水稻直链淀粉合成调控新基因Wx410的功能与效应分析  

Function and Effect Analysis of a New Gene Wx410 Regulating Amylose Synthesis in Rice

作　　者：毛慧 彭彦[2] 毛毕刚 韶也[2] 郑文杰 胡黎明 周凯 赵炳然 MAO Hui;PENG Yan;MAO Bigang;SHAO Ye;ZHENG Wenjie;HU Liming;ZHOU Kai;ZHAO Bingran(Longping Branch of Graduate School,Hunan University,Changsha 410125,China;Hunan Hybrid Rice Research Center/State Key Laboratory of Hybrid Rice,Changsha 410125,China)

机构地区：[1]湖南大学研究生院隆平分院,长沙410125 [2]湖南杂交水稻研究中心/杂交水稻国家重点实验室,长沙410125

出　　处：《中国水稻科学》2022年第6期579-585,共7页Chinese Journal of Rice Science

基　　金：国家自然科学基金联合基金项目(U19A2032);湖南省自然科学基金资助项目(2020JJ5401);现代农业产业技术体系建设专项资金资助项目(CARS-01-14)。

摘　　要：【目的】挖掘Wx新等位变异,明确Wx410新等位基因对稻米品质性状的影响。【方法】以Wx^(lv)、Wx^(a)和Wx^(b)等位基因为模板,利用PCR进行第10外显子第101位碱基的A-G单点突变,分别构建了不同Wx等位背景下的Wx410定点突变植物表达载体pEGFC-Wx^(lv)410、pEGFC-Wx^(a)410和pEGFC-Wx^(b)410,阳性对照组载体分别为pEGFC-Wx^(lv)、pEGFC-Wx^(a)和pEGFC-Wx^(b)。通过转化糯稻品种苏御糯,分析该位点的变异对稻米品质的遗传效应。【结果】花后7 d和14 d,转基因植株pEGFC-Wx^(lv)410,pEGFC-Wx^(a)410及pEGFC-Wx^(b)410的胚乳Wx基因表达量较各自的阳性对照材料无显著变化,而颗粒结合淀粉合酶活性极显著降低;转基因植株直链淀粉含量较野生型显著降低,而糊化温度无明显变化;pEGFC-Wx^(a)410及pEGFC-Wx^(b)410的胶稠度较各自的阳性对照材料显著升高,而pEGFC-Wx^(lv)410的胶稠度较其阳性对照材料显著降低。【结论】pEGFC-Wx410为水稻淀粉合成的一个新的功能等位基因,控制的直链淀粉含量为4%~6%,刚好弥补了目前所鉴定的复等位基因所调控的直链淀粉含量在这个范围内的空缺,为稻米食味和加工相关品质改良提供更丰富的遗传资源。【Objective】Mining new allelic variants of the Wx gene and identifying the effect of the new Wx410 allele on rice quality traits.【Method】Using Wx^(lv),Wx^(a) and Wx^(b) alleles as templates,the A-G point mutation at base 101 of exon 10 was performed by PCR,and Wx410 sentinel mutation plant expression vectors in different Wx allelic backgrounds(pEGFC-Wx^(lv)410,pEGFC-Wx^(a)410 and pEGFC-Wx^(b)410)were constructed respectively,and the genetic effect of the variation at this locus on rice quality was analyzed by transforming the glutinous rice variety Suyunuo.【Results】The expression level of the Wx gene in the endosperm of the transgenic plants pEGFC-Wx^(lv)410,pEGFC-Wx^(a)410 and pEGFC-Wx^(b)4107 and 14 days after flowering was not significantly different from that of the positive control,while the activity of GBSSⅠwas highly significantly lower than that of the positive control.The transgenic plants had significantly lower amylose content in mature seeds compared to the wild-type.pEGFC-Wx^(a)410 and pEGFC-Wx^(b)410 had significantly higher gelatinous consistency and pEGFC-Wx^(lv)410 had significantly lower gelatinous consistency of endosperm compared to the positive control.【Conclusion】Wx410 is a new functional allele for starch synthesis in rice.The allele explains 4%−6%of amylose content variation,which just fills the gap in the range of amylose content regulated by the currently identified complex alleles,providing a richer genetic resource for rice taste and processing-related quality improvement.

关 键 词：水稻 WX基因 直链淀粉含量 

分 类 号：S511[农业科学—作物学]