Holoparasitic plant–host interactions and their impact on Mediterranean ecosystems

Abstract

Although photosynthesis is essential to sustain life on Earth, not all plants use sunlight to synthesize nutrients from carbon dioxide and water. Holoparasitic plants, which are important in agricultural and natural ecosystems, are dependent on other plants for nutrients. Phytohormones are crucial in holoparasitic plant–host interactions, from seed germination to senescence, not only because they act as growth and developmental regulators, but also because of their central role in the regulation of host photosynthesis and source–sink relations between the host and the holoparasitic plant. Here, we compile and discuss current knowledge on the impact and ecophysiology of holoparasitic plants (such as the broomrapes Orobanche sp. and Phelipanche sp.) that infest economically important dicotyledonous crops in Mediterranean agroecosystems (legumes [Fabaceae], sunflowers [Helianthus sp.] or tomato [Solanum lycopersicum] plants). We also highlight the role of holoparasitic plant–host interactions (such as those between Cytinus hypocistis and various shrubs of the genus Cistus) in shaping natural Mediterranean ecosystems. The roles of phytohormones in controlling plant–host interactions, abiotic factors in parasitism, and the biological significance of natural seed banks and how dormancy and germination are regulated, will all be discussed. Holoparasitic plants are unique organisms; improving our understanding of their interaction with hosts as study models will help us to better manage parasitic plants, both in agricultural and natural ecosystems.

Induction of systemic resistance to Orobanche crenata in lentil by exogenous application of salicylic acid and indole acetic acid

“…This could be explained by the delayed tubercle establishment and development. Several studies reported the involvement of phytohormones such as salicylic acid and jasmonic acid in host defense responses against Orobanche at initial stages of the holoparasitic plant-host interaction (Gutjahr and Paszkowski 2009;Torres-Vera et al 2016;Casadesús and Munné-Bosch 2021). Previous studies performed on faba bean under O. foetida infestation reported that SA treatments significantly decreased Orobanche seed germination resulting in low infestation (Abbes et al 2014;Triki et al 2018).…”

Identifying the natural reserve area of Cistanche salsa under the effects of multiple host plants and climate change conditions using a maximum entropy model in Xinjiang, China

“…Niche overlap simply indicates that there is competition between two or more species sharing the source in the same area ( Pianka, 1974 ; Jakob et al, 2010 ; Sales et al, 2022 ). Additionally, if we bring the parasitic relationship between holoparasitic plants and host plants into the niche overlap theory, then the niche overlap value can be taken as the effect of host plant distribution on the distribution of parasitic plants ( Jakob et al, 2010 ; Broennimann et al, 2012 ; Casadesús and Munné-Bosch, 2021 ). According to this, what niche overlap represents is not the competitive relationship between host and parasitic plants, but rather the similarity in their distribution ( Li et al, 2014 ; Pili et al, 2020 ).…”

A potential role of heat‐moisture couplings in the range expansion of Striga asiatica

“…The life cycles of these plants include a preconditioning phase (Brown & Edwards, 1946 ) that allows their seeds to respond to host‐exuded strigolactones and some other small‐molecule germination stimulants (Nelson, 2021 ). Orobanche and Striga seeds can lie dormant in the soil for decades until suitable environmental conditions induce seed preconditioning (Casadesus & Munne‐Bosch, 2021 ; Joel et al., 2013 ; Kebreab & Murdoch, 1999 ). However, suboptimal preconditioning parameters may substantially decrease seed germination rates or even prevent germination altogether.…”