TY - JOUR
T1 - Death, sex, and sugars
T2 - variations in nonstructural carbohydrate concentrations in a sexually plastic tree
AU - Blake-Mahmud, Jennifer
AU - Struwe, Lena
N1 - Funding Information:
The authors thank Dr. Bingru Huang, Dr. Pat Burgess, Stephani Rossi, Cathryn Chapman, Dhara Patel, and Rachel Rodriquez for their assistance in the carbohydrate analyses. Thanks also to Gerard Sapes, Dr. Greg Anderson, and two anonymous reviewers for assistance with the manuscript and to Kepler Mahmud for field assistance. Research permits were obtained from the New Jersey Department of Environmental Protection. This work was supported by the Ecology and Evolution Graduate Program, Rutgers University, the Torrey Botanical Society, NSF IGERT grant (NSF-DGE/IGERT 0903675), and USDA-Hatch grant NJ17142. Specimens collected by J.B.-M. are vouchered at Chrysler Herbarium (CHRB) in New Brunswick, NJ.
Publisher Copyright:
© 2020 Botanical Society of America
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Premise: Environmental sex determination (ESD) is a rare sex determination system in which individuals may switch sex expression throughout their lifetimes in response to environmental factors. In sexually stable species, individuals usually bear more female flowers if the plants are larger, have greater access to limiting resources, or are in better condition. Research regarding sexually plastic species with ESD and how resources correlate with sex expression is limited. Furthermore, most research investigates resources at the population level, failing to account for resources available to individuals for growth, maintenance, or reproduction. Methods: Acer pensylvanicum is a species that is known to switch sex. Using twig samples collected during 2014–2016 in December and May, we analyzed resource status in the form of stored nonstructural carbohydrates (NSCs) and compared this with expressed sex. Results: We found that females had higher sugar concentrations than males. Furthermore, males changing expression to female had higher sugar concentrations during the prior winter than did males remaining male. We found that size was not a key predictor: neither male nor female-flowering individuals increased NSC concentrations with size. Dying female trees had high concentrations of NSCs throughout the dying process and only manifested reduced NSCs once dead. Conclusions: This is the first study showing significant correlations between NSCs and sex expression in a plant species with ESD. These findings support the hypothesis that sex switching could be a consequence of increased resource availability and that the high female mortality of A. pensylvanicum populations is likely not a direct result of carbon starvation.
AB - Premise: Environmental sex determination (ESD) is a rare sex determination system in which individuals may switch sex expression throughout their lifetimes in response to environmental factors. In sexually stable species, individuals usually bear more female flowers if the plants are larger, have greater access to limiting resources, or are in better condition. Research regarding sexually plastic species with ESD and how resources correlate with sex expression is limited. Furthermore, most research investigates resources at the population level, failing to account for resources available to individuals for growth, maintenance, or reproduction. Methods: Acer pensylvanicum is a species that is known to switch sex. Using twig samples collected during 2014–2016 in December and May, we analyzed resource status in the form of stored nonstructural carbohydrates (NSCs) and compared this with expressed sex. Results: We found that females had higher sugar concentrations than males. Furthermore, males changing expression to female had higher sugar concentrations during the prior winter than did males remaining male. We found that size was not a key predictor: neither male nor female-flowering individuals increased NSC concentrations with size. Dying female trees had high concentrations of NSCs throughout the dying process and only manifested reduced NSCs once dead. Conclusions: This is the first study showing significant correlations between NSCs and sex expression in a plant species with ESD. These findings support the hypothesis that sex switching could be a consequence of increased resource availability and that the high female mortality of A. pensylvanicum populations is likely not a direct result of carbon starvation.
KW - Acer pensylvanicum
KW - Sapindaceae
KW - dioecy
KW - diphasy
KW - environmental sex determination
KW - mortality
KW - nonstructural carbohydrates
KW - patchy-environment model
KW - sexual plasticity
KW - size-dependent sex allocation model
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U2 - 10.1002/ajb2.1429
DO - 10.1002/ajb2.1429
M3 - Article
C2 - 32080831
AN - SCOPUS:85079900597
SN - 0002-9122
VL - 107
SP - 375
EP - 382
JO - American Journal of Botany
JF - American Journal of Botany
IS - 2
ER -