Microbes and Plant Diseases

 Yes, it is correct. As microorganisms are present everywhere (in water, air, and soil). In fact, micro-organisms can survive under all types of environment. The black round structure seen growing when observed under microscope was found to be microorganisms.

This enzyme is involved in the production of RNA from DNA through transcription. It adds ribonucleotides to growing RNA transcripts at the 3’ end. The pol gene does not encode for NA polymerase.

Plasmids are small rings of DNA and contain some genes, which are obtained through genetic recombination.

The prostrate hypae over the substratum are called stolon.

Amanita muscaria is deadly poisonous and should not be eaten.

In the process of cheese production, Asperigillus and Penicillium are used for flavouring cheese.

It is a cyclic hexapeptide composed of three glycine and three modified ornithine residues that bind Fe (ІІІ) with hydroxamate groups. It has been produced by fungi of the genera Aspergillus, Ustilago, and Penicillium.

E. coli is a bacterium and carries plasmids.

Pythium insidiosum is the causative agent of swamp cancer (especially in horses), mainly in wet tropical environments. Infections are characterised by tumour-like masses, which develop mostly on the legs.

A. flavus is the major producer of carcinogenic aflatoxins in crops worldwide.

This is a bacterial disease, which attacks seedlings as they emerge. It thrives in wet, poorly drained and cool soils.

Puccinia graminis tritici belongs to basidiomycotina and causes black rust of wheat. It is internal obligate parasite. It is found everywhere, where wheat is grown. The teleutospore of the fungus causes the rust. They are produced inside teleutosori. These telia form elongated, dark brown to black pustules on the surface of stems and leaves of the wheat.

Association between roots of higher plants, e.g., pine, birch and fungal hyphae is called mycorrhiza. It exhibits the phenomenon of symbiosis. Here both the organisms in association are mutually benefitted. In this, fungal hyphae take nutrition from the plant and in return increase surface area for absorption of water and minerals for the plant. Mycorrhizal roots occur in superficial layers of the soil.

Ceratium furca blooms because of coastal eutrophication. Blooms of this species cause toxic red tides (red-brown), damage fish gills and deplete dissolved oxygen causing anoxic conditions.