Abstract
It is known that red light induces jasmonate (JA) synthesis in rice. On the other hand, elicitor-responsive genes are activated by cytoplasmic acidification in suspension-cultured rice (Oryza sativa cv. Nipponbare) cells. There is a possibility that the cytoplasmic acidification can be a key step (trigger) in the signal transduction leading to the expression of several genes. Therefore, we measured the cytoplasmic pH chenge induced by JA in suspension cultured rice (Oryza sativa cv. musasikogane) cells with 31P-NMR method. Jasmonate (4.5 nM-450 μM MeJA) induces transient cytoplasmic acidification in suspension-cultured rice cells. The patterns of pH change were similar to those induced by elicitor. However, 0.45 nM MeJA does not induce the transient cytoplasmic acidification. These results suggest that red light could be a trigger in the signal transduction events leading to the expression of some elicitor-responsive genes in rice.
