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.