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1.
Plant Physiol Biochem ; 181: 1-11, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35421744

RESUMO

The unfolded protein response (UPR) plays a significant role in the maintenance of cellular homeostasis under endoplasmic reticulum (ER) stress, which is highly dependent on the regulation of defense-related phytohormones. In this study, the role of ethylene (ET) in ER stress and UPR was investigated in the leaves of intact tomato (Solanum lycopersicum) plants. Exogenous application of the ET precursor 1-aminocyclopropane-1-carboxylic acid not only resulted in higher ET emission from leaves but also increased the expression of the UPR marker gene SlBiP and the transcript levels of the ER stress sensor SlIRE1, as well as the levels of SlbZIP60, after 24 h in tomato leaves. Using ET receptor Never ripe (Nr) mutants, a significant role of ET in tunicamycin (Tm)-induced ER stress sensing and signaling was confirmed based on the changes in the expression levels of SlIRE1b and SlBiP. Furthermore, the analysis of other defense-related phytohormones showed that the Tm-induced ET can affect positively the levels of and response to salicylic acid. Additionally, it was found that nitric oxide production and lipid peroxidation, as well as the electrolyte leakage induced by Tm, is regulated by ET, whereas the levels of H2O2 and proteolytic activity seemed to be independent of ET under ER stress in the leaves of tomato plants.


Assuntos
Lycopersicon esculentum , Etilenos/metabolismo , Peróxido de Hidrogênio/metabolismo , Lycopersicon esculentum/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Resposta a Proteínas não Dobradas
2.
Plant Physiol Biochem ; 181: 61-70, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35430395

RESUMO

Flower opening is a process primarily caused by water uptake-driven petal cell expansion. while which is easily affected by water deficit during transportation of cut flowers, resulting in abnormal flower opening. The knowledge of important players during this process remains limited. We previously reported that the aquaporin RhPIP1;1 plays an important role in ethylene-regulated petal cell expansion in rose flower. Here, we identified RhRab5ip as a new interactor of RhPIP1;1. RhRab5ip belongs to the Rab5-interacting protein (Rab5ip) family and may function in vesicle trafficking pathway. By using split ubiquitin yeast two-hybrid (SUY2H) system, bimolecular fluorescence complementation (BiFC) and subcellular colocalization we confirmed the existence of physical interaction between RhPIP1;1 and RhRab5ip in yeast and plant cell. The interaction of these two proteins happened at the small punctate structures in the cytoplasm. Expression of RhRab5ip in petals increased substantially at the initial stage of flower opening and maintained at high level until flower wilting. The transcripts of both RhRab5ip and RhPIP1;1 were greatly up-regulated by ABA and GA3 treatments, while only RhPIP1;1 was down-regulated by ethylene. Moreover, both RhRab5ip and RhPIP1;1 were significantly induced by water deficit treatment after 12 h-treatment, when flowers started to wilt and showed neck bending. Taken together, these findings suggested that RhRab5ip might functionally coordinate with RhPIP1;1 in response to water deficit stress in rose flower, expanding our understanding of the possible involvement of Rab5ip protein in the regulatory network of flower opening during water deficit.


Assuntos
Rosa , Desidratação/metabolismo , Etilenos/metabolismo , Flores/metabolismo , Rosa/metabolismo , Saccharomyces cerevisiae/metabolismo , Água/metabolismo
3.
J Plant Res ; 135(3): 485-500, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35380307

RESUMO

Rhynchophylline (RIN) and isorhynchophylline (IRN) are extracted from Uncaria rhynchophylla, which are used to treat Alzheimer's disease. However, the massive accumulation of RIN and IRN in U. rhynchophylla requires exogenous stimulation. Ethylene is a potential stimulant for RIN and IRN biosynthesis, but there is no study on the role of ethylene in RIN or IRN synthesis. This study investigated the regulation of ethylene in RIN and IRN biosynthesis in U. rhynchophylla. An increase in the content of RIN and IRN was observed that could be attributed to the release of ethylene from 18 mM ethephon, while ethylene released from 36 mM ethephon reduced the content of RIN and IRN. The transcriptome and weighted gene co-expression network analysis indicated the up-regulation of seven key enzyme genes related to the RIN/IRN biosynthesis pathway and starch/sucrose metabolism pathway favored RIN/IRN synthesis. In comparison, the down-regulation of these seven key enzyme genes contributed to the reduction of RIN/IRN. Moreover, the inhibition of photosynthesis is associated with a reduction in RIN/IRN. Photosynthesis was restrained owing to the down-regulation of Lhcb1 and Lhcb6 after 36 mM ethephon treatment and further prevented supply of primary metabolites (such as α-D-glucose) for RIN/IRN synthesis. However, uninterrupted photosynthesis ensured a normal supply of primary metabolites at 18 mM ethephon treatment. AP2/ERF1, bHLH1, and bHLH2 may positively regulate the RIN/IRN accumulation, while NAC1 may play a negative regulatory role. Our results construct the potential bidirectional model for ethylene regulation on RIN/IRN synthesis and provide novel insight into the ethylene-mediated regulation of the metabolism of terpenoid indole alkaloids.


