Pharbitis nil

The alkaline hydrolysis of the ether-insoluble resin glycoside fraction from seeds of Ipomoea nil (L.) Roth (syn. Pharbitis nil Choisy) yielded a pentasaccharide of ipurolic acid, which was named pharbitic acid C (tetradecanoic acid, ll-[(0-6-deoxy- S-D-glucopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(l—>6)-0-[6-deoxy-a-L-mannopyranosyl-(l—>2)-0-jS-D-glucopyranosyl-(l—>2)]- S-D-glucopyra-nosyl)oxy]-3-hydroxy). On complete hydrolysis, it produced two o-glucoses, two L-rhamnoses, one o-quinovose, and the aglycone moiety (77). 

Ono M, NodaN, Kawasaki T, Miyahara K (1990) Resin Glycosides. VII. Reinvestigation of the Component Organic and Glycosidic Acids of Pharbitin, the Crude Ether-Insoluble Resin Glycoside ( Convolvulin ) of Pharbitis Semen (Seeds of Pharbitis nil). Chem Pharm Bull 38 1892... 

Dangles, O., Saito, N., and Brouillard, R., Kinetic and thermodynamic control of flavylium hydration in the pelargonidin-cinnamic acid complexation. Origin of the extraordinary flower color diversity of Pharbitis nil, J. Am. Chem. Soc., 115, 3125, 1993. 

Lu, T.S. et al., Acylated pelargonidin glycosides in the red-purple flowers of Pharbitis nil. 

GA glucosides and glucosyl esters Pharbitis nil Cytisus scoparius Phaseolus vulgaris METMS direct probe MS (14)... 

Pharbitis CBP Pn-AMPl, Pn-AMP2 (4 kDa, single hevein-like CBD) Pharbitis nil (Convolvulaceae) Chitin [antifungal] Pn-AMPl... 

Felsheim, R.F., and A. Das. 1992. Structure and expression of a heat-shock protein 83 gene of Pharbitis nil. Plant Physiol. 100 1764-1771. 

Another possible reason why GA treatments do not induce flower initiation may be due to improper timing and/or supraoptimal doses. For example, exogenous GAs either promoted or inhibited flower formation (as measured by number of flower buds produced) in plants of the dwarf strain Kidachi of the SDP Pharbitis nil that were marginally induced by 1 inductive long night. Promotion of flowering was observed when the GA treatment occurred 11 to 17 h before the inductive dark period, while GA application immediately after the inductive dark period caused a reduction in the flowering response [9, 18]. 

There are other difficulties in the interpretation of data from experiments using growth retardants. First of all, the site of action of the compounds should be determined, since this will have important implications for the role of GAs in flower initiation. For example, CCC inhibits flower initiation following photoinduction in both the LSDP Bryophyllum daigremontianum and the SDP Pharbitis nil, but in the former case the growth retardant acts in the leaf whereas it is the apex that is the affected tissue in the latter [25,27]. 

The floral stimulus acts at the apex and therefore determination of the site of GA action is important in formulating logical hypotheses about the role of GAs in flower initiation. Although not examined in many species, the evidence indicates that GAs can affect flower initiation at different sites. Flower induction brought about by GAg treatments in Bryophyllum daigremontianum and Hyoscyamus niger is the result of GA action in the leaves, not the apex where the floral stimulus acts [21, 22]. The situation is quite different in the SDP Pharbitis nil and Impatiens balsamina, where it was determined that the apex is the site of GA action [ 16,25,27]. 

Barendse GWM (1974) Accumulation and metabolism of radioactive gibberellic acid in seedlings of Pharbitis nil Chois. In Plant Growth Substances 1973. Tokyo Hiro-kawa 1974, pp 332-341... 

Lu TS, Saito N, Yokoi M, Shigihara A, Honda T (1991) Acylated peonidin glycoside in the violet-blue flowers of Pharbitis nil. Phytochemistry 30 2387-2390 Lu TS, Saito N, Yokoi M, Shigihtua A, Honda T (1992a) Acylated pelaigonidin glycosides in the red-purple flowers of Pharbitis nil. Phytochemistry 31 289-295... 

Whitehead IM, ThrelfaU DR, Ewing DF (1989) 5-epi-Aristolochene is a common precursor of the sesquiterpenoid phytoalexins capsidiol and debneyol. Phytochemistry 28 775-779 Wijayanti L, Kobayashi M, Eujioka S, Yoshizawa K, Sakuiai A (1995) Identification and quantification of abscisic acid, indole-3-acetic acid and gibberellins in phloem exudates of Pharbitis nil. 

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