Non‐specific Phospholipase C4 Improves Phosphorus Remobilization From Old to Young Leaves in Camelina

Camelina sativa is regarded as a low-input oilseed crop for versatile food, biofuels and industrial applications with potential production on marginal lands, whereas phosphate (P_i) deficiency greatly reduces camelina seed production. To improve camelina resilience to low P conditions, here we overexpressed the P_i deficiency-induced non-specific phospholipase C4 (NPC4) to test its effect on camelina seed production under different levels of P_i availability. NPC4-overexpressing (OE) plants displayed increased seed yield and oil production, with a greater magnitude of increases under P_i-deficient than P_i-sufficient conditions. NPC4-OE camelina had a higher level of total P and free P_i in young leaves but a lower level in old leaves than in wild-type plants. More P_i was moved from old leaves to young leaves in NPC4-OE than in wild-type plants. NPC4-OE increased the expression of P_i transporter genes, and the increase was greater in old leaves and under P_i-deficient conditions. These data indicate that NPC4 improves camelina growth by promoting P_i remobilization from old to young tissues, revealing a mechanism by which NPC4 mediates plant response to P_i deficiency.