Search results
Results from the WOW.Com Content Network
[note 1] A carpel is the female reproductive part of the flower—usually composed of the style, and stigma (sometimes having its individual ovary, and sometimes connecting to a shared basal ovary) —and usually interpreted as modified leaves that bear structures called ovules, inside which egg cells ultimately form. A pistil may consist of ...
The bacteria tend to be seed-borne, and are dispersed between plants by rain splash. [18] Although it is a plant pathogen, it can also live as a saprotroph in the phyllosphere when conditions are not favourable for disease. [19] Some saprotrophic strains of P. syringae have been used as biocontrol agents against postharvest rots. [20]
Plant pathogens, organisms that cause infectious plant diseases, include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. [2] In most plant pathosystems, virulence depends on hydrolases and enzymes that degrade the cell wall.
Phytoplasmas can infect and cause various symptoms in more than 700 plant species. One characteristic symptom is abnormal floral organ development, including phyllody (the production of leaf -like structures in place of flowers ), virescence (the development of green flowers attributable to a loss of pigment by petal cells), [ 8 ] and ...
However, a small number, around 100 known species, cause disease, especially in subtropical and tropical regions of the world. [15] [page needed] Most plant pathogenic bacteria are bacilli. Erwinia uses cell wall–degrading enzymes to cause soft rot. Agrobacterium changes the level of auxins to cause tumours with phytohormones.
Fasciation that is caused by bacteria can be controlled by not using fasciated plants and disposing of fasciated material. [10] Avoiding injury to plant bases and keeping them dry can reduce the spread of bacteria. [10] Avoidance of grafting fasciated plants and the pruning of fasciated matter can also reduce the spread of bacteria. [10]
The stigma, together with the style and ovary (typically called the stigma-style-ovary system) comprises the pistil, which is part of the gynoecium or female reproductive organ of a plant. The stigma itself forms the distal portion of the style, or stylodia, and is composed of stigmatic papillae, the cells of which are receptive to pollen ...
Ralstonia solanacearum is an aerobic non-spore-forming, Gram-negative, plant pathogenic bacterium. R. solanacearum is soil-borne and motile with a polar flagellar tuft.It colonises the xylem, causing bacterial wilt in a very wide range of potential host plants.