细胞分裂素中,ＩＢＡ ４ｍｇ／Ｌ和Ｋｔ０．０５ｍｇ／Ｌ最有地促进ＥＣＡ,而ＮＡＡ２ｍｇ／Ｌ和Ｋｔ０．０２５ｍｇ／Ｌ则最有利于支持处在乙醇胁迫下的细胞的增殖。实验中还发现提高维生素浓度有利于细胞的ＥＣＡ。通过将细胞从低乙醇浓度的培养基转移到较高乙醇浓度的培养基中,能够诱导细胞耐受更高     

墨兰的无菌播种和植株再生

墨兰的无菌播种结果发现,在不添加细胞分裂素的培养基上,种子可以发芽,但只有原球茎和根状茎产生,不可能进一步分化成苗,只有在含有不同激素成分ＭＳ或ＫｎｕｄｓｏｎＣ培养基上,才有可能诱导芽的分化,其中以附加６－ＢＡ０．５－１．０ｍｇ／Ｌ＿ＮＡＡ０．１ｍｇ／Ｌ诱导效果最佳,在附加６－ＢＡ２．０ｍｇ／Ｌ＋ＮＡＡ０．４ｍｇ／Ｌ的ＭＳ培养基中,能加速芽的增殖,根状茎转入含有相同激素成分的液体增殖培养基中振荡培     

影响大麦叶肉原生质体分离和培养的一些因子（简报）

从大麦幼苗分离叶肉原生质体，５ｄ苗龄的较４ｄ及６ｄ以上苗龄的得率高。提高Ｃａ＾２＋浓度有利于原生质体的分离，浓度为１０ｍｍｏｌ／Ｌ时的得率最高。在以添加０．５ｍｇ／Ｌ２，４－Ｄ、１．０ｍｇ／Ｌ ＮＡＡ及０．５ｍｇ／Ｌ ＺＴ的改良ＭＳ培养基和微弱的光照条件下，原生质体能持续分裂，并形成小细胞团。     

草木樨状黄芪单细胞培养再生植株及其影响因素的研究

从草木樨状黄芪的子叶和胚轴诱导的愈伤组织中选取结构松脆的颗粒状愈伤组织,用液体培养基Ｓ１２进行悬浮培养建立了悬浮细胞。取换液３天左右生长旺盛的悬浮系材料分离单细胞,用基本培养基Ｓ１２与不同浓度的植物血球凝集素组成的系列培养基ＭＣ１－ＭＣ６进行液体浅层静置暗培养;形成小愈伤组织后,经Ｍ３（ＭＳ＋２,４－Ｄ ２ｍｇ／Ｌ,ＮＡＡ ０．２ｍｇ／Ｌ,ＫＴ １ｍｇ／Ｌ）培养基增殖,ＭＲ２培养基诱导分化出苗,再     

百脉根愈伤组织原生质体再生植株

百脉根无菌苗幼茎在含２．０ｍｇ／Ｌ－,２,４－Ｄ,０．１ｍｇ／Ｌ２－ｉｐ的ＭＳ培养基上诱导和继代培养愈伤组织。选取绿色松散颗粒愈伤组织分离原生质体。原生质体培养在调整珠ＫＭ８Ｐ,Ｖ－ＫＭ,ＭＳ和ＳＨ培养基上「含３００ｍｇ／Ｌ,ＣＨ,２％ＣＷ,２％蔗糖,６％葡萄糖,２．０ｍｇ／Ｌ,２,４－Ｄ,０．５ｍｇｇ／Ｌ,ＢＡ,５ｍｍｏｌ／Ｌ ＭＥＳ」,原生质体再生细胞均能分裂,并形成小愈伤组织,但以ＫＭ８０为     

麻体细胞胚胎发生研究初报

将苎麻“浏阳大叶绿”的子叶培养在附加０．５ｍｇ／ＬＣＰＡ、０．０５ｍｇ／ＬＢＲ的ＣＸＷ培养基上,可获得淡黄色或浅灰绿色的颗粒状愈伤组织。将愈伤组织转移至附加０．１ｍｇ／ＬＣＰＡ、０．０５ｍｇ／ＬＮＡＡ、１．５ｍｇ／ＬＺＴ的ＣＸＷ培养基上继代,颗粒状结构非常明显。继续培养在添加２ｍｇ／ＬＭｅｔ,３ｇ／ＬＹＥ的上述继代培养基上,可分化出一些相互独立的胚状体,继而发育成为胚状体幼苗。     

