Background： The conversion from non-embryogenic callus （NEC） to embryogenic callus （EC） is the key bottleneck step in regeneration of upland cotton （Gossypium hirsutum）, and hinders the transgenic breeding of u...Background： The conversion from non-embryogenic callus （NEC） to embryogenic callus （EC） is the key bottleneck step in regeneration of upland cotton （Gossypium hirsutum）, and hinders the transgenic breeding of upland cotton. To investigate molecular mechanisms underlying acquisition of embryogenic potential during this process, comparation analysis of transcriptome dynamics between two upland cotton cultivars with different somatic embryogenesis abilities was conducted. Results： Differentially expressed genes involved in the transformation from NEC to EC were detected in the two different cultivars. Principal component analysis based on DEGs showed that the NEC tissues of the two cultivars were highly heterogeneous, whereas the derived EC tissues were similar, which suggested the homogeneousness of EC between different lines. In the highly embryogenic cultivar CCRI 24, more of these genes were down-regulated, whereas, in the recalcitrant cultivar CCRI 12, more were up-regulated. Bioinformatics analysis on these DEGs showed that the vast majority of differentially expressed genes were enriched in metabolism and secondary metabolites biosynthesis pathways. Flavonoid biosynthesis and phenylpropanoid biosynthesis pathways were enriched in both cultivars, and the associated genes were down-regulated more in CCRI 24 than in CCRI 12. We deduced that vigorous secondary metabolism in CCRI 12 may hinder primary metabolism, resulting in tardiness of cell differentiation. Interestingly, genes involved in the plant hormone signal transduction pathway were enriched in the recalcitrant cultivar CCRI 12, but not in CCRI 24, suggesting more radical regulation of hormone signal transduction in the recalcitrant cultivar. Signal transduction rather than biosynthesis of plant hormones is more likely to be the determining factor triggering NEC to EC transition in recalcitrant cotton lines. Transcription factor encoding genes showed differential regulation between two cultivars. Conclusions： Our study provides valuable information about the molecular mechanism of conversion from NEC to EC in cotton and allows for identification of novel genes involved. By comparing transcriptome changes in transformation from NEC to EC between the two cultivars, we identified 46 transcripts that may contribute to initiating embryogenic shift.展开更多
γ-ECS基因编码的γ-谷氨酰半胱氨酸合成酶是细胞内谷胱甘肽(GSH)从头合成的限速酶。以龙眼转录组数据库为基础,采用同源克隆的方法从龙眼胚性愈伤组织中分离得到γ-ECS基因cDNA全长序列,在GenBank上的登录号为JF815477。γ-ECS基因序...γ-ECS基因编码的γ-谷氨酰半胱氨酸合成酶是细胞内谷胱甘肽(GSH)从头合成的限速酶。以龙眼转录组数据库为基础,采用同源克隆的方法从龙眼胚性愈伤组织中分离得到γ-ECS基因cDNA全长序列,在GenBank上的登录号为JF815477。γ-ECS基因序列全长1 812 bp,包括17 bp 5′UTR及254 bp 3′UTR;ORF长度为1 541 bp编码511个氨基酸。生物信息学分析结果表明,龙眼胚性愈伤组织γ-ECS的核甘酸序列及其推导的氨基酸序列分别与蓖麻、毛果杨等具有较高的同源性;γ-ECS为1个具有跨膜结构的非分泌蛋白,具有亲水性;亚细胞定位于过氧化物酶体,不含信号肽,并存在亮氨酸拉链结构。龙眼胚性愈伤组织γ-ECS基因在龙眼体胚发生过程中的整体表达趋势是先升高,后降低,其表达量在心形胚阶段达到最大值之后在鱼雷形胚阶段急剧下降。γ-ECS基因表达量变化可能与GSH在龙眼体胚发生过程中的含量变化一致。展开更多
Abstract： Somatic embryogenesis from lily bulb scales has not been studied in details, although tissue culture methods have been applied to the propagation for decades. The effects of different kinds and concentratio...Abstract： Somatic embryogenesis from lily bulb scales has not been studied in details, although tissue culture methods have been applied to the propagation for decades. The effects of different kinds and concentration of auxins for oriental lily somatic embryogenesis were investigated （Lilium hybrida var. Sorbonne）. 2, 4-dichlorophenoxyacetic acid （2, 4-D）, thidiazuron （TDZ） and α-naphthaleneacetic acid （NAA） media with benzyladenine（6-BA） and lactalbumin hydrolysate （LH） were used for embryogenic callus in the darkness. The best response on embryogenic callus formation was obtained on MS media supplemented 2, 4-D 2.0 mg·L^-1, 6-BA 0.5 mg·L^-1 and LH 300 mg·L^-1. Transfer embryogenic callus to the media with TDZ, 6-BA, kinetin （KT） supplemented 2, 4-D. The highest number of somatic embryos has been produced on medium with 0.5 mg·L^-1 2, 4-D and 0.3 mg·L^-1 KT. Germinated embryos with shoot axes were changed to MS media with 6-BA 0.5 mg·L^-1. The results suggest that in vitro culture of somatic embryogenesis from lily bulb scales can be used for plant regeneration.展开更多
