Overexpression of the selective autophagy receptor AtNBR1

Cargo receptors are well established elements of the selective autophagy in all eukaryotes. The NBR1-like family of such receptors is evolutionarily conserved, however plants have only one member of the family, which is a functional and structural hybrid of its two animal counterparts, p62 (SQSTM1) and NBR1. Examination of plants overexpressing NBR1 indicates that they are oversensitive to TOR inhibitors and have more autophagosomes than the parental lines. The observed changes in shoots suggested induction of ABA signalling pathway, what was further corroborated by the germination tests and the assay of ABA level. The transcriptome changes in roots, such as lower level of snoRNA and some tRNAs, suggested inhibition of ribosome biogenesis, what is supported by identification of RPS6, an important component of TOR-dependent translational control, as a novel partner of NBR1. Grant number: 2014/15/B/NZ3/04854 Grant funding source: National Science Centre (Poland) Grantee Name: Agnieszka Sirko Grant title: Upstream regulators and cellular targets of the selective autophagy cargo receptor AtNBR1 in different phases of sulfur deficiency in plants. Arabidopsis plants, 33 days old, were harvested and total RNA were separately isolated from shoots and roots. We looked for effects of the NBR1 gene overexpression in the OX.7.5 line compared to the the wild type plants (Col-0). These effects were investigated in roots and shoots separately under conditions of both nutritional sufficiency and sulfur limitation. Totally, 24 samples of RNA were prepared.