Molecular hydrogen can take part in phytohormone signal pathways in wild rice

Abstract

Molecular hydrogen (H2) could be a novel signal in phytohormone signaling pathways in response to biotic and abiotic stresses. Here, we employed two wild rice species (Oryza rufipogon Griff. and O. minuta J. Presl) to test this hypothesis using hydrogen-rich water (HW). The expression differences of phytohormone and hydrogenase genes between conventional rice (Oryza sativa L,) and wild rice were determined by real-time quantitative polymerase chain reaction, and the effects of HW on gene expression of wild rice were detected during three growth stages. Expression of hydrogenase genes, synthesis genes, and receptor genes of salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) signalling pathways was higher in six wild rice types than in conventional rice. Hydrogen-rich water up-regulated expression of two hydrogenase genes, SA, JA, and ET receptor genes and synthesis genes in the seedling stage of wild rice. But this positive regulation by HW was less significant in the vegetative and reproductive stages.

Keywords

• abiotic and biotic stresses
• ethylene
• hydrogen-rich water
• jasmonic acid
• oryza minuta
• oryza rufipogon
• oryza sativa
• salicylic acid