Background

The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all the commercially important rosaceous species.

Results

We use gene specific primers to show that the three MYB activators of apple anthocyanin (MYB10/MYB1/MYBA) are likely alleles of each other. MYB transcription factors, with high sequence identity to the apple gene were isolated from across the rosaceous family (e.g. apples, pears, plums, cherries, peaches, raspberries, rose, strawberry). Key identifying amino acid residues were found in both the DNA-binding and C-terminal domains of these MYBs. The expression of these MYB10 genes correlates with fruit and flower anthocyanin levels. Their function was tested in tobacco and strawberry. In tobacco, these MYBs were shown to induce the anthocyanin pathway when co-expressed with bHLHs, while over-expression of strawberry and apple genes in the crop of origin elevates anthocyanins.

Conclusions

This family-wide study of rosaceous R2R3 MYBs provides insight into the evolution of this plant trait. It has implications for the development of new coloured fruit and flowers, as well as aiding the understanding of temporal-spatial colour change.

An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae

A 1.1 kb rice genomic DNA fragment, containing a chitinase gene under the control of the CaMV 35S promoter, was cloned into the rice transformation vector pGL2. After transformation of Indica rice protoplasts in the presence of polyethyleneglycol, plants were regenerated. The presence of the chimeric chitinase gene in T0 and T1 transgenic rice plants was detected by Southern blot analysis. Western blot analysis of transgenic plants and their progeny revealed the presence of two proteins with apparent molecular weights of 30 and 35 kDa that reacted with the chitinase antibody. Progeny from the chitinase-positive plants were tested for their resistance to the sheath blight pathogen, Rhizoctonia solani. The degree of resistance displayed by the transgenic plants to this pathogen correlated with the level of chitinase expression.

Genetic engineering of rice for resistance to sheath blight and other agronomic characters

Recombinant antibodies are highly specific detection probes in research, diagnostics and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines and transgenic plants are promising to obtain antibodies with “human-like” post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications.

/pdf/expression-of-recombinant-antibodies-2c6ed3edz4.pdf

Expression of recombinant Antibodies

Soil salinization is one of the major environmental stressors hampering the growth and yield of crops all over the world. A wide spectrum of physiological and biochemical alterations of plants are induced by salinity, which causes lowered water potential in the soil solution, ionic disequilibrium, specific ion effects, and a higher accumulation of reactive oxygen species (ROS). For many years, numerous investigations have been made into salinity stresses and attempts to minimize the losses of plant productivity, including the effects of phytohormones, osmoprotectants, antioxidants, polyamines, and trace elements. One of the protectants, selenium (Se), has been found to be effective in improving growth and inducing tolerance against excessive soil salinity. However, the in-depth mechanisms of Se-induced salinity tolerance are still unclear. This review refines the knowledge involved in Se-mediated improvements of plant growth when subjected to salinity and suggests future perspectives as well as several research limitations in this field.

https://www.mdpi.com/1422-0067/21/1/148/pdf

An Overview of Hazardous Impacts of Soil Salinity in Crops, Tolerance Mechanisms, and Amelioration through Selenium Supplementation.

β-1,3-Glucanases are abundant in plants and have been characterized from a wide range of species. They play key roles in cell division, trafficking of materials through plasmodesmata, in withstanding abiotic stresses and are involved in flower formation through to seed maturation. They also defend plants against fungal pathogens either alone or in association with chitinases and other antifungal proteins. They are grouped in the PR-2 family of pathogenesis-related (PR) proteins. Use of β-1,3-glucanase genes as transgenes in combination with other antifungal genes is a plausible strategy to develop durable resistance in crop plants against fungal pathogens. These genes, sourced from alfalfa, barley, soybean, tobacco, and wheat have been co-expressed along with other antifungal proteins, such as chitinases, peroxidases, thaumatin-like proteins and α-1-purothionin, in various crop plants with promising results that are discussed in this review.

