| Title: | Thermogenic respiratory processes drive the exponential increase of volatile organic compound emissions in Macrozamia cycad cones |
| Author(s): | Terry LI; Roemer RB; Booth DT; Moore CJ; Walter GH; |
| Address: | "Department of Biology, University of Utah, 257 S. 1400 E., Salt Lake City, UT, 84112, USA. Department of Mechanical Engineering, University of Utah, 50 S. Central Campus Dr., 2202 Merrill Engineering Bldg, Salt Lake City, UT, 84112, USA. School of Biological Sciences, The University of Queensland, Brisbane, 4072, Queensland, Australia" |
| ISSN/ISBN: | 1365-3040 (Electronic) 0140-7791 (Linking) |
| Abstract: | "An important outcome of plant thermogenesis is increased emissions of volatiles that mediate pollinator behaviour. We investigated whether the large increase in emissions, mainly the monoterpene ss-myrcene (>90%), during daily thermogenic events of Macrozamia macleayi and lucida cycad cones are due solely to the influence of high cone temperatures or are, instead, a result of increased respiratory rates during thermogenesis. We concurrently measured temperature, oxygen consumption and ss-myrcene emission profiles during thermogenesis of pollen cones under typical environmental temperatures and during experimental manipulations of cone temperatures and aerobic conditions, all in the dark. The exponential rise in ss-myrcene emissions never occurred without a prior, large increase in respiration, whereas an increase in cone temperature alone did not increase emissions. When respiration during thermogenesis was interrupted by anoxic conditions, ss-myrcene emissions decreased. The increased emission rates are not a result of increased cone temperature per se (through increased enzyme activity or volatilization of stored volatiles) but are dependent on biosynthetic pathways associated with increased respiration during thermogenesis that provide the carbon, energy (ATP) and reducing compounds (NADPH) required for ss-myrcene production through the methylerythritol phosphate (MEP) pathway. These findings establish the significant contribution of respiration to volatile production during thermogenesis" |
| Keywords: | Acyclic Monoterpenes Cell Respiration Monoterpenes/*metabolism Oxygen/metabolism Temperature *Thermogenesis Volatile Organic Compounds/*metabolism Zamiaceae/*metabolism MEP pathway index: Macrozamia cycads monoterpenes respiration thermogenesis volatile e; |
| Notes: | "MedlineTerry, L Irene Roemer, Robert B Booth, David T Moore, Chris J Walter, Gimme H eng 2016/03/01 Plant Cell Environ. 2016 Jul; 39(7):1588-600. doi: 10.1111/pce.12730. Epub 2016 May 5" |
