Capacities and constraints of amino acid utilization in Arabidopsis

Sammanfattning

Various amino acids, including both L- and D-enantiomers, may be present in soils, and recent studies have indicated that plants may access such nitrogen (N) forms. Here, the capacity of Arabidopsis to utilize different L- and D-amino acids is investigated and the constraints on this process are explored.Mutants defective in the lysine histidine transporter 1 (LHT1) and transgenic plants overexpressing LHT1 as well as plants expressing D-amino acid-metabolizing enzymes, were used in studies of uptake and growth on various N forms.Arabidopsis absorbed all tested N-forms, but D-enantiomers at lower rates than L-forms. Several L- but no D-forms were effective as N sources. Plants deficient in LHT1 displayed strong growth reductions and plants overexpressing LHT1 showed strong growth enhancement when N was supplied as amino acids, in particular when these were supplied at low concentrations. Several D- amino acids inhibited growth of wild-type plants, while transgenic Arabidopsis-expressing genes encoding D-amino acid-metabolizing enzymes could efficiently utilize such compounds for growth.These results suggest that several amino acids, and in particular L-Gln and L-Asn, promote growth of Arabidopsis, and increased expression of specific amino acid transporters enhances growth on amino acids. The efficiency by which transgenic plants exploit D-amino acids illustrates how plants can be engineered to utilize specific N sources otherwise inaccessible to them.

Nyckelord

D-amino acid; D-amino acid oxidase; D-serine dehydratase; growth; lysine histidine transporter 1; metabolism; nitrogen uptake

Publicerad i

New Phytologist
2008, volym: 179, nummer: 4, sidor: 1058-1069
Utgivare: BLACKWELL PUBLISHING

SLU författare

• Forsum, Oskar

  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

• Svennerstam, Henrik

  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

• Ganeteg, Ulrika

  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

• Näsholm, Torgny

  • Institutionen för skogens ekologi och skötsel, Sveriges lantbruksuniversitet
    
  • Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Skogsvetenskap

Publikationens identifierare

• DOI: https://doi.org/10.1111/j.1469-8137.2008.02546.x

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/18567