水稻黄叶突变体yl1的鉴定与基因定位

发布时间：2018-03-12 20:55

本文选题：水稻　切入点：黄叶突变体　出处：《湖南农业大学》2016年硕士论文　论文类型：学位论文

【摘要】：作物的光能利用率与作物的产量息息相关,而水稻叶色突变体是研究水稻光合作用的理想材料。本研究以超级稻品种中嘉早17(YK17)的黄叶突变体yl1为研究材料,对突变体yl1进行表型鉴定与精细定位,主要研究结果如下：1)性状调查结果表明：yl1 在全生育期内茎、叶和穗都表现为淡黄色,同时株高降低、每穗粒数减少、剑叶宽变窄和粒长变长,其他性状如分蘖数、穗长、结实率、千粒重、剑叶长和粒厚则无显著变化,yl1 花粉育性正常。2)叶绿素含量测定结果表明：苗期YK17叶片中叶绿素a、叶绿素b及总叶绿素含量都高于yl1 ,差异极显著,其中叶绿素b含量为yl1的6倍,总叶绿素含量为yl1的2.5倍。抽穗期YK17的叶片中叶绿素b含量高于yl1,是yl1的3倍,差异极显著：而叶绿素a含量略有升高,但总的叶绿素含量依旧极显著低于YK17,为YK17的二分之一。抽穗期yl1的穗中的叶绿素a、叶绿素b及总叶绿素含量都显著低于YK17,含量仅为YK17的一半,因此穗也表现为淡黄色。同时由叶绿素a与叶绿素b的比值分析得知,叶片中叶绿素含量的下降主要是由于叶绿素b的下降,而穗中叶绿素含量的降低则主要是由于叶绿素a和叶绿素b的同步下降。光合特性分析表明：yl1的净光合速率和气孔导度与YK17相比都有所降低。叶绿体的电镜观察表明：yl1叶肉细胞内的叶绿体数目明显低于YK17。3)遗传分析结果表明：yl1基因为单隐性核基因,通过图位克隆将该基因定位在Chrl短臂中端44.8kb内,预测区间内有4个开放阅读框(ORFs),其中ORF1(Os01g17170)编码镁原卟啉Ⅸ单甲脂环化酶,测序分析发现该基因CDS序列的第515个碱基由C变为T,从而导致编码蛋白的第172个氨基酸由丝氨酸变为苯丙氨酸。RT-PCR实验表明ORF1在突变体的叶和穗中的表达量都低于野生型,由此确认Os01g17170为yl1的候选基因。亚细胞定位实验将YL1蛋白定位在细胞质内。
[Abstract]:The light energy utilization efficiency of crops is closely related to the yield of crops, and the rice leaf color mutant is an ideal material for studying photosynthesis. In this study, the yellow leaf mutant yl1 of Zhongjia Zongzao YK17) was used as the research material. Phenotypic identification and fine mapping of the mutant yl1 were carried out. The main results were as follows: 1) the results showed that the stem, leaves and panicles of the mutant were yellowish in the whole growth period, and the plant height was decreased, and the number of grains per panicle was decreased. Other traits such as tiller number, ear length, seed setting rate, 1000-grain weight, There was no significant change in leaf length and grain thickness. The results showed that chlorophyll a, chlorophyll b and total chlorophyll content in YK17 leaves at seedling stage were higher than those in yl1, and the difference was very significant. The content of chlorophyll b was 6 times of that of yl1, and the content of total chlorophyll was 2.5 times of that of yl1. The content of chlorophyll b in leaves of YK17 at heading stage was 3 times higher than that of yl1, and the content of chlorophyll a was slightly higher than that of yl1. However, the total chlorophyll content of yl1 was still significantly lower than that of YK17, which was 1/2 of that of YK17. The contents of chlorophyll a, chlorophyll b and total chlorophyll in panicle of yl1 at heading stage were all significantly lower than that of YK17, and the content was only half of that of YK17. From the analysis of the ratio of chlorophyll a to chlorophyll b, it was found that the decrease of chlorophyll content in leaves was mainly due to the decrease of chlorophyll b. The decrease of chlorophyll content in ear was mainly due to the simultaneous decrease of chlorophyll a and chlorophyll b. The analysis of photosynthetic characteristics showed that the net photosynthetic rate and stomatal conductance of 1 / 1 were lower than those of YK17. The results showed that the number of chloroplasts in the mesophyll cells was significantly lower than that in YK17.3). The gene was located within 44.8 kb of Chrl short arm by map-cloning, and four open reading frames were predicted in the region, in which ORF1 + Os01g17170) encodes magnesium protoporphyrin IX monomethylenecyclic enzyme. Sequencing analysis showed that the 515th base of the CDS sequence of the gene changed from C to T, which led to the transformation of the 172nd amino acid of the encoded protein from serine to phenylalanine. RT-PCR results showed that the expression of ORF1 in the leaves and panicles of the mutant was lower than that in the wild type. Therefore, Os01g17170 was identified as a candidate gene for yl1. Subcellular localization of YL1 protein in cytoplasm was performed.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S511;Q943.2

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