大叶紫花苜蓿愈伤组织原生质体再生植株

大叶紫花苜蓿下胚轴诱导的愈伤组织在继代培养基上生长快速,易于分散。继代第１２ｄ的愈伤组织原生质体的得率为６．５×１０７／ｇ鲜重。原生质体培养基为ＳＨ基本培养基,含有１．０ｍｇ／Ｌ２,４－０、０．５ｍｇ／ＬＢＡ、２．０ｇ／ＬＣＨ、２％蔗糖、６％葡萄糖、５ｍｍｏｌ／ＬＭＥＳ,培养密度为１．０×１０５／ｍＬ。培养至第１２ｄ时的原生质体再生细胞植板率为３．７％。由原生质体形成的小愈伤组织在含２．０ｍｇ／Ｌ２,４－Ｄ的ＭＳ固体培养基上大量增殖。增殖的愈伤组织转移至２．０ｍｇ／Ｌ２－ｉｐ＋０．１ｍｇ／ＬＮＡＡ的Ｂ５培养基上,形成体细胞胚并发育成完整植株。     

火炬松成熟合子胚培养直接器官发生和植株再生

基因型Ｈｂ,Ｍａ和Ｍｃ的火炬松成熟合子胚在附加１．０ｍｇ／ＬＮＡＡ,４．０ｍｇ／ＬＢＡ,５００ｍｇ／ＬＬＨ和５００ｍｇ／Ｌ谷氨酰胺的ＴＥ培养基上培养１２周后,在子叶和胚轴部位形成不定芽原基。然后将合子胚转移到附加０．５ｍｇ／／ＬＮＡＡ,０．０５ｍｇ／ＬＩＢＡ,２ｍｇ／ＬＢＡ,５００ｍｇ／ＬＬＨ和５００ｍｇ／Ｌ谷氨酰胺的ＴＥ不定芽分化培养基上,６周后分化产生大量不定芽,３种基因型中,Ｈｂ的直接不定芽     

荷兰鸢尾(Iris xiphium L. var. hybridum)的组织培养

取荷兰鸢尾（ＩｒｉｓｘｉｐｈｉｕｍＬ．ｖａｒ．ｈｙｂｒｉｄｕｍ）鳞茎片不同部位外植体块,接种于附加不同激素配比的基本培养基上,其中取自鳞茎片基部外植体块２ｍｍ×２ｍｍ×２ｍｍ,培养基为ＭＳ＋ＢＡ１．０ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ的不定芽诱导率为最高（７０％）;最理想的增殖培养基为ＭＳ＋ＢＡ２．０ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ。不定芽直径４～５ｍｍ,培养基为ＭＳ＋ＢＡ０．２ｍｇ／Ｌ＋ＮＡＡ０．５ｍｇ／Ｌ有利于不定根的发生,诱导生根率达８３３％。试管苗不经练苗可直接出瓶,移栽于泥炭∶田土∶河沙＝１∶１∶１（Ｖ／Ｖ）的基质中。     

中麻黄悬浮培养体系的建立

本文用中麻黄无菌苗为外植体,其切段培养在附加２ｍｇ／Ｌ２,４－Ｄ和０．５ｍｇ／Ｌ　６　ＢＡ的ＭＳ培养基上,全部脱分化形成白色疏松愈伤组织。愈伤组织继代培养于ＭＳ＋０．５ｍｇ／Ｌ２,４－Ｄ＋０．２ｍｇ／Ｌ６ＢＡ＋０．２ｍｇ／Ｌ　ＮＡＡ＋４％蔗糖的培养某上。以继代培养愈伤组织为材料进行悬浮培养,培养基为附加０．２ｍｇ／Ｌ２,４－Ｄ＋０．１ｍｇ／Ｌ６ＢＡ＋０．１ｍｇ／ＬＮＡＡ＋２％蔗糖的ＭＳ液体培养基,得到分散性好,细胞形状接近圆形,细胞大小均一,细胞团多由２－３０个细胞组成的悬浮培养体系。第三代悬浮培养细胞增长率为０．３５ｇ·ｆｗ／２０ｍｌ·ｄ,细胞有丝分裂指数为１１．２％。条件培养和高密度接种可缩短延迟期,条件培养不能提高分裂指数,１ｇ／１０ｍｌ接种密度可使分裂指数提高至２１．２％。     

