Life‐long growth of Quercus ilex L. at natural CO₂ springs acclimates sulphur, nitrogen and carbohydrate metabolism of the progeny to elevated pCO₂

Abstract

The aim of the present study was to analyse whether offspring of mature Quercus ilex trees grown under life-long elevated p CO 2 show alterations in the physiological response to elevated p CO 2 in comparison with those originating from mature trees grown at current ambient p CO 2 . To investigate changes in C-(for changes in photosynthesis, biomass and lignin see Polle, McKee & Blaschke Plant, Cell and Environment 24, 1075-1083, 2001), N-, and Smetabolism soluble sugar, soluble non-proteinogenic nitrogen compounds (TSNN), nitrate reductase (NR), thiols, adenosine 5 ¢ -phosphosulphate (APS) reductase, and anions were analysed. For this purpose Q. ilex seedlings were grown from acorns of mother tree stands at a natural spring site (elevated p CO 2 ) and a control site (ambient p CO 2 ) of the Laiatico spring, Central Italy. Short-term elevated p CO 2 exposure of the offspring of control oaks lead to higher sugar contents in stem tissues, to a reduced TSNN content in leaves, and basipetal stem tissues, to diminished thiol contents in all tissues analysed, and to reduced APS reductase activity in both, leaves and roots. Most of the components of C-, N-and S-metabolism including APS reductase activity which were reduced due to short-term elevated p CO 2 exposure were recovered by life-long growth under elevated p CO 2 in the offspring of spring oaks. Still TSNN contents in phloem exudates increased, nitrate contents in lateral roots and glutathione in leaves and phloem exudates remained reduced in these plants. The present results demonstrated that metabolic adaptations of Q. ilex mother trees to elevated p CO 2 can be passed to the next generation. Short-and long-term effects on source-to-sink relation and physiological and genetic acclimation to elevated p CO 2 are discussed.

Stomatal index responses of Agrostis canina to CO2 and sulphur dioxide: implications for palaeo‐[CO2] using the stomatal proxy

“…However, an identical result is observed in herbaceous species from CO 2 -degassing vents when grown under free-air carbon enrichment (Marchi et al, 2004) where the SI shows no significant response to elevated [CO 2 ]. A similar pattern is also observed in this study of A. canina from Mefite (Figs 4,7), suggesting that long-term multigenerational growth at elevated [CO 2 ] may have led to evolutionary adaptation (Schulte et al, 2002;Onoda et al, 2009) and that these selective pressures have constrained, or negated, the SI-[CO 2 ] relationship that is evident in the control A. canina (e.g. Marchi et al, 2004).…”

“…The volcanic-degassing vent-derived Mefite population of A. canina possesses an evolutionary adaptation to growth under elevated [CO 2 ] and resistance to fumigation with SO 2 which is not apparent in the control A. canina that has not experienced similar stresses and selective pressures (e.g. Bradshaw, 1952;McNeilly, 1968;Schulte et al, 2002;Onoda et al, 2009). This adaptive resistance to toxic volcanic gases is not manifested in reduced SI values relative to the control A. canina when grown under identical atmospheric conditions.…”

Influence of the photoperiod on redox regulation and stress responses in Arabidopsis thaliana L. (Heynh.) plants under long- and short-day conditions

“…The amounts of GSH and of GSSG were determined with a modified method of Schulte et al (2002). Frozen powder from Arabidopsis leaves was weighed and then deproteinized with 2% (v/v) perchloric acid for 30 min on ice.…”

Decades‐long effects of high CO2 concentration on soil nitrogen dynamics at a natural CO2 spring

“…However, natural CO 2 springs provide unique opportunities to explore and predict potential ecosystem processes at the end of this century after ecosystems have been exposed to high [CO 2 ] for decades. For example, plants near natural CO 2 springs have been exposed to high [CO 2 ] over generations and have adapted to the ecosystem (Fordham et al 1997;Cook et al 1998;Schulte et al 2002;Onoda et al 2009;Nakamura et al 2011). There are several studies investigating soil properties and ecosystem processes in natural CO 2 springs in Europe and New Zealand (Gahrooee 1998;Ross et al 2000;Kool et al 2007).…”