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The mitochondrial NAD + transporter ( NDT 1) plays important roles in cellular NAD + homeostasis in Arabidopsis thaliana
Author(s) -
Souza Chaves Izabel,
Feitosa-Araújo Elias,
Florian Alexandra,
Medeiros David B.,
FonsecaPereira Paula,
Charton Lennart,
Heyneke Elmien,
Apfata Jorge A.C.,
Pires Marcel V.,
MettlerAltmann Tabea,
Araújo Wagner L.,
Neuhaus H. Ekkehard,
Palmieri Ferdinando,
Obata Toshihiro,
Weber Andreas P.M.,
Linka Nicole,
Fernie Alisdair R.,
NunesNesi Adriano
Publication year - 2019
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14452
Subject(s) - nad+ kinase , arabidopsis thaliana , biology , arabidopsis , biochemistry , microbiology and biotechnology , nicotinamide adenine dinucleotide , mitochondrion , peroxisome , mutant , gene , enzyme
Summary Nicotinamide adenine dinucleotide ( NAD + ) is an essential coenzyme required for all living organisms. In eukaryotic cells, the final step of NAD + biosynthesis is exclusively cytosolic. Hence, NAD + must be imported into organelles to support their metabolic functions. Three NAD + transporters belonging to the mitochondrial carrier family ( MCF ) have been biochemically characterized in plants. At NDT1 ( At 2g47490), focus of the current study, At NDT 2 ( At 1g25380), targeted to the inner mitochondrial membrane, and At PXN ( At 2g39970), located in the peroxisomal membrane. Although At NDT 1 was presumed to reside in the chloroplast membrane, subcellular localization experiments with green fluorescent protein ( GFP ) fusions revealed that At NDT 1 locates exclusively in the mitochondrial membrane in stably transformed Arabidopsis plants. To understand the biological function of At NDT 1 in Arabidopsis, three transgenic lines containing an antisense construct of At NDT 1 under the control of the 35S promoter alongside a T‐ DNA insertional line were evaluated. Plants with reduced At NDT 1 expression displayed lower pollen viability, silique length, and higher rate of seed abortion. Furthermore, these plants also exhibited an increased leaf number and leaf area concomitant with higher photosynthetic rates and higher levels of sucrose and starch. Therefore, lower expression of At NDT 1 was associated with enhanced vegetative growth but severe impairment of the reproductive stage. These results are discussed in the context of the mitochondrial localization of At NDT 1 and its important role in the cellular NAD + homeostasis for both metabolic and developmental processes in plants.