Root parasite

Unidentified Stimulators. Growth-inhibitory materials in, or secreted by, plants have for the most part been emphasized in this paper. However, root secretions of many plants also contain constituents required for the germination of seeds of angiospermous root parasites (Striga, Orobanche, Alectra, and Sopubia genera). This phenomenon has been reviewed by Brown (17). Striga asiatica was identified for the first time in the western hemisphere in 1956 in two... 

Wyss, U. (1997) Root parasitic nematodes an overview. In Fenoll, C., Grandler, F.M.W. and Ohl, S.A. (eds) Cellular and Mohcular Aspects of Plant-Nematode Interactions. Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 5-22. 

Allelopathy found hopeful utilization in plant protection against parasite weeds. The main world parasitic species are the witchweeds (Striga spp.), broomrapes (Orobanche spp.), and eventually dodder (Cuscuta spp.). Witchweeds and broom-rapes attack many economically important crops especially throughout the semi-arid regions. Early detection of parasitic weed infestation and protection is difficult because of the growth habit of a root parasite and huge production of dust-like seeds viable up to 20 years (Kebreab and Murdoch 1999). 

Plant-Plant Recognition Chemistry-Mediating Host IdentiHcation in the Scrophulariaceae Root Parasites... 

Pheromones are classified in at least ten different categories. The most conq)lex category involves enantiomers at a specific composition (Mori 2000), implying multiple receptors. Other complex networks of biological events involve terpenoids released by plants in response to grazing by herbivores. These metabolites can be used to attract parasitic wasps for pest control (Tumlinson 1993), or, like the strigolactones (Table 12.1), as useful germination stimulants of root parasites of plants in the families Scrophulariaceae and Orobanchaceae (Welzel 1999 Ryan 2001). 

Albrecht, H., Yoder, J.I., and Phillips, D.A., Flavonoids promote haustoria formation in the root parasite Triphysaria versicolor. Plant Physiol, 119, 585, 1999. 

Sato, D., Awad, A. A., Takeuchi, Y., Yokota, T. Sugimoto, Y., and Yoneyama, K. 2002. Analysis of germination stimulants for weedy root parasites by LC/MS/MS. Proceedings of the Third World Congress on Allelopathy. Challenge for the New Millennium. Fujii, Y., Hiradate, S., and Haraya, H., (Eds.). Tsukuba, Japan, 215. 

Musselman, L. J. 1980. The biology of Striga, Orobanche, and other root-parasitic weeds. Annu. Rev. Phytopathol. 18, 463-489... 

Plants belonging to the family Asteraceae, including asters, daisies, and sunflowers, are rich sources of allelopathic sesquiterpenes and sesquiterpene lactones. Heliannuol A (19) and its related compounds heliannanes, found in sunflower leaves, are thought to be involved in the allelopathic effects displayed by the plants.8 Some sesquiterpene lactones such as dehydrocostuslactone (20), santamarine (21), and reynosin (22) have been shown to induce seed germination of root parasitic plants,9 especially of sunflower broomrape Orobanche cumana.10... 

Allelochemicals involved in plant—plant interactions are diverse in their structures. Some are unstable and their activities are short-lived. In addition, some are highly hydrophobic and thus are barely soluble in water. Therefore, there are arguments that only stable and water-soluble compounds contribute to plant—plant interactions in the field. However, in the case of strigolactones, for example, seeds of root parasitic plants and also AM fungi use these unstable short-lived rather lipophilic compounds as host recognition signals. Therefore, unstable short-lived allelochemicals should be further explored to identify unknown signaling chemicals involved in plant—plant interactions. 

Many of the earliest applications of API-MS used direct syringe infusion of crude alkaloidal extracts into the ESI source. In this manner, Marko and Stermitz [55] were able to detect the transfer of alkaloids from Delphinium occidentale to the root parasitic Castilleja sulphurea. 

Natural and biological extraction [16], The active ingredients for some important drugs are sometimes isolated from natural sources such as plants, roots, parasitic fungi, or animal glands. Medicines such as insulin, morphine, anticancer drugs, and others with unique properties are produced by natural product extraction [16]. 

Bharathalakshmi. Studies on the Root Parasite - Striga asiatica (L.) Kuntze, Ph.D. Thesis, Bangalore University, India, 1982. 

Ammodendrine (258) has been isolated from a number of plant genera, usually in the presence of quinolizidine alkaloids [592], Its presence, sometimes accompanied by related alkaloids such as A -methylammodendrine (259), A -acetylhystrine (262) and smipine (264) can be useful in chemotaxonomy [593], The root parasite Viscum cruciatum was found to take up 258, along with quinolizidine alkloids from its host Relama sphaerocarpa [594],... 

---