Phenotypic Analysis and Gene Mapping of a Floury Endosperm Mutant we1 in Rice

doi:10.16819/j.1001-7216.2025.240508

Abstract

Abstract:

【Objective】 The study of floury endosperm mutants is helpful for elucidating the molecular mechanisms underlying rice grain quality formation. 【Method】 A stably inherited floury endosperm mutant we1 (white endosperm 1) was isolated from a ⁶⁰Co-irradiated mutant pool of japonica rice cultivar Nipponbare. Phenotypic characterization and physicochemical analyses of we1 were conducted. An F₂ population derived from a cross between we1 and indica variety 9311 was used for fine mapping. 【Result】 Compared with the wild type, we1 exhibited white, shrunken endosperm with irregularly shaped and loosely packed compound starch granules. The mutant showed significant reductions in 1000-grain weight, plant height, total starch content, and amylose content, along with a marked increase in lipid content. Genetic analysis indicated that the mutant phenotype was controlled by a single recessive nuclear gene. For map-based cloning, we1 was crossed with 9311 and recessive F₂ individuals were selected. The WE1 locus was initially mapped to chromosome 6 and fine-mapped to a 181-kb physical interval. Twenty-three open reading frames (ORFs) were predicted in this region. qRT-PCR analysis revealed altered expression levels of starch synthesis-related genes in the we1 mutant. 【Conclusion】 WE1 likely encodes a novel gene involved in starch synthesis, providing a foundation for further elucidating its molecular regulatory mechanisms in rice.

Key words: rice, floury endosperm, starch, physicochemical property, fine mapping

摘要：

【目的】对粉质胚乳突变体的研究有助于解析稻米品质形成的分子机制。【方法】从日本晴⁶⁰Co诱变突变体库中筛选到一份粉质皱缩胚乳突变体we1(white endosperm1)，对其表型、理化性质进行分析，并利用we1与9311杂交获得的F₂群体对目标基因进行精细定位。【结果】we1胚乳表现为白色粉质皱缩状，淀粉颗粒排列疏松且不规则；千粒重、株高、总淀粉、直链淀粉含量显著下降，脂肪含量显著上升。遗传分析表明we1粉质皱缩胚乳性状受单个隐性基因控制。利用we1/9311 F₂群体进行基因定位，WE1被定位在6号染色体短臂P16和P18之间约181 kb区间内，该区间包含23个开放阅读框(Open reading frame, ORFs)。qRT-PCR 结果显示，WE1的突变会影响淀粉合成相关基因的表达。【结论】WE1可能是一个参与淀粉合成的新基因，本研究为进一步解析WE1调控水稻淀粉合成的分子机制奠定了基础。

关键词: 水稻, 粉质胚乳, 淀粉, 理化性质, 精细定位

ZHU Jianping, LI Xia, LI Wenqi, XU Yang, WANG Fangquan, TAO Yajun, JIANG Yanjie, CHEN Zhihui, FAN Fangjun, YANG Jie. Phenotypic Analysis and Gene Mapping of a Floury Endosperm Mutant we1 in Rice[J]. Chinese Journal OF Rice Science, 2025, 39(4): 543-551.

朱建平, 李霞, 李文奇, 许扬, 王芳权, 陶亚军, 蒋彦婕, 陈智慧, 范方军, 杨杰. 水稻粉质胚乳突变体we1的表型分析与基因定位[J]. 中国水稻科学, 2025, 39(4): 543-551.

Figures/Tables 11

References 31

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引物名称 Primer name	正向引物序列 Forward primer (5’-3’)	反向引物序列 Reverse primer(5’-3’)
P1	CCCCAACTTTCAGCTTTGCT	GACAAAATCCTCCGTGGCG
P5	AATGCGAAGTTTGGGGGAAC	CAATCAGACGACGAAACGGG
P8	CGTGGACGGTGATGGAATTC	CCTCAGTGACATGCTCAAGG
P12	ACTCAGTAGCAGTTGAGGAGA	TCAAATCCTTGCACATAACCCA
P16	ACTCAGCCGATACTTGAGGG	TTTGGAGTCTATTAGGCTTGAAGC
P18	TGCATGTGTTCACACTGTGA	ACTAATGATCAGCTAGGTGCCT

引物名称 Primer name	正向引物序列 Forward primer (5’-3’)	反向引物序列 Reverse primer(5’-3’)
P1	CCCCAACTTTCAGCTTTGCT	GACAAAATCCTCCGTGGCG
P5	AATGCGAAGTTTGGGGGAAC	CAATCAGACGACGAAACGGG
P8	CGTGGACGGTGATGGAATTC	CCTCAGTGACATGCTCAAGG
P12	ACTCAGTAGCAGTTGAGGAGA	TCAAATCCTTGCACATAACCCA
P16	ACTCAGCCGATACTTGAGGG	TTTGGAGTCTATTAGGCTTGAAGC
P18	TGCATGTGTTCACACTGTGA	ACTAATGATCAGCTAGGTGCCT

