THE POLYAMINES OF Xanthium strumarium and THEIR RESPONSE TO PHOTOPERIOD

Abstract

Flowering plants of Xanthium strumarium L., grown in 8 h photoperiods, were analysed for polyamines. Putrescine, spermidine and spermine were found throughout the plant in three forms: (a) as free polyamines; (b) conjugates soluble in 5% trichloracetic acid (TCA); and (c) bound to the TCA-insoluble precipitate. On a fresh weight basis, total polyamines are most abundant in young leaves and buds, especially flower buds. Spermidine predominates in the free polyamine fractions, while spermine is dominant in the conjugated fraction. Transfer of vegetative plants from 16 h photoperiods to 1, 2, 3, or 4 inductive cycles (8 h light + 16 h uninterrupted dark) caused rapid and marked changes in the polyamine titer of the leaves and ultimately, floral initiation. The titer of free putrescine per mg protein declined progressively with induction in all leaf sizes, while the titers of free spermidine and spermine rose during days 2 and 3 in small and expanding leaves. Conjugated putrescine, spermidine and spermine rose sharply after only 1 inductive cycle, especially in small and expanding leaves, and maintained the higher level for at least several cycles. In plants given 4 inductive cycles, buds harvested after 4 additional days had sharply elevated levels of conjugated polyamines, especially spermine, on a protein basis.

Endogenous polyamine profiles in different tissues of Coffea sp., and their levels during the ontogeny of fruits

“…Along with this, biogenic amine-tyramine also was found (0.177 lg g -1 FW). The presence of one or other polyamines in flowers of Coffea is further supported by similar reports in other plants Pharbitis nil (Dai and Wang 1987), Xanthium strumarium (Hamasaki and Galston 1990), Polianthes tuberosa (Huang et al 2004), strawberry (Tarenghi and Martin-Tanguy 1995), wherein, the involvement of polyamines in floral development has been reported. Especially during flower opening the PAs level increases in the sepals, petals and sex organs, the ovary being most active in accumulating Spm (de Dios et al 2006).…”

Polyamines in plant physiology.

“…Oligosaccharins may trigger ethylene production, and PAs might work by suppressing or antagonizing ethylene biosynthesis or action. We therefore undertook an examination of the relation between photoperiodic induction and PA titer in a well characterized short day plant, Xanthium strumarium L. Present evidence indicates that exposure to one to two consecutive inductive long nights greatly increases the titer of conjugates of the higher PAs in leaves, and later in buds (13 . 3).…”

Involvement of Polyamine in Floral and Fruit Development

“…JARQ 40 (1) 2006 eral lines of evidence. Firstly, in some plants, an accordant change in total polyamine titers or a single polyamine type accompanies the floral development, as is revealed in Pharbitis nil 19 , Xanthium strumarium 30 , Polianthes tuberosa 31 , strawberry 80 , and tobacco…”