Establishment of in vitro culture, plant regeneration, and genetic transformation of Camelina sativa

The results of establishing an in vitro culture, plantlet regeneration, and rooting of Camelina sativa cultivar Peremozhets and cultivar Mirazh are presented. The effective concentrations of sterilizing agents and the duration of plant material treatment were estimated. The phytohormone ratio, the sucrose concentration in the nutrient medium that induced the effective formation of C. sativa shoots, and the NAA concentration for plantlet rooting have been established. A method of Agrobacterium-mediated transformation of Camelina by using binary vector pGH217 carrying the reporter β-glucoronidase (gus) gene driven under the 35S CaMV promoter and nos-terminator, as well as the selective marker hpt gene conferring hygromycin-resistance in transgenic plant, was elaborated.     

In vitro plant regeneration and genetic transformation of Dichanthium annulatum

Optimization of in vitro plant regeneration and genetic transformation of apomictic species such as Dichanthium annulatum would enable transfer of desirable genes. Seven genotypes of this grass species were screened through mature seed explant for embryogenic callus induction, callus growth and quality (color and texture), and shoot induction. Genotype IG-1999, which produced highly embryogenic, rapidly growing good-quality callus capable of regenerating at a high frequency, was selected for transformation experiments. Using a binary vector (pCAMBIA1305), frequency of GUS expression was compared between two methods of transformation. Bombardment of embryogenic calli with gold particles coated with pCAMBIA1305 at a distance of 11 cm, pressure of 4 bars, and vacuum of 27 Hg passing through 100 muM mesh produced maximum GUS expression (23%). Agrobacterium infection was maximum at an optical density of 2.0 when cocultured under vacuum for 15 min and cocultivated for 3 days at 28 degrees C in constant dark on MS medium of pH 5.8 with 3 mg/l 2,4-D, and 400 muM acetosyringone. Among two binary vectors used for Agrobacterium-mediated transformation, pCAMBIA1301 showed higher frequency of GUS expression while pCAMBIA1305 recorded more of the GUS spots per callus. Supplementation of acetosyringone in the cocultivation medium was found indispensable for Agrobacterium-mediated transformation. Injuring the calli through gold particle bombardment before their cocultivation with Agrobacterium improved the transformation efficiency. Several transgenic plants were developed using the PIG method, while stable GUS-expressing calli were multiplied during selection on MS medium containing 250 mg/l cefotaxime and 50 mg/l hygromycin, incubated in constant dark. A highly significant difference was observed between two methods of transformation for both frequency of GUS expression and GUS spots per callus. PIG-mediated transformation resulted in higher GUS expression compared to the Agrobacterium method. These results demonstrate that Dichanthium annulatum is amenable to Agrobacterium-mediated genetic transformation using a binary vector.     

Sandalwood: basic biology,tissue culture,and genetic transformation

Planta - Sustainable resource preservation of Santalum species that yield commercially important forest products is needed. This review provides an understanding of their basic biology,...     

Isozymes,plant population genetic structure and genetic conservation

Summary The exploration, conservation and use of the genetic resources of plants is a contemporary issue which requires a multidisciplinary approach. Here the role of population genetic data, particularly those derived from electrophoretic analysis of protein variation, is reviewed. Measures of the geographic structure of genetic variation are used to check on sampling theory. Current estimates justify the contention that alleles which have a highly localised distribution, yet are in high frequency in some neighbourhoods, represent a substantial fraction of the variation. This class, which is the most important class in the framing of sampling strategies, accounts for about 20–30% of variants found in 12 plant species. The importance of documenting possible coadapted complexes and gene-environment relationships is discussed. Furthermore, the genetic structure of natural populations of crop relatives might suggest the best structure to use in the breeding of crops for reduced vulnerability to pest and disease attack, or for adaptation to inferior environments. The studies reported to date show that whilst monomorphic natural populations do occur, particularly in inbreeding colonisers, or at the extreme margins of the distribution, polymorphism seems to be the more common mode. It is stressed here that the genetic resources of the wild relatives of crop plants should be systematically evaluated. These sources will supplement, and might even rival, the primitive land races in their effectiveness in breeding programmes. We may look forward to a wider application of gel electrophoresis in the evaluation of plant genetic resources because this technique is currently the best available for detecting genetic differences close to the DNA level on samples of reasonable size.     