Modeling of Xanthophyllomyces dendrorhous growth on glucose and overflow metabolism in batch and fed-batch cultures for astaxanthin production

An astaxanthin-producing yeast Xanthophyllomyces dendrorhous ENM5 was cultivated in a liquid medium containing 50 g/L glucose as the major carbon source in stirred fermentors (1.5-L working volume) in fully aerobic conditions. Ethanol was produced during the exponential growth phase as a result of overflow metabolism or fermentative catabolism of glucose by yeast cells. After accumulating to a peak of 3.5 g/L, the ethanol was consumed by yeast cells as a carbon source when glucose in the culture was nearly exhausted. High initial glucose concentrations and ethanol accumulation in the culture had inhibitory effects on cell growth. Astaxanthin production was partially associated with cell growth. Based on these culture characteristics, we constructed a modified Monod kinetic model incorporating substrate (glucose) and product (ethanol) inhibition to describe the relationship of cell growth rate with glucose and ethanol concentrations. This kinetic model, coupled with the Luedeking-Piret equation for the astaxanthin production, gave satisfactory prediction of the biomass production, glucose consumption, ethanol formation and consumption, and astaxanthin production in batch cultures over 25-75 g/L glucose concentration ranges. The model was also applied to fed-batch cultures to predict the optimum feeding scheme (feeding glucose and corn steep liquor) for astaxanthin production, leading to a high volumetric yield (28.6 mg/L) and a high productivity (5.36 mg/L/day).     

Involvement of branched-chain amino acid aminotransferase (Bcat1/Eca39) in apoptosis.

The branched-chain amino acid aminotransferase, Bcat1/Eca39, catalyzes the first step of branched-chain amino acid catabolism. Bcat1/Eca39 was originally isolated from a c-myc-induced tumor and was proven to be a direct target for c-Myc regulation. The gene is highly conserved in evolution and disruption of its yeast homolog affects cell growth. To assess the role of Bcat1/Eca39 in mammalian cells, we overexpressed Bcat1/Eca39 in murine cells and studied effects on cell growth. Overexpression of Bcat1/Eca39 had no apparent effect on the proliferation of cells grown with high serum concentrations, but under serum deprivation conditions, led to a decrease in cell viability. Cell death under these conditions displayed apoptotic features. The branched-chain keto acid, alpha-ketoisocaproate, a metabolite of leucine catabolism produced by BCAT1/ECA39, was previously found to inhibit cell growth. We show that alpha-ketoisocaproate can induce rapid apoptotic cell death. This observation suggests that the growth inhibitory effect of BCAT1/ECA39 and its apoptosis promoting effect may be mediated by the levels of the products of BCAT1/ECA39 activity, namely, branched-chain keto acids.     

Rooting and the Metabolism of Nicotine in Tobacco Callus Cultures

The usefulness of exogenous nicotine as a factor in the induction of morphogenesis in a tobacco tissue culture medium has been demonstrated. Nicotiana rustica callus cell cultures were grown on a modified Murashige and Skoog medium with 2 mg/l indoleacetic acid (IAA) and 0.2 mg/l kinetin (MMS). Root morphogenesis was induced in roller tube callus cell cultures and solid callus cell cultures grown on MMS without kinetin supplemented with 10–100 mg/l nicotine. Optimal nicotine concentration for root induction was 50 mg/l. Other tests using varying combinations of IAA, kinetin and nicotine produced no obvious morphogenesis, although some changes in the amount of callus growth and endogenous protein concentration did correlate with nicotine concentration relative to the presence of IAA and/or kinetin. In liquid MMS medium, ¹⁴C-nicotine was primarily incorporated into the protein fraction of cultured cells while primarily incorporated into the cell wall and/or cell membrane fraction of cells cultured on MMS without kinetin in the medium. In MMS without IAA and MMS without both IAA and kinetin, there was incorporation, but to a lesser extent in both the protein and the cell wall and/or cell membrane fractions.     

