Improving Agricultural Traits While Maintaining High Resistant Starch Content in Rice
Abstract Background Resistant starch (RS) is beneficial for human health. Loss of starch branching enzyme IIb (BEIIb) increases the proportion of amylopectin long chains, which greatly elevates the RS content. Although high RS content cereals are desired, an increase in RS content is often accompani...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2022-06-01
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| Series: | Rice |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12284-022-00573-5 |
| _version_ | 1818533733977817088 |
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| author | Satoko Miura Maiko Narita Naoko Crofts Yuki Itoh Yuko Hosaka Naoko F. Oitome Misato Abe Rika Takahashi Naoko Fujita |
| author_facet | Satoko Miura Maiko Narita Naoko Crofts Yuki Itoh Yuko Hosaka Naoko F. Oitome Misato Abe Rika Takahashi Naoko Fujita |
| author_sort | Satoko Miura |
| collection | DOAJ |
| description | Abstract Background Resistant starch (RS) is beneficial for human health. Loss of starch branching enzyme IIb (BEIIb) increases the proportion of amylopectin long chains, which greatly elevates the RS content. Although high RS content cereals are desired, an increase in RS content is often accompanied by a decrease in seed weight. To further increase the RS content, genes encoding active-type starch synthase (SS) IIa, which elongates amylopectin branches, and high expression-type granule-bound SSI (GBSSI), which synthesizes amylose, were introduced into the be2b mutant rice. This attempt increased the RS content, but further improvement of agricultural traits was required because of a mixture of indica and japonica rice phonotype, such as different grain sizes, flowering times, and seed shattering traits. In the present study, the high RS lines were backcrossed with an elite rice cultivar, and the starch properties of the resultant high-yielding RS lines were analyzed. Results The seed weight of high RS lines was greatly improved after backcrossing, increasing up to 190% compared with the seed weight before backcrossing. Amylopectin structure, gelatinization temperature, and RS content of high RS lines showed almost no change after backcrossing. High RS lines contained longer amylopectin branch chains than the wild type, and lines with active-type SSIIa contained a higher proportion of long amylopectin chains compared with the lines with less active-SSIIa, and thus showed higher gelatinization temperature. Although the RS content of rice varied with the cooking method, those of high RS lines remained high after backcrossing. The RS contents of cooked rice of high RS lines were high (27–35%), whereas that of the elite parental rice was considerably low (< 0.7%). The RS contents of lines with active-type SSIIa and high-level GBSSI expression in be2b or be2b ss3a background were higher than those of lines with less-active SSIIa. Conclusions The present study revealed that backcrossing high RS rice lines with elite rice cultivars could increase the seed weight, without compromising the RS content. It is likely that backcrossing introduced loci enhancing seed length and width as well as loci promoting early flowering for ensuring an optimum temperature during RS biosynthesis. |
| first_indexed | 2024-12-11T18:02:38Z |
| format | Article |
| id | doaj.art-fea62aa0f8fc4f678a5ab567579c3df0 |
| institution | Directory Open Access Journal |
| issn | 1939-8425 1939-8433 |
| language | English |
| last_indexed | 2024-12-11T18:02:38Z |
| publishDate | 2022-06-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Rice |
| spelling | doaj.art-fea62aa0f8fc4f678a5ab567579c3df02022-12-22T00:55:50ZengSpringerOpenRice1939-84251939-84332022-06-0115111610.1186/s12284-022-00573-5Improving Agricultural Traits While Maintaining High Resistant Starch Content in RiceSatoko Miura0Maiko Narita1Naoko Crofts2Yuki Itoh3Yuko Hosaka4Naoko F. Oitome5Misato Abe6Rika Takahashi7Naoko Fujita8Department of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityDepartment of Biological Production, Akita Prefectural UniversityAbstract Background Resistant starch (RS) is beneficial for human health. Loss of starch branching enzyme IIb (BEIIb) increases the proportion of amylopectin long chains, which greatly elevates the RS content. Although high RS content cereals are desired, an increase in RS content is often accompanied by a decrease in seed weight. To further increase the RS content, genes encoding active-type starch synthase (SS) IIa, which elongates amylopectin branches, and high expression-type granule-bound SSI (GBSSI), which synthesizes amylose, were introduced into the be2b mutant rice. This attempt increased the RS content, but further improvement of agricultural traits was required because of a mixture of indica and japonica rice phonotype, such as different grain sizes, flowering times, and seed shattering traits. In the present study, the high RS lines were backcrossed with an elite rice cultivar, and the starch properties of the resultant high-yielding RS lines were analyzed. Results The seed weight of high RS lines was greatly improved after backcrossing, increasing up to 190% compared with the seed weight before backcrossing. Amylopectin structure, gelatinization temperature, and RS content of high RS lines showed almost no change after backcrossing. High RS lines contained longer amylopectin branch chains than the wild type, and lines with active-type SSIIa contained a higher proportion of long amylopectin chains compared with the lines with less active-SSIIa, and thus showed higher gelatinization temperature. Although the RS content of rice varied with the cooking method, those of high RS lines remained high after backcrossing. The RS contents of cooked rice of high RS lines were high (27–35%), whereas that of the elite parental rice was considerably low (< 0.7%). The RS contents of lines with active-type SSIIa and high-level GBSSI expression in be2b or be2b ss3a background were higher than those of lines with less-active SSIIa. Conclusions The present study revealed that backcrossing high RS rice lines with elite rice cultivars could increase the seed weight, without compromising the RS content. It is likely that backcrossing introduced loci enhancing seed length and width as well as loci promoting early flowering for ensuring an optimum temperature during RS biosynthesis.https://doi.org/10.1186/s12284-022-00573-5AmylopectinAmyloseBackcrossingEndosperm starchResistant starchRice (Oryza sativa) |
| spellingShingle | Satoko Miura Maiko Narita Naoko Crofts Yuki Itoh Yuko Hosaka Naoko F. Oitome Misato Abe Rika Takahashi Naoko Fujita Improving Agricultural Traits While Maintaining High Resistant Starch Content in Rice Rice Amylopectin Amylose Backcrossing Endosperm starch Resistant starch Rice (Oryza sativa) |
| title | Improving Agricultural Traits While Maintaining High Resistant Starch Content in Rice |
| title_full | Improving Agricultural Traits While Maintaining High Resistant Starch Content in Rice |
| title_fullStr | Improving Agricultural Traits While Maintaining High Resistant Starch Content in Rice |
| title_full_unstemmed | Improving Agricultural Traits While Maintaining High Resistant Starch Content in Rice |
| title_short | Improving Agricultural Traits While Maintaining High Resistant Starch Content in Rice |
| title_sort | improving agricultural traits while maintaining high resistant starch content in rice |
| topic | Amylopectin Amylose Backcrossing Endosperm starch Resistant starch Rice (Oryza sativa) |
| url | https://doi.org/10.1186/s12284-022-00573-5 |
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