The effects of anther culture and plant genetic background on Agrobacterium rhizogenes-mediated transformation of commercial cultivars and derived doubled-haploid Brassica oleracea

The production of transgenic roots was scored for eight Brassica oleracea cultivars from broccoli, cabbage, cauliflower and kale following inoculation with an Agrobacterium rhizogenes cell line carrying a binary plasmid bearing the green fluorescence protein (gfp) gene in the T-DNA. Significant differences in the numbers of explants producing transgenic roots were observed between cultivars, ranging from 1.4% for Marathon F1 to 57.8% for the Green Duke F1. Three F1 cultivars were subjected to anther culture, and doubled-haploid (DH) lines were used for transformation. The DH lines produced showed considerable variation for transgenic root production with some lines showing increased efficiency compared to the parental F1 cultivar. Grouping of the DH lines into response classes with respect to transgenic root production allowed the development of potential genetic models to explain the variation in performance released from each F1 cultivar. No apparent segregation distortion for transgenic root production was observed in the DH lines following anther culture.     

Stromules: Origin, structure and functions in a plant cell

The review presents a critical analysis of experimental achievements concerning structure and peculiarities of stromules over the last years. Stromules are dynamic thin protrusions of membrane envelope from plant cell plastids. The prospects of further studies of the stromules are discussed.     

In vitro regeneration and genetic transformation of the berberine-producing plant,Thalictrum flavum ssp. glaucum

Protocols have been developed for the in vitro regeneration and Agrobacterium -mediated genetic transformation of meadow rue, Thalictrum flavum ssp. glaucum . Ten-day-old seedlings were bisected along the embryonic axis and the cotyledons were co-cultured with various Agrobacterium tumefaciens strains for 3 days. The cotyledons were cultured on a shoot induction medium (B5 salts and vitamins, 30 g l⁻¹ sucrose, 2 mg l⁻¹ kinetin, and 3 g l⁻¹ Gelrite) containing 25 mg l⁻¹ hygromycin B as the selection agent and 250 mg l⁻¹ timentin to facilitate the elimination of Agrobacterium . Only the oncogenic A. tumefaciens strains A281 and C58 produced transgenic T. flavum callus tissues. A281 was the most effective strain producing hygromycin-resistant callus on 85% of the explants. Transgenic callus was subcultured on the shoot induction medium every 2 weeks. After 12 weeks, hygromycin-resistant shoots that formed on explants exposed to strain A281 were transferred to a root induction medium (B5 salts and vitamins, 25 mg l⁻¹ hygromycin B, 250 mg l⁻¹ timentin, and 3 g l⁻¹ Gelrite). Detection of the β -glucuronidase ( GUS ) gene using a polymerase chain reaction assay, the high levels of GUS mRNA and enzyme activity, and the cytohistochemical localization of GUS activity confirmed the genetic transformation of callus cultures and regenerated plants. The transformation process did not alter the normal content of berberine in transgenic roots or cell cultures; thus, the reported protocol is valuable to study the molecular and metabolic regulation of protoberberine alkaloid biosynthesis.     

Biological functions of antioxidants in plant transformation

Browning and necrosis of transformed cells/tissues, and difficulty to regenerate transgenic plants from the transformed cells/tissues (recalcitrance) are common in Agrobacterium-mediated transformation process in many plant species. In addition, most crop transformation methods that use NPTII selection produce a significant number of nontransgenic shoots, called “shoot escapes” even under stringent selection conditions. These common problems of plant transformation, (browning and necrosis of transformed cells/tissues, recalcitrance, and the occurrence of shoot escapes) severely reduces transformation efficiency. Recent research indicates that reactive oxygen species (ROS) such as superoxide radical , the hydrogen peroxide (H₂O₂), the hydroxyl radical (OH′), and the peroxyl radical () may be playing an important role in tissue browning and necrosis during transformation. This review examines the role of ROS in in vitro recalcitrance and genetic transformation and the opportunities to improve transformation efficiency using antioxidants.     

植物遗传转化中抑菌剂的选择

农杆菌介导法进行植物遗传转化, 在农杆菌和外植体共培养后, 为使转化的外植体正常生长, 必须选择适宜的抑菌剂进行除菌。本文通过抑菌圈试验和稀释法试验测试了发根农杆菌pRi15834、pRiA₄b 、pRi1724 、pRiA13 对三种头孢霉素的敏感性, 其中头孢曲松钠的抑菌效果最好, 最适宜浓度为100~300 mg/L。     

Identification of a novel elite genotype for in vitro culture and genetic transformation of cotton

Hypocotyls of cotton (Gossypium hirsutum L.) cultivars cv. YZ-1, Coker 312 and Coker 201 were inoculated on Murashige and Skoog callus induction medium. YZ-1 exhibited a very high regeneration potential, with 81.9 % of the explants inoculated differentiated into embryogenic callus within 8–10 weeks. During the process of callus maintenance (subculture for 1 to 3 years), the total embryos number in Coker 312 and Coker 201 calli dropped sharply, and the percentage of embryo germination decreased. On the contrary, the callus of YZ-1 consistently maintains a high frequency of plant regeneration after long-time subculture. Transgenic kanamycin-resistant calli of Coker 201 partially lost the ability of somatic embryogenesis and plant regeneration. The stress produced by the transformation procedure slightly affected somatic embryogenesis and plant regeneration of YZ-1, which showed minimum loss of plant regeneration ability.     

