Plasma membrane intrinsic proteins PIP1;1 and PIP1;3 contribute to the
tolerance to nitrogen deficiency in potato
Nitrogen (N) deficiency is one of the major constraints for potato
(Solanum tuberosum L.) production, due to its shallow root system and
poor capabilities of N mobilization from the deeper layers of the soil.
The aim of this study was to elucidate plasma membrane (PM) proteins
potentially involved in the tolerance towards N deficiency. We compared
the PM proteome of the two potato cultivars ‘Lambada’ and ‘Topas’,
contrasting in their N deficiency response under in vitro conditions.
Using mass spectrometry we identified 65 proteins, which were
differentially abundant in the two cultivars when submitted to N
deficiency. Amongst those, candidate proteins were selected based on
their potential to be involved in N transport under deficient
conditions. Two members of the aquaporin family, StPIP1;1 and StPIP1;3,
were studied in more detail. By means of a yeast growth assay we showed
that these proteins do not facilitate transport of ammonia. The
Arabidopsis (Arabidopsis thaliana) knockout mutants AtPIP1;1 and
AtPIP1;3 showed a reduced N content and accumulation of anthocyanins
under N deficiency. We conclude that PIP1;1 and PIP1;3 are indirectly
involved in the N uptake under N deficient conditions and contribute to
an increased N deficiency tolerance.