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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Whole plant chamber to examine sensitivity of cereal gas exchange to changes in evaporative demand
AU - Jauregui, Jauregui
AU - Rothwell, Shane Andrew
AU - Taylor, Samuel
AU - Parry, Martin Afan John
AU - Carmo-Silva, Ana Elizabete
AU - Dodd, Ian Charles
PY - 2018/11/1
Y1 - 2018/11/1
N2 - Background: Improving plant water use efficiency (WUE) is a major target for improving crop yield resilience to adverse climate change. Identifying genetic variation in WUE usually relies on instantaneous measurements of photosynthesis (An) and transpiration (Tr), or integrative measurements of carbon isotope discrimination, at the leaf level. However, leaf gas exchange measurements alone do not adequately represent whole plant responses, especially if evaporative demand around the plant changes. Results: Here we describe a whole plant gas exchange system that can rapidly alter evaporative demand when measuring An, Tr and intrinsec WUE (iWUE) and identify genetic variation in this response. An was not limited by VPD under steady-state conditions but some wheat cultivars restricted Tr under high evaporative demand, thereby improving iWUE. These changes may be ABA-dependent, since the barley ABA-deficient mutant (Az34) failed to restrict Tr under high evaporative demand. Despite higher Tr, Az34 showed lower An than wild-type (WT) barley because of limitations in Rubisco carboxylation activity. Tr and An of Az34 were more sensitive than WT barley to exogenous spraying with ABA, which restricted photosynthesis via substrate limitation and decreasing Rubisco activation. Conclusions: Examining whole plant gas exchange responses to altered VPD can identify genetic variation in whole plant iWUE, and facilitate an understanding of the underlying mechanism(s).
AB - Background: Improving plant water use efficiency (WUE) is a major target for improving crop yield resilience to adverse climate change. Identifying genetic variation in WUE usually relies on instantaneous measurements of photosynthesis (An) and transpiration (Tr), or integrative measurements of carbon isotope discrimination, at the leaf level. However, leaf gas exchange measurements alone do not adequately represent whole plant responses, especially if evaporative demand around the plant changes. Results: Here we describe a whole plant gas exchange system that can rapidly alter evaporative demand when measuring An, Tr and intrinsec WUE (iWUE) and identify genetic variation in this response. An was not limited by VPD under steady-state conditions but some wheat cultivars restricted Tr under high evaporative demand, thereby improving iWUE. These changes may be ABA-dependent, since the barley ABA-deficient mutant (Az34) failed to restrict Tr under high evaporative demand. Despite higher Tr, Az34 showed lower An than wild-type (WT) barley because of limitations in Rubisco carboxylation activity. Tr and An of Az34 were more sensitive than WT barley to exogenous spraying with ABA, which restricted photosynthesis via substrate limitation and decreasing Rubisco activation. Conclusions: Examining whole plant gas exchange responses to altered VPD can identify genetic variation in whole plant iWUE, and facilitate an understanding of the underlying mechanism(s).
KW - Photosynthesis
KW - Transpiration
KW - Water use efficiency
KW - VPD
KW - ABA
U2 - 10.1186/s13007-018-0357-9
DO - 10.1186/s13007-018-0357-9
M3 - Journal article
VL - 14
JO - Plant Methods
JF - Plant Methods
SN - 1746-4811
M1 - 97
ER -