Scion-rootstock interaction and drought systemic effect modulate the organ-specific terpene profiles in grafted Pinus pinaster Ait

Aerial and underground organs display specific metabolic strategies to cope with water stress under rising atmospheric CO2 in Fagus sylvatica L.

“…However, it was not only the intensity of the response to the drought that differed between organs. We also found organ‐specific drought‐triggered metabolomics changes, as in other tree species, both deciduous, such as Eucalyptus (Merchant et al, 2006), and evergreen, such as Pinus pinaster (de Miguel et al, 2016; Fernández de Simón et al, 2021).…”

“…In both organs, the levels of secondary metabolites were also affected by water stress that limited their accumulation, decreasing flavonoids and phenylpropanoids, together with its precursor, the quinic acid, although those of benzoic and cinnamic compounds increased slightly in the roots. This has been reported in beech trees (Aranda et al, 2018) and other tree species such as eucalyptus (Correia et al, 2016), willow (Turtola et al, 2005) or oak (Suseela et al, 2020), although unfavorable environmental conditions are usually related to higher foliar levels of terpene and phenolic compounds (Fernández de Simón et al, 2017, 2021; Sumbele et al, 2012; Tattini et al, 2004). As in the leaves, the organic acids involved in the TCA cycle (citric, malic, fumaric, and succinic) also showed a high drought‐triggered accumulation level in the roots, implying that this metabolic pathway was more active in beech trees under a mild–moderate drought.…”

“…The foliar levels of secondary metabolites, mainly phenolic compounds, are also affected differently by water stress depending on the specie. Drought limits their accumulation in beech (Aranda et al, 2018), as in other tree species such as eucalyptus (Correia et al, 2016) or willow (Turtola et al, 2005), while the impact of unfavorable environmental conditions is usually related to higher levels of foliar terpenic and phenolic compounds in other species (Fernández de Simón et al, 2017, 2021; Sumbele et al, 2012; Tattini et al, 2004). Foliar phenolics in trees are related to the chemical defense, but they also play a role as antioxidants and in photoprotection (Agati et al, 2012; Agati et al, 2013; Noctor et al, 2015).…”

Rootstock effects on scion gene expression in maritime pine

“…Trees were watered to field capacity when soil volumetric water content (VWCs) dropped below 20 vol%. Different phenotypic evaluations were carried out and described in Fernández de Simón et al 84 . Needles were harvested, frozen in liquid nitrogen, and stored at − 80 °C until RNA extraction.…”

Maritime Pine Rootstock Genotype Modulates Gene Expression Associated with Stress Tolerance in Grafted Stems

“…Moreover, due to the divergence between gymnosperms and angiosperms 140–270 Mya [ 40 , 41 ] and their morphological and functional differences, particularly in vascular systems (tracheids vs. vessels) [ 42 ], functional information from grafts in flowering plants cannot be applied to conifers. Recent studies on maritime pine grafts have shown differences in their physiological and metabolic responses to drought [ 43 ]. In addition, rootstock genotype has been shown to significantly modify the transcriptomic profile of scion needles in maritime pine grafts, where rootstock genotypes with contrasting drought response could have regulated the accumulation of transcripts associated with drought response prior to water deprivation [ 44 ].…”