Background: Cucumber is an important melon crop in the world, with different pericarp colors. However, the candidate genes and the underlying genetic mechanism for such an important trait in cucumber are unknown. In this study, a locus controlling pericarp color was found on chromosome 3 of cucumber genome.Results: In this study, the light green inbred line G35 and the dark green inbred line Q51 were crossed to produce one F₂population. Consequently, we identified a major locusCsPC1(Pericarp color 1). Next, we mapped theCsPC1locus to a 94-kb region chromosome 3 which contains 15 genes. Among these genes,Csa3G912920, which encodes a GATA transcription factor, was expressed at a higher level in the pericarp of the NIL-1334 line (with light-green pericarp) than in that of the NIL-1325 line (with dark-green pericarp). This study provides a new allele for the improvement of cucumber pericarp color.Conclusion: A major QTL that controls pericarp color in cucumber,CsPC1, was identified in a 94-kb region that harbors the strong candidate geneCsGATA1.

The developmental plasticity of the maize inflorescence depends on meristems, which directly affect reproductive potential and yield. However, the molecular roles of upper floral meristem (UFM) and lower floral meristem (LFM) in inflorescence and kernel development have not been fully elucidated. In this study, we characterized the reversed kernel1 (rk1) novel mutant, which contains kernels with giant embryos but shows normal vegetative growth like the wild type (WT). Total RNA was extracted from the inflorescence at three stages for transcriptomic analysis. A total of 250.16-Gb clean reads were generated, and 26,248 unigenes were assembled and annotated. Gene ontology analyses of differentially expressed genes (DEGs) detected in the sexual organ formation stage revealed that cell differentiation, organ development, phytohormonal responses and carbohydrate metabolism were enriched. The DEGs associated with the regulation of phytohormone levels and signaling were mainly expressed, including auxin (IAA), jasmonic acid (JA), gibberellins (GA), and abscisic acid (ABA). The transcriptome, hormone evaluation and immunohistochemistry observation revealed that phytohormone homeostasis were affected in rk1. BSA-Seq and transcriptomic analysis also provide candidate genes to regulate UFM and LFM development. These results provide novel insights for understanding the regulatory mechanism of UFM and LFM development in maize and other plants.

Background: Cucumber is an important melon crop in the world, with different skin colors. However, the candidate genes and the underlying genetic mechanism for such an important trait in cucumber are unknown. In this study, a locus controlling fruit skin color was found on chromosome 3 of cucumber genome.Results: In this study, the light green inbred line G35 and the dark green inbred line Q51 were used as parents to construct an F₂ population. On chromosome 3, we identified a major QTL CsFS1 (Fruit skin 1). We further narrowed down the CsFS1 locus to a 94-kb interval containing 15 candidate genes. Among these genes, Csa3G912920, which encodes a GATA transcription factor, was expressed at a higher level in the pericarp of the NIL-1334 line (with light-green fruit skin) than in that of the NIL-1325 line (with dark-green fruit skin). This study provides a new allele for the improvement of cucumber fruit skin color.Conclusion: A major QTL that controls fruit skin color in cucumber, CsFS1, was identified in a 94-kb region that harbors the strong candidate gene CsGATA1.