Wheat high-molecular-weight glutenin subunits(HMW-GS) determine dough elasticity and play an essential role in processing quality. HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level, i...Wheat high-molecular-weight glutenin subunits(HMW-GS) determine dough elasticity and play an essential role in processing quality. HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level, implemented through the interactions between cis-acting elements and trans-acting factors. However, transcriptional mechanism of Glu-1 genes remains elusive. Here we made a comprehensive analysis of cis-regulatory elements within 1-kb upstream of the Glu-1 start codon(-1000 to-1) and identified 30 conserved motifs. Based on motif distribution pattern, three conserved cis-regulatory modules(CCRMs), CCRM1(-300 to-101), CCRM2(-650 to-400), and CCRM3(-950 to-750), were defined, and their functions were characterized in wheat stable transgenic lines transformed with progressive 5′ deletion promoter::GUS fusion constructs. GUS staining, qP CR and enzyme activity assays indicated that CCRM2 and CCRM3 could enhance the expression level of Glu-1, whereas the 300-bp promoter(-300 to-1), spanning CCRM1 and core region(-100 to-1), was enough to ensure accurate Glu-1 initiation at 7 days after flowering(DAF) and shape its spatiotemporal expression pattern during seed development. Further transgenic assays demonstrated that CCRM1-2(-300 to-209) containing Complete HMW Enhancer(-246 to-209) was important for expression level but had no effect on expression specificity in the endosperm. In contrast, CCRM1-1(-208 to-101) was critical for both expression specificity and level of Glu-1. Our findings not only provide new insights to uncover Glu-1 transcription regulatory machinery but also lay foundations for modifying Glu-1 expression.展开更多
Eighty two F1 seeds selected randomly from 33 hybrid ears of 23 crosses between 8 parental varieties were examined by 10% SDS PAGE for HMW glutenin expression and accumulation. The following results were obtained. 1. ...Eighty two F1 seeds selected randomly from 33 hybrid ears of 23 crosses between 8 parental varieties were examined by 10% SDS PAGE for HMW glutenin expression and accumulation. The following results were obtained. 1. All tested 8 alleles co dominated in the F1 seeds of 22 crosses. 2. In the 6 F1 seeds of the cross Pan 555 / Zheng 891, a novel subunit appeared in stead of the expected subunit 9 (contributed by Pan 555) and subunit 10 (contributed by Zheng 891), indicating that an interaction of unknown nature between the maternal and paternal genome had affected the expression of some HMW glutenin genes in the endospermic cells of the hybrid seed. 3. The subunits specified by the maternal genes accumulated twice as much as those specified by the paternal genes.展开更多
基金This work was supported by the National Natural Science Foundation of China (No. 30170502) and Chunhui Plan of Ministry of Education (No. 2004251008).
基金funded by the National Key Research and Development Program of China (2016YFD0100500)the National Natural Science Foundation of China (31571663, 31371623)Genetically Modified Organisms Breeding Major Project (2016ZX08009003-004)
文摘Wheat high-molecular-weight glutenin subunits(HMW-GS) determine dough elasticity and play an essential role in processing quality. HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level, implemented through the interactions between cis-acting elements and trans-acting factors. However, transcriptional mechanism of Glu-1 genes remains elusive. Here we made a comprehensive analysis of cis-regulatory elements within 1-kb upstream of the Glu-1 start codon(-1000 to-1) and identified 30 conserved motifs. Based on motif distribution pattern, three conserved cis-regulatory modules(CCRMs), CCRM1(-300 to-101), CCRM2(-650 to-400), and CCRM3(-950 to-750), were defined, and their functions were characterized in wheat stable transgenic lines transformed with progressive 5′ deletion promoter::GUS fusion constructs. GUS staining, qP CR and enzyme activity assays indicated that CCRM2 and CCRM3 could enhance the expression level of Glu-1, whereas the 300-bp promoter(-300 to-1), spanning CCRM1 and core region(-100 to-1), was enough to ensure accurate Glu-1 initiation at 7 days after flowering(DAF) and shape its spatiotemporal expression pattern during seed development. Further transgenic assays demonstrated that CCRM1-2(-300 to-209) containing Complete HMW Enhancer(-246 to-209) was important for expression level but had no effect on expression specificity in the endosperm. In contrast, CCRM1-1(-208 to-101) was critical for both expression specificity and level of Glu-1. Our findings not only provide new insights to uncover Glu-1 transcription regulatory machinery but also lay foundations for modifying Glu-1 expression.
文摘Eighty two F1 seeds selected randomly from 33 hybrid ears of 23 crosses between 8 parental varieties were examined by 10% SDS PAGE for HMW glutenin expression and accumulation. The following results were obtained. 1. All tested 8 alleles co dominated in the F1 seeds of 22 crosses. 2. In the 6 F1 seeds of the cross Pan 555 / Zheng 891, a novel subunit appeared in stead of the expected subunit 9 (contributed by Pan 555) and subunit 10 (contributed by Zheng 891), indicating that an interaction of unknown nature between the maternal and paternal genome had affected the expression of some HMW glutenin genes in the endospermic cells of the hybrid seed. 3. The subunits specified by the maternal genes accumulated twice as much as those specified by the paternal genes.