RESUMEN
Ethylene can accelerate the postharvest ripening process of kiwifruit, while indole-3-acetic acid (IAA) delays it. However, the molecular mechanism by which ethylene regulates IAA degradation is unclear. Here, we found that ethephon promotes the degradation of free IAA in kiwifruit. Furthermore, ethylene can promote the expression of AcGH3.1 and enhance its promoter activity. Two ethylene response factors (ERFs), AcERF1B and AcERF073, were obtained using an AcGH3.1 promoter as bait for a yeast one-hybrid screening library. Both AcERF1B and AcERF073 bind to the AcGH3.1 promoter to activate it. Also, AcERF1B/073 enhanced AcGH3.1 expression, decreased the free IAA content, and increased the IAA-Asp content in kiwifruit. In addition, we found that the AcERF1B and AcERF073 proteins directly interact, and this interaction enhanced their binding to the AcGH3.1 promoter. In summary, our results suggest that AcERF1B and AcERF073 positively regulate IAA degradation by activating AcGH3.1 transcription, which accelerated postharvest kiwifruit ripening.
Asunto(s)
Actinidia , Regulación de la Expresión Génica de las Plantas , Actinidia/genética , Actinidia/metabolismo , Ácidos Indolacéticos/farmacología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
How aerobic organisms exploit inevitably generated but potentially dangerous reactive oxygen species (ROS) to benefit normal life is a fundamental biological question. Locally accumulated ROS have been reported to prime stem cell differentiation. However, the underlying molecular mechanism is unclear. Here, we reveal that developmentally produced H2O2 in plant shoot apical meristem (SAM) triggers reversible protein phase separation of TERMINATING FLOWER (TMF), a transcription factor that times flowering transition in the tomato by repressing pre-maturation of SAM. Cysteine residues within TMF sense cellular redox to form disulfide bonds that concatenate multiple TMF molecules and elevate the amount of intrinsically disordered regions to drive phase separation. Oxidation triggered phase separation enables TMF to bind and sequester the promoter of a floral identity gene ANANTHA to repress its expression. The reversible transcriptional condensation via redox-regulated phase separation endows aerobic organisms with the flexibility of gene control in dealing with developmental cues.
Asunto(s)
Flores/genética , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , ARN de Planta/genética , Especies Reactivas de Oxígeno/metabolismo , Solanum lycopersicum/genética , Agrobacterium/genética , Agrobacterium/metabolismo , Flores/crecimiento & desarrollo , Flores/metabolismo , Regulación del Desarrollo de la Expresión Génica , Hidroponía/métodos , Proteínas Intrínsecamente Desordenadas/genética , Proteínas Intrínsecamente Desordenadas/metabolismo , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/metabolismo , Meristema/genética , Meristema/crecimiento & desarrollo , Meristema/metabolismo , Oxidación-Reducción , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Protoplastos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN de Planta/metabolismo , Especies Reactivas de Oxígeno/uso terapéutico , S-Adenosilmetionina/metabolismo , Plantones/genética , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transformación GenéticaRESUMEN
Crop improvement by inbreeding often results in fitness penalties and loss of genetic diversity. We introduced desirable traits into four stress-tolerant wild-tomato accessions by using multiplex CRISPR-Cas9 editing of coding sequences, cis-regulatory regions or upstream open reading frames of genes associated with morphology, flower and fruit production, and ascorbic acid synthesis. Cas9-free progeny of edited plants had domesticated phenotypes yet retained parental disease resistance and salt tolerance.
