Antibody production and identity of MLOs associated with sugar-cane whiteleaf disease and bermuda-grass whiteleaf disease from Thailand

Cuttings from sugar-cane plants with symptoms of whiteleaf disease and bermuda-grass plants also showing whiteleaf symptoms were collected in Thailand and transferred to a glasshouse at East Mailing. Using these plants as source material, procedures were devised for the partial purification of MLO-associated immunogens. Antisera were raised separately to the sugar-cane whiteleaf and bermuda-grass whiteleaf immunogens. These antisera exhibited specificity for their homologous MLO antigens in F(ab')₂ indirect enzyme immunosorbent assays (ELISA). Detection of MLO infection was possible in crude tissue extracts diluted several hundredfold. No cross-reactions were observed in reciprocal tests between these two MLO sources and their antisera, nor were there reactions between either antiserum and extracts of other graminaceous hosts showing symptoms of natural whiteleaf infection. No cross-reactions were obtained in reciprocal tests with Spiroplasma citri or aster yellows MLO and their homologous antibodies.