Overexpression of mitochondrial uncoupling protein 1 (UCP1) induces a hypoxic response inNicotiana tabacumleaves

Abstract

HighlightEvidence was found linking alterations in carbon fixation and mitochondrial metabolism that lead to increased stress tolerance in UCP1-overexpressing plants.

Mitochondrial Uncoupling Protein 1 Overexpression Increases Yield in Nicotiana tabacum under Drought Stress by Improving Source and Sink Metabolism

“…Although, the mechanistic effects of UCP1-oe are not yet clearly understood (Barreto et al, 2016 ), it has been observed that UCP1-oe confers tolerance to multiple stresses (Brandalise et al, 2003 ; Smith et al, 2004 ; Begcy et al, 2011 ; Chen et al, 2013 ; Barreto et al, 2014 ). Nevertheless, all these studies thus far have been conducted on plants during the vegetative phase of development.…”

“…Tobacco plants ( Nicotiana tabacum , ecotype SR1) (WT) and three transgenic lines (P07, P30, and P49) overexpressing A. thaliana UCP1 (Brandalise et al, 2003 ) were used in this study. These lines have been previously used by our group (Barreto et al, 2014 , 2016 ) and others (Begcy et al, 2011 ). Seeds were sown in trays containing a soil:vermiculite (1:1) mixture; 15 days after planting, the seeds were transferred to 0.2-L pots.…”

“…Metabolites were isolated from flower buds as described (Barreto et al, 2016 ), with minor modifications. A total of 100 mg of frozen tissue was powdered in liquid nitrogen, incubated with 1 ml of extraction solution containing a chloroform:methanol:water solution (2:4:1) for 30 min on ice, and vigorously homogenized for an additional 15 min.…”

“…After the addition of 1 ml of water, samples were centrifuged at 12,200 × g for 5 min for phase separation. The methanol:water phase was collected and vacuum-dried for 8 h. Metabolites were analyzed using a 1H-nuclear magnetic resonance (NMR) spectrometer as described (Barreto et al, 2016 ). Spectral phase and baseline corrections and the identification and quantification of the metabolites were performed using Chenomx NMR Suite 7.6 software.…”

“…In contrast, knockouts of UCP1 in Arabidopsis thaliana decrease carbon assimilation due to impaired photorespiration (Sweetlove et al, 2006 ). UCP1-oe also alters the expression of chloroplast genes and induces the expression of a large subset of stress-responsive genes, which may explain the broad abiotic and biotic stress tolerance (Barreto et al, 2016 ).…”