Exposure to plant growth regulators mainly causes which type of variation?
Plant growth regulators drive developmental plasticity in vitro, and prolonged exposure creates reversible adaptive responses rather than permanent DNA changes. High levels of synthetic auxins like 2,4-D and cytokinins such as BAP increase endogenous hormone synthesis, alter receptor sensitivity, and remodel chromatin through changes in DNA methylation and histone acetylation. Cells become habituated, growing without external hormones, show vitrification with water-soaked translucent appearance, or lose morphogenetic competence. Such phenotypes affect culture behavior, shoot regeneration frequ
Ref: Alberts Molecular Biology of Cell 6th ed Ch 21 Plant tissue culture; NCERT Biology XII Unit 9; NCBI Bookshelf NBK218342 somaclonal variation physiology and habituation.
