Involved in target of rapamycin (TOR)-regulated translation control, especially under energy-deficient conditions (PubMed:29084871). Involved in the regulation of the ethylene-mediated signaling pathway (PubMed:21631530). Involved in salt stress responses (PubMed:21631530). Reduced cotyledons size and early flowering (PubMed:21631530). Interacts with EIN2, ETR2 and EIN4 (PubMed:21631530). Binds to EIF4A1 (PubMed:29084871). The association with ribosomes is modulated by cellular energy status and TOR activity (PubMed:29084871). Mostly expressed in vegetative tissues, such as leaves and stems, and, to a lower extent, in roots and reproductive tissues, such as flower buds and flowers (PubMed:29084871). Expressed in seedlings, roots, cauline leaf tips and flowers (PubMed:21631530). In seedlings, observed in the root tips, root vascular tissues and at the junction region of hypocotyl and root. In flowers, mainly detected at the connection of petiole and stem, and in young flower buds. Also present at low levels in sepals and pistils. Induced by dark and starvation but repressed by glucose feeding subsequent to starvation in a TOR-dependent manner. Enhanced ethylene response, but altered salt response during seed germination and plant growth leading to an increased tolerance to salt stress (PubMed:21631530). Increased susceptibility to dark and starvation, and to treatment with the TOR inhibitor (PubMed:29084871). Decreased translation activity associated with altered ribosome patterns, especially in the dark and starvation conditions, in which mRNAs distribution is altered and rRNA abnormally degraded (PubMed:29084871). Slightly early flowering time under long-day conditions (PubMed:29084871). Belongs to the PDCD4 family.