De Novo Characterization of the Mung Bean Transcriptome and Transcriptomic Analysis of Adventitious Rooting in Seedlings Using RNA-Seq

Yuan

et al. 2018

Physiologia Plantarum

Cytokinin (CK) inhibits adventitious root (AR) formation in stem cuttings. Little is known, however, about the mechanism underlying the inhibitory effect. In this study, 2 mg l of exogenous 6-benzyl adenine (6-BA) was administered to 3 and 7-day-old apple rootstocks 'M.26' cuttings (3 and 7 days 6-BA) by transferring them from a rooting medium containing indole-3-butanoic acid to the medium containing 6-BA. Anatomical and morphological observations revealed that the exogenous application of 6-BA inhibited primordia formation in the 3 days 6-BA but not the 7 days 6-BA group. The concentration of auxin (IAA), the ratios of IAA/CK and IAA/abscisic acid were lower in 3 days 6-BA than in 7 days 6-BA. Expression analysis of genes known to be associated with AR formation was also analyzed. In the 3 days 6-BA group, high level of CK inhibited the synthesis and transport of auxin, as a result, low endogenous auxin level suppressed the auxin signaling pathway genes, as were other AR development and cell cycle related genes; all of which had an inhibitory impact on AR primordium formation. On the contrary, low CK level in the 7 days 6-BA, reduced the inhibitory impact on auxin levels, leading to an upregulated expression of genes known to promote AR primordia formation. Collectively, our data indicated that 3-7 days is the time period in which AR primordia formation occurs in cuttings of 'M.26' and that the inhibition of AR development by CK is due to the suppression of AR primordia development over 3-7 days period after culturing in rooting medium.

Section: Introductionmentioning

confidence: 99%

Inhibition of adventitious root development in apple rootstocks by cytokinin is based on its suppression of adventitious root primordia formation

Mao

Yuan

et al. 2018

Physiologia Plantarum

“…Furthermore, some other genes and proteins have been studied to relate to the vegetative propagation, like RP [47], HSP [48], and histone [49,50]. While very few studies have been demonstrated to investigate their functions and associations in the SE of Eucalyptus, our results indicate that the dysregulation of these genes or the known pathways like metabolisms involved by these genes might be related to the SE of Eucalyptus.…”

Section: Snps and Indelsmentioning

confidence: 72%

Transcriptome Analysis Identifies Genes Involved in the Somatic Embryogenesis of Eucalyptus

Xiao

et al. 2020

Preprint

Background: Eucalyptus, a highly diverse genus of the Myrtaceae family, is the most widely planted hardwood due to its increasing importance for fiber and energy in the word. Somatic embryogenesis is one method to provide large-scale commercial use for the vegetative propagation of Eucalyptus and dedifferentiation is a key step for plant cells to become meristematic. However, little is known about the molecular changes during the SE of Eucalyptus on transcriptional level.Results: We compared the transcriptome profiles of the differentiated and dedifferentiated tissues of two Eucalyptus cultivars – E. camaldulensis (high embryogenetic potential) and E. grandis x urophylla (low embryogenetic potential). In total, we identified 18,777 to 20,240 genes in all samples. Compared to the differentiated tissues, we identified 9,229 and 8,989 differentially expressed genes (DEGs) in the dedifferentiated tissues of E. camaldulensis and E. grandis x urophylla, respectively. Comparison of DEGs showed that they shared 2,687 up-regulated and 2,581 down-regulated genes. Next, we found 2,003 up-regulated and 1,958 down-regulated genes specifically identified in E. camaldulensis, including 6 somatic embryogenesis receptor kinase, 17 ethylene, 12 auxin, 83 ribosomal protein, 28 zinc finger protein, 10 heat shock protein, 9 histone and 98 transcription factor genes. Genes from other families like ABA, arabinogalactan protein and late embryogenesis abundant protein were also found to be specifically dysregulated in E. camaldulensis. Further, we identified 48,447 variants (SNPs and small indels) specific to E. camaldulensis, including 13,434 exonic variants from 4,723 genes (e.g., annexin, GN, ARF and AP2-like ethylene-responsive transcription factor). qRT-PCR was used to confirm the gene expression patterns in both E. camaldulensis and E. grandis x urophylla. Conclusions: This is the first time to study the somatic embryogenesis of Eucalyptus using transcriptome sequencing. Our results will improve our understanding of the molecular mechanisms of somatic embryogenesis and dedifferentiation in Eucalyptus. Our results provide a valuable resource for future studies in the field of Eucalyptus and will benefit the Eucalyptus breeding program.

“…The functions of cell wall related genes need future experiments to be explored. Furthermore, RP [48], HSP [49], and histone [50,51] have been reported to function in the vegetative propagation in plants. While very few studies have been demonstrated to investigate their functions and associations in the SE of Eucalyptus, our results indicate that the dysregulation of these genes and pathways like metabolisms involved by these genes might play important roles in the SE of Eucalyptus.…”

Section: Discussionmentioning

confidence: 99%

Transcriptome analysis identifies genes involved in the somatic embryogenesis of Eucalyptus

Xiao

et al. 2020

Preprint

Background: Eucalyptus, a highly diverse genus of the Myrtaceae family, is the most widely planted hardwood in the world due to its increasing importance for fiber and energy. Somatic embryogenesis (SE) is one large-scale method to provide commercial use of the vegetative propagation of Eucalyptus and dedifferentiation is a key step for plant cells to become meristematic. However, little is known about the molecular changes during the Eucalyptus SE.Results: We compared the transcriptome profiles of the differentiated and dedifferentiated tissues of two Eucalyptus species – E. camaldulensis (high embryogenetic potential) and E. grandis x urophylla (low embryogenetic potential). Initially, we identified 18,777 to 20,240 genes in all samples. Compared to the differentiated tissues, we identified 9,229 and 8,989 differentially expressed genes (DEGs) in the dedifferentiated tissues of E. camaldulensis and E. grandis x urophylla, respectively, and 2,687 up-regulated and 2,581 down-regulated genes shared. Next, we identified 2,003 up-regulated and 1,958 down-regulated genes only in E. camaldulensis, including 6 somatic embryogenesis receptor kinase, 17 ethylene, 12 auxin, 83 ribosomal protein, 28 zinc finger protein, 10 heat shock protein, 9 histone, 122 cell wall related and 98 transcription factor genes. Genes from other families like ABA, arabinogalactan protein and late embryogenesis abundant protein were also found to be specifically dysregulated in the dedifferentiation process of E. camaldulensis. Further, we identified 48,447 variants (SNPs and small indels) specific to E. camaldulensis, including 13,434 exonic variants from 4,723 genes (e.g., annexin, GN, ARF and AP2-like ethylene-responsive transcription factor). qRT-PCR was used to confirm the gene expression patterns in both E. camaldulensis and E. grandis x urophylla. Conclusions: This is the first time to study the somatic embryogenesis of Eucalyptus using transcriptome sequencing. It will improve our understanding of the molecular mechanisms of somatic embryogenesis and dedifferentiation in Eucalyptus. Our results provide a valuable resource for future studies in the field of Eucalyptus and will benefit the Eucalyptus breeding program.