Arbuscular mycorrhizal symbiosis elicits proteome responses opposite of P-starvation in SO4 grapevine rootstock upon root colonisation with two Glomus species

Abstract

Although plant biotisation with arbuscular mycorrhizal fungi (AMF) is a promising strategy for improving plant health, a better knowledge regarding the molecular mechanisms involved is required. In this context, we sought to analyse the root proteome of grapevine rootstock Selection Oppenheim 4 (SO4) upon colonisation with two AMF. As expected, AMF colonisation stimulates plant biomass. At the proteome level, changes in protein amounts due to AMF colonisation resulted in 39 differentially accumulated two-dimensional electrophoresis spots in AMF roots relative to control. Out of them, 25 were co-identified in SO4 roots upon colonisation by Glomus irregulare and Glomus mosseae supporting the existence of conserved plant responses to AM symbiosis in a woody perennial species. Among the 18 proteins whose amount was reduced in AMF-colonised roots were proteins involved in glycolysis, protein synthesis and fate, defence and cell rescue, ethylene biosynthesis and purine and pyrimidine salvage degradation. The six co-identified proteins whose amount was increased had functions in energy production, signalling, protein synthesis and fate including proteases. Altogether these data confirmed that a part of the accommodation program of AMF previously characterized in annual plants is maintained within roots of the SO4 rootstock cuttings. Nonetheless, particular responses also occurred involving proteins of carbon metabolism, development and root architecture, defence and cell rescue, anthocyanin biosynthesis and P remobilization, previously reported as induced upon P-starvation. This suggests the occurrence of P reprioritization upon AMF colonization in a woody perennial plant species with agronomical interest.

Root Proteomic Analysis of Grapevine Rootstocks Inoculated with Rhizophagus irregularis and Fusarium oxysporum f. sp. herbemontis

“…It has been shown that mycorrhizal plants may have fewer and shorter roots than non-mycorrhizal plants, since extraradicular AMF mycelium increases the volume of soil explored by the plant root system, allowing higher water and nutrient uptake (Locatelli et al, 2002). Therefore, these results confirm the ability of AMF to benefit plant growth, and the increase in shoot and root biomass is consistent with previous studies with grapevine rootstocks (Dalla Costa et al, 2010;Anzanello et al, 2011;Cangahuala-Inocente et al, 2011) or with other plant species (Lovato et al, 2006;Farzaneh et al, 2011;Cavagnaro et al, 2012;Evelin et al, 2012;Mohandas, 2012;Steinkellner et al, 2012). Anzanello et al (2011) detected an increase in shoot and root biomass in SO4 and P1103 rootstocks inoculated with AMF, and Dalla Costa et al (2010) also showed an increase in shoot biomass in SO4 rootstock inoculated with AMF.…”

“…Among the grapevine rootstocks available in southern Brazil, the SO4 rootstock (Vitis berlandieri × V. riparia) was commonly used in grapevine production due to its adaptability to different types of soils and climate, as well as to its vigour, which ensures high yield and fruit quality. However, SO4 was replaced, due to its susceptibility to FOH (Andrade et al, 1993;Dalla Costa et al, 2010;Cangahuala-Inocente et al, 2011), by Paulsen 1103, R99 and R110 (V. berlandieri × V. rupestris), and VR043-43 (V. vinifera × V. rotundifolia) grapevine rootstocks, resistant to FOH, which are currently the most recommended rootstocks in southern Brazil (Sônego et al, 2005;Souza et al, 2013). These rootstocks have low root development, and consequently low yield, but they have a long production cycle (Dalla Costa et al, 2010).…”

“…Dumas-Gaudot et al (2004) and Recorbet et al (2008) identified extra-radicular fungal proteins from in vitro AMF. Using 2DE analyses, Aloui et al (2011) showed an up-accumulation of shoot proteins in Medicago truncatula inoculated with AMF, and Cangahuala-Inocente et al (2011) identified 39 differentially accumulated proteins in SO4 grapevine rootstock inoculated with AMF, including proteins related to plant defence. It is thus possible to identify plant proteins differentially expressed by inoculation with mutualistic or pathogenic fungi.…”

Proteomic studies of arbuscular mycorrhizal associations

“…In that work both G. mosseae and G. irregulare were shown to induce modifications in the display of 39 proteins, 25 of which were identified by matrix assisted laser desorption ionization-time of flight (MALDI-TOF) spectrometry. These identifications showed that several proteins with decreased expression in mycorrhizal plants are involved in response to hypoxia, and downregulation of proteins involved in production of free radical and antioxidant defenses was also observed [51].…”

“…More recently, phenol extraction of proteins was shown to be very efficient also for recalcitrant tissues, such as grapevine roots [51]. In that work both G. mosseae and G. irregulare were shown to induce modifications in the display of 39 proteins, 25 of which were identified by matrix assisted laser desorption ionization-time of flight (MALDI-TOF) spectrometry.…”