基金supported by National Science and Technology Major Project(2016ZX08010004),China
文摘Background： The conversion from non-embryogenic callus （NEC） to embryogenic callus （EC） is the key bottleneck step in regeneration of upland cotton （Gossypium hirsutum）, and hinders the transgenic breeding of upland cotton. To investigate molecular mechanisms underlying acquisition of embryogenic potential during this process, comparation analysis of transcriptome dynamics between two upland cotton cultivars with different somatic embryogenesis abilities was conducted. Results： Differentially expressed genes involved in the transformation from NEC to EC were detected in the two different cultivars. Principal component analysis based on DEGs showed that the NEC tissues of the two cultivars were highly heterogeneous, whereas the derived EC tissues were similar, which suggested the homogeneousness of EC between different lines. In the highly embryogenic cultivar CCRI 24, more of these genes were down-regulated, whereas, in the recalcitrant cultivar CCRI 12, more were up-regulated. Bioinformatics analysis on these DEGs showed that the vast majority of differentially expressed genes were enriched in metabolism and secondary metabolites biosynthesis pathways. Flavonoid biosynthesis and phenylpropanoid biosynthesis pathways were enriched in both cultivars, and the associated genes were down-regulated more in CCRI 24 than in CCRI 12. We deduced that vigorous secondary metabolism in CCRI 12 may hinder primary metabolism, resulting in tardiness of cell differentiation. Interestingly, genes involved in the plant hormone signal transduction pathway were enriched in the recalcitrant cultivar CCRI 12, but not in CCRI 24, suggesting more radical regulation of hormone signal transduction in the recalcitrant cultivar. Signal transduction rather than biosynthesis of plant hormones is more likely to be the determining factor triggering NEC to EC transition in recalcitrant cotton lines. Transcription factor encoding genes showed differential regulation between two cultivars. Conclusions： Our study provides valuable information about the molecular mechanism of conversion from NEC to EC in cotton and allows for identification of novel genes involved. By comparing transcriptome changes in transformation from NEC to EC between the two cultivars, we identified 46 transcripts that may contribute to initiating embryogenic shift.
文摘γ-ECS基因编码的γ-谷氨酰半胱氨酸合成酶是细胞内谷胱甘肽(GSH)从头合成的限速酶。以龙眼转录组数据库为基础,采用同源克隆的方法从龙眼胚性愈伤组织中分离得到γ-ECS基因cDNA全长序列,在GenBank上的登录号为JF815477。γ-ECS基因序列全长1 812 bp,包括17 bp 5′UTR及254 bp 3′UTR;ORF长度为1 541 bp编码511个氨基酸。生物信息学分析结果表明,龙眼胚性愈伤组织γ-ECS的核甘酸序列及其推导的氨基酸序列分别与蓖麻、毛果杨等具有较高的同源性;γ-ECS为1个具有跨膜结构的非分泌蛋白,具有亲水性;亚细胞定位于过氧化物酶体,不含信号肽,并存在亮氨酸拉链结构。龙眼胚性愈伤组织γ-ECS基因在龙眼体胚发生过程中的整体表达趋势是先升高,后降低,其表达量在心形胚阶段达到最大值之后在鱼雷形胚阶段急剧下降。γ-ECS基因表达量变化可能与GSH在龙眼体胚发生过程中的含量变化一致。
文摘Abstract： Somatic embryogenesis from lily bulb scales has not been studied in details, although tissue culture methods have been applied to the propagation for decades. The effects of different kinds and concentration of auxins for oriental lily somatic embryogenesis were investigated （Lilium hybrida var. Sorbonne）. 2, 4-dichlorophenoxyacetic acid （2, 4-D）, thidiazuron （TDZ） and α-naphthaleneacetic acid （NAA） media with benzyladenine（6-BA） and lactalbumin hydrolysate （LH） were used for embryogenic callus in the darkness. The best response on embryogenic callus formation was obtained on MS media supplemented 2, 4-D 2.0 mg·L^-1, 6-BA 0.5 mg·L^-1 and LH 300 mg·L^-1. Transfer embryogenic callus to the media with TDZ, 6-BA, kinetin （KT） supplemented 2, 4-D. The highest number of somatic embryos has been produced on medium with 0.5 mg·L^-1 2, 4-D and 0.3 mg·L^-1 KT. Germinated embryos with shoot axes were changed to MS media with 6-BA 0.5 mg·L^-1. The results suggest that in vitro culture of somatic embryogenesis from lily bulb scales can be used for plant regeneration.
