著者

Hyungjun Park Yosuke Narasako Tomoko Abe Hisato Kunitake Tomonari Hirano

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.39, no.3, pp.311-316, 2022-09-25 (Released:2022-09-25)

参考文献数

41

被引用文献数

1

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Sweet potato is a major root crop with nutritious tuberous roots. The mechanism of tuberous root development has not yet been adequately elucidated. Genetic resources are required to develop the molecular understanding of sweet potato. Heavy-ion beams were applied to hexaploid sweet potato for an increase in genetic variation, after which the comprehensive effects of heavy-ion beam irradiation were investigated. In vitro cultured shoots with an axillary bud of ‘Beniharuka’ were irradiated with Ar-ions at a dose of 1–5 Gy and C-ions at a dose of 5–20 Gy, and three irradiated lines were separated from each irradiated shoot. The shoot regeneration was inhibited at high doses of each ion irradiation. Ar-ion irradiation had an especially high biological effect on shoot regeneration. A total of 335 lines were obtained, consisting of 104 and 231 lines derived from Ar- and C-ion irradiation, respectively. The change in the DNA content of the lines was analyzed by flow cytometry to evaluate the irradiation-induced damage to the DNA. The two lines demonstrated significant differences in the DNA content and changes at the chromosome level. The screening for the morphological mutants was conducted in the field. Some irradiated lines showed inhibited or no tuberous root phenotype as mutant candidates. Additionally, the high-yield mutant candidates were dominated by Ar-ion irradiation. It was indicated that heavy-ion beam mutagenesis is effective in broadening the range of the phenotypes corresponding to tuberous root formation in hexaploid sweet potato.

著者

Hyungjun Park Tomoko Abe Hisato Kunitake Tomonari Hirano

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

vol.73, no.2, pp.212-218, 2023 (Released:2023-06-06)

参考文献数

35

被引用文献数

1

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Sweet potato is a widely cultivated crop with storage roots. Although many studies have been conducted on the mechanism of its storage root formation, the details have not been fully elucidated. We screened mutant lines with inhibition of storage root formation to clarify parts of the mechanism. In this study, the process of storage root formation in one of the mutant lines, C20-8-1, was investigated. The inhibition of storage root formation was observed during the early stages of growth. The roots in C20-8-1 did not show histological differences compared to those in wild type. The transition from fibrous roots to pencil roots, which are the developmental stages prior to mature storage root formation, was delayed or inhibited in C20-8-1. The upregulation of starch biosynthesis-related genes and downregulation of lignin biosynthesis genes with storage root swelling were not confirmed in the root of C20-8-1 during the developmental transition stage, suggesting that most of the roots in C20-8-1 are in the pre-transition state toward the storage root swelling. C20-8-1 showed a mutant phenotype during the critical period of storage root swelling initiation, and further clarification of this mutation is expected to provide new insights into storage root formation.

著者

Tomonari Hirano Yusuke Kazama Hisato Kunitake Tomoko Abe

出版者

Japan Mendel Society, International Society of Cytology

雑誌

CYTOLOGIA (ISSN:00114545)

巻号頁・発行日

vol.87, no.1, pp.3-6, 2022-03-25 (Released:2022-03-25)

参考文献数

37

被引用文献数

4

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Heavy-ion beams have been used as an effective mutagen in plants. Various studies have extended our understanding of the mutagenic effects of heavy-ion beam irradiation on the plant genome. Heavy-ion beams can be characterized by the linear energy transfer (LET) value, and the LET-dependent mutagenic effects are observed in plant survival, mutation frequency, and mutation spectrum. When we integrate the results of the mutagenic effects obtained from experiments using different detection methods, we must consider a bias, depending on the experimental system. For example, the plant materials, developmental processes, and heredity of induced mutations must be considered. In this review, we organized the mutagenic effects from the perspective of irradiated plant materials and the heredity of the induced mutations.

著者

Tomonari Hirano Yuka Matsuyama Anna Hanada Yoriko Hayashi Tomoko Abe Hisato Kunitake

出版者

Japan Mendel Society, International Society of Cytology

雑誌

CYTOLOGIA (ISSN:00114545)

巻号頁・発行日

vol.86, no.4, pp.311-315, 2021-12-25 (Released:2021-12-24)

参考文献数

23

被引用文献数

2

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Heavy-ion beams have been applied as effective mutagens to various plant materials. Pollen has been used as material for mutant induction and genetic analysis. However, our knowledge of the DNA damage response of plant male gametes remains limited. In the present study, we irradiated Cyrtanthus mackenii pollen with an argon ion beam, which induced complex DNA damage, and investigated the DNA damage response of male gametes during pollen tube growth. Male gametes derived from the irradiated pollen grains were isolated from pollen tubes after 12 and 24 h of culture and subjected to cell cycle analysis. After 12 h of culture, the irradiated generative cells were frequently arrested at metaphase during pollen mitosis II (PMII), and the proportion of metaphase cells increased with increasing absorbed dose. These results suggest that the genomic lesions induced by the argon ion beam caused spindle assembly checkpoint (SAC)-dependent arrest. After 24 h of culture, the irradiated male gametes completed PMII, albeit forming sperm cells with abnormalities in chromosome separation, and chromosomal bridges were often formed between these cells. Moreover, phosphorylated H2AX foci, an indicator of DNA double-strand breaks, were detected in the irradiated male gametes after 24 h of culture, regardless of passing through the SAC. Taken together, these results indicate that male gametes activate functions to cope with radiation-induced complex DNA damage during pollen tube growth.

著者

Yoichi Sato Tomonari Hirano Yoriko Hayashi Nobuhisa Fukunishi Tomoko Abe Shigeyuki Kawano

出版者

Japan Mendel Society, International Society of Cytology

雑誌

CYTOLOGIA (ISSN:00114545)

巻号頁・発行日

vol.86, no.4, pp.291-295, 2021-12-25 (Released:2021-12-24)

参考文献数

29

被引用文献数

3

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In Undaria pinnatifida, an effective method for mutant screening in sporophytes has not been established. The present study developed a novel mutant screening method for Undaria sporophyte by combining gametophyte mutagenesis with heavy-ion beam and land-based tank culture system. When we irradiated gametophytes and sporophytes with carbon- and argon-ion beams, survival rates of the female gametophytes and the sporophytes decreased with increasing dose. However, those of the male gametophyte did not decrease after both of the irradiations. Mutant screening during the sporophyte development was performed by using a land-based tank culture system. High-growth plants were selected in the first mutant (M1) population derived from the irradiated materials. We successfully obtained mutant candidates with higher growth than the wild type in the M2 generation obtained from brother-sister inbreeding of selected M1 plants. Four high-growth mutant candidate lines were selected from M2 populations of 48 lines. The mutant candidates were derived from 3 lines of the gametophyte irradiation and 1 line of the sporophyte irradiation, suggesting that the materials for the irradiation are applicable for mutant induction. The mutant screening method and the selected mutant candidates would advance the breeding and molecular biology in U. pinnatifida.