In situ mRNA hybridization (ISH) is a powerful tool for examining the spatiotemporal expression of genes in shoot apical meristems and flower buds of cucumber.  The most common ISH protocol uses paraffin wax; however, embedding tissue in paraffin wax can take a long time and might result in RNA degradation and decreased signals.  Here, we developed an optimized protocol to simplify the process and improve RNA sensitivity.  We combined embedding tissue in low melting-point Steedman’s wax with processing tissue sections in solution, as in the whole-mount ISH method in the optimized protocol. Using the optimized protocol, we examined the expression patterns of the CLAVATA3 (CLV3) and WUSCHEL (WUS) genes in shoot apical meristems and floral meristems of Cucumis sativus (cucumber) and Arabidopsis thaliana (Arabidopsis).  The optimized protocol saved 4–5 days of experimental period compared with the standard ISH protocol using paraffin wax.  Moreover, the optimized protocol achieved high signal sensitivity.  The optimized protocol was successful for both cucumber and Arabidopsis, which indicates it might have general applicability to most plants

Sex determination in plants gives rise to unisexual flowers.  A better understanding of the regulatory mechanism underlying the production of unisexual flowers will help to clarify the process of sex determination in plants and allow researchers and farmers to harness heterosis.  Androecious cucumber (Cucumis sativus L.) plants can be used as the male parent when planted alongside a gynoecious line to produce heterozygous seeds, thus reducing the cost of seed production.  The isolation and characterization of additional androecious genotypes in varied backgrounds will increase the pool of available germplasm for breeding.  Here, we discovered an androecious mutant in a previously generated ethyl methanesulfonate (EMS)-mutagenized library of the cucumber inbred line ‘406’.  Genetic analysis, whole-genome resequencing, and molecular marker-assisted verification demonstrated that a nonsynonymous mutation in the ethylene biosynthetic gene 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE 11 (ACS11) conferred androecy.  The mutation caused an amino acid change from serine (Ser) to phenylalanine (Phe) at position 301 (S301F).  In vitro enzyme activity assays revealed that this S301F mutation leads to a complete loss of enzymatic activity.  This study provides a new germplasm for use in cucumber breeding as the androecious male parent, and it offers new insights into the catalytic mechanism of ACS enzymes.

SSR markers are useful in pepper linkage mapping and gene location. 446 SSR markers have been reported, but they are insufficient. It is costly to develop SSR markers from DNA library, whereas it seems much easy to find in EST sequences in the GenBank of pepper through internet. In this study, attempts have been made to develop SSR markers in the EST sequences by using bioinformatics. EST sequences were trimmed by ‘est-trimmer.pl’ software, while 116915 EST sequences were obtained without poly ‘A’ or poly ‘T’, ranged between 100 and 700 bp. Using ‘e-PCR’ and ‘del.pl’ softwares, SSR sequences were identified. 2 508 microsatellite loci (larger than 20 repeats) were established and 755 SSR primers were designed using SSR finder software and Primer 3 software. There were 498 (0.43%) mono-, 1 026 (0.89%) di-, 518 (0.45%) tri-, 245 (0.21%) tetra-, 114 (0.10%) penta-, and 107 (0.09%) hexa-nucleotide SSRs. The estimated frequency of SSRs was approximately 1/25.12 kb. According to the distribution of SSRs in pepper, the mean length of pepper SSRs was 22.68 bp and the adenine rich repeats such as A/T, AG, AT, AAG, AAAT, and AAAC were predominant in each type of SSRs (mono-, di-, tri-, tetra-, penta-, and hexa-), whereas the C/G, CG, CCG repeats were less abundant. 210 primers were tested in 8 pepper cultivars and the PCR result revealed the existence of polymorphism among 127 (60.48%) SSR primers within 8 pepper cultivars. It is confirmed that pepper EST database could be efficiently exploited for availability of SSR markers.