TY  - JOUR
A1  - Gamarra, B.
A1  - Sachse, Dirk
A1  - Kahmen, A.
T1  - Effects of leaf water evaporative H-2-enrichment and biosynthetic fractionation on leaf wax n-alkane H-2 values in C3 and C4 grasses
JF  - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology
N2  - Leaf wax n-alkane H-2 values carry important information about environmental and ecophysiological processes in plants. However, the physiological and biochemical drivers that shape leaf wax n-alkane H-2 values are not completely understood. It is particularly unclear why n-alkanes in grasses are typically H-2-depleted compared with plants from other taxonomic groups such as dicotyledonous plants and why C3 grasses are H-2-depleted compared with C4 grasses. To resolve these uncertainties, we quantified the effects of leaf water evaporative H-2-enrichment and biosynthetic hydrogen isotope fractionation on n-alkane H-2 values for a range of C3 and C4 grasses grown in climate-controlled chambers. We found that only a fraction of leaf water evaporative H-2-enrichment is imprinted on the leaf wax n-alkane H-2 values in grasses. This is interesting, as previous studies have shown in dicotyledonous plants a nearly complete transfer of this H-2-enrichment to the n-alkane H-2 values. We thus infer that the typically observed H-2-depletion of n-alkanes in grasses (as opposed to dicots) is because only a fraction of the leaf water evaporative H-2-enrichment is imprinted on the H-2 values. Our experiments also show that differences in n-alkane H-2 values between C3 and C4 grasses are largely the result of systematic differences in biosynthetic fractionation between these two plant groups, which was on average -198 and-159 parts per thousand for C3 and C4 grasses, respectively. We present novel and exciting data on how leaf wax n-alkane 2H values from grasses are affected by plant physiological (leaf water evaporative 2H-enrichment) or biochemical processes (biosynthetic hydrogen isotope fractionation). These results are very interesting because they shed new light on how naturally observed differences between 2H values from C3 and C4 grasses and dicots can be explained by systematic differences in the biosynthesis of n-alkanes between these plant group (i.e. largely driven by NADPH origins).
KW  - biosynthetic fractionation
KW  - C3 and C4 grasses
KW  - deuterium
KW  - leaf water evaporative H-2-enrichment
KW  - leaf wax n-alkanes
Y1  - 2016
U6  - https://doi.org/10.1111/pce.12789
SN  - 0140-7791
SN  - 1365-3040
VL  - 39
SP  - 2390
EP  - 2403
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -