【目的】水稻株高和穗型在产量形成中发挥着重要作用。鉴定与克隆水稻株高和穗型发育相关基因,可以丰富水稻株高穗型发育调控的分子机理,为分子设计育种奠定理论基础和提供基因资源。【方法】在粳稻日本晴T-DNA插入群体中筛选到矮化小...【目的】水稻株高和穗型在产量形成中发挥着重要作用。鉴定与克隆水稻株高和穗型发育相关基因,可以丰富水稻株高穗型发育调控的分子机理,为分子设计育种奠定理论基础和提供基因资源。【方法】在粳稻日本晴T-DNA插入群体中筛选到矮化小穗突变体dsp2-D(dwarf and small panicle 2-Dominant),对其主要农艺性状进行了分析;采用图位克隆法结合T-DNA标签分离法进行了基因定位和克隆;利用半定量PCR和q RT-PCR进一步确定dsp2-D的候选基因;遗传转化实验验证了DSP2的功能。【结果】与野生型日本晴相比,dsp2-D突变体表现为半矮化、穗轴和枝梗明显缩短、穗型直立、千粒重降低等特征;遗传分析表明该突变体受一对不完全显性单基因控制;利用图位克隆将DSP2定位于第2染色体标记RM208和RM7337之间,与RM3850共分离;随后遗传分析发现,T-DNA插入位点与dsp2-D表型共分离,利用TAIL-PCR分离T-DNA插入序列,显示T-DNA插入到上述RM208和RM7337之间的两个基因之间。RT-PCR检测发现,位于T-DNA插入位点下游的一个编码LOB家族转录因子基因的表达量明显增加,而其他5个基因的表达量变化不明显,表明该基因可能为DSP2的候选基因;在野生型日本晴中过量表达DSP2基因,转化植株出现半矮化、小穗的表型,与dsp2-D表型类似,从而验证了DSP2的功能。【结论】DSP2基因的过量表达是产生dsp2-D突变表型的原因;DSP2基因对水稻株高和穗长发育具有负向调控作用;为进一步丰富株高和穗型的遗传调控网络打下了基础。展开更多
Heading date is one of the most important agronomic traits of rice,which critically affects rice ecogeographical adaptation,yield and quality.In this study,a late heading date 3(lhd3)mutant was screened from the^(60)...Heading date is one of the most important agronomic traits of rice,which critically affects rice ecogeographical adaptation,yield and quality.In this study,a late heading date 3(lhd3)mutant was screened from the^(60)Co-γirradiation mutant library.The lhd3 delayed heading date in rice under both short day and long day conditions.Map-based cloning combined with Mutmap strategy was adopted to isolate the causal LHD3 gene.The LHD3 gene encodes a DNA_J domain protein,which was ubiquitously expressed in various plant organs,and dominant expressed in stems and leaves.Subcellular localization analysis showed that LHD3 was localized to nucleus,indicating that LHD3 may interact with other elements to regulate the expression of flowering genes.The transcriptions of the heading activators Ehd1,Hd3a and RFT1 significantly decreased in the lhd3 mutant,suggesting that LHD3 may control the heading date through the Ehd1-Hd3a/RFT1 photoperiodic flowering pathway.The variation and haplotype analyses of the genomic region of LHD3 showed that there were 7 haplotypes in the LHD3 region from 4702 accessions.The haplotypes of LHD3 can be divided into two classes:class a and class b,and the heading dates of these two classes were significantly different.Further study showed that two single nucleotide polymorphisms(SNPs),SNP10(G2100C)in Hap II and SNP3(C861T)in Hap VII,may be the functional sites causing early and late heading in accessions.Nucleotide diversity analysis showed LHD3 had been selected in the indica population,rather than in the japonica population.Therefore,the present study sheds light on the regulation of LHD3 on heading date in rice and suggests that LHD3 is a novel promising new target for rice molecular design and breeding improvement.展开更多
文摘【目的】水稻株高和穗型在产量形成中发挥着重要作用。鉴定与克隆水稻株高和穗型发育相关基因,可以丰富水稻株高穗型发育调控的分子机理,为分子设计育种奠定理论基础和提供基因资源。【方法】在粳稻日本晴T-DNA插入群体中筛选到矮化小穗突变体dsp2-D(dwarf and small panicle 2-Dominant),对其主要农艺性状进行了分析;采用图位克隆法结合T-DNA标签分离法进行了基因定位和克隆;利用半定量PCR和q RT-PCR进一步确定dsp2-D的候选基因;遗传转化实验验证了DSP2的功能。【结果】与野生型日本晴相比,dsp2-D突变体表现为半矮化、穗轴和枝梗明显缩短、穗型直立、千粒重降低等特征;遗传分析表明该突变体受一对不完全显性单基因控制;利用图位克隆将DSP2定位于第2染色体标记RM208和RM7337之间,与RM3850共分离;随后遗传分析发现,T-DNA插入位点与dsp2-D表型共分离,利用TAIL-PCR分离T-DNA插入序列,显示T-DNA插入到上述RM208和RM7337之间的两个基因之间。RT-PCR检测发现,位于T-DNA插入位点下游的一个编码LOB家族转录因子基因的表达量明显增加,而其他5个基因的表达量变化不明显,表明该基因可能为DSP2的候选基因;在野生型日本晴中过量表达DSP2基因,转化植株出现半矮化、小穗的表型,与dsp2-D表型类似,从而验证了DSP2的功能。【结论】DSP2基因的过量表达是产生dsp2-D突变表型的原因;DSP2基因对水稻株高和穗长发育具有负向调控作用;为进一步丰富株高和穗型的遗传调控网络打下了基础。
基金funded by the National Basic Research Program of China(Grant No.2016YFD0100401)National Natural Science Foundation of China(Grant No.31571742)Scientific Research Initiation Fund of Zhejiang University of Science and Technology,China(Grant No.19042142-Y)。
文摘Heading date is one of the most important agronomic traits of rice,which critically affects rice ecogeographical adaptation,yield and quality.In this study,a late heading date 3(lhd3)mutant was screened from the^(60)Co-γirradiation mutant library.The lhd3 delayed heading date in rice under both short day and long day conditions.Map-based cloning combined with Mutmap strategy was adopted to isolate the causal LHD3 gene.The LHD3 gene encodes a DNA_J domain protein,which was ubiquitously expressed in various plant organs,and dominant expressed in stems and leaves.Subcellular localization analysis showed that LHD3 was localized to nucleus,indicating that LHD3 may interact with other elements to regulate the expression of flowering genes.The transcriptions of the heading activators Ehd1,Hd3a and RFT1 significantly decreased in the lhd3 mutant,suggesting that LHD3 may control the heading date through the Ehd1-Hd3a/RFT1 photoperiodic flowering pathway.The variation and haplotype analyses of the genomic region of LHD3 showed that there were 7 haplotypes in the LHD3 region from 4702 accessions.The haplotypes of LHD3 can be divided into two classes:class a and class b,and the heading dates of these two classes were significantly different.Further study showed that two single nucleotide polymorphisms(SNPs),SNP10(G2100C)in Hap II and SNP3(C861T)in Hap VII,may be the functional sites causing early and late heading in accessions.Nucleotide diversity analysis showed LHD3 had been selected in the indica population,rather than in the japonica population.Therefore,the present study sheds light on the regulation of LHD3 on heading date in rice and suggests that LHD3 is a novel promising new target for rice molecular design and breeding improvement.
