The double knockdown of the mitochondrial uncoupling protein isoforms reveals partial redundant roles during Arabidopsis thaliana vegetative and reproductive development

Metabolism and Signaling of Plant Mitochondria in Adaptation to Environmental Stresses

“…However, under reductive stress, no alterations in NAD content were found in the ucp1 mutant lines after exposure to DTT, which contrasts with the results observed for aox1 plants, suggesting distinct mechanisms of adaptation in these lines. In this scenario, the presence of a compensatory mechanism upon other UCPs when a specific isoform is mutated should be considered [ 24 ]. A striking feature of UCP1 is that it exhibits relatively constant expression under a variety of developmental stages and in response to different mitochondrial inhibitors, such as antimycin (AA) [ 25 ], oligomycin [ 26 ], or rotenone [ 27 ] ( Figure 2 ).…”

“…This seems counterintuitive because UCP1 function is thought to be in energy dissipation; however, because UCP1 is a major component of the MIM, it may simply be a consequence of increased mitochondrial content. In this context, alterations in UCP1 content seem to affect germination when the seeds face adverse conditions [ 24 , 30 ], although the precise mechanisms or in vivo function of UCP1 during this developmental stage have not been investigated thus far. The association of UCP1 expression with reproductive organs/tissues was further investigated using transgenic tobacco plants harboring the promoter regions of Arabidopsis UCP1 and UCP2 fused with the GUS reporter [ 30 ].…”

“…Consistent with transcriptome data [ 29 ], UCP1 promoter activity was markedly increased in both male and female reproductive organs. The ucp1 mutant line [ 23 ] and double mutant lines for different UCP family members [ 24 ] exhibited strong hydrogen peroxide (H 2 O 2 ) accumulation in male and female organs. In addition, alteration in the expression of several regulators of reproductive development was observed in these lines when grown under regular conditions [ 24 , 30 ].…”

“…The ucp1 mutant line [ 23 ] and double mutant lines for different UCP family members [ 24 ] exhibited strong hydrogen peroxide (H 2 O 2 ) accumulation in male and female organs. In addition, alteration in the expression of several regulators of reproductive development was observed in these lines when grown under regular conditions [ 24 , 30 ]. These changes resulted in the reduced seed and silique size observed in double mutant lines [ 24 ].…”

“…In addition, alteration in the expression of several regulators of reproductive development was observed in these lines when grown under regular conditions [ 24 , 30 ]. These changes resulted in the reduced seed and silique size observed in double mutant lines [ 24 ]. The opposite effect was observed in tobacco lines overexpressing Arabidopsis UCP1 [ 21 ].…”