Phytoecdysteroid Levels and Distribution during Development in Limnanthes alba Hartw. ex Benth. (Limnanthaceae)

Abstract

Ecdysteroid, Ponasterone A, 20-Hhydroxyecdysone Phytoecdysteroid (PE) production and accumulation in Limnanthes alba Hartw. ex Benth. is associated with flowering. PE content per plant remains fairly constant during the primary growth phase of the plant and only begins to increase significantly above amounts found in the seed once the development of the flower stalk has begun. Both content and concentration increase concomitantly from this point. Distributions in individual plants also associated the highest levels of PE accumulation with the reproductive tissues. This substantiates the association of PE with tissues of greatest fitness value and therefore the hypothesis that they contribute to defence. Analysis of extracts of L. alba tissues by reversed-phase HPLC coupled with ecdysteroid-specific RIA was used to monitor ecdysteroid profiles. RIA-positive peaks co-chromatographing with 20-hydroxyecdysone, ecdysone and ponasterone A were detected and several tissues also contain PE conjugates. Seedmeal of L. alba appears to be a convenient and promising source for the commercial isolation of the potent PE ponasterone A.

Glucosinolates in the new oilseed crop meadowfoam: natural variation in Section Inflexae of Limnanthes, a new glucosinolate in L. floccosa, and QTL analysis in L. alba

“…1996, Machado 2007, Stevens et al. 2009) and phytoecdysteroids (Preston‐Mafham and Dinan 2002, Stevens et al. 2008).…”

Characterization of Phytoecdysteroid Glycosides in Meadowfoam (Limnanthes alba) Seed Meal by Positive and Negative Ion LC-MS/MS

“…The spent seed material (seed meal) has potential value as a biopesticide due to the glucosinolate, glucolimnanthin (2-4% w/w), and its degradation products, that is, 3-methoxyphenylacetonitrile and 3-methoxybenzylisothiocyanate (12), and ecdysteroids (4). Glycosides of the ecdysteroids, ponasterone A (1) and 20-hydroxyecdysone (2), named "limnantheosides A-C" were reported from L. alba and L. douglasii by Dinan and co-workers (13)(14)(15). These authors used HPLC in combination with a radio-immunoassay method to detect ecdysteroids in HPLC fractions.…”

Distribution and Biosynthesis of 20-Hydroxyecdysone in Plants ofAchyranthes japonicaNakai

“…This result is consistent with a previous report on L. alba. 20) In contrast to the concentration, the total amount of 20E per plant was maintained at the initial level of the seed during early vegetative growth, and thereafter increased. The increase in 20E at the late stages was proportional to the increase in plant biomass (data not shown).…”

“…[28][29][30] The high level of PEs in these vital plant organs, requiring intensive protection, is well-documented in previous reports. 2,17,20,31) Thus, many of the plants containing PEs appear to be able to accumulate PEs in organs at high levels for protection against non-adapted insects. This high accumulation of PEs in a specific organ of a plant can be explained by the source-sink partitioning mechanism proposed here.…”

“…[14][15][16][17][18][19][20] These studies have reported a high accumulation of PEs in the tissues. In several studies, the fluctuation and distribution of PEs within a plant have been discussed in relation to its biosynthesis and transport.…”