Characterization of molecular mechanisms of sporophytic self-incompatibility in Ipomoea trifida

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 18580004
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Breeding science
• Research Institution: Mie University
• Principal Investigator: TSUCHIYA Tohru Mie University, Life Science Research Center, Associate Professor (30293806)
• Project Period (FY): 2006 – 2007
• Keywords: Self-incomoatibility / Wild type Sweet potato / Ioomoea trifida

Research Abstract

To identify genes correlated to self-incompatibility(S-genes)of wild type sweet potato(Ipomoea trifida), genomic sequences of S-locus from S1, 53, S10, S29 self-incompatible lines and Sc, the self-compatible line, were isolated and sequenced.
By the expression analysis and sequence polymorphism, several S-gene candidates were identified ; AB1 to AB4 as male S-gene candidates and SE1 to SE2 and SEA as female S-gene candidates. Among these genes, AB2, A83, SE2 and SEA were found from all analyzed S-locus sequence. In the Sc S-haplotype, however, some mutations were observed in the promoter sequence and gene itself in some of the S-gene candidates. These mutations may contribute the Sc-haplotype as self-compatible.
To determine spatial and temporal expression of these four S-gene candidates, in situ hybridization analyses were carried out. In situ analyses indicated that all of the male part S-candidate genes were expressed in the tapetum at early developmental stage, and all of the female part S-candidate genes were expressed in the papilla cells of stigma at mature stage. These results indicated that all S-candidate genes share a necessary and sufficient condition for S-genes.
Comparison between the genomic sequences of five S-haplotypes indicated that the existence of a regions which have highly sequence polymorphisms, designated as S-locus diversed regions(SDRs). Within this SDRs, three S-candidate genes were located, which are AB2, AB3 and SEA, therefore, these gene products might play key roles in the self-incompatibility reaction.
Furthermore, comparison of the length of the SDRs from self-incompatible lines indicated that SDR length is longest in the most dominant S-haplotype and is shortest in the most recessive line, and the order of the SDR length is consistent with the dominance-recessive hierarchy of the self-incompatibility. In the dominance line have additional sequence to recessive line, such as transposon-like sequences, repetitive sequences, and fragments of organelle genome-like sequences. From this observation, it was considered that the lines at the higher hierarchy in the self-incompatibility of Ipomoea trifida was developed from recessive line.

Research Products

• [Journal Article] Expression of stigma- and anther-specific genes located in the S locus region of Ipomoea trifida (2007)
  • Author(s): Rahman, H., Uchiyama, M., Kuno, M., Hirashima, N., Suwabe, K., Tsuchiya, T., Kagaya, Y., Kobayashi, I., Kakeda, K., Kowyama, Y
  • Journal Title: Sexual Plant Reproduction 20 Pages: 73-85
  • Description: 「研究成果報告書概要(和文)」より
  • Peer Reviewed
• [Journal Article] Physical size of the S locus region defined by genetic recombination and genome sequencing in Ipomoea trifida, Convolvulaceae (2007)
  • Author(s): Rahman, H., Tsuchiya, T., Suwabe, K., Kohori, J., Tomita, RN., Kagaya, Y., Kobayashi, I., Kakeda, K., Kowyama, Y
  • Journal Title: Sexual Plant Reproduction 20 Pages: 63-72
  • Description: 「研究成果報告書概要(和文)」より
  • Peer Reviewed
• [Journal Article] Expression of stigma-and anther-specific genes located in the S locus region of Ipomoea trifida (2007)
  • Author(s): Rahman, H., Uchiyama, M., Kuno, M., Hirashima, N., Suwabe, K., Tsuchiya, T., Kagaya, Y., Kobayashi, I., Kakeda, K., Kowyama, Y
  • Journal Title: Sexual Plant Reproduction 20 Pages: 73-85
  • Description: 「研究成果報告書概要(欧文)」より
• [Presentation] サツマイモ野生種のSハプロタイプ間におけるゲノム配列多型性と優劣性関係 (2007)
  • Author(s): 神山康夫・M. Rahman・高北英治・谷口理・掛田克行・土屋亨
  • Organizer: 日本育種学会
  • Place of Presentation: 山形大学農学部
  • Year and Date: 2007-09-23
  • Description: 「研究成果報告書概要(和文)」より
• [Presentation] Genomic sequence polymorphism and dominance-recessive relationship between several S haplotype of Ipomoea trifida (2007)
  • Author(s): Kowyama, Y., Rahman, H., Takakita, H., Taniguchi, O., Kakeda, K., Tsuchiya, T
  • Organizer: Plant Breeding Society of Japan
  • Place of Presentation: Yamagata University
  • Year and Date: 2007-09-23
  • Description: 「研究成果報告書概要(欧文)」より
• [Book] Molecular genetics of sporophytic self-incompatibility in Ipomoea, a member of the Convolvulaceae (2008)
  • Author(s): Kowyama Y, Tsuchiya T, Kakeda K
  • Publisher: Springer-Verlag(印刷中)
  • Description: 「研究成果報告書概要(和文)」より