Gibberellin 3-oxidase catalyzes the conversion of inactive gibberellin(GA) species into GAs with biological activity and it is subjected to strict developmental controls in the life cycle of a plant. In this study, 33...Gibberellin 3-oxidase catalyzes the conversion of inactive gibberellin(GA) species into GAs with biological activity and it is subjected to strict developmental controls in the life cycle of a plant. In this study, 33 gene sequences, encoding the gibberellin 3-oxidase(GA3ox) from Dasypyrum villosum and its dwarf mutant, were obtained. Each contained a 1 107 bp coding sequence(CDS) that encoded a putative protein containing 369 amino acids. The GA3ox protein showed 77% to 97% homology and shared the major conserved structural domains of GA3ox proteins with rice, sorghum bicolor, oat, barley, and wheat. Sequence alignment showed that there were 20 single nucleotide polymorphisms(SNPs) and 22 Insertion/deletions(In Dels) among these sequences, which could be divided into 2 haplotypes, haplotypes Ⅰ and Ⅱ. Haplotype Ⅰ was found in the wild type and was1 495 bp in length, and haplotype Ⅱ was found in the dwarf mutant and was 1 485 bp in length. The Q-PCR results showed that GA3ox was expressed in the leaves, roots, internodes, and stem nodes, and that there was a significant difference in the transcript level of the GA3ox between the wild type and dwarf mutant. The transcript levels of GA3ox in the leaves at the seedling stage, stem elongation stage and the heading stage, in the root and stem nodes at the stem elongation stage and in the internodes at the heading stage of the wild type, were significantly higher than those in the dwarf mutant. However, GA3ox expression in the rest of the wild type tissues at the 3 stages was slightly higher than or not different from the dwarf mutant.The results suggested that the wild type and mutant allele sequences of GA3ox in D. villosum showed 2 amino acid changes in exons and variations in the lengths of introns or the SNPs in introns, which most probably impaired the function of the enzyme,affected the GA3ox expression level, and eventually gave rise to dwarfing.展开更多
建立了固相萃取-高效液相色谱法同时测定植物根际促生菌发酵产物中吲哚-3-乙酸、赤霉素和玉米素3种植物激素含量的方法。固相萃取采用Agilent Bond Elut C18固相萃取柱,6 mL甲醇+6 mL 10%甲醇活化;以5 mL 10%甲醇淋洗2次;以5mL 80%甲醇...建立了固相萃取-高效液相色谱法同时测定植物根际促生菌发酵产物中吲哚-3-乙酸、赤霉素和玉米素3种植物激素含量的方法。固相萃取采用Agilent Bond Elut C18固相萃取柱,6 mL甲醇+6 mL 10%甲醇活化;以5 mL 10%甲醇淋洗2次;以5mL 80%甲醇洗脱2次。采用Agilent ZORBAX Eclipse Plus C18色谱柱(250×4.6mm,5μm)分离,流动相采用体积比为2∶3的甲醇-水(含0.2%冰乙酸)二元混合溶剂,流速为1mL·min^(-1),柱温为30℃,进样量为20μL,检测波长为210nm。结果表明:10株供试菌株发酵产物中均能检测到3种植物激素,除菌株003NXZ4外,其余菌株均呈现出玉米素含量最高,赤霉素次之,吲哚-3-乙酸含量最低的趋势。3种植物激素在12min内分离完全,样品的加标回收率达90.3%~104.3%,相对标准偏差(n=6)在1.04%~2.98%之间。该方法简便、准确,可同时检测植物根际促生菌发酵产物中吲哚-3-乙酸、赤霉素和玉米素3种植物激素含量。展开更多
Seed dormancy of cultivated rice was largely weakened during the progress of domestication.Correct timing and uniformity of seed germination are important for rapid seedling establishment and highyield production.In t...Seed dormancy of cultivated rice was largely weakened during the progress of domestication.Correct timing and uniformity of seed germination are important for rapid seedling establishment and highyield production.In the present study,we found that the heading-date gene Ghd7 acted as a negative regulator of germination.A mutant of ghd7 showed low sensitivity to exogenous ABA treatment during seed germination.Further investigation revealed reduced accumulation of ABA in mature ghd7 seeds as a consequence of dampened expression of OsNCED genes.Moreover,elevated GA_(3) level was detected in seeds of ghd7 mutant during imbibition course,which was attributed to the induction of genes responsible for the synthesis pathways of bioactive GAs.Thus,Ghd7 inhibits seed germination by increasing the ABA/GA_(3) ratio.Besides revealing pleiotropic effects of Ghd7,our results indicate its role in linking seed germination to growth-phase transition in rice,which would enrich the theoretical basis for future breeding practices.展开更多
