Phosphorus (P) starvation in rice facilitates the
reutilization of root cell wall P by enhancing the pectin content. NaCl
modulates pectin content, however, it is still unknown whether NaCl is also
involved in the process of pectin regulated
cell wall P remobilization in rice under P starved conditions.
In this study, we found that 10 mmol/L
NaCl increased the shoot and root biomasses under P deficiency to a remarkable
extent, in company with the elevated shoot and root soluble P contents in rice.
Further analysis indicated that exogenous NaCl enhanced the root cell wall P
mobilization by increasing the
methylesterase activity and uronic acid content in pectin suggesting the
involvement of NaCl in the process of cell wall P reutilization in P starved rice roots. Additionally, exogenous NaCl
up-regulated the expression of P transporter OsPT6,
induced by P deficiency,
suggesting that NaCl also facilitated the P translocation prominently from root
to shoot in P starved rice. Moreover, exogenous abscisic acid (ABA) can reverse
the NaCl-mediated mitigation under P deficiency, indicating the involvement of
ABA in the NaCl
regulated root cell wall P
reutilization. Taken together, our results demonstrated that NaCl can activate
the reutilization of root cell wall P in P starved rice, which is dependent on the
ABA accumulation pathway.