Hydrogen, Oxygen, and Carbon Isotope Ratios of Cellulose from Submerged Aquatic Crassulacean Acid Metabolism and Non-Crassulacean Acid Metabolism Plants

Abstract

ABSTRACIÌsotope ratios of cellulose and cellulose nitrate from aquatic Crassulacean acid metabolism (CAM) and DoD-CAM plants were determined. Cellulose oxygen istope ratios for all plants that grew together were virtuayl identical whereas large differences were observed for hydrogen Recently it has been shown that hydrogen isotope ratios of 'Abbreviations: PEP, P-enolpyruvate; SMOW, standard mean ocean water; PDB, Peedee belemnite. organic matter from terrestrial plants are also related to photosynthetic mode (17,19,20,22,23). For example, AD values of cellulose nitrate from field grown CAM plants are from 45%o to 223%o higher than those observed for C3 and C4 plants growing in the same vicinity (17,20). In this study, we present stable isotopic analysis of aquatic plants which have known photosynthetic modes, and demonstrate that hydrogen isotope ratios of aquatic plant cellulose nitrate can be used as an indicator of photosynthetic mode. Further, we show that the differences in AD values between aquatic CAM and non-CAM plants are similar to the differences observed between terrestrial CAM plants and C3 and C4 plants. These observations are consistent with the proposal that isotopic fractionations occurring during biochemical steps (rather than during evapotranspiration) are responsible for the hydrogen isotopic differences between terrestrial CAM and non-CAM plants (17, 29,20).

A preliminary survey for crassulacean acid metabolism (CAM) in submerged aquatic macrophytes in New Zealand

“…Vallisneria spiralis Graeb. has not been specifically tested for CAM but Sternberg et al (1984) reported that the 14 C: 13 C ratio in tissues was lower than in the surrounding environment. Such preferential uptakes of ' 3 C are characteristic of CAM species.…”

“…Only a few general surveys of CAM in native aquatic populations have been published (Keeley & Morton 1982;Sternberg et al 1984;Farmer & Spence 1985). This paper presents the first known survey of this kind in New Zealand.…”

Compensation Point and Isotopic Characteristics of C3/C4 Intermediates and Hybrids in Panicum

“…In addition to the well known separation of C3 plants from C4 and CAM plants based on stable carbon isotope ratios (17), oxygen and hydrogen isotope ratios ofcellulose and cellulose nitrate, respectively, also are influenced by photosynthetic mode (20,(22)(23)(24)(25). Analysis of C3, C4, and CAM plants growing in the vicinity of each other show that cellulose nitrate from CAM plants is enriched in deuterium relative to C3 and C4 plants (20, 22, 25).…”

Composição lignocelulósica e isótopica da vegetação e da matéria orgânica do solo de uma turfeira tropical: I - composição florística, fitomassa e acúmulo de carbono

“…O processo de lignificação concentra C nos tecidos vegetais, de forma que quanto maior o teor de C, mais empobrecido torna-se o tecido em 13 C (Sternberg & Deniro, 1983;Sternberg et al, 1984). Verificou-se empobrecimento em 13 C na lignina nas espécies que compõem o CLU de 3,57 ‰ e nas que colonizam a FES de 2,30 ‰ (Quadro 5), em relação ao conjunto do tecido vegetal, e esse foi acima do preconizado por Eglin et al (2008), que foi de 1-2 ‰ de δ 13 C, com relação ao conjunto tecido vegetal.…”