Figure 5.

Transcript levels of the genes involved in proline and arginine catabolism in arginine- and proline-fed rice cells. The expression of the genes involved in proline and ornithine oxidation to glutamate was quantified in suspension cultured cells of rice (cv Loto) by real-time PCR following reverse transcription. Levels were normalized with respect to Actin 1 cDNA (A). The same experiment was performed with cells treated with either 2 mM proline (B) or 2 mM arginine (C), harvested at increasing time after the addition of the exogenous amino acid. Expression levels were in this case normalized with respect to those in untreated controls. All treatments were carried out in triplicate, and means ± SE are reported. Results were subjected to analysis of variance, taking into account the Bonferroni correction for multiple testing; ^*, ^***: significantly different at the 10% and 1% level, respectively, from time 0 (A) or untreated controls (B,C).