Helianthus annuus

Compositae (composite) Helianthus annuus Argentina, FSU, EU-15, United States edible oil, animal feed, food... 

Guy, R.D. Wample, R.L. (1984). Stable carbon isotope ratios of flooded and non- flooded sunflowers Helianthus annuus). Canadian Journal of Botany, 62, 1770-4. 

Turner, N.C., Schulze, B.-D. Gollan, T. (1985). The response of stomata and leaf gas exchange to vapour pressure deficits and soil water content. II. In the mesophytic herbaceous species Helianthus annuus. Oecologia, 65, 348-55. 

Millichip, M. et al.. Purification and characterization of oil-bodies (oleosomes) and oil-body boundary proteins (oleosins) from the developing cotyledons of sunflower (Helianthus annuus L.), Biochem. J., 314, 333, 1996. 

Immunologically active polysaccharides from cell suspension of Helianthus annuus 1805... 

A considerable amount of extracellular polysaccharides is produced in the process of cultivation of certain plant suspension cultures and the spent culture medium has proved to be an accessible source for their production (1-3). The interest in investigating these extracellular polysaccharides has been quite strong over the past 10-15 years, motivated by their biological activity (4,5). Plants of the Asteraceae family, as well as their cell cultures, have been established to contain polysaccharides with immunostimulating activity (1-6). The object of our research was Helianthus annuus 1805 cell culture (Asteraceae), which according to the preliminary investigation produces a considerable amount of exopolysaccharides. 

Cell culture and biosynthesis of polysaccharides. The Helianthus annuus 1805 cell culture was initiated according to a previously described method (7), using germs of Helianthus annuus as an explant. 

Growth of the Helianthus annuus 1805 cell suspension and biosynthesis of extracellular polysaccharides. A particular characteristic of plant cell suspensions is the requirement for a high inoculation density in order to initiate growth. This is due to one of their special features in order that their growth be initiated when transferred into the new medium, they need certmn growth factors which are released and secreted into the medium by the cells themselves. Consequently, to ensure the growth of plant cell suspensions, a certain volume (in which plant cells have to be present at above certain densities) has to be used to import the necessary quantity of these substances (17). 

Fig. 1. Growth of Helianthus annuus 1805 cell suspension inoculated with different amounts of inoculum...

Cell culture. The Helianthus annuus 1805 cell culture was grown in Linsmayer-Skoog medium (9), supplemented with 0.2 mg/L 2.4 - dichlorphenoxyacetic acid and 3% sucrose. The callus cultures were kept in an agar medium of the same composition. They were grown in a thermostat in the dark at 26-28 °C for two weeks and could be stored up to two months in a refrigerator. 

Sunflower plant Helianthus annuus L.) is an important crop in Portugal and its head residues, remaining on soil after the seeds have been removed for oil industry, are one of the richest sources of low-methoxyl pectin (ca 19% original dry matter), the most important property being the ability to form gels even without sugar addition, if correct amounts of divalent ions (usually calcium) are present. 

The phenolic and related components present in stems and leaves of sunflower, Helianthus annuus L., and Jerusalem artichoke, Helianthus tuberosus L., were extracted sequentially and their activity as phytotoxic agents evaluated. Total acids and neutral compounds were isolated by extraction with methanol, acetone, and water. The free acids and neutral compounds were partitioned into the organic phase, whereas the acids, present as esters and aglycones, were liberated by subsequent alkaline hydrolysis of the aqueous phase. 

The term allelopathy, when first proposed by Molisch (1 ), referred to either the beneficial or detrimental interaction between all types of plants and microorganisms. As presently used, this definition is generally accepted. Since 1970 a concerted effort has been made to understand the phenomenon of allelopathic interaction. The many interpretations resulting from these studies are well documented in the literature (2-4). An area currently receiving considerable attention is the allelopathic effect resulting from weed-crop and weed-weed interactions (2, 5-7). One study conducted by Wilson and Rice (7) showed that the common sunflower, Helianthus annuus L., possessed allelopathic properties. Realizing the inherent potential... 

Table IV. Helianthus annuus. Growth Inhibition of L. minor. The Effect of the Fractions on Final Frond Number as Percentage of Control after 5 Days Exposure...

Table V. Helianthus annuus. Description of Fronds after 5 Days Exposure...

Glycine max hypocotyls Nicotiana tobacum plants Helianthus annuus plants Sorghum vulgare seedlings Brassica rapa seedlings Vaccinium macrocarpon fruit Euphorbia pulcherrima bracts Amaranthus tricolor seedlings Oryza sativa leaves... 

Helianthus annuus, root Chlorogenic, isochlorogenic acids scopoletin 79-81... 

Ambrosia artemisifolia Chenopodium album Helianthus annuus... 

The first enantioselective total synthesis of the sesquiterpenoid heliannuol D 56 has been reported by Shishido and co-workers. The key step was a base-mediated (NaOH) intramolecular cyclisation of the phenolic epoxide mixture 55 (R1 = MOM, R2 = H and R1 = H, R2 = MOM). Heliannuol D (and the eight-membered congener, heliannuol A) is an allelopathic agent isolated from cultivated sunflowers (Helianthus annuus L.SH-222) <00JCS(P 1)1807>. 

Soudek, P., Tykva, R., Vahkova, R., and Vanek, T., 2006b, Accumulation of radioiodine from aqueous solution by hydroponicaUy cultivated sunflower Helianthus annuus L.). Environ. Exp. Bot. 57 220-225. 

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