Tulip (Tulipa gesneriana L.) is a bulbous plant species that requires a period of low temperature for proper growth and flowering. The mechanism of sensing the low temperature period is unknown. The study presented in this paper shows that the essential developmental change in tulip bulbs during cold treatment is an increase in sensitivity to the phytohormone auxin. This is demonstrated using a...

Plants of Pharbitis nil were treated with the growth retardant (2-chloroethyl) trimethylammonium chloride (CCC) shortly before and after anthesis. Fresh and dry weight of immature seeds were not affected by the CCC treatment.The level of gibberellin-like activity in Pharbitis seeds as compared to control seeds was strongly reduced by CCC application. The progenies of the treated plants also had...

Summiary. Immature (8-mmii11), miie(liumiii mature (1l-mm), andI muature green (16an1d 17-mm1ni) )ean seeds (Phlaseolis zvitlgaris L. cv. Ken,tucl-y \Wonder andl Bountiful) were incubated in gil,bberellin A1 soluitionis for 24 lhours at 200. Extracts from the seeds were separated ilnto nionacidic, acidic ethyl acetate, and acidic butalnol fractionis. These were chromatographed. The eluates of t...

The effects of gibberellic acid on lignification in seedlings of a dwarf and a tall cultivar of pea (Pisum sativum) grown under red or white light or in the darkness, were studied. Gibberellic acid (10(-6)-10(-4)m) promoted stem elongation in both light and dark and increased the percentage of lignin in the stems of the light-grown dwarf pea. The gibberellin had no effect on the lignin content ...

18 Potato virus Y is the most economically important potato viral pathogen. We aimed at 19 unraveling the roles of small RNAs (sRNAs) in the complex immune signaling network 20 controlling the establishment of tolerant response of potato cv. Désirée to the virus. We 21 constructed a sRNA regulatory network connecting sRNAs and their targets to link sRNA 22 level responses to physiological proce...

The stepwise metabolism of gibberellin A12-aldehyde (GA12-aldehyde) to GA20 is demonstrated from seedling shoots of maize (Zea mays L.). The labeled substrates [13C,3H]GA12-aldehyde, [13C,3H]GA12, [14C4]GA53, [14C4/2H2]GA44, and [14C4/2H2]GA19 were fed individually to dwarf-5 vegetative shoots. Both [13C,3H]GA12-aldehyde and [13C,3H]GA12 were also added individually to normal shoots. The labele...

The distribution of endogenous gibberellins in Dwarf-1, a single gene dwarf mutant of Mexico 80-R red beans, was studied. Parallel extraction and fractionation of seeds of this mutant and those of a normal homozygous line followed by thin layer chromatography and bioassays using Rumex obtusifolius, wheat seed endosperm and dwarf bean plants revealed that a stem elongation control factor was con...

Gibberellin A(1)-3,4-(3)H was prepared by selective catalytic reduction of gibberellic acid with a mixture of tritium and hydrogen. (3)H-GA(1) was applied at physiological concentrations to dwarf peas and the metabolism of the hormone was investigated. (3)H-GA(1) was converted to an acidic, biologically active compound. Radioactive but biologically inactive compounds were also found in the neut...