文摘Gibberellin 3-oxidase catalyzes the conversion of inactive gibberellin(GA) species into GAs with biological activity and it is subjected to strict developmental controls in the life cycle of a plant. In this study, 33 gene sequences, encoding the gibberellin 3-oxidase(GA3ox) from Dasypyrum villosum and its dwarf mutant, were obtained. Each contained a 1 107 bp coding sequence(CDS) that encoded a putative protein containing 369 amino acids. The GA3ox protein showed 77% to 97% homology and shared the major conserved structural domains of GA3ox proteins with rice, sorghum bicolor, oat, barley, and wheat. Sequence alignment showed that there were 20 single nucleotide polymorphisms(SNPs) and 22 Insertion/deletions(In Dels) among these sequences, which could be divided into 2 haplotypes, haplotypes Ⅰ and Ⅱ. Haplotype Ⅰ was found in the wild type and was1 495 bp in length, and haplotype Ⅱ was found in the dwarf mutant and was 1 485 bp in length. The Q-PCR results showed that GA3ox was expressed in the leaves, roots, internodes, and stem nodes, and that there was a significant difference in the transcript level of the GA3ox between the wild type and dwarf mutant. The transcript levels of GA3ox in the leaves at the seedling stage, stem elongation stage and the heading stage, in the root and stem nodes at the stem elongation stage and in the internodes at the heading stage of the wild type, were significantly higher than those in the dwarf mutant. However, GA3ox expression in the rest of the wild type tissues at the 3 stages was slightly higher than or not different from the dwarf mutant.The results suggested that the wild type and mutant allele sequences of GA3ox in D. villosum showed 2 amino acid changes in exons and variations in the lengths of introns or the SNPs in introns, which most probably impaired the function of the enzyme,affected the GA3ox expression level, and eventually gave rise to dwarfing.
文摘建立了固相萃取-高效液相色谱法同时测定植物根际促生菌发酵产物中吲哚-3-乙酸、赤霉素和玉米素3种植物激素含量的方法。固相萃取采用Agilent Bond Elut C18固相萃取柱,6 mL甲醇+6 mL 10%甲醇活化;以5 mL 10%甲醇淋洗2次;以5mL 80%甲醇洗脱2次。采用Agilent ZORBAX Eclipse Plus C18色谱柱(250×4.6mm,5μm)分离,流动相采用体积比为2∶3的甲醇-水(含0.2%冰乙酸)二元混合溶剂,流速为1mL·min^(-1),柱温为30℃,进样量为20μL,检测波长为210nm。结果表明:10株供试菌株发酵产物中均能检测到3种植物激素,除菌株003NXZ4外,其余菌株均呈现出玉米素含量最高,赤霉素次之,吲哚-3-乙酸含量最低的趋势。3种植物激素在12min内分离完全,样品的加标回收率达90.3%~104.3%,相对标准偏差(n=6)在1.04%~2.98%之间。该方法简便、准确,可同时检测植物根际促生菌发酵产物中吲哚-3-乙酸、赤霉素和玉米素3种植物激素含量。
基金This work was supported by the National Key Research and Development Program of China(2017YFD0100406)China Postdoctoral Science Foundation(2019M652606).
文摘Seed dormancy of cultivated rice was largely weakened during the progress of domestication.Correct timing and uniformity of seed germination are important for rapid seedling establishment and highyield production.In the present study,we found that the heading-date gene Ghd7 acted as a negative regulator of germination.A mutant of ghd7 showed low sensitivity to exogenous ABA treatment during seed germination.Further investigation revealed reduced accumulation of ABA in mature ghd7 seeds as a consequence of dampened expression of OsNCED genes.Moreover,elevated GA_(3) level was detected in seeds of ghd7 mutant during imbibition course,which was attributed to the induction of genes responsible for the synthesis pathways of bioactive GAs.Thus,Ghd7 inhibits seed germination by increasing the ABA/GA_(3) ratio.Besides revealing pleiotropic effects of Ghd7,our results indicate its role in linking seed germination to growth-phase transition in rice,which would enrich the theoretical basis for future breeding practices.