Plant β-1,3-glucanases: their biological functions and transgenic expression against phytopathogenic fungi

One way of enhancing and broadening resistance of plants to different biotic and abiotic stresses is to combine transgenes expressing several genes into a single line. This can be done using different strategies such as crossing, single vector with multiple genes, co-transformation, sequential transformation and IRES elements. In the present study conventional crossing method was used. Parental transgenic lines transformed via Agrobacterium tumefasciens-mediated gene transformation with pGreenII binary vector harbouring a bar gene as selectable marker in combination with the family 19 chitinase gene from Streptomyces olivaceoviridis for one line and 1,3-β-glucanase from barley (Hordeum vulgare) for the other line were used for crossing. Both chitinase and glucanase genes were cloned into pGreenII vector under the control of the constitutive double 35S-promoter from cauliflower mosaic virus. Progenies expressing the two genes were characterised at the molecular level using PCR, RT-PCR and Southern blot analysis, as well as segregation and stability studies of the respective expression levels. Leaf paint assay was used as functional test for herbicide resistant gene. Stable inheritance of the antifungal genes in the transgenic plants was demonstrated. The synergistic effect of crossed plants was tested using in vitro assay which shows higher inhibition of spore germination.

/pdf/enhancing-transgenic-pea-pisum-sativum-l-resistance-against-3blfm17odl.pdf

Enhancing transgenic pea (Pisum sativum L.) resistance against fungal diseases through stacking of two antifungal genes (chitinase and glucanase).

Key message
We report for the first time that expression of potato PR10a gene in faba bean causes enhanced tolerance to drought and salinity.

Enhanced tolerance to drought and salt stresses in transgenic faba bean (Vicia faba L.) plants by heterologous expression of the PR10a gene from potato

A family 19 chitinase (Chit30) from Streptomyces olivaceoviridis ATCC 11238 expressed in transgenic pea affects the development of T. harzianum in vitro.

Modern biotechnological methods like in vitro micropropagation technique hold tremendous potential for the production of high-quality plant-based medicine. They also allow to achieve the large scale multiplication of disease-free plants, faster cloning and the conservation of desired genotypes, in a very short span of time. Via genetic transformation techniques, the modification of both genetic information of MAPs and the regulation of genes responsible for the production of valuable biologically active substances has also become possible in either higher amounts or with better properties.

In Vitro Micropropagation of Medicinal and Aromatic Plants

Transformation experiments were carried out using different explants of two varieties of white jute ( Corchorus capsularis L.), namely, CVL-1 and CVE-3 with Agrobacterium tumefaciens strain (LBA4404/pBI121) containing the GUS and npt II genes. Maximum transformation ability was obtained from petiole-attached cotyledons and mature embryo explants. Kanamycin at a concentration of 200 mg/l was found optimum for selection of transformed shoots developed from mature embryos. Histochemical assay revealed the stable expression of the GUS gene within the various tissues of transformed plantlets. Stable integration of GUS and npt II genes were confirmed by PCR analysis of genomic DNA isolated from these transformed shoots. Key words: Jute, Transformation, GUS expression, PCR analysis D.O.I. 10.3329/ptcb.v18i1.3245 Plant Tissue Cult. & Biotech. 18 (1): 7-16, 2008 (June)

/pdf/agrobacterium-mediated-genetic-transformation-of-two-3co1ekvgj1.pdf

Fathi Hassan

Papers

Enhancing transgenic pea (Pisum sativum L.) resistance against fungal diseases through stacking of two antifungal genes (chitinase and glucanase).

Enhanced tolerance to drought and salt stresses in transgenic faba bean (Vicia faba L.) plants by heterologous expression of the PR10a gene from potato

A family 19 chitinase (Chit30) from Streptomyces olivaceoviridis ATCC 11238 expressed in transgenic pea affects the development of T. harzianum in vitro.

In Vitro Micropropagation of Medicinal and Aromatic Plants

Agrobacterium-mediated Genetic Transformation of Two Varieties of Jute (Corchorus capsularis L.)