Low secondary leaf waxn-alkane synthesis on fully mature leaves of C3 grasses grown at controlled environmental conditions and variable humidity

Abstract

Our investigation provides new evidence on the timing of cuticular wax synthesis in grass leaves and indicates that the majority of n-alkanes are synthesized during the initial development of the leaf. Our study will improve the interpretation of leaf wax n-alkane δ H values in environmental and geological studies as it suggests that secondary synthesis of leaf wax n-alkanes in grass leaves contributes only slightly to the geological record. Copyright © 2016 John Wiley & Sons, Ltd.

The δ18O and δ2H of water in the leaf growth‐and‐differentiation zone of grasses is close to source water in both humid and dry atmospheres

“…() found no effect of atmospheric humidity on 2 H enrichment of leaf wax n ‐alkanes of grasses, and why the enrichment is much greater in dicot leaves (Kahmen et al ., ), which expand while being directly exposed to the atmospheric environment. Occurrence of some n ‐alkane synthesis outside of the LGDZ (Richardson et al ., ) – in young tissue that is directly exposed to the atmosphere – may contribute to explain some effect of atmospheric humidity on 2 H enrichment of leaf wax n ‐alkanes in grasses (Kahmen et al ., ; Gamarra & Kahmen, ). McInerney et al .…”

“…That work also influenced views on the δ 2 H of medium or synthesis waters for grass leaf cuticular wax formation (e.g. McInerney et al ., ; Sachse et al ., ; Kahmen et al ., ; Gamarra & Kahmen, ). However, recent work suggested that p ex for oxygen in cellulose synthesis may vary in a greater range than previously assumed (Song et al ., ).…”

“…As the LGDZ is fully enclosed, it was thought that it is nontranspiring and that evaporatively enriched water in the LGDZ stems from diffusion from adjacent transpiring tissue or import of water via the phloem (e.g. Gamarra & Kahmen, 2017;Liu et al, 2016).…”

Evaluating Leaf Wax and Bulk Leaf Carbon Isotope Surrogates for Water Use Efficiency and Grain Yield in Winter Wheat

“…Fannin and TAM 305 also share common parents (Ibrahim et al, 2015). n-Alkanes are not decomposed on the leaf surface after synthesis and harvest (Wang et al, 2015;Gamarra and Kahmen, 2017), which suggests potential for a convenient surrogate for assessing WUE l . Fannin and WB Cedar generally preform below the average in the High Plains due to the low winter temperature.…”

“…In contrast, leaf wax n-alkanes have a long-carbon-chain aliphatic structure, and they are the first or second most abundant component in the leaf wax of many species ( Jetter and Schäffer, 2001;Wang et al, 2015). n-Alkanes are not decomposed on the leaf surface after synthesis and harvest (Wang et al, 2015;Gamarra and Kahmen, 2017), which suggests potential for a convenient surrogate for assessing WUE l . Leaf alkane biosynthesis is well studied (Cassagne and Lessire, 1974;Cheesbrough and Kolattukudy, 1984;Bernard et al, 2012;Andre et al, 2013), and some genes have been found to regulate alkane accumulation (Aharoni et al, 2004;Zhang et al, 2005;Bourdenx et al, 2011;Laila et al, 2017).…”