Studies on the Growth in Culture of Plant Cells: VII. EFFECTS OF KINETIN ON THE CARBOHYDRATE AND NITROGEN METABOLISM OF ACER PSEUDOPLATANUS, L CELLS GROWN IN SUSPENSION CULTURE

Aspects of the carbohydrate and nitrogen metabolism of Acerpseudcplatanus, L cell suspension cultures grown on a syntheticmedium containing 2 per cent glucose and 1.0 mg/l 2,4-dichlorophenoxyaceticacid and kinetin either at 0.25 mg/l (low kinetin) or at 2.5mg/l (high kinetin) are described. High kinetin inhibits growthas measured by increase in cell number, packed-cell volume,and cell dry weight. Although not inhibitory to glucose utdization,high kinetin inhibits the O₂ uptake of the cells. Such cellscontain only a trace amount of fructose and their rate of O₂uptake can be raised to that of the low kinetin cells by a periodof fructose feeding. The O₂ uptake of both kinds of cell issensitive to malonate but the stimulation of O₂ uptake inducedby bis(hexafiuoroacetonyl)-acetone (‘1799’) at 0.2mM is much less with the high-kinetin than the low-kinetin cells.The enzymes phosphoglucoseiseomerase and glucose-6-phosphatedehydrogenase are much less active in the high-kinetin cells.Mitochondria isolated from both kinds of cells show good respiratorycontrol although slightly lower values for Q_O2(N), ADP/O ratioand control ratio are recorded with mitochondria from the highkinetin cells. Kinetin at 2.5 mg/l slightly reduces the ADP/Oratio of isolated mitochondria but at 4.0 mg/l their responseto ADP is completely suppressed. Extracellular hemicelluloseformed in presence of high kinetin has a reduced content ofgalactose and xylose and an increased content of glucose. Theseobservations indicate that the inhibition of respiration byhigh kinetin is mainly due to suppression of glucose conversionto other sugars rather than to inhibition of glycolysis or terminalrespiration. High kinetin decreases the rate of protein but not of amino-acidsynthesis. Suppression of the synthesis of particular proteinsmay be an important factor responsible for the reduced cellyield of the cultures in presence of high kinetin. The significanceof these observations to our understanding of the critical metaboliceffects of cytokinina is discussed. Acer pseudoplatanus cells release amino acids into their culturemedium early in the period of batch culture and largely reabsorbthem as incubation proceeds.     

Influence of growth regulators on plant regeneration from epicotyl and hypocotyl cultures of two groundnut (Arachis hypogaea L.) cultivars

This study was designed to evaluate the effect of phytohormones on plant regeneration from epicotyl and hypocotyl explants of two groundnut (Arachis hypogaea) cultivars. Explants cultured on media with auxins and in combination with cytokinin produced high frequency of callus. After four weeks, callus from these cultures was transferred to medium with cytokinin and reduced auxin, shoot buds regenerated from the cultures. A high rate of shoot bud regeneration was observed on medium supplemented with 2.0 mg/L BAP and 0.5 mg/L NAA. Among the different auxins tested, NAA was found to be most effective, producing the highest frequency of shoot buds per responding cultures. Of the two explants tested, epicotyl was found to be best for high frequency shoot bud regeneration. Multiple shoots arose on MS medium supplemented with BAP or kinetin (1.0–5.0 mg/L) plus IBA (1.0 mg/L), with maximum production occurring at 5.0 mg/L. The elongated shoots developed rootsin vitro upon transfer to MS medium supplemented with NAA or IBA (0.5–2.0 mg/L) and kinetin (0.5 mg/L) for 15 days.In vitro produced plantlets, were transferred to soil and placed in a glasshouse developed successfully, matured, and set seeds.     

The Relationships Between Activities of Indoleacetic Acid Oxidase,Peroxidase ahd Isoenzymes in Four Kinds of Calli

Aspen, Hami melon, soybean and tobacco calli were incubated in Miller's solid medium supplemented with IAA 4 mg/L and kinetin 0.5 mg/L. Activities of IAA-oxidase and peroxidase were determined at 0,5,10,15 and 25 days after incubation. The activities of IAA oxidase and peroxidase of Hami melon callus were found to be the highest and the tobacco was the lowest among the four different kinds of calli, both enzymes showed their peak value in 10 days after incubation. There were no change in pattern of peroxidase isoenzyme among the four kinds of calli during the incubation, but the activities of IAA-oxidase and its isoenzyme of Hami melon at bands A6, A7 and A8 were 3 to 17 folds higher than that of corresponding isoenzyme of other three kinds of calli.     

