RESEARCH PAPER Identification and characterization of genes connected with flower morphogenesis in cucumber

Abstract

Sex determination and flower morphogenesis are very broad and complex processes controlled at many levels. Four clones have been isolated from cucumber transcriptomes, mapped onto the cucumber genome and checked if the corresponding genes expression differed between the vegetative and generative tissues (leaf, shoot apex, and 1-to 2-mm flower buds) of monoecious and gynoecious cucumber lines. To determine the role, and characteristics of identified genes in flower morphogenesis, as well as to understand the flower reproduction in cucumber, comprehensive computational studies using upstream regulatory elements and protein motifs were performed. A genome-wide overview of cucumber clones revealed that sequence of only one clone was mapped in the coding site. The gene was described as CsPSTK1 encoding serine/threonine kinase. The results allow us to conclude that cucumber generative organs differ in responsiveness to plant hormones due to the distinct signal transductions that are mediated by protein kinases in male and female organs of the floral buds and shoot apices. Protein kinases may be an alternative way for hormonal signal transduction in flowers of the opposite sex, taking part in the inhibition of unwanted generative organs that cause the development of a unisex flower.

Next generation sequencing and omics in cucumber ( Cucumis sativus L.) breeding directed research

“…Genome sequencing and structural and functional annotation of its sequence provide us with a large dataset, among which are some potentially important genes for crop improvement. For example in 2009 Li et al study, using the genome sequence, authors were able to successfully clone and identify the M/m gene involved in sex determination in cucumber [30] and the GY/gy involved in sex determination was connected with CsPSTK1-kinase [31]. The other genes and markers of great breeding importance, thanks to mapping population and the whole genome sequence of cucumber was also discovered.…”

Genetic and molecular bases of cucumber (Cucumis sativus L.) sex determination

“…gy (gynoecious)-This recessive allele is responsible for femininity that is much more highly stable than that conferred by the F gene (recessive femininity rF; Bhard femininity^). The gy gene (also abbreviated as g) is frequently assumed to be the gene indirectly influencing sex (Pawełkowicz et al 2012) and it could be correlated with CsWIP (Boualem et al 2015). h (andromonoecious-2)-This allele produces bisexual flowers with normal ovaries (Kubicki 1974).…”

“…Whereas information on the function of the F and M genes is described, little is known about the functions of A/a, Gy/gy, and H/h alleles. In one study, the A/a allele was suggested to be linked to the copper transporter gene CsRAN1 (Terefe 2005), whereas the dominant allele Gy/gy gene can be correlated with the putative serine/threonine kinase gene CsPSTK1 (Pawełkowicz et al 2012). Because CsPSTK1 expression is related to the recessive gy allele, the associated inhibition of the CsPSTK1 gene may require the presence of the dominant Gy allele.…”

“…Presumably, CsPSTK1 inhibition by the Gy allele negatively affects ethylene biosynthesis. When gy is present, the inhibition is removed and the CsPSTK1 gene has a positive effect on ethylene levels (Pawełkowicz et al 2012). According to recent reports, the recessive female state is conditioned (similar to Cucumis melo) by mutational changes in the WIP (CmWIP1-CsWIP1) gene, which possesses a zinc finger domain and controls transcription (Martin et al 2009;Boualem et al 2015;Chen et al 2016).…”

“…3). The dominant Gy gene inhibits CsPSTK1, which has a positive influence on ethylene production (Pawełkowicz et al 2012).…”