Solute flux into parasitic plants

Abstract

Parasitic plants form intimate contacts with host tissue in order to gain access to host solutes. There are a variety of cell types within the host which parasitic plants could access to extract solutes. Depending on the degree to which the parasite has embraced the parasitic lifestyle, the extent of solute flux and the pathways used to transfer solutes from host to parasite will vary. To date, a variety of experimental approaches argue for diversity in the mechanisms and the routes by which parasites accumulate host solutes. Contact between host and parasite ranges from direct lumen-to-lumen links between host and parasite xylem and continuity between the sieve elements of host and parasite, to the involvement of transfer cells between host and parasite. Progress has been slow since Solms-Laubach distinguished types of parasitic plants that fed from host phloem or xylem in 1867, but advances in clearly delineating the pathways that link host and parasite should now be possible using fluorescent proteins expressed and restricted to particular cell types of the host. This will initially necessitate using Arabidopsis, but should allow the types of connection, i.e. symplasmic or apoplasmic, to be determined and then the identification of parasite transporters responsible for solute flux.

Morphological and plant hormonal changes during parasitization by Cuscuta japonica on Momordica charantia

“…Some previous studies on parasitic plant interactions have dealt with carbon and nitrogen flows (Hibberd & Jeschke 2001), and the translocation of chemical compounds (including metabolites, small proteins, and mRNA) (Birschwilks et al 2006(Birschwilks et al , 2007LeBlanc et al 2012). While, others focused on defensive responses from host plants to parasitic plants, i.e.…”

Field dodder - how to control it?

“…The ability to form specialized organs for absorption, i.e. haustoria, is the chief adaptive character of all higher parasitic plants (Hibberd & Jeschke, 2001). Obligate parasites are unable to develop without assimilates drawn from their host plants because they are either unable to perform photosynthesis (Kujit, 1969;Losner-Goshen et al, 1998) or their photosynthetic capacility is very small (Hibberd & Jeschke, 2001).…”

“…haustoria, is the chief adaptive character of all higher parasitic plants (Hibberd & Jeschke, 2001). Obligate parasites are unable to develop without assimilates drawn from their host plants because they are either unable to perform photosynthesis (Kujit, 1969;Losner-Goshen et al, 1998) or their photosynthetic capacility is very small (Hibberd & Jeschke, 2001). Even though dodder plants possess a functional photosynthetic apparatus within a ring of cells surrounding vascular tissue (Hibberd & Jeschke, 2001) the amount of organic matter produced there is too small to provide for the plant, so that 99% of the required carbon is still drawn from the host (Jeschke et al, 1994).…”

“…Holoparasites are believed to use primarily products conducted through the phloem but their haustoria reach into the xylem too for nutrients such as calcium, which is deficient in the phloem. However, field dodder has been reported to get not only organic matter from its host through the phloem but minerals too, such as nitrogen, magnesium and calcium, although they are to be found in greater amounts in the xylem than in the phloem (Hibberd & Jeschke, 2001). Field dodder parasitism interferes with the balance of contents of nitrogen, phosphorus, potassium, organic and inorganic matter in the host plant (e.g.…”

History of the race structure of Orobanche cumana and the breeding of sunflower for resistance to this parasitic weed: A review

“…Once the appressorium penetrates the endodermis, parasite cells progress towards host vessels and then initiate a specialized endophytic organ called haustorium that proceeds to the establishment of vascular connections (Hibberd & Jeschke, 2001). The haustorium is also the transfer structure that enables the parasite to uptake water and nutrients (carbohydrates and nitrogen compounds) from host conductive system.…”