Somatic Embryogenesis in Genera Medicago: an Overview

Iantcheva, Anelia; Vlahova, M.; Atanassov, A.

doi:10.1007/7089_025

Cited by 5 publications

(3 citation statements)

References 66 publications

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“…The concentration of 2,4-D is important for the dedifferentiation and redifferentiation process. Too high levels of 2,4-D can block the embryogenesis of cells that already have acquired embryogenic potential (Iantcheva et al, 2005). There may be a complex interaction between cells that form the embryo and nonembryogenic cells that support the competent cells.…”

Section: How Does Repression Of the Auxin Response Lead To Increased Se?mentioning

confidence: 99%

Gene Regulation by the AGL15 Transcription Factor Reveals Hormone Interactions in Somatic Embryogenesis

Zheng

et al. 2016

Plant Physiol.

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The MADS box transcription factor Arabidopsis (Arabidopsis thaliana) AGAMOUS-LIKE15 (AGL15) and a putative ortholog from soybean (Glycine max), GmAGL15, are able to promote somatic embryogenesis (SE) in these plants when ectopically expressed. SE is an important means of plant regeneration, but many plants, or even particular cultivars, are recalcitrant for this process. Understanding how (Gm)AGL15 promotes SE by identifying and characterizing direct and indirect downstream regulated genes can provide means to improve regeneration by SE for crop improvement and to perform molecular tests of genes. Conserved transcription factors and the genes they regulate in common between species may provide the most promising avenue to identify targets for SE improvement. We show that (Gm)AGL15 negatively regulates auxin signaling in both Arabidopsis and soybean at many levels of the pathway, including the repression of AUXIN RESPONSE FACTOR6 (ARF6) and ARF8 and TRANSPORT INHIBITOR RESPONSE1 as well as the indirect control of components via direct expression of a microRNA-encoding gene. We demonstrate interaction between auxin and gibberellic acid in the promotion of SE and document an inverse correlation between bioactive gibberellic acid and SE in soybean, a difficult crop to transform. Finally, we relate hormone accumulation to transcript accumulation of important soybean embryo regulatory factors such as ABSCISIC ACID INSENSITIVE3 and FUSCA3 and provide a working model of hormone and transcription factor interaction in the control of SE.

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Section: How Does Repression Of the Auxin Response Lead To Increased Se?mentioning

confidence: 99%

Gene Regulation by the AGL15 Transcription Factor Reveals Hormone Interactions in Somatic Embryogenesis

Zheng

et al. 2016

Plant Physiol.

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“…The ploidy level and nuclear genome size also influence the in vitro response of somatic embryogenesis (Zhang et al 2006;Iantcheva and Revalska 2018). In Medicago genus, such as Medicago truncatula L., embryogenic competence is directly associated with nuclear genome size.…”

Section: Canephora and C Eugenioides Statistically Showed The Same Is...mentioning

confidence: 99%

“…In Medicago genus, such as Medicago truncatula L., embryogenic competence is directly associated with nuclear genome size. Individuals with a smaller genome size responded faster and regenerated a higher number of somatic embryos than individuals with a larger genome size (Iantcheva and Revalska 2018). In Coffea, studies correlating the ploidy level and nuclear genome size with the in vitro response are still initial and need to be more investigated.…”

Section: Canephora and C Eugenioides Statistically Showed The Same Is...mentioning

confidence: 99%

Indirect somatic embryogenesis in Coffea canephora and Coffea eugenioides: endogenous hormone levels and copy number of genes related to auxin biosynthetic pathway and morphogenic in vitro response

Santos¹

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Coffea canephora and Coffea eugenioides indirect somatic embryogenesis (ISE) has been established and compared during callus formation and somatic embryo regeneration, showing that these species exhibit the same response in vitro. However, intraspecific differences regarding ISE responses have also been reported. ISE is influenced by genetic and physiological aspects. We aimed to: (a) induce ISE in C. canephora and C. eugenioides; (b) identify and quantify the endogenous levels of indole-3-acetic acid (IAA), zeatin (Z) and gibberellic acid GA 3 and GA 4 during the callus induction; and (c) determine the number of gene copies of AUX/IAA33 and YUC4 that are involved in the auxin biosynthetic pathway, and of WOX4 and LEC1 that are involved in the morphogenic pathway. Using liquid chromatography coupled to mass spectrometry (LC-MS), the identification and quantification of IAA, GA 3 , GA 4 and Z was performed in both Coffea. From the fluorescence in situ hybridization, the copy number of the AUX/IAA33, YUC4, WOX4 and LEC1 genes was verified. ISE was established for C. canephora and C. eugenioides, which exhibited the same in vitro response. However, the two Coffea differed in relation to endogenous hormone levels, with the exception of IAA at 90 days. These species possess two gene copies of AUX/IAA33, YUC4, WOX4 and LEC1, corroborating to their diploidy. Therefore, our results show that C. canephora and C. eugenioides differ in the physiological aspect, but not in the genetic aspect investigated here. Thus, our data contribute as a basis to understand the in vitro response and for the improvement of the in vitro propagation procedures. Keywords: Coffee. Plant Tissue Culture. In vitro regeneration. Somatic Embryo. Genetic. Plant Physiology.

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