Rust (fungus) fungi may be able to infect two different plant hosts in different stages of its life cycle, and may produce up to five morphologically and cytologically distinct spore-producing structures viz., spermogonia, aecia, uredinia, telia, and basidia in successive stages of reproduction. Each spore type is very host specific, and can typically infect only one kind of plant. Rust fungi are obligate plant pathogens that only infect living plants. Infections begin when a spore lands on the plant surface, germinates, and invades its host. Infection is limited to plant parts such as leaves, petioles, tender shoots, stem, fruits, etc. Plants with
Genetically modified organism be genetically engineered and is considered a model organism for not only genetic engineering, but a range of other fields. As such the transgenic tools and procedures are well established making it one of the easiest plants to transform. Another major model organism relevant to genetic engineering is "Arabidopsis thaliana." Its small genome and short life cycle makes it easy to manipulate and it contains many homolgs to important crop species. It was the first plant sequenced, has abundant bioinformatic resources and can be transformed by simply dipping a flower in a transformed "Agrobacterium" solution. In research, plants are engineered