WRKY33 MODULATES THE RESPONSES TO LOW NITROGEN SUPPLY OF CONTRASTING
N-USE EFFICIENT EGGPLANTS
Nitrogen use efficiency (NUE) is an important and complex crops trait
and its improvement represents a strategy to maintain high yield
reducing N-supply. We report the genome-wide transcriptomic analysis of
four eggplants contrasting for NUE to identify key genes related to the
NUE pathway, after short- and long-term low-N exposure, in both root and
shoot. Co-expression Gene Networks (CGN) analysis permitted to identify
up-regulated differential expressed genes (DEGs) involved in the light
reaction pathway, the biological processes response to inorganic
substance, abiotic stimulus and cellular response to nitrogen starvation
in high NUE genotypes. Some transcription factor (TF) were up-regulated
in the N-use efficient genotypes, in particular, WRKY33 showed a
significant up-regulation triggering the higher expression of 21 genes
cluster including other TFs, many of which associated to N-metabolism.
To validate our results, an independent de novo experiment including two
other NUE-contrasting genotypes, at both low and high N supply, was
carried out. Interestingly, the high significant WRKY33 expression and
its cluster were confirmed in the high NUE genotypes at low-N supply.
Moreover, the WRKY33 role was confirmed in Arabidopsis as the
35S::AtWRKY33 over expressing line showed a more competitive root system
able to uptake more efficiently N from the soil.