, Volume 226, Issue 4, pp 805–813

The amino acid permease AAP8 is important for early seed development in Arabidopsis thaliana

Original Article

DOI: 10.1007/s00425-007-0527-x

Cite this article as:
Schmidt, R., Stransky, H. & Koch, W. Planta (2007) 226: 805. doi:10.1007/s00425-007-0527-x


The development of seeds depends on the import of carbohydrates and amino acids supplied by the maternal tissue via the phloem. Several amino acid transporters have been reported to be expressed during seed and silique development in Arabidopsis thaliana (L.) Heynh. Here we show that mutants lacking the high affinity amino acid permease 8 (At1g10010) display a severe seed phenotype. The overall number of seeds and the number of normally developed seed is reduced by ∼50% in siliques of the Ataap8 T-DNA insertion mutant. This result could be reproduced in plants where expression of AtAAP8 is targeted with an RNAi approach. The seed phenotype is correlated with a specifically altered amino acid composition of young siliques. Aspartic acid and glutamic acid are significantly reduced in young siliques of the mutants. In correlation with the fact that AAP8 is a high affinity transporter for acidic amino acids, translocation of 14C-labelled aspartate fed via the root system to seeds of the mutants is reduced. AAP8 plays a crucial role for the uptake of amino acids into the endosperm and supplying the developing embryo with amino acids during early embryogenesis.


Amino acid contentAmino acid permease (AtAAP8)AspartateSeed development



Amino acid permease


Peptide transporter


Oligopeptide transporter


RNA interference


Reverse transcriptase polymerase chain reaction


Cauliflower mosaic virus


Dry weight

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Roberto Schmidt
    • 1
  • Harald Stransky
    • 1
  • Wolfgang Koch
    • 1
  1. 1.Plant Physiology, Zentrum für Molekularbiologie der Pflanzen (ZMBP)TübingenGermany