Coffee (Coffea L.) belongs to the family Rubiaceae and is a main cash crop for tropical farmers. It has more quantity of medicinal value and protein (25–28%). As an environmentally sensitive crop, climate change has a significant impact on the quality and stable production of coffee. To develop abiotic baroreceptors on the tolerance response in coffee, tremendous research is going on to improve the productivity under varying degrees of stress at various growth stages. Physiological, morphological and biochemical parameters change the productivity and quality of coffee. This paper reviews some of the important aspects of biotic and abiotic tolerance in coffee. We explain the best implementation methods for the improvement of coffee production and briefly advantages or importance of coffee in medicinal values, significances of biotechnological aspects and genetic engineering approaches for crop improvements.
To increase thennotolerance of forage crops, transgenic rice plants as a model for transformation of monocots were generated. A cDNA encoding the chloroplast-localized small heat shock protein (small HSP) of rice, Oshsp21, was introduced into rice plants
A variety of genetically modified (GM) crops have been developed in Korea. In these crops, the resveratrol-enriched transgenic rice plant (Agb0102) has moved ahead to generate the dossier for regulatory review process required for commercialization of GM crop. The resveratrol-enriched transgenic rice plant could be released to farmers for cultivation after national regulators have determined that it is safe for the environment and human health. Here, we developed a PCR-based DNA marker based on flanking sequences of transgene for the discrimination of resveratrol-enriched transgenic rice plant. This DNA markers will be useful for identifying of resveratrol-enriched transgenic rice plant, and can also be used to estimate transgene movement occurred by pollen transfer or seed distribution. Moreover, it is helpful for prompt screening of a homozygote-transgenic progeny in the breeding program.
Leaf water and osmotic potential, chlorophyll content, photosynthetic rate, and electrolyte leakage were measured to evaluate tolerance to water stress in wild-type (WT) and transgenic tobacco plants (TR) expressing copper/zink superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) in chloroplasts. Leaf water potential of both WT and TR plants decreased similarly under water stress condition. However, leaf osmotic potential of TR plants more negatively decreased in the process of dehydration, compared with WT plants, suggesting osmotic adjustment. Stomatal conductance (Gs) in WT plants markedly decreased from the Day 4 after withholding water, while that in TR plants retained relatively high values. Relatively low chlorophyll content and photosynthetic rate under water stress were shown in WT plants since 4th day after treatment. In particular, damage indicated by electrolyte leakage during water stress was higher in WT plants than in TR plants. On the other hand, SOD and APX activity was remarkably higher in TR plants. These results indicate that transgenic tobacco plants expressing copper/zink superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) in chloroplasts improve tolerance to water stress.
A variety of genetically modified (GM) crops have been developed in Korea. In these crops, the resveratrol-enriched transgenic rice plant has moved ahead to generate the dossier for regulatory review process required for commercialization of GM crop. The resveratrol-enriched transgenic rice plant could be released to farmers for cultivation after national regulators have determined that it is safe for the environment and human health. Here we developed a PCR-based DNA marker based on flanking sequences of transgene for the discrimination of zygosity in resveratrol-enriched transgenic rice plant. This DNA marker will be useful for identifying of resveratrol-enriched transgenic rice plant, and can also be use to estimate transgene movement occurred by pollen transfer or seed distribution.
Small RNAs including microRNAs (miRNAs) and small interfering RNAs (siRNAs) play crucial roles in post-transcriptional gene silencing (PTGS) in eukaryotes. Small RNAs function cell-autonomously as well as non-cell-autonomously. It has been well characterized that pathogenic fungi secrete some effector molecules, which facilitate their infection into plants. However, it is not clear whether molecules in plant cells are able to move into fungal cells during infection. To test if small RNAs generated from plant cells can also move to fungal cells during infection, we generated transgenic Arabidopsis and rice plants ectopically expressing either double-stranded RNA interference (dsRNAi) or artificial miRNA (amiRNA) constructs targeting GFP gene. And then these transgenic plants were inoculated with transgenic rice blast fungus, Magnaporthe oryzae, expressing GFP transgene. Here, we showed that ectopic expression of both dsRNAi and amiRNA targeting GFP gene in transgenic plants significantly suppressed GFP expression in rice blast fungi inoculated, indicating that small RNA molecules generated in plant cells can move into infected fungal cells and efficiently degrade fungal GFP transcripts. Our results would provide a new small RNA-based strategy for the development of resistant crops against fungal pathogens.
In this study, we generated and characterized the transgenic rice plant expressing a spider silk protein. A cDNA coding for the C-terminus of spider dragline silk protein (AvDrag) was cloned from the spider Araneus ventricosus. Analysis of the cDNA sequence shows that the C-terminus of AvDrag consists of 165 amino acids of are petitive region and 99 amino acids of a C-terminalnon-repetitive region. The peptide motifs found in spider drag line silk proteins, GGX and An, were conserved in the repetitive region of AvDrag. The AvDrag cDNA was expressed as a 28kDa polypeptide in baculovirus-infected insect cells. To produce transgenic rice plant with high contents of glycine and alanine, the prolamin promoter-driven AvDrag was introduced into rice plant via Agrobacteriumtumefaciens-mediated gene transformation. Because of seeds pecific prolamin promoter, expression of AvDrag protein has been achieved inriceseed. The introduction and copy number of the AvDrag gene in transgenic rice plants were determined by PCR and Southern blot analysis. AvDrag expression in transgenic rice seeds was examined by Northern blot and Western blot analysis. Immuno fluorescence staining with the AvDrag antiserum revealed that the recombinant AvDrag proteins were localized in transgenic rice seeds. Furthermore, the amino acid content analysis showed that transgenic rice seeds were greatly increased in glycine and alanine as compared to controls. The present study is the first to show the expression of spider silk protein in rice seed.
Haploid system by anther culture allows the development of homozygous lines when doubled. The response of anther culture to Basta (glufosinate) resistance was investigated on transgenic plants (cv. Anjungbyeo) in order to identify inheritance of bar gene associated with Basta. Most of the regenerated transgenic plants were sterile, and only a few plants produced viable seeds (A1) in the greenhouse. The bar gene was analysis by PCR in basta resistant transgenic plant (TA0). The transgenic seeds (A1) were significantly germinated in Basta solution compared with non-transformed seeds. As a result of anther culture, in regenerated haploid plants, segregation ratio was 1:1 in five of eight cross combinations. In diploid plants, segregation ratio was 1:1 in seven of eight cross combinations. Although there was some differences in the cross combinations, most of the combinations had 1:1 segregation ratio which supports the theory. The difference may be a result of the small sample size or the difference of anther culture response caused by genotypic difference. Hence, when many cross combinations were anther-cultured the results would support the theory.