Assuntos
Uncaria , Etilenos/metabolismo , Alcaloides Indólicos/metabolismo , Alcaloides Indólicos/farmacologia , Oxindóis , Transcriptoma , Uncaria/genética , Uncaria/metabolismo
4.
New Phytol ; 234(5): 1735-1752, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35274300

RESUMO

Root hair development is regulated by hormonal and environmental cues, such as ethylene and low phosphate. Auxin efflux carrier PIN2 (PIN-FORMED 2) plays an important role in establishing a proper auxin gradient in root tips, which is required for root hair development. Ethylene promotes root hair development through increasing PIN2 abundance in root tips, which subsequently leads to enhanced expression of auxin reporter genes. However, how PIN2 is regulated remains obscure. Here, we report that Arabidopsis thaliana sav4 (shade avoidance 4) mutant exhibits defects in ethylene-induced root hair development and in establishing a proper auxin gradient in root tips. Ethylene treatment increased SAV4 abundance in root tips. SAV4 and PIN2 co-localize to the shootward plasma membrane (PM) of root tip epidermal cells. SAV4 directly interacts with the PIN2 hydrophilic region (PIN2HL) and regulates PIN2 abundance on the PM. Vacuolar degradation of PIN2 is suppressed by ethylene, which was weakened in sav4 mutant. Furthermore, SAV4 affects the formation of PIN2 clusters and its lateral diffusion on the PM. In summary, we identified SAV4 as a novel regulator of PIN2 that enhances PIN2 membrane clustering and stability through direct protein-protein interactions. Our study revealed a new layer of regulation on PIN2 dynamics.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Etilenos/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Raízes de Plantas/metabolismo
5.
New Phytol ; 234(5): 1714-1734, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35254663

RESUMO

Nitric oxide (NO) is known to modulate the action of several phytohormones. This includes the gaseous hormone ethylene, but the molecular mechanisms underlying the effect of NO on ethylene biosynthesis are unclear. Here, we observed a decrease in endogenous NO abundance during apple (Malus domestica) fruit development and exogenous treatment of apple fruit with a NO donor suppressed ethylene production, suggesting that NO is a ripening suppressor. Expression of the transcription factor MdERF5 was activated by NO donor treatment. NO induced the nucleocytoplasmic shuttling of MdERF5 by modulating its interaction with the protein phosphatase, MdPP2C57. MdPP2C57-induced dephosphorylation of MdERF5 at Ser260 is sufficient to promote nuclear export of MdERF5. As a consequence of this export, MdERF5 proteins in the cytoplasm interacted with and suppressed the activity of MdACO1, an enzyme that converts 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene. The NO-activated MdERF5 was observed to increase in abundance in the nucleus and bind to the promoter of the ACC synthase gene MdACS1 and directly suppress its transcription. Together, these results suggest that NO-activated nucleocytoplasmic MdERF5 suppresses the action of ethylene biosynthetic genes, thereby suppressing ethylene biosynthesis and limiting fruit ripening.


Assuntos
Malus , Transporte Ativo do Núcleo Celular , Etilenos/metabolismo , Fator V/genética , Fator V/metabolismo , Fator V/farmacologia , Frutas/genética , Regulação da Expressão Gênica de Plantas , Malus/metabolismo , Óxido Nítrico/metabolismo , Proteínas de Plantas/metabolismo
6.
Planta ; 255(5): 94, 2022 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-35347454

