Inhibition of stem elongation in spinach by theobroxide

Abstract

In the current study, we investigated the influences of theobroxide on stem elongation in spinach (Spinacia oleracea). Our results showed that stem elongation and flower formation were inhibited by spraying spinach plants with theobroxide under inductive, long day conditions (16 h light/8 h dark), while application of exogenous applied GA3 prevented the effect of theobroxide. Quantitative analysis showed that theobroxide suppressed GA1 biosynthesis, whereas the endogenous content of jasmonic acid was unchanged. However, under short day conditions (10 h light/14 h dark), there were no differences in stem length between treated and untreated plants. These results suggest that the inhibition of stem elongation by theobroxide is probably due to the suppression of gibberellin biosynthesis.

Isolation and Structural Elucidation of a New Cyclohexenone Compound fromLasiodiplodia theobromae

“…All of the compounds showed inhibitory effects at a concentration of 0.5 mM, and the mixture of 1a and 1b showing the strongest activity. Although there have been some previous reports on the biological activity of 2, [3][4][5][6][7] this is the first report of the growth inhibitory activity of 2 and related compounds 1, 3, and 4 against seedlings of N. tabacum. Three other related oxygenated cyclohexenone derivatives, 6, 7 and 8, have been isolated from unpolished rice fermented with a xylariaceous endophytic fungus (strain YUA-026) by Shiono et al 10) Some of these compounds exhibited phytotoxic activity against lettuce (Lactuca sativa L.) at a concentration of 50 mg/ml.…”

“…3) Compound 2 has also been shown to inhibit stem elongation in morning glory and spinach through the suppression of gibberellin biosynthesis and stimulation of jasmonic acid biosynthesis. [4][5][6][7] We have subsequently encountered its co-metabolites, (1S,4R,5S,6R)-7,9-dioxa-3-methyl-8-oxobicyclo [4.3.0]-2-nonene-4,5-diol (3), (4S,5S)-4,5-dihydroxy-2-methyl-cyclohex-2-enone (4), and (3aS,4R,5S,7aR)-7,9-dioxa-3-methyl-8-oxobicyclo-[4.3.0]-2-nonene-4,5-diol (5). 8,9) In this paper, we report the isolation, structural elucidation, and biological activities of the novel theobroxide-related compound, 4,5-dihydroxy-3-methyl-cyclohex-2-enone (1).…”

Expression of Allene Oxide Cyclase fromPharbitis nilupon Theobroxide Treatment

“…Violet (Marutane Seed, Kyoto, Japan) were treated with concentrated H 2 SO 4 for 1 h, washed with running tap water for another 3 h, and then soaked in distilled water overnight at 25 C. The swollen seeds were sown in pots filled with peat moss and perlite (1:1 v/v) under long-day (LD, 18 L/6 D) conditions in growth chambers (NK System, Biotron NC 350, Osaka, Japan). Theobroxide was prepared as described previously, 3) and dissolved in distilled water containing 100 ppm Tween 20 to give a concentration of 1 mM. Water containing 100 ppm Tween 20 was used as a control solution.…”

“…2) Furthermore, theobroxide has been shown to suppress stem elongation in spinach (Spinacia oleracea L.) 3) and morning glory. 4) In morning glory, the inhibitory effect of theobroxide on stem elongation was achieved both by suppression of gibberellin biosynthesis and by promotion of JA biosynthesis.…”

Influence of photoperiod on growth and flowering of dwarf purple loosestrife

“…In Silene armeria, plants under LD contained higher levels of GA 19 , GA 20 , and GA 1 , but lower level of GA 53 , whereas plants under SD showed the opposite contents of GAs (Talon and Zeevaart, 1990). Stem elongation of spinach (LDP) under LD (16 h) was inhibited by theobroxide, because theobroxide reduced endogenous GA 1 level in spinach (Kong et al, 2006). Thus, we assumed that elongation between internodes in dwarf purple loosestrife is caused by quantitative change in the levels of endogenous GAs under LD.…”