Two titans finally meet each other under nitrogen deficiencies: FERONIA-TORC1 activation promotes plant growth.

Plant growth is determined by well-defined developmental pro-cesses that integrate cell-intrinsic factors and external environ-mental cues,and it is largely dependent on the assimilation of macro-and micro-nutrients from the environment.Between the macro-nutrients,the inorganic nitrogen(e.g.,nitrate and ammo-nium)and amino acids are essential for plant survival and produc-tivity.Beyond acting as macro-nutrients and structural compo-nents of macro-molecules,these nitrogen-containing molecules could also act as signaling molecules to orchestrate diverse ge-netic programs(Wang et al.,2018).Plant nutritional cues that rapidly change over time and space in the soils are tightly linked to signaling pathways that execute fast cellular programs to adjust to a challenging environment.Plant Rapid Alkalinization Factors(RALFs)are secreted peptides that function as extracellular signals and bind to Catharanthus roseus recep-tor-like kinase 1-like family members such as FERONIA(FER)(Liao et al.,2017).RALF1-FER complexes are central regulators of plant growth that allow plants to respond to environmental changes(Du et al.,2016;Zhu et al.,2020).This interaction triggers the recruitment of RPM1-induced protein kinase(RIPK)and the phosphorylation of both FER and RIPK in a mutually dependent manner(Du et al.,2016),followed by the recruitment and activation via phosphorylation of an early translation initiation factor(eIF4E1)(Zhu et al.,2020).These findings highlighted that the RALF1-FER-RIPK pathway is an important hub to control plant cell growth under specific conditions.