PMID- 27578764
OWN - NLM
STAT- MEDLINE
DCOM- 20170821
LR  - 20181113
IS  - 1095-8290 (Electronic)
IS  - 0305-7364 (Print)
IS  - 0305-7364 (Linking)
VI  - 118
IP  - 6
DP  - 2016 Nov
TI  - Reduced plant water status under sub-ambient pCO2 limits plant productivity in 
      the wild progenitors of C3 and C4 cereals.
PG  - 1163-1173
AB  - BACKGROUND AND AIMS: The reduction of plant productivity by low atmospheric CO(2) 
      partial pressure (pCO(2)) during the last glacial period is proposed as a 
      limiting factor for the establishment of agriculture. Supporting this hypothesis, 
      previous work has shown that glacial pCO(2) limits biomass in the wild 
      progenitors of C(3) and C(4) founder crops, in part due to the direct effects of 
      glacial pCO(2) on photosynthesis. Here, we investigate the indirect role of 
      pCO(2) mediated via water status, hypothesizing that faster soil water depletion 
      at glacial (18 Pa) compared to post-glacial (27 Pa) pCO(2), due to greater 
      stomatal conductance, feeds back to limit photosynthesis during drying cycles. 
      METHODS: We grew four wild progenitors of C(3) and C(4) crops at glacial and 
      post-glacial pCO(2) and investigated physiological changes in gas exchange, 
      canopy transpiration, soil water content and water potential between regular 
      watering events. Growth parameters including leaf area were measured. KEY 
      RESULTS: Initial transpiration rates were higher at glacial pCO(2) due to greater 
      stomatal conductance. However, stomatal conductance declined more rapidly over 
      the soil drying cycle in glacial pCO(2) and was associated with decreased 
      intercellular pCO(2) and lower photosynthesis. Soil water content was similar 
      between pCO(2) levels as larger leaf areas at post-glacial pCO(2) offset the 
      slower depletion of water. Instead the feedback could be linked to reduced plant 
      water status. Particularly in the C(4) plants, soil-leaf water potential 
      gradients were greater at 18 Pa compared with 27 Pa pCO(2), suggesting an 
      increased ratio of leaf evaporative demand to supply. CONCLUSIONS: Reduced plant 
      water status appeared to cause a negative feedback on stomatal aperture in plants 
      at glacial pCO(2), thereby reducing photosynthesis. The effects were stronger in 
      C(4) species, providing a mechanism for reduced biomass at 18 Pa. These results 
      have added significance when set against the drier climate of the glacial period.
CI  - (c) The Author 2016. Published by Oxford University Press on behalf of the Annals 
      of Botany Company. All rights reserved. For Permissions, please email: 
      journals.permissions@oup.com.
FAU - Cunniff, Jennifer
AU  - Cunniff J
AD  - Department of Animal and Plant Sciences, Alfred Denny Building, University of 
      Sheffield, Western Bank, Sheffield S10 2TN, UK j.cunniff@cabi.org.
FAU - Charles, Michael
AU  - Charles M
AD  - Institute of Archaeology, 36 Beaumont St, Oxford OX1 2PG, UK.
FAU - Jones, Glynis
AU  - Jones G
AD  - Department of Archaeology, Northgate House, University of Sheffield, West Street, 
      Sheffield S1 4ET, UK.
FAU - Osborne, Colin P
AU  - Osborne CP
AD  - Department of Animal and Plant Sciences, Alfred Denny Building, University of 
      Sheffield, Western Bank, Sheffield S10 2TN, UK.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20160829
PL  - England
TA  - Ann Bot
JT  - Annals of botany
JID - 0372347
RN  - 059QF0KO0R (Water)
RN  - 142M471B3J (Carbon Dioxide)
SB  - IM
MH  - Carbon Dioxide/metabolism
MH  - Hordeum/*growth & development/metabolism/physiology
MH  - Panicum/*growth & development/metabolism/physiology
MH  - Photosynthesis/physiology
MH  - Plant Leaves/physiology
MH  - Plant Transpiration/physiology
MH  - Setaria Plant/*growth & development/metabolism/physiology
MH  - Triticum/*growth & development/metabolism/physiology
MH  - Water/metabolism
PMC - PMC5091726
OTO - NOTNLM
OT  - C3 photosynthesis
OT  - C4 photosynthesis
OT  - Hordeum spontaneum
OT  - Panicum miliaceum var. ruderale
OT  - Setaria viridis
OT  - Triticum boeoticum
OT  - crop progenitors.
OT  - origin of agriculture
OT  - sub-ambient pCO2
OT  - water relations
EDAT- 2016/10/30 06:00
MHDA- 2017/08/22 06:00
PMCR- 2017/11/01
CRDT- 2016/09/01 06:00
PHST- 2016/02/28 00:00 [received]
PHST- 2016/06/13 00:00 [accepted]
PHST- 2016/10/30 06:00 [pubmed]
PHST- 2017/08/22 06:00 [medline]
PHST- 2016/09/01 06:00 [entrez]
PHST- 2017/11/01 00:00 [pmc-release]
AID - mcw165 [pii]
AID - 10.1093/aob/mcw165 [doi]
PST - ppublish
SO  - Ann Bot. 2016 Nov;118(6):1163-1173. doi: 10.1093/aob/mcw165. Epub 2016 Aug 29.