Competitive interactions are mediated in a sex‐specific manner by arbuscular mycorrhiza in Antennaria dioica

Abstract

ABSTRACT• Plants usually interact with other plants, and the outcome of such interaction ranges from facilitation to competition depending on the identity of the plants, including their sexual expression. Arbuscular mycorrhizal (AM) fungi have been shown to modify competitive interactions in plants. However, few studies have evaluated how AM fungi influence plant intraspecific and interspecific interactions in dioecious species.• The competitive abilities of female and male plants of Antennaria dioica were examined in a greenhouse experiment. Females and males were grown in the following competitive settings: (i) without competition, (ii) with intrasexual competition, (iii) with intersexual competition, and (iv) with interspecific competition by Hieracium pilosella -a plant with similar characteristics to A. dioica. Half of the pots were grown with Claroideoglomus claroideum, an AM fungus isolated from the same habitat as the plant material. We evaluated plant survival, growth, flowering phenology, and AM fungal structure production.• Plant survival was unaffected by competition or AM fungi. Competition and the presence of AM fungi reduced plant biomass. However, the sexes responded differently to the interaction between fungal and competition treatments. Both intraand interspecific competition results were sex-specific, and in general, female performance was reduced by AM colonization. Plant competition or sex did not affect the intraradical structures, extraradical hyphae, or spore production of the AM fungus.• These findings suggest that plant sexual differences affect fundamental processes such as competitive ability and symbiotic relationships with AM fungi.

The role of plant–soil feedbacks in stabilizing a reindeer‐induced vegetation shift in subarctic tundra

“…The discrepancy between mycorrhizal colonization and B. nana growth is surprising, because especially ectomycorrhizal associations have been found to generally benefit conspecific plants (Bennett et al, 2017). However, the role of mycorrhizas has increasingly been shown to vary from mutualistic to parasitic, depending on the abiotic and biotic context (Johnson & Graham, 2013;Varga, Vega-Frutis, & Kytöviita, 2017). Moreover, the beneficial effect of mycorrhiza is not always correlated with level of root colonization (Treseder, 2013), and mycorrhiza also influence plants in ways unrelated to the nutrient uptake, for example influencing water uptake or disease resistance (Delavaux et al, 2017).…”

Additional AM Fungi Inoculation Increase Populus cathayana Intersexual Competition

“…Studies have reported that AM fungi can improve water-absorbing and nutrient uptake abilities ( Pfetffer and Bloss, 1988 ; Hodge et al, 2001 ; Wu and Xia, 2006 ), increase biomass accumulation ( Al-Karaki et al, 2004 ; Mena-Violante et al, 2006 ; van der Heijden et al, 2006 ; Romero-Munar et al, 2017 ), enhance the survival capacity of host plants ( Rosendahl and Rosendahl, 1991 ; Evelin et al, 2009 ), and even be involved in interactions among plants ( Allen et al, 2003 ; Mack and Rudgers, 2008 ; Wagg et al, 2011 ). For example, mycorrhizal infection increased the level of competition for the same resources between Holcus lanatus and Dactylis glomerata ( West, 1996 ), and the composition of AM fungi communities regulated plant interactions and determined the structure of plant communities among Lotus corniculatus , Festuca ovina , and Plantago lanceolata ( Scheublin et al, 2007 ). The presence of AM fungi decreased the competitive inequality between Trifolium pratense and Lolium multiflorum by reducing growth suppression ( Wagg et al, 2011 ), and AM fungi increased the negative effects of exotic plant Centaurea maculosa on the native plant Festuca idahoensis and enhanced the ability of C .…”

“…cathayana ( Chen et al, 2015a ). Meanwhile, in dioecious plant populations, root systems of female and male individuals are closely connected to a common hyphal network through AM fungi and drain carbon or mineral nutrients from other individuals ( Hart et al, 2003 ; Varga et al, 2017 ). Because there exist sex-specific responses to mycorrhiza in a dioecious species (e.g., Varga and Kytöviita, 2008 , 2010b ; Eppley et al, 2009 ; Rogers and Eppley, 2012 ; Varga, 2013 ), the intersexual interactions between male and female individuals should be affected by AM fungi.…”

“…Because there exist sex-specific responses to mycorrhiza in a dioecious species (e.g., Varga and Kytöviita, 2008 , 2010b ; Eppley et al, 2009 ; Rogers and Eppley, 2012 ; Varga, 2013 ), the intersexual interactions between male and female individuals should be affected by AM fungi. However, the current understanding of the AM fungi affecting intersexual competition in dioecious plants is still limited (see Sánchez-Vilas et al, 2011 ; Varga et al, 2017 ).…”

Sexual dimorphism in response to stress

“…Lastly, little is known on patterns of dimorphism in below-ground processes and structures. Considering that sexual dimorphism would be the outcome of below versus above processes (Varga et al, 2017), and allocation to above and below-ground sinks (Harris and Pannell, 2008), studies that will focus on these aspects would be especially useful to make a compelling story of sexual dimorphism in plants under stress.…”