ANAC044 is associated with P reutilization in P deficient Arabidopsis thaliana root cell wall in an ethylene dependent manner

Phosphorus (P) deficiency is a major problem in agriculture, thus identifying mechanisms affecting plant's ability to reutilize previously assimilated P is a prerequisite for improving the P homeostasis in crops grown with P deficient soil. Here, we reported the involvement of a NAC (No apical meristem [NAM], Arabidopsis transcription activation factor [ATAF] and Cup-shaped cotyledon [CUC]) transcription factor in response to P deficiency. Compared to the wild type (WT, Col-0) and two independent complementary lines, the anac044 mutant displayed P deficiency resistant phenotype, together with the increased root length, root and shoot biomass under P deficiency. In addition, ANAC044 was highly expressed in root and silique. Upon P deficient treatment even within 1 d, ANAC044 transcript accumulation was strongly up-regulated. Further analysis revealed that, under P-deficient condition, the cell wall, particularly the pectin of anac044, released more P than that of WT and complementary lines, accompanied by an increment of ethylene production, as a result, more soluble and total P were available in anac044 root and shoot. Thus, the study here uncovers the role of ANAC044-regulated cell wall P remobilization through ethylene signaling under P deficiency.