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Hydrogen peroxide alleviates P starvation in rice by facilitating P remobilization from the root cell wall

Zhu, Chun Quan, Hu, Wen Jun, Cao, Xiao Chuang, Zhu, Lian Feng, Bai, Zhi Gang, Liang, Qing Duo, Huang, Jie, Jin, Qian Yu, Zhang, Jun Hua
Journal of plant physiology 2019 v.240 pp. 153003
Oryza sativa, biosynthesis, cell walls, crop production, genes, homeostasis, hydrogen peroxide, nitrate reductase, nitric oxide, nitroprusside, pectinesterase, pectins, phosphorus, physiological transport, rice, roots
Phosphorus (P) deficiency limits rice production. Increasing the remobilization of P stored in the root cell wall is an efficient way to alleviate P starvation in rice. In the current study, we found that the addition of 50 μM H2O2 significantly increased soluble P content in rice. H2O2 stimulated pectin biosynthesis and increased pectin methylesterase (PME) activity, thus stimulating the release of P from the cell wall in roots. H2O2 also regulates internal P homeostasis by increasing the expression of P transporter genes OsPT2, OsPT6, and OsPT8 at different treatment times. In addition, the H2O2 treatment increased the expression of nitrate reductase (NR) genes OsNIA1 and OsNIA2 and the activity of NR, then increased the accumulation of nitric oxide (NO) in the rice root. The application of the NO donor sodium nitroprusside (SNP) and the H2O2 scavenger 4-hydroxy-TEMPO significantly increased soluble P content by increasing pectin levels and PME activity to enhance the remobilization of P from the cell wall. However, the addition of NO scavenger 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) with and without H2O2 had the opposite effect, suggesting that NO functions downstream of H2O2 to increase the remobilization of cell wall P in rice.