著者
Hiroaki Kusano Ami Takeuchi Hiroaki Shimada
出版者
Japanese Society for Plant Biotechnology
雑誌
Plant Biotechnology (ISSN:13424580)
巻号頁・発行日
pp.23.0611a, (Released:2023-09-07)
参考文献数
29
被引用文献数
3

Potato (Solanum tuberosum L.) has a tetraploid genome. To make a mutant lacking a specific gene function, it is necessary to introduce mutations into all four gene alleles. To achieve this goal, we developed a powerful genome editing tool, CRISPR/dMac3-Cas9, which installed the translation enhancer dMac3 that greatly increased the translation of the downstream open reading frame. The CRISPR/dMac3-Cas9 system employing three guide RNAs (gRNAs) greatly elevated the frequency of the generation rate of mutation. This system enabled to create the 4-allele mutants of granule-bound starch synthase (GBSS) and starch branching enzyme (SBE). These mutants indicated functionally defective features, suggesting that we succeeded in efficient genome editing of the potato tetraploid genome. Here, we show the effect of the number of gRNAs for efficient mutagenesis of the target gene using the mutants of the GBSS1 gene. CRISPR/dMac3-Cas9 employing three gRNA genes achieved a higher mutation efficiency than the CRISPR/dMac3-Cas9 with two gRNAs, suggesting being influenced by the dose effect of the number of gRNAs at the target region. The alleles of the SBE3 gene contained SNPs that caused sequence differences in the gRNAs but these gRNAs functioned efficiently. However, many rearrangement events and large deletions were induced. These results support the importance of accurate binding of gRNA to the target sequence, which may lead to a hint to avoid the unexpected mutation on the off-target sites.
著者
Ami Takeuchi Yuna Akatsu Takahiro Asahi Yukino Okubo Mariko Ohnuma Hiroshi Teramura Koji Tamura Hiroaki Shimada
出版者
Japanese Society for Plant Biotechnology
雑誌
Plant Biotechnology (ISSN:13424580)
巻号頁・発行日
vol.39, no.2, pp.195-197, 2022-06-25 (Released:2022-06-25)
参考文献数
6
被引用文献数
3

Potato, Solanum tuberosum L. is an important crop. However, it is difficult to breed potato cultivars by applying conventional crossing methods because potato has a tetraploid genome and is vegetatively propagated. Flower formation and tuber development occur simultaneously. Many potato cultivars hardly produce any fruits after crossing and fail to produce seeds. We report an improved procedure for obtaining progeny seeds by grafting potatoes onto tomatoes. The rate of fruit formation was more than 19% when the grafted potatoes were used for the crossing experiments, whereas crossing using the ungrafted plants showed a rate of 1.1%. This result suggests that our procedure results in the easy acquisition of null-segregant progenies by crossing mutant lines. It is also expected to improve conventional potato breeding.
著者
Chika Honda Kaoru Ohkawa Hiroaki Kusano Hiroshi Teramura Hiroaki Shimada
出版者
Japanese Society for Plant Biotechnology
雑誌
Plant Biotechnology (ISSN:13424580)
巻号頁・発行日
vol.38, no.1, pp.153-156, 2021-03-25 (Released:2021-03-25)
参考文献数
8
被引用文献数
4

Tomato transformation is conventionally performed using Agrobacterium tumefaciens-infected cotyledons. Here, we propose a simple procedure for tomato transformation, by which A. tumefaciens cells were smeared onto floral buds of a tomato plant using a paintbrush. Sufficient numbers of fruits were obtained from them, although the smearing of an excess number of A. tumefaciens cells led to an adverse effect on the plant growth. Progeny plants were screened by growth on a kanamycin-containing selection medium plate. The nptII gene was detected in 10 plants among 1,599 progenies. These transformants were derived from fruits other than those obtained from the smeared buds. This suggested that A. tumefaciens cells moved to the buds located near the smeared buds and caused the transformation event. Our findings suggest that this procedure can be used for the introduction of a foreign gene into plant cells.
著者
Mariko Ohnuma Kosuke Ito Karin Hamada Ami Takeuchi Kenji Asano Takahiro Noda Akira Watanabe Akiko Hokura Hiroshi Teramura Fuminori Takahashi Hiromi Mutsuro-Aoki Koji Tamura Hiroaki Shimada
出版者
Japanese Society for Plant Biotechnology
雑誌
Plant Biotechnology (ISSN:13424580)
巻号頁・発行日
vol.40, no.3, pp.219-227, 2023-09-25 (Released:2023-09-25)
参考文献数
34
被引用文献数
2

