Characterization of candidate gene and abnormal of carbohydrate metabolism during pollen development in a male sterility clone, sosyun

In recent years, candidate regions containing causative genes of Sosyun, a male sterility trait, have been identified by a linkage map in Cryptomeria japonica with quantitative trait loci analysis. Of which, reCj19250 was found to be closely linked to the causative gene in this candidate region. Another gene called reCj11611, which is presumed to be related to carbohydrate metabolism, was mapped to the same locus as reCj19250, but no details about this gene have been reported to date. In this study, the gene expression of both reCj11611 and reCj19250, or the monosaccharide and starch content, were investigated in C. japonica clones during pollen formation. The monosaccharide or starch content during pollen formation increased significantly in Sosyun, suggesting that carbohydrate metabolism is abnormal in plants with this trait. However, evidence that gene expression of reCj11611 is related to abnormal carbohydrate metabolism was not obtained. A specific mutation of the reCj11611 cDNA sequence associated with Sosyun was determined. Deletion of 20 bps sequences in the 3′UTR region for the reCj11611 cDNA sequence was applied to approximately 760 C. japonica clones using a DNA marker which was able to identify this deletion. Although six clones were shown to be heterozygotic for this gene, five of them were incongruent with the presence of reCj19250. Therefore, the genes cited to be in the same position on the C. japonica linkage map were, in fact, at neighboring loci. © 2020 Nihon Ringakkai. All rights reserved.