引物名称	正向引物序列	反向引物序列
Primer name	Forward primer(5’-3’)	Reverse primer(5’-3’)
Actin	CATGCTATCCCTCGTCTCGACCT	CGCACTTCATGATGGAGTTGTAT
AGPS1	AGAATGCTCGTATTGGAGAAAATG	GGCAGCATGGAATAAACCAC
AGPS2b	AACAATCGAAGCGCGAGAAA	GCCTGTAGTTGGCACCCAGA
AGPL1	GGAAGACGGATGATCGAGAAAG	CACATGAGATGCACCAACGA
AGPL2	AGTTCGATTCAAGACGGATAGC	CGACTTCCACAGGCAGCTTATT
AGPL4	TCAACGTCGATGCAGCAAAT	ATCCCTCAGTTCCTAGCCTCATT
GBSSI	TCCGAGAGGTTCAGGTCATC	ATGAGCTCCTCGGCGTAGTA
SSI	GGGCCTTCATGGATCAACC	CCGCTTCAAGCATCCTCATC
SSIIa	GCTTCCGGTTTGTGTGTTCA	CTTAATACTCCCTCAACTCCACCAT
SSIIc	GCAAAGCGGCTATAGAGGTTCC	ATTTCCATCACCGTAGCAGTAGC
SSIIIa	GCCTGCCCTGGACTACATTG	GCAAACATATGTACACGGTTCTGG
SSIVa	GGGAGCGGCTCAAACATAAA	CCGTGCACTGACTGCAAAAT
BEI	TGGCCATGGAAGAGTTGGC	CAGAAGCAACTGCTCCACC
BEIIa	AGCGCTGAAGGCATTACCTACC	CTACTAATGCTGCAGACTGTGCTC
BEIIb	ATGCTAGAGTTTGACCGC	AGTGTGATGGATCCTGCC
ISA1	TGCTCAGCTACTCCTCCATCATC	AGGACCGCACAACTTCAACATA
ISA2	TAGAGGTCCTCTTGGAGG	AATCAGCTTCTGAGTCACCG
ISA3	ACAGCTTGAGACACTGGGTTGAG	GCATCAAGAGGACAACCATCTG

引物名称	正向引物序列	反向引物序列
Primer name	Forward primer(5’-3’)	Reverse primer(5’-3’)
Actin	CATGCTATCCCTCGTCTCGACCT	CGCACTTCATGATGGAGTTGTAT
AGPS1	AGAATGCTCGTATTGGAGAAAATG	GGCAGCATGGAATAAACCAC
AGPS2b	AACAATCGAAGCGCGAGAAA	GCCTGTAGTTGGCACCCAGA
AGPL1	GGAAGACGGATGATCGAGAAAG	CACATGAGATGCACCAACGA
AGPL2	AGTTCGATTCAAGACGGATAGC	CGACTTCCACAGGCAGCTTATT
AGPL4	TCAACGTCGATGCAGCAAAT	ATCCCTCAGTTCCTAGCCTCATT
GBSSI	TCCGAGAGGTTCAGGTCATC	ATGAGCTCCTCGGCGTAGTA
SSI	GGGCCTTCATGGATCAACC	CCGCTTCAAGCATCCTCATC
SSIIa	GCTTCCGGTTTGTGTGTTCA	CTTAATACTCCCTCAACTCCACCAT
SSIIc	GCAAAGCGGCTATAGAGGTTCC	ATTTCCATCACCGTAGCAGTAGC
SSIIIa	GCCTGCCCTGGACTACATTG	GCAAACATATGTACACGGTTCTGG
SSIVa	GGGAGCGGCTCAAACATAAA	CCGTGCACTGACTGCAAAAT
BEI	TGGCCATGGAAGAGTTGGC	CAGAAGCAACTGCTCCACC
BEIIa	AGCGCTGAAGGCATTACCTACC	CTACTAATGCTGCAGACTGTGCTC
BEIIb	ATGCTAGAGTTTGACCGC	AGTGTGATGGATCCTGCC
ISA1	TGCTCAGCTACTCCTCCATCATC	AGGACCGCACAACTTCAACATA
ISA2	TAGAGGTCCTCTTGGAGG	AATCAGCTTCTGAGTCACCG
ISA3	ACAGCTTGAGACACTGGGTTGAG	GCATCAAGAGGACAACCATCTG

杂交组合 Cross	正常透明种子数 No. of wild type seeds	突变粉质种子数 No. of mutant seeds	χ²_（3:1）
we1/野生型F₂ F₂of we1/wild type	132	50	0.469
野生型/we1 F₂ F₂ of wild type/we1	151	47	0.108