RESUMEN
Although ABA signaling has been widely studied in Arabidopsis, the roles of core ABA signaling components in fruit remain poorly understood. Herein, we characterize SlPP2C1, a group A type 2C protein phosphatase that negatively regulates ABA signaling and fruit ripening in tomato. The SlPP2C1 protein was localized in the cytoplasm close to AtAHG3/AtPP2CA. The SlPP2C1 gene was expressed in all tomato tissues throughout development, particularly in flowers and fruits, and it was up-regulated by dehydration and ABA treatment. SlPP2C1 expression in fruits was increased at 30 d after full bloom and peaked at the B + 1 stage. Suppression of SlPP2C1 expression significantly accelerated fruit ripening which was associated with higher levels of ABA signaling genes that are reported to alter the expression of fruit ripening genes involved in ethylene release and cell wall catabolism. SlPP2C1-RNAi (RNA interference) led to increased endogenous ABA accumulation and advanced release of ethylene in transgenic fruits compared with wild-type (WT) fruits. SlPP2C1-RNAi also resulted in abnormal flowers and obstructed the normal abscission of pedicels. SlPP2C1-RNAi plants were hypersensitized to ABA, and displayed delayed seed germination and primary root growth, and increased resistance to drought stress compared with WT plants. These results demonstrated that SlPP2C1 is a functional component in the ABA signaling pathway which participates in fruit ripening, ABA responses and drought tolerance.
Asunto(s)
Frutas/genética , Regulación de la Expresión Génica de las Plantas/genética , Fosfoproteínas Fosfatasas/genética , Proteínas de Plantas/genética , Solanum lycopersicum/genética , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacología , Adaptación Fisiológica/genética , Sequías , Etilenos/metabolismo , Flores/genética , Flores/metabolismo , Frutas/metabolismo , Frutas/fisiología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Solanum lycopersicum/metabolismo , Solanum lycopersicum/fisiología , Fosfoproteínas Fosfatasas/clasificación , Fosfoproteínas Fosfatasas/metabolismo , Filogenia , Reguladores del Crecimiento de las Plantas/metabolismo , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/metabolismo , Interferencia de ARN , Transducción de Señal/genética , Estrés FisiológicoRESUMEN
Abscisic acid (ABA) glucose conjugation mediated by uridine diphosphate glucosyltransferases (UGTs) is an important pathway in regulating ABA homeostasis. In the present study, we investigated three tomato SlUGTs that are highly expressed in fruit during ripening, and these SlUGTs were localized to the cytoplasm and cell nucleus. Among these three UGTs, SlUGT75C1 catalyzes the glucosylation of both ABA and IAA in vitro; SlUGT76E1 can only catalyze the conjugation of ABA; and SlUGT73C4 cannot glycosylate either ABA or IAA. Therefore, SlUGT75C1 was selected for further investigation. SlUGT75C1 RNA interference significantly up-regulated the expression level of SlCYP707A2, which encodes an ABA 8'-hydroxylase but did not affect the expression of SlNCED1, which encodes a key enzyme in ABA biosynthesis. Suppression of SlUGT75C1 significantly accelerated fruit ripening by enhancing ABA levels and promoting the early release of ethylene. SlUGT75C1-RNAi altered the expression of fruit ripening genes (genes involved in ethylene release and cell wall catabolism). SlUGT75C1-RNAi seeds showed delayed germination and root growth compared with wild-type as well as increased sensitivity to exogenous ABA. SlUGT75C1-RNAi plants were also more resistant to drought stress. These results demonstrated that SlUGT75C1 plays a crucial role in ABA-mediated fruit ripening, seed germination, and drought responses in tomato.
