Please Help with the following questions 1.) plant tissues are extremely sensiti
ID: 193325 • Letter: P
Question
Please Help with the following questions
1.) plant tissues are extremely sensitive to damage by the powerfully oxidizing effects of ozone (O3) . what effects would you expect this to have on urban-rural gradients and stomata density, and how would this effect interact with other urban-rural gradient effect on plants? what are the implications of these issues to Urban agriculture?
2.)many bacteria and fungi that are parasitic of plants face the daunting task of finding and infecting a new host by Airborne Spore dispersal followed by germinating upon and then penetrating the leaf surface of their host. What are some of the specific adaptations possessed by some of these parasites to gain access to leave tissue by entering through stomata thereby evading the plant leave cuticle? search on Rust fungi, Uromyces
3.)Among bryophytes, stomata are restricted to the sporophyte life stage (found in mosses and some hornworts). Why? Why might it be adaptive for the only sporophyte and not the gametophyte stage in the life cycle to possess the stomata ?
Explanation / Answer
1. Ans. Plant tissues are highly damaged by oxidizing effects of ozone (O3) . At ground level, ozone is the main cinstituent of industrial smog and it is released by the chemical reaction of volatile organic compounds such as benzene ,toluene and nitrous oxides (nitrous oxides,nitrates,nitric acids ) in the presence of sunlight. The excess amount of ozone leads to strengthened of invasive species in the urban forest ecosystem. Some scientists studied that air pollution in urban forests is damaging the ecosystem. The native species are less euipped to defend themselves against incresed level of oxides of ozone than invasive species.
When stomata are open in plants, the ozone enters their cavity and oxidises the mesophyll cell wall and increses permeability of cell wall and injures the cell. Research shows that in some plants where ozone exchange is more there is more stomatal density and more aperture size of stomata.
The ozone causes chlorosis and necrosis like symptoms on leaves of crop. The ozone affects yield of crops at higher level. It may lead to low yield of crop.