Molecular characterization and isolation of the F/f gene for femaleness in cucumber (Cucumis sativus L.)

Abstract

The biological processes leading to sex expression in plants are of tremendous practical significance for fruit production of many agricultural and horticultural crops. Sex-expression studies in cucumber showed that the different sex types are determined by three major genes: M/m, F/f and A/a. The M/m gene in the dominant condition suppresses stamina development and thus leads to female flowers. The F/f gene in the dominant condition shifts the monoecious sex pattern downwards and promotes femaleness by causing a higher level of ethylene in the plant. To investigate the molecular character of the gene F/f, we used nearly isogenic gynoecious ( MMFF) and monoecious ( MMff) lines (NIL) produced by our own backcross programme. Our investigations confirmed the result of other groups that an additional genomic ACC synthase (key enzyme of ethylene biosynthesis) sequence ( CsACS1G) should exist in gynoecious genotypes. A linkage was also verified between the F/f locus and the CsACS1G sequence with our plant material. After the exploration of different Southern hybridization patterns originating from different CsACS1 probes, a restriction map of the CsACS1 locus was constructed. By using this restriction map, the duplication of the CsACS1 gene and following mutation of the CsACS1G gene could be explained. The promoter regions of the genes CsACS1G and CsACS1 were amplified in a splinkerette PCR and sequenced. An exclusive amplification of the new isolated sequence ( CsACS1G) in gynoecious ( MMFF) and sub-gynoecious ( MMFf) genotypes confirmed that the isolated gene is the dominant F allele.

Cloning and characterisation of two CTR1-like genes in Cucurbita pepo: regulation of their expression during male and female flower development

“…Gynoecious lines of cucumber produce more ethylene than monoecious or andromonoecious ones (Owens et al 1980;Yamasaki et al 2001), and have an additional gene for ACS1 (1-aminocyclopropane-1-carboxylate synthase 1) (Trebitsh et al 1997;Mibus and Tatlioglu 2004;Knopf and Trebitsh 2006). Recently, it has also been reported that the andromonoecious sex-phenotype of cucumber and melon is the result of a reduction in ethylene production conferred by a mutation in an ACC-synthase gene (Boualem et al 2008(Boualem et al , 2009Li et al 2009).…”

Stamen development in Arabidopsis is arrested by organ-specific overexpression of a cucumber ethylene synthesis gene CsACO2

“…Yin and Quinn (1995) proposed that ethylene played a crucial role in regulating the sex expression in cucumber, while Kater et al (2001) proposed that the sex determination is restricted to particular whorls, rather than to their sexual identity. Recent studies cloned the F-locus in gynoecious lines as an additional copy of the ACC synthase (ACS) gene, which further conWrmed the role of ethylene in the promotion of female cucumber Xowers (Trebitsh et al 1997;Mibus and Tatlioglu 2004;Knopf and Trebitsh 2006). Kahana et al (1999) and Yamasaki et al (2003), respectively, examined the expression patterns of genes responsible for ethylene production and reception.…”

CORRECTED VERSION Identification and characterization of genes connected with flower morphogenesis in cucumber

“…Sex determination follows selective arrest of development of either the staminate or the pistillate primordia (Bai et al, 2004). Cucumber sex expression is mainly determined by the genes F, m, a, gy, and h. The Female (F ) gene regulates the number of female flowers and was cloned and shown to encode 1-aminocyclopropane-1-carboxylic acid synthase (CsACS1G), which is involved in ethylene biosynthesis (Trebitsh et al, 1997;Mibus et al, 2004). The andromonoecious gene (M ) was also identified as a previously characterized putative 1-aminocyclopropane-1-carboxylic acid syn-thase gene CsACS2, while the m allele is mutated at a conserved site (Gly33Cys).…”