Abundance of bacterial genes encoding for proteases and chitinases in the rhizosphere of three different potato cultivars

In terrestrial ecosystems, the majority of soil N is present in organic macromolecules like proteins, nucleic acids and chitin. Because these compounds cannot be assimilated by plants, plant growth is often N-limited. Therefore, the hydrolysis of proteins and chitin is particularly important in making N available for plants. In this study, we investigated the influence of different potato cultivars and different plant developmental stages on the abundance of genes encoding for alkaline and neutral metalloproteases (apr, npr) as well as bacterial chitinases (chiA) in the rhizosphere using quantitative real-time PCR in a greenhouse trial and a field study. It could be clearly demonstrated that abundance pattern was mainly affected by the plant vegetation stage, whilst the used plant genotype had only a minor influence on the development of the two functional populations.