Asunto(s)
Ácido Abscísico/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Glucosiltransferasas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Solanum lycopersicum/fisiología , Sistema Enzimático del Citocromo P-450/genética , Sequías , Etilenos/metabolismo , Frutas/citología , Frutas/enzimología , Frutas/genética , Frutas/fisiología , Germinación , Glucosiltransferasas/genética , Solanum lycopersicum/citología , Solanum lycopersicum/enzimología , Solanum lycopersicum/genética , Modelos Biológicos , Fenotipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Interferencia de ARN , Semillas/citología , Semillas/enzimología , Semillas/genética , Semillas/fisiología , Estrés Fisiológico , Uridina Difosfato/metabolismoRESUMEN
The VlMYBA subfamily of transcription factors has been known to be the functional regulators in anthocyanin biosynthesis in red grapes. In this study, the expressions of the VlMYBA1-2 and VlMYBA 2 genes, and the responses of the VlMYBA1-2/2 promoters to ABA and ACC treatments in Kyoho grape berries are examined through quantitative real-time PCR analysis and the transient expression assay. The results show that the expressions of VlMYBA1-2/2 increase dramatically after véraison and reach their highest levels when the berries are nearly fully ripe. Exogenous ABA promotes the expressions of VlMYBA1-2/2, whereas the ACC treatment increases the expression of VlMYBA2, however, it has no effect on VlMYBA1-2. The ABA treatment has a faster and stronger effect on berry pigmentation than ACC does. The VlMYBA1-2 promoter sequence contains two ABA response elements (ABRE) but no ethylene response element (ERE), whereas the VlMYBA2 promoter sequence contains two ABRE and one ERE in the upstream region of the start codon. The VlMYBA2 promoter can be activated by both ABA (more effective) and ACC, whereas the VlMYBA1-2 promoter can be activated by ABA only. In sum, ABA can promote the coloring of Kyoho grape by the promotion of VlMYBA1-2/2 transcriptions via activating the response of their promoters to ABA, whereas ethylene only regulates VlMYBA2 through the response activation of its promoter to ACC which partially enhances the coloring.
Asunto(s)
Ácido Abscísico/farmacología , Aminoácidos Cíclicos/farmacología , Frutas/genética , Proteínas de Plantas/genética , Regiones Promotoras Genéticas/genética , Vitis/genética , Antocianinas/metabolismo , Secuencia de Bases , Frutas/efectos de los fármacos , Frutas/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas , Fenoles/farmacología , Proteínas de Plantas/metabolismo , Alineación de Secuencia , Vitis/efectos de los fármacos , Vitis/crecimiento & desarrolloRESUMEN
Abscisic acid (ABA) regulates fruit development and ripening via its signaling. However, the exact role of ABA signaling core components in fruit have not yet been clarified. In this study, we investigated the potential interactions of tomato (Solanum lycopersicon) ABA signaling core components using yeast two-hybrid analysis, with or without ABA at different concentrations. The results showed that among 12 PYR/PYL/RCAR ABA receptors (SlPYLs), SlPYL1, SlPYL2, SlPYL4, SlPYL5, SlPYL 7, SlPYL8, SlPYL9, SlPYL10, SlPYL11, and SlPYL13 were ABA-dependent receptors, while SlPYL3 and SlPYL12 were ABA-independent receptors. Among five SlPP2Cs (type 2C protein phosphatases) and seven SlSnRK2s (subfamily 2 of SNF1-related kinases), all SlSnRK2s could interact with SlPP2C2, while SlSnRK2.8 also interacted with SlPP2C3. SlSnRK2.5 could interact with SlABF2/4 (ABA-responsive element binding factors). Expressions of SlPYL1, SlPYL2, SlPYL8, and SlPYL10 were upregulated under exogenous ABA but downregulated under nordihydroguaiaretic acid (NDGA) at the mature green stage of fruit ripening. The expressions of SlPP2C1, SlPP2C2, SlPP2C3, and SlPP2C5 were upregulated in ABA-treated fruit, but downregulated in NDGA-treated fruit at the mature green stage. The expressions of SlSnRK2.4, SlSnRK2.5, SlSnRK2.6, and SlSnRK2.7 were upregulated by ABA, but downregulated by NDGA. However, SlSnRK2.2 was down regulated by ABA. Expression of SlABF2/3/4 was enhanced by ABA but decreased by NDGA. Based on these results, we concluded that the majority of ABA receptor PYLs interact with SlPP2Cs in an ABA-dependent manner. SlPP2C2 and SlPP2C3 can interact with SlSnRK2s. SlSnRK2.5 could interact with SlABF2/4. Most ABA signaling core components respond to exogenous ABA.