水稻粉质胚乳突变体ws的表型分析及基因克隆

发布时间：2018-01-31 12:53

本文关键词： 胚乳粉质突变体 AGPase 淀粉基因表达理化性质水稻　出处：《中国水稻科学》2016年05期 　论文类型：期刊论文

【摘要】：从甲基亚硝基脲(1-Methyl-1-Nitrosourea,MNU)处理的粳稻品种滇粳优1号突变体库中,筛选到一个稳定遗传的胚乳粉质突变体ws,其籽粒的千粒重、籽粒大小、总淀粉含量、直链淀粉含量等指标均降低,淀粉在尿素溶液中的膨胀能力减弱。对成熟及发育中的胚乳淀粉结构进行观察,发现ws突变体的胚乳中产生大量小而不规则排布的单淀粉颗粒。利用F2群体中分离出的92个隐性极端个体将突变基因连锁在第8染色体近着丝粒位置,随后共用2025个极端个体将目标基因定位于95kb的区间。测序发现ws突变体中编码腺苷二磷酸葡萄糖焦磷酸化酶(Adenosine diphosphate glucose pyrophosphorylase,AGPase)小亚基S2的基因发生点突变,导致编码氨基酸的替换。基因表达分析发现,突变体胚乳中编码AGPase各亚基的相关基因表达量没有发生显著改变,而Western杂交分析显示突变体中AGPS2b的蛋白含量下降。同时,ws突变体的胚乳中AGPase活性下降为野生型的一半。研究结果表明,OsAGPS2的突变导致水稻胚乳中AGPase活性降低,从而影响了淀粉合成。
[Abstract]:A japonica rice variety Dianjingyou 1 was treated with 1-Methyl-1-Nitrosourea- MNU). A stable endosperm powdery mutant wswas screened. Its grain weight, grain size, total starch content and amylose content were all decreased. The swelling ability of starch in urea solution was weakened. The structure of endosperm starch in maturation and development was observed. It was found that a large number of small and irregular single starch granules were produced in the endosperm of ws mutants. Using 92 recessive extreme individuals isolated from F2 population, the mutant gene was linked to the near centromere position on chromosome 8. The target gene was then located at 95kb in 2025 extreme individuals. Sequencing revealed that the ws mutant encodes an adenosine diphosphate glucose pyrophosphorylase (ADP). Adenosine diphosphate glucose pyrophosphorylase. The gene of small subunit S2 of AGPase had a point mutation, which led to the substitution of encoded amino acids. The expression of the related genes encoding AGPase subunits in the endosperm of the mutant did not change significantly, while Western blot analysis showed that the protein content of AGPS2b in the mutant decreased. The activity of AGPase in the endosperm of ws mutant decreased by half of that of the wild type. The results showed that the mutation of OsAGPS2 resulted in the decrease of AGPase activity in the endosperm of rice. Thus, starch synthesis was affected.
【作者单位】：南京农业大学作物遗传与种质创新国家重点实验室/农业部长江中下游粳稻生物学与遗传育种重点实验室/长江流域杂交水稻协同创新中心/江苏省现代作物生产中心;
【基金】：国家转基因生物新品种培育重大专项(2014ZX08001006) 国家自然科学基金资助项目(31371598) 江苏省科技支撑计划资助项目(BE2014394) 农业部长江中下游粳稻生物学与遗传育种重点实验室、长江流域杂交水稻协同创新中心、江苏省现代作物生产中心资助项目
【分类号】：Q943.2;S511
【正文快照】： 水稻是世界上最重要的粮食作物之一,世界上子的主要贮藏物质,其结构和性质决定了稻米的外有1/3以上的人口以稻米为主食。淀粉作为水稻种观品质和食味品质。因此,对淀粉合成相关基因的克隆和鉴定,不仅在科学上对阐明水稻淀粉合成及研究显示,AGPase的催化功能由大小亚基相互协

【相似文献】