Transcriptomic Analysis Implies That GA Regulates Sex Expression via Ethylene-Dependent and Ethylene-Independent Pathways in Cucumber (Cucumis sativus L.)

Abstract

Sex differentiation of flower buds is an important developmental process that directly affects fruit yield of cucumber (Cucumis sativus L.). Plant hormones, such as gibberellins (GAs) and ethylene can promote development of male and female flowers, respectively, however, the regulatory mechanisms of GA-induced male flower formation and potential involvement of ethylene in this process still remain unknown. In this study, to unravel the genes and gene networks involved in GA-regulated cucumber sexual development, we performed high throughout RNA-Seq analyses that compared the transcriptomes of shoot tips between GA3 treated and untreated gynoecious cucumber plants. Results showed that GA3 application markedly induced male flowers but decreased ethylene production in shoot tips. Furthermore, the transcript levels of M (CsACS2) gene, ethylene receptor CsETR1 and some ethylene-responsive transcription factors were dramatically changed after GA3 treatment, suggesting a potential involvement of ethylene in GA-regulated sex expression of cucumber. Interestingly, GA3 down-regulated transcript of a C-class floral homeotic gene, CAG2, indicating that GA may also influence cucumber sex determination through an ethylene-independent process. These results suggest a novel model for hormone-mediated sex differentiation and provide a theoretical basis for further dissection of the regulatory mechanism of male flower formation in cucumber.Statement: We reveal that GA can regulate sex expression of cucumber via an ethylene-dependent manner, and the M (CsACS2), CsETR1, and ERFs are probably involved in this process. Moreover, CAG2, a C-class floral homeotic gene, may also participate in GA-modulated cucumber sex determination, but this pathway is ethylene-independent.

Screening and identification of miRNAs related to sexual differentiation of strobili in Ginkgo biloba by integration analysis of small RNA, mRNA, and degradome sequencing

“…Transcriptional analysis indicated that MYB108 and MYB24 have overlapping functions and acted downstream of MYB21 in a transcriptional cascade that mediated stamen and pollen maturation [47,48]. Our ndings was consistent with the results of previous studies, which demonstrated that GA could promote differentiation of male owers [8]. The present study found that miR159.1, miR159.2, miR159.3, miR159.4 and miR858 were identi ed to target GAMYB1 in MB, FB, MS and OS.…”

“…IAA (indoleacetic acid) and auxin-like substances mainly act on the elongation of plant cells and promoting female phenotype. Spraying exogenous GA to C. sativus increased the male proportion in male and monoecious cucumber and induced the formation of male owers in gynoecious plants [8]. Therefore, phytohormones play important roles in ower development and sexual differentiation in plant.…”

“…Subsequently, two MADS-box genes, SpAPETALA3 and SpPISTILLATA, were characterized to be involved in formation of male ower primordia in Spinacia oleracea [7]. In Cucumis sativus, CsACS2 gene was proved to inhibit male ower formation and promote female ower formation [8]. More recently, two important sex-differentiated genes, Shy Girl (SyGI) and Friendly boy (FrBy),, were cloned from Actinidia chinensis and identi ed to act for the maintenance of male functions [9,10].…”

Gene networks orchestrated by MeGI: a single‐factor mechanism underlying sex determination in persimmon

“…The expression of gibberellin‐regulated genes, such as GASA1 , is also mediated by auxin (Paponov et al ., ). Gibberellin signaling is often involved in activities associated with the formation of unisexual flowers, such as the abortion of androecium primordia in female flowers in maize (Lebel‐Hardenack and Grant, ) and the promotion of male flower development in cucumber ( Cucumis sativus L.) (Zhang et al ., ). Our results suggest that gibberellin signaling is important for sex determination in persimmon, potentially through cooperative effects with cytokinin signals.…”

PEMANFAATAN AIR KELAPA (Cocos nucifera) UNTUK MASKULINISASI IKAN GUPPY (Poecilia reticulata)

“…Auksin berperan dalam pembentukan kelamin betina sedangkan gibberellin cenderung bekerja sebagai hormon jantan pada tanaman (Zhang et al, 2017;Ming et al, 2014;Martinez et al, 2013) Kandungan…”