Glucose chains in starch are phosphorylated and contribute to structural stabilization. Phosphate groups contained in starch also play a role in retaining moisture. α-Glucan water dikinase 1 (GWD1) is involved in the phosphorylation of glucose chains in starch. In this study, we generated potato mutants of the GWD1 gene using the CRISPR/dMac3-Cas9 system. Observation of the phenotypes of the GWD1-deficient mutants revealed their physiological roles in tuber starch formation. The 4-allele mutants showed growth retardation and a delay in tuber formation. A significant decrease in phosphorus content was detected in the tuber starch of the gwd1 mutant. This mutant starch showed a higher amylose content than the wild-type starch, whereas its gelatinization temperature was slightly lower than that of the WT starch. The peak viscosity of the mutant starch was lower than that of the WT starch. These observations revealed that the starch of the gwd1 mutants had peculiar and unique properties compared to those of WT, sbe3 and gbss1 mutant starches. The amount of tissue-released water due to freeze–thawing treatment was determined on tubers of the gwd1 mutant and compared with those of WT and the other mutants. Significantly less water loss was found in the gwd1, sbe3 and gbss1 mutant tubers than in the WT tubers. Our results indicate that the GWD1 gene is not only important for potato growth, but also largely effective for the traits of tuber starch.
著者
Hiroaki Kusano Ami Takeuchi Hiroaki Shimada
出版者
Japanese Society for Plant Biotechnology
雑誌
Plant Biotechnology (ISSN:13424580)
巻号頁・発行日
vol.40, no.3, pp.201-209, 2023-09-25 (Released:2023-09-25)
参考文献数
29
被引用文献数
3

Potato (Solanum tuberosum L.) has a tetraploid genome. To make a mutant lacking a specific gene function, it is necessary to introduce mutations into all four gene alleles. To achieve this goal, we developed a powerful genome editing tool, CRISPR/dMac3-Cas9, which installed the translation enhancer dMac3 that greatly increased the translation of the downstream open reading frame. The CRISPR/dMac3-Cas9 system employing three guide RNAs (gRNAs) greatly elevated the frequency of the generation rate of mutation. This system enabled to create the 4-allele mutants of granule-bound starch synthase (GBSS) and starch branching enzyme (SBE). These mutants indicated functionally defective features, suggesting that we succeeded in efficient genome editing of the potato tetraploid genome. Here, we show the effect of the number of gRNAs for efficient mutagenesis of the target gene using the mutants of the GBSS1 gene. CRISPR/dMac3-Cas9 employing three gRNA genes achieved a higher mutation efficiency than the CRISPR/dMac3-Cas9 with two gRNAs, suggesting being influenced by the dose effect of the number of gRNAs at the target region. The alleles of the SBE3 gene contained SNPs that caused sequence differences in the gRNAs but these gRNAs functioned efficiently. However, many rearrangement events and large deletions were induced. These results support the importance of accurate binding of gRNA to the target sequence, which may lead to a hint to avoid the unexpected mutation on the off-target sites.
著者
Kaho Miyazaki You Ohkubo Hiroto Yasui Ryoka Tashiro Rintaro Suzuki Hiroshi Teramura Hiroaki Kusano Hiroaki Shimada
出版者
Japanese Society for Plant Biotechnology
雑誌
Plant Biotechnology (ISSN:13424580)
巻号頁・発行日
vol.38, no.3, pp.367-371, 2021-09-25 (Released:2021-09-25)
参考文献数
25
被引用文献数
3

Late embryogenesis abundant protein (LEA) genes are widely conserved in seed plant species and form a multigene family. While some LEAs are known to respond to environmental stresses, the function of many LEAs is unknown. OsLEA5 (Lea14A) interacts with a regulator of the endosperm storage production, FLO2, suggesting that OsLEA5 may be involved in endosperm quality control. RNAi knockdown line of OsLEA5 showed decreased seed weight. Transformant lines overexpressing OsLEA5 exhibited improved quality and seed weight of mature seeds when they were developed under high-temperature conditions, while seed quality strongly declined in wild-type plants exposed to high-temperature stress. These findings indicate that OsLEA5 contributes to suppressing the deterioration of seed quality when developed under high-temperature conditions.
著者
Ami Takeuchi Mariko Ohnuma Hiroshi Teramura Kenji Asano Takahiro Noda Hiroaki Kusano Koji Tamura Hiroaki Shimada
出版者
Japanese Society for Plant Biotechnology
雑誌
Plant Biotechnology (ISSN:13424580)
巻号頁・発行日
vol.38, no.3, pp.345-353, 2021-09-25 (Released:2021-09-25)
参考文献数
31
被引用文献数
16

The potato tuber starch trait is changed depending on the composition of amylose and amylopectin. The amount of amylopectin is determined by the activity of the starch branching enzymes SBE1, SBE2, and SBE3 in potato. SBE3, a homolog of rice BEI, is a major gene that is abundant in tubers. In this study, we created mutants of the potato SBE3 gene using CRISPR/Cas9 attached to the translation enhancer dMac3. Potato has a tetraploid genome, and a four-allele mutant of the SBE3 gene is desired. Mutations in the SBE3 gene were found in 89 of 126 transformants of potato plants. Among these mutants, 10 lines contained four mutant SBE3 genes, indicating that 8% efficiency of target mutagenesis was achieved. These mutants grew normally, similar to the wild-type plant, and yielded sufficient amounts of tubers. The potato starch in these tubers was similar to that of the rice BEI mutant. Western blot analysis revealed the defective production of SBE3 in the mutant tubers, suggesting that these transformants were loss-of-function mutants of SBE3.