Wu Qi, Jing Huai-Kang, Feng Zhi-Hang, Huang Jing, Shen Ren-Fang, Zhu Xiao-Fang
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing, 210008, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Rice (N Y). 2022 Aug 3;15(1):42. doi: 10.1186/s12284-022-00588-y.
Salicylic acid (SA) is thought to be involved in phosphorus (P) stress response in plants, but the underlying molecular mechanisms are poorly understood. Here, we showed that P deficiency significantly increased the endogenous SA content by inducing the SA synthesis pathway, especially for up-regulating the expression of PAL3. Furthermore, rice SA synthetic mutants pal3 exhibited the decreased root and shoot soluble P content, indicating that SA is involved in P homeostasis in plants. Subsequently, application of exogenous SA could increase the root and shoot soluble P content through regulating the root and shoot cell wall P reutilization. In addition, - P + SA treatment highly upregulated the expression of P transporters such as OsPT2 and OsPT6, together with the increased xylem P content, suggesting that SA also participates in the translocation of the P from the root to the shoot. Moreover, both signal molecular nitric oxide (NO) and auxin (IAA) production were enhanced when SA is applied while the addition of respective inhibitor c-PTIO (NO scavenger) and NPA (IAA transport inhibitor) significantly decreased the root and shoot cell wall P remobilization in response to P starvation. Taken together, here SA-IAA-NO-cell wall P reutilization pathway has been discovered in P-starved rice.
水杨酸（SA）被认为参与植物对磷（P）胁迫的响应，但其潜在的分子机制尚不清楚。在此，我们表明缺磷通过诱导SA合成途径显著增加了内源SA含量，尤其是上调了PAL3的表达。此外，水稻SA合成突变体pal3的根和地上部可溶性磷含量降低，表明SA参与植物的磷稳态。随后，外源SA的施用可通过调节根和地上部细胞壁磷的再利用来增加根和地上部可溶性磷含量。此外，-P+SA处理高度上调了OsPT2和OsPT6等磷转运蛋白的表达，同时木质部磷含量增加，表明SA也参与了磷从根到地上部的转运。此外，施用SA时信号分子一氧化氮（NO）和生长素（IAA）的产生均增强，而添加各自的抑制剂c-PTIO（NO清除剂）和NPA（IAA运输抑制剂）显著降低了响应磷饥饿的根和地上部细胞壁磷的再动员。综上所述，在缺磷水稻中发现了SA-IAA-NO-细胞壁磷再利用途径。
