title: Expression and genomic structure of the dormancy-associated MADS box genes MADS13 in Japanese pears (Pyrus pyrifolia Nakai) that differ in their chilling requirement for endodormancy release.
abstract: We isolated three dormancy-associated MADS-box (DAM) genes (MADS13-1, MADS13-2 and MADS13-3) and showed regulated expression concomitant with endodormancy establishment and release in the leaf buds of Japanese pear 'Kosui'. Comparative analysis between 'Kosui' and Taiwanese pear TP-85-119 ('Hengshanli'), a less dormant pear cultivar, showed reduction of MADS13-1 expression level in 'Hengshanli' earlier than in 'Kosui' towards endodormancy release, suggesting the possible relationship between chilling requirement and MADS13-1 expression. Application of hydrogen cyanamide accelerated endodormancy release with a reduction in MADS13 expression, whereas heat treatment in autumn inhibited endodormancy establishment without induction of MADS13 expression, indicating a close relationship between the MADS13 expression pattern and endodormancy phase transitions. Moreover, both the cis-acting regulatory elements and the methylation status in the 5' upstream region of the MADS13-1 gene were not largely different between 'Kosui' and 'Hengshanli'. Genomic structures of MADS13-1 from 'Kosui' and 'Hengshanli' revealed a 3218 bp insertion in the first intron of 'Hengshanli' that might be ascribed to the lower expression of MADS13-1tw; however, this insertion was also found in pear genotypes with a high chilling requirement. These results indicated that the low expression of MADS13-1 in 'Hengshanli' towards endodormancy release could not be explained by the identified cis-acting regulatory elements, the methylation status of the putative promoter or by intron insertion.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Saito
authors.forename: Songling
authors.initials: S
authors.lastname: Bai
authors.forename: Akiko
authors.initials: A
authors.lastname: Ito
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sakamoto
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Saito
authors.forename: Banjamin Ewa
authors.initials: BE
authors.lastname: Ubi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Imai
authors.forename: Takaya
authors.initials: T
authors.lastname: Moriguchi
mesh_terms: D003080:Cold Temperature; D019175:DNA Methylation; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D005838:Genotype; D006358:Hot Temperature; D007438:Introns; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D018519:Meristem; D057445:Plant Dormancy / Q000235:genetics*; D018515:Plant Leaves / Q000254:growth & development*; D010940:Plant Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D031989:Pyrus / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D012621:Seasons; D013045:Species Specificity
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins
keywords: dormancy-associated MADS box gene; endodormancy; pear (Pyrus pyrifolia Nakai)