TY - JOUR

T1 - Export of defensive glucosinolates is key for their accumulation in seeds

AU - Xu, Deyang

AU - Sanden, Niels Christian

AU - Hansen, Line Lykke

AU - Belew, Zeinu Mussa

AU - Madsen, Svend Roesen

AU - Meyer, Lasse

AU - Jørgensen, Morten Egevang

AU - Hunziker, Pascal

AU - Veres, Dorottya

AU - Crocoll, Christoph

AU - Schulz, Alexander

AU - Nour-Eldin, Hussam Hassan

AU - Halkier, Barbara

PY - 2023

Y1 - 2023

N2 - Plant membrane transporters controlling metabolite distribution contribute key agronomic traits1,2,3,4,5,6. To eliminate anti-nutritional factors in edible parts of crops, the mutation of importers can block the accumulation of these factors in sink tissues7. However, this often results in a substantially altered distribution pattern within the plant8,9,10,11,12, whereas engineering of exporters may prevent such changes in distribution. In brassicaceous oilseed crops, anti-nutritional glucosinolate defence compounds are translocated to the seeds. However, the molecular targets for export engineering of glucosinolates remain unclear. Here we identify and characterize members of the USUALLY MULTIPLE AMINO ACIDS MOVE IN AND OUT TRANSPORTER (UMAMIT) family—UMAMIT29, UMAMIT30 and UMAMIT31—in Arabidopsis thaliana as glucosinolate exporters with a uniport mechanism. Loss-of-function umamit29 umamit30 umamit31 triple mutants have a very low level of seed glucosinolates, demonstrating a key role for these transporters in translocating glucosinolates into seeds. We propose a model in which the UMAMIT uniporters facilitate glucosinolate efflux from biosynthetic cells along the electrochemical gradient into the apoplast, where the high-affinity H+-coupled glucosinolate importers GLUCOSINOLATE TRANSPORTERS (GTRs) load them into the phloem for translocation to the seeds. Our findings validate the theory that two differently energized transporter types are required for cellular nutrient homeostasis13. The UMAMIT exporters are new molecular targets to improve nutritional value of seeds of brassicaceous oilseed crops without altering the distribution of the defence compounds in the whole plant.

AB - Plant membrane transporters controlling metabolite distribution contribute key agronomic traits1,2,3,4,5,6. To eliminate anti-nutritional factors in edible parts of crops, the mutation of importers can block the accumulation of these factors in sink tissues7. However, this often results in a substantially altered distribution pattern within the plant8,9,10,11,12, whereas engineering of exporters may prevent such changes in distribution. In brassicaceous oilseed crops, anti-nutritional glucosinolate defence compounds are translocated to the seeds. However, the molecular targets for export engineering of glucosinolates remain unclear. Here we identify and characterize members of the USUALLY MULTIPLE AMINO ACIDS MOVE IN AND OUT TRANSPORTER (UMAMIT) family—UMAMIT29, UMAMIT30 and UMAMIT31—in Arabidopsis thaliana as glucosinolate exporters with a uniport mechanism. Loss-of-function umamit29 umamit30 umamit31 triple mutants have a very low level of seed glucosinolates, demonstrating a key role for these transporters in translocating glucosinolates into seeds. We propose a model in which the UMAMIT uniporters facilitate glucosinolate efflux from biosynthetic cells along the electrochemical gradient into the apoplast, where the high-affinity H+-coupled glucosinolate importers GLUCOSINOLATE TRANSPORTERS (GTRs) load them into the phloem for translocation to the seeds. Our findings validate the theory that two differently energized transporter types are required for cellular nutrient homeostasis13. The UMAMIT exporters are new molecular targets to improve nutritional value of seeds of brassicaceous oilseed crops without altering the distribution of the defence compounds in the whole plant.

U2 - 10.1038/s41586-023-05969-x

DO - 10.1038/s41586-023-05969-x

M3 - Journal article

C2 - 37076627

VL - 617

SP - 132

EP - 138

JO - Nature

JF - Nature

SN - 0028-0836

ER -