N deficiency induced variation in the PM proteome of potato
cultivars
Plants as sessile organisms must constantly adapt their PM composition
to properly sense and respond to the variations in their environment. N
deficiency is known to cause changes in the expression of genes
participating in the nitrate and ammonia uptake (as reviewed by Kiba and
Krapp (2016)), signaling, as well as hormone translocation (O’Brien et
al., 2016). Information about the PM protein composition under stress
conditions and in particular, in response to N deficiency, remains
however absent for potato. Two potato cultivars that show contrasting N
deficiency tolerance (Jozefowicz et al., 2017; Meise et al., 2017; Schum
& Jansen, 2014; Schum et al., 2017) (‘Lambada’-sensitive, and
‘Topas’-tolerant) formed the basis of the present study to identify PM
proteins associated with N deficiency tolerance. Our study revealed that
changes in the root PM composition occur in potato upon N deficiency.
The alterations in the root PM proteome are cultivar specific, as we
observed that many proteins respond in a cultivar dependent manner
(Clusters I, III, IV, V, Fig. 2). Those proteins which were higher
abundant only in the tolerant cultivar under N deficiency, were
considered as potential candidates for improving tolerance to N
shortages in potato.