Biology 2217B Lecture Notes - Lecture 23: Plant Cell, Phloem, Xylem
13 Jul 2019
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Lecture 23 why plants get sick (plant pathology) Definitions: plant pathology study of plant diseases, plant disease physiological or morphological change in plant, pathogen organism that causes disease, symptom abnormal appearance. Pathogens may interfere with plant cell functions using: toxins, growth regulators, enzymes, by absorbing water and nutrients from host cells. Pathogens can also cause disease by: blocking xylem or phloem vessels, by inserting parts of their dna or rna into the host cell and commandeering the cell"s replication machinery. Classes: abiotic (not transmissible) = 70 % Cold, drought, wind, hail, people, fertilizers, herbicides, pets, physiological disorders: biotic (transmissible) = 30 % Biotic diseases: fungi, bacteria, viruses, viroids, protozoa, nematodes, parasitic plants. Mildews, rusts, smuts, parasitic plants: necrotrophs. Kill host and live on dead tissue. Plant diseases symptoms: leaf spots, blights, mildews, rusts, smuts, cankers, root rots, wilts, galls, mosaics and ring sots.
