Expression of Genes Encoding Manganese Peroxidase and Laccase of in Response to Nitrogen Sources, Hydrogen Peroxide and Phytohormones.

produces lignolytic enzymes that can degrade the lignin component of plant cell walls, causing basal stem rot to oil palms. Nitrogen sources may affect plant tolerance to root pathogens while hydrogen peroxide (HO), salicylic acid (SA) and jasmonic acid (JA) play important roles in plant defense against pathogens. In this study, we examined the expression of genes encoding manganese peroxidase (MnP) and laccase (Lac) in treated with different nitrogen sources (ammonium nitrate, ammonium sulphate, sodium nitrate and potassium nitrate), JA, SA and HO. Transcripts encoding MnP and Lac were cloned from . Of the three GbMnP genes, GbMnP_U6011 was up-regulated by all nitrogen sources examined and HO but was down-regulated by JA. The expression of GbMnP_U87 was only up-regulated by JA while was up-regulated by ammonium nitrate but suppressed by sodium nitrate and down-regulated by HO. Among the three genes examined, was up-regulated by ammonium nitrate, JA, SA and HO; was up-regulated by JA and HO while was up-regulated by SA but suppressed by ammonium sulphate, sodium nitrate, JA and HO. Differential expression of these genes may be required by their different functional roles in .