EFFECTS OF GROWTH SUBSTANCES ON EXCISED FLORAL BUDS OF AQUILEGIA

Buds at various stages of development were grown for 3 weeks on solid media containing coconut milk, minerals, vitamins, sucrose, and varying quantities of gibberellic acid, indoleacetic acid, and kinetin. The best average growth was obtained on media containing GA at 2.0 mg/liter, IAA at 1.0 mg/liter, and kinetin at 0.05 mg/liter. When results were compared for buds explanted at very young stages and at older stages, however, young buds attained better average growth on media with 0.5 mg/liter of IAA. Evidence is presented for interaction between IAA and kinetin. With buds explanted at young stages, as the kinetin concentration was increased, optimum growth occurred on media with increasing concentrations of IAA. With older buds, on the other hand, as the kinetin concentration was increased, optimum growth occurred on decreasing concentrations of IAA. Bud growth was compared on media with growth substances sterilized by autoclaving with growth on similar media with these substances filter-sterilized. Better growth occurred generally on the media with filter-sterilized ingredients. A long-range objective of this research is the development of a system that would make possible quantitative measurements of floral development in vitro.     

An improved method for micropropagation and regeneration of date palm (Phoenix dactylifera L.)

We developed a novel large-scale micropropagation pathway for date palm (Phoenix dactylifera L.) based on organogenesis. We obtained organogenic stems from shoot tip explants of the Moroccan date palm cultivar Najda, and investigated shoot proliferation from these organogenic stems in vitro on various media; Beauchesne medium (BM) and Murashige and Skoog medium (MS) at full-strength, half-strength, and one-third-strength, containing various concentrations (0, 0.25, 0.5, and 1 mg/L) of 2-naphthoxyacetic acid (NOAA) and kinetin. The optimal medium during the multiplication phase was half-strength Murashige and Skoog medium (MS/2) supplemented with 0.5 mg/L NOAA and 0.5 mg/L kinetin (23.5 morphologically superior shoots per explant, with low vitrification rates). For the shoot elongation phase, shoots were transferred to the same proliferation medium, or to MS or MS/2 media without plant growth regulators (PGRs). Shoots elongated rapidly and showed a high rate of root formation on media supplemented with PGRs. For example, on MS/2 medium containing 1 mg/L NOAA and 1 mg/L kinetin, the average shoot length was 15.1 cm, the average number of roots per shoot was 6.2, and their average length was 3.4 cm. On PGR-free media, shoots were shorter with wider and greener leaves, and had fewer roots. The plantlets were transferred to a greenhouse for acclimation. The survival rate after 2 months was related to the medium used during the elongation phase; >90 % of shoots that were cultured on PGR-free media survived, while there was a poor survival rate of shoots that had been cultured on media containing PGRs.     

High-frequency regeneration and transformation ofRaphanus savus

We have achieved high-frequency shoot regeneration in radish(Raphanus sativus). Cotyledon explants from four-day-old seedlings were suitable for the effective induction of shoots on Murashige and Skoog’s (MS) medium containing 3.0 mg/L kinetin. We also determined that it was essential to include 1- to 2-ram petiole segments with the cotyledons for efficient induction. When the regenerated shoots were transferred to an MS liquid medium containing 0.1 mg/L NAA, roots formed within four weeks, and normal plant development ensued. We established a transformation protocol using anAgrobacterium binary vector that carries the GUS reporter gene. Preculturing the explants for I d in an MS medium containing 3.0 mg/L kinetin also increased efficiency. Five days of cocultivation proved best for delivering T-DNA into radish. Transformation frequencies of up to 52% were obtained in shoot induction media that contained 3.0 mg/L kinetin.     

GROWTH AND DIFFERENTIATION OF JUICE VESICLES OF ORANGE GROWN IN VITRO

Juice vesicles of Valencia orange were grown on agar bases containing different concentrations of kinetin plus mineral and organic constituents, or in comparable liquid solution (shake cultures), maintained at approximately 26 C. Shake cultures enlarge most rapidly, but both maintain similar patterns of anatomical development. Typically, marginal parenchymatous cells of the sac become meristematic and develop, largely by periclinal division, generalized cambial meristems that enlarge the callus by the addition of linear rows of cells. Chloroplasts and wound tracheids with bordered pits mature within 30 days, but to date no further differentiation has been noted. Surface cells frequently enlarge, detach, and grow into branched hyphal aggregations of cells. Media containing 1.0 mg/liter kinetin causes greater enlargement of callus than media with 0.02 mg/liter kinetin.