About Lesson
Plant growth regulators (PGRs) and its relation with pathology
a) Auxin:
- If Auxin concentration is more , its concentration is reduced by enzyme IAA oxidase.
- Increased IAA means plant is diseased.
- Eg: Late blight of potato, Maize smut (Ustilago maydis), Club root of crucifers, etc. are caused due to increased IAA concentration.
b) Gibberellins:
- Scelerospora sacchari, the causal agent of downy mildew of sugarcane induces GA production.
- Cause Bakanae or foolish seedling disease of rice.
- Abnormal elongation due to excessive elongation of internodes.
c) Cytokinin
- Increased Club root, Crown galls and rust infected bean leaves.
d) Ethylene
- Involved in moko disease of banana, Pseudomonas solanacearum.
e) Abscissic acid:
- Involved in stunting of plants.