草坪植物遗传转化的研究进展

从草坪植物组织培养与植株再生体系的建立、转基因的研究现状以及转基因育种的应用前景和存在的问题入手,综述了近年来草坪植物遗传转化的研究进展,并对草坪植物遗传转化的几种主要方法作了较为详细的阐述。     

月季的组织培养和基因转化研究进展

分子生物学技术在花卉产业中展示了巨大的、潜在的应用前景。月季是世界性的重要观赏花卉 ,其生物技术研究一直是国际的热点。综述了多年来月季的组织培养和基因转化的研究进展     

Correction to: Construction of genetic transformation system of Salix mongolica: in vitro leaf-based callus induction,adventitious buds differentiation,and plant regeneration

Plant Cell, Tissue and Organ Culture (PCTOC) - There was an error in the second author’s name in the original article. The name is correctly shown here.     

Progress in tissue culture,genetic transformation and applications of biotechnology to trees: an overview

Trees are an integral part of human life, and a vital component of biodiversity. Forest trees in particular are renewable sources of food, fodder, fuel wood, timber and other valuable non-timber products. Due to the rapid growth of population and the human desire to progress, there has been a tremendous reduction in forest cover from the earths surface. To maintain and sustain forest vegetation, conventional approaches have been exploited in the past for propagation and improvement. However, such efforts are confronted with several inherent bottlenecks. Biotechnological interventions for in vitro regeneration, mass micropropagation and gene transfer methods in forest tree species have been practised with success, especially in the last decade. Against the background of the limitations of long juvenile phases and life span, development of plant regeneration protocols and genetic engineering of tree species are gaining importance. Genetic engineering assumes additional significance, because of the possibility of introducing a desired gene in a single step for precision breeding of forest trees. There are no comprehensive and detailed reviews available combining research developments with major emphases on tissue culture and basic genetic transformation in tree species. The present communication attempts to overview the progress in tissue culture, genetic transformation and biotechnological applications in the last decade and future implications.     

Oxidative stress and physiological,epigenetic and genetic variability in plant tissue culture: implications for micropropagators and genetic engineers

A number of well defined problems in physiological, epigenetic and genetic quality are associated with the culture of plant cell, tissue and organs in vitro, namely, absence or loss of organogenic potential (recalcitrance), hyperhydricity (`vitrification') and somaclonal variation. These broad terms are used to describe complex phenomena that are known to be genotype and environment dependent. These phenomena affect the practical application of plant tissue culture in plant propagation and in plant genetic manipulation. Here it is hypothesised much of the variability expressed in microplants may be the consequence of, or related to, oxidative stress damage caused to the plant tissues during explant preparation, and in culture, due to media and environmental factors. The characteristics of these phenomena are described and causes discussed in terms of the known effects of oxidative stress on eukaryote genomes. Parameters to characterise the phenomena are described and methods to remediate the causes proposed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Electroporation: Mechanism and transient expression, stable transformation and biological effects in plant protoplasts

The present state of knowledge about the mechanistic and theoretical aspects of electroporation is summarized. Parameters affecting the efficiency of transient expression and stable transformation of electroporated plant protoplasts are rewieved. Biological effects of electroporation on plant protoplasts are described.     

Improvement of tissue culture,genetic transformation,and applications of biotechnology to Brassica

Development of in vitro plant regeneration method from Brassica explants via organogenesis and somatic embryogenesis is influenced by many factors such as culture environment, culture medium composition, explant sources, and genotypes which are reviewed in this study. An efficient in vitro regeneration system to allow genetic transformation of Brassica is a crucial tool for improving its economical value. Methods to optimize transformation protocols for the efficient introduction of desirable traits, and a comparative analysis of these methods are also reviewed. Hence, binary vectors, selectable marker genes, minimum inhibitory concentration of selection agents, reporter marker genes, preculture media, Agrobacterium concentration and regeneration ability of putative transformants for improvement of Agrobacterium-mediated transformation of Brassica are discussed.