Trehalose In Transgenic Plants Increase Stress Tolerance
Plants are highly adaptable and have many mechanisms to survive environmental stresses. Drought and high salinity of irrigation water are two stresses that pose problems in growing crop plants. In drought-tolerant plants, fungi, and bacteria, the sugar trehalose protects the organism during times of stress. Trehalose is a nonreducing storage carbohydrate that has the capacity […]
Insect Resistance-Transgenic Plants
Although weeds are a nuisance, even worse enemies of plants, and correspondingly more expensive to farmers, are: 1 . Insects and roundworms 2 . Fungal diseases (molds, blights, rusts, and rots) 3 . Viral diseases of plants It is possible to engineer plants for resistance to all of these, but we will consider just the […]
Herbicide Resistant, Transgenic Plants
Herbicides cost the world’s farmers more than $12 billion each year. Yet despite this, around 10% of the crop is lost due to weeds. One problem is that many of the chemicals used do not discriminate between crops and weeds. So they kill any plant they touch. One solution is to make the crop plants […]
Particle Bombardment Technology
Another strategy for getting a gene of interest into plant tissue is to blast the DNA through the plant cell walls with a particle gun. Unlike Ti plasmid transfer by Agrobacterium , this technique works with all types of plants. The basic idea is that DNA is carried on microscopic metal particles. These are fired […]
Genetic Engineering of Plants
The first step in genetically engineering a plant is to identify a gene that will confer a specific desirable trait on the plant. In some ways, this is the hardest part of genetic engineering. The most desirable traits for a crop are increases in the amount of seed, grain, or other plant products. Increased resistance […]
Artificial Chromosomes
BACs Bacterial Artificial Chromosomes, i) use fertility F plasmid ii) 75-300 kb inserts possible iii) Developed during the humane genome project YACs Yeast Artificial Chromosomes i) Mimics Yeast chromosome ii) Contains all regions for replication (Yeast Ori and centromere) iii) Produced during the human genome progect
Pythium
Species of Pythium grow in water and soil as saprotrophs, but under suitable conditions, e.g. where seedlings are grown crowded together in poorly drained soil, they can become parasitic, causing diseases such as pre-emergence killing, damping off and foot rot. Damping off of cress (Lepidium sativum) can be demonstrated by sowing seeds densely on heavy […]
Plasmids
Fundamental concepts and definition: Plasmids are autonomous extrachromosomal replicons found commonly in prokaryotes, but also in eukaryotes and their organelles. They are generally covalently closed and superfoiled circles of double-stranded DNA with sizes ranging from 1 to 300 kbp. They contain fmm one to over 100 genes. Some plasmids integrate into the host genome and […]
Ribozymes in Gene Therapy
RNA molecules with catalytic ability are known as ribozymes . Some ribozymes act by cleaving other RNA molecules. Such ribozymes have catalytic domains that carry out the reaction fused to domains that recognize the substrate RNA by base pairing. If the sequence of the substrate recognition domain is changed, the ribozyme will recognize a different […]
Aggressive Gene Therapy For Cancer
Although most cancers are not inherited via the germ line, cancer is nonetheless a genetic disease. In the case of hereditary disease we may attempt to replace the defective component, thus preventing cell death. In contrast, when dealing with a cancer we need to destroy the cancer cells, or at least inhibit their growth and division. […]