title: Inhibition of lettuce seed germination and seedling growth by antimetabolites of nucleic acids, and reversal by nucleic acid precursors and gibberellic acid.
abstract: Germination of White Paris lettuce seeds is inhibited by 2-thiouracil up to 24 hours. This inhibition is reversed by RNA precursors only. Seedling growth of lettuce is inhibited by 2-thiouracil and 5-fluorouracil; and white the effect of 2-thiouracil is counteracted by RNA precursors, inhibition due to 5-fluorouracil is not reversed significantly by any nucleic acid precursors. Possibly 2-thiouracil controls germination and seedling growth by interfering with RNA synthesis, while the effect of 5-fluorouracil is non-specific.In the presence of gibberellic acid, 5-fluorouracil and 2-thiouracil are relatively ineffective in causing inhibition of hypocotyl growth. Mechanism of gibberellic acid action remains obscure.
authors.affiliation: Department of Biochemistry, Michigan State University, E. Lansing, Michigan, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Khan