Molecular characterization of SCARECROW (CsSCR) gene expressed during somatic embryo development and in root of cucumber (Cucumis sativus L.)

Abstract

Somatic embryogenesis (SE) in plants can be used as a model for studying genes engaged in the embryogenic transition of somatic cells. The CsSCARECROW (CsSCR) gene was previously identified among a panel of genes upregulated after the induction of SE in cucumber (Cucumis sativus). The putative CsSCR protein contains conserved GRAS family domains and is extremely similar to AtSCR from Arabidopsis thaliana. SCR proteins are transcription factors involved in root radial patterning and are required for maintenance of the quiescent centre and differentiation of the endodermis. In comparison with other GRAS proteins from cucumber, phylogenetic analyses showed that CsSCR belongs to the SCR cluster. Increased CsSCR transcript accumulation was detected in somatic embryos and roots. Southern blot analysis and screening of the draft version of the cucumber genome confirmed the lack of close homologues in this species. CsSCR transcripts were localized by in situ hybridization in undifferentiated cells in the globular and heart stages of somatic embryogenesis, and in the endodermis of torpedo and cotyledonary stage somatic embryos, and developing primary and lateral roots. This localization was supported by the pattern of reporter gene activity driven by the CsSCR promoter in transgenic cucumber organs. These results suggest that CsSCR is likely to act in tissue radial organization during somatic embryogenesis and root development.Keywords Cucumber Á GRAS protein family Á Root anatomy Á Scarecrow Á SCR Á Somatic embryogenesis Abbreviations ECS Embryogenic cell suspension LRP Lateral root primordia SE Somatic embryogenesis Communicated by S. Werbrouck. Electronic supplementary materialThe online version of this article

Lateral root initiation and formation within the parental root meristem of Cucurbita pepo: is auxin a key player?

“…The pKGW-RR-MGW-DR5 (DR5::GUS) construct containing the auxin-inducible synthetic promoter DR5, the gusA reporter gene and the pAtUBQ10::DsRED1 cassette as a screenable marker was developed in a previous study (Ilina et al, 2012). To create the pKGW-RR-MGW-pCsSCR (CsSCR::GUS) construct, a 1684 bp fragment of the promoter of the C. sativus SCARECROW (SCR) gene (Wiśniewska et al, 2013) was amplified by PCR using cucumber genomic DNA. The construct was cloned into pUC18-entry8 (Hornung et al, 2005).…”

The GRAS gene family and its roles in seed development in litchi (Litchi chinensis Sonn)

“…In Arabidopsis, the collaboration between the SHR-SCR complex and auxin influx carriers (LAX3 and AUX1) could lead to synergistic effect on primary/lateral root development [77]. In pine and cucumber, relatively high expressing GRAS transcripts, such as SCR and SHR, were measured in non-differentiated proliferating embryogenic cultures and during embryo development [15,78]. In our study, LcGRAS14 in SHR was highly expressed in root, and LcGRAS48 was highly expressed in fruit, indicating that LcGRAS members might function in root and seed development by participating in auxin signal pathway.…”

Developmental expression of the cucumber Cs-XTH1 and Cs-XTH3 genes, encoding xyloglucan endotransglucosylase/hydrolases, can be influenced by mechanical stimuli

“…Cucumber embryogenic suspension cultures provide an efficient and useful means of studying gene expression during embryogenesis (Malinowski et al 2004;Grabowska et al 2009;Wiśniewska et al 2012Wiśniewska et al , 2013, mainly because there is no need for plant regeneration and de novo induction of somatic embryogenesis. Previously, we described two cucumber XTH genes, CsXTH1 and CsXTH3, which were involved in somatic embryogenesis (Linkiewicz et al 2004;Malinowski et al 2004;Wiśniewska et al 2012).…”