FIG. 2.

Northern blot and RT-PCR analysis of XYL-6 transcripts. (A) The total RNA sample for construction of the cDNA library was subjected to Northern blot analysis using digoxigenin-labeled cDNA fragments as probes according to the manufacturer's instructions (Roche Applied Sciences catalogue no. 1636090, 1363514, and 1603558). Probes XYL-1 (transcript = 1.1 kb) and XYL-2 (transcript = 1.3 kb) have been described previously (35, 37); probe XYL-6 is EST RCW105 (transcript = 1.5 kb); and probe Ces1 is EST RCW100 (transcript = 1.7 kb). The Ces1 gene encodes a homolog of a yeast sporulation-related gene, SPS2 (26). Ces1 is constitutively transcribed in M. grisea culture (unpublished observations). (B) RT-PCR measurement of gene transcripts in infected rice leaves. Seedlings of rice cultivar Sariceltik were grown for 14 days in a growth chamber and inoculated with an aqueous conidial suspension (10⁷/ml) of M. grisea strain CP987 as previously described (37). Total RNA samples were isolated from the infected seedlings 24, 46, 68, 84, or 96 h postinoculation. The RNA samples were treated with DNase I prior to RT-PCR as previously described (36). RT-PCR was performed using gene-specific primers (Table 1) designed for fragments of XYL-1 (397 bp), XYL-2 (621 bp), XYL-6 (325 bp), and Ces1 (349 bp), respectively.