Figure 5. An Xb15 Tos17 Mutant Exhibits Cell Death Lesions.

(A) Representation of Xb15 genomic DNA structure and the position of the Tos17 insertion site. Four exons (boxes) are separated by three introns (lines). The protein-coding regions are indicated by shaded boxes with the start codon (ATG) and stop codon (TAA). Gray boxes correspond to untranslated sequences. Arrows indicate locations of primers designed for RT-PCR.

(B) The transcripts levels of Xb15 in Nipponbare wild type (WT), homozygous Tos17 insertion (−/−), heterozygote (−/+), no-insertion plants (+/+). Total RNA was extracted from fully extended 5-wk-old leaves. RT-PCR analysis was performed with Xb15 specific primers indicated in (A). 18S rRNA was used for an internal control.

(C) Morphological phenotype of the Tos17 insertional line (M₅) of Xb15. Photographs were taken 6 wk after germination. Symbols for genotypes for Tos17 in Xb15 are as described above.

(D) PR gene expressions in plants Xb15 Tos17 mutants (M₅). Total RNA was extracted from 5-wk-old wild type and insertion mutant line plants, and RT-PCR was performed with specific primers for PR1a, PR1b, PR10, major birch allergen (Betv1), and PBZ1. Control RT-PCR reactions were carried out with EF1α and 18S rRNA. Symbols for genotypes for Tos17 in Xb15 are same as described above.