RESUMO

MAIN CONCLUSION: Genetic analysis reveals a previously unknown role for ethylene signaling in regulating Arabidopsis thaliana nitrogen metabolism. Nitrogen (N) is essential for plant growth, and assimilation of soil nitrate (NO3-) and ammonium ions is an important route of N acquisition. Although N import and assimilation are subject to multiple regulatory inputs, the extent to which ethylene signaling contributes to this regulation remains poorly understood. Here, our analysis of Arabidopsis thaliana ethylene signaling mutants advances that understanding. We show that the loss of CTR1 function ctr1-1 mutation confers resistance to the toxic effects of the NO3- analogue chlorate (ClO3-), and reduces the activity of the nitrate reductase (NR) enzyme of NO3- assimilation. Our further analysis indicates that the lack of the downstream EIN2 component (conferred by novel ein2 mutations) suppresses the effect of ctr1-1, restoring ClO3- sensitivity and NR activity to normal. Collectively, our observations indicate an important role for ethylene signaling in regulating Arabidopsis thaliana NO3- metabolism. We conclude that ethylene signaling enables environmentally responsive coordination of plant growth and N metabolism.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Etilenos/metabolismo , Nitratos/metabolismo , Transdução de Sinais
7.
BMC Plant Biol ; 22(1): 108, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35264115

RESUMO

BACKGROUND: Potassium (K) is important in the regulation of plant growth and development. It is the most abundant mineral element in kiwifruit, and its content increases during fruit ripening. However, how K+ transporter works in kiwifruit postharvest maturation is not yet clear. RESULTS: Here, 12 K+ transporter KT/HAK/KUP genes, AcKUP1 ~ AcKUP12, were isolated from kiwifruit, and their phylogeny, genomic structure, chromosomal location, protein properties, conserved motifs and cis-acting elements were analysed. Transcription analysis revealed that AcKUP2 expression increased rapidly and was maintained at a high level during postharvest maturation, consistent with the trend of K content; AcKUP2 expression was induced by ethylene, suggesting that AcKUP2 might play a role in ripening. Fluorescence microscopy showed that AcKUP2 is localised in the plasma membrane. Cis-elements, including DER or ethylene response element (ERE) responsive to ethylene, were found in the AcKUP2 promoter sequence, and ethylene significantly enhanced the AcKUP2 promoter activity. Furthermore, we verified that AcERF15, an ethylene response factor, directly binds to the AcKUP2 promoter to promote its expression. Thus, AcKUP2 may be an important potassium transporter gene which involved in ethylene-regulated kiwifruit postharvest ripening. CONCLUSIONS: Therefore, our study establishes the first genome-wide analysis of the kiwifruit KT/HAK/KUP gene family and provides valuable information for understanding the function of the KT/HAK/KUP genes in kiwifruit postharvest ripening.


Assuntos
Actinidia/crescimento & desenvolvimento , Actinidia/genética , Etilenos/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Antiportadores de Potássio-Hidrogênio/metabolismo , China , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Genes de Plantas , Desenvolvimento Vegetal/efeitos dos fármacos , Desenvolvimento Vegetal/genética , Antiportadores de Potássio-Hidrogênio/genética
8.
Plant Sci ; 318: 111235, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35351307

RESUMO

Fruit development and ripening is a complicated biological process, that is not only regulated by plant hormones and transcription factors, but also affected by epigenetic modifications. Histone deacetylation is an important way of epigenetic modification, and little information about it is available. In this study, an RNAi vector was constructed and transferred successfully into wild-type tomato for further research on the detailed functions of the histone deacetylation gene SlHDT1. The expression level of PSY1 was upregulated, and the transcription levels of LCY-B, LCY-E and CYC-B were downregulated, which was consistent with the increased accumulation of carotenoids. In addition, the expression levels of ethylene biosynthetic genes (ACS2, ACS4 and ACO1, ACO3), ripening-associated genes (RIN, E4, E8, PG, Pti4 and LOXB) and fruit cell wall metabolism genes (HEX, MAN, TBG4, XTH5 and XYL) were significantly upregulated further strengthening the results, including an increased ethylene content, advanced fruit ripening time and a shortened shelf life of tomato fruits. In addition, the increased total histone H3 acetylation level also provides evidence of a connection between epigenetic regulation by histone deacetylation and fruit development and ripening. Hence, SlHDT1 is a negative regulator and plays an essential role in regulating ethylene and carotenoid biosynthesis during fruit ripening through influences on the acetylation level.


Assuntos
Lycopersicon esculentum , Carotenoides/metabolismo , Epigênese Genética , Etilenos/metabolismo , Frutas , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
9.
Food Chem ; 384: 132490, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35193019

RESUMO

Fruit ripening involves changes in physical, physiological, biochemical, and metabolic activities through the actions of enzymes and regulatory genes. In this study, we elucidate primary and secondary metabolites and antioxidant activities of green 'Hayward' and gold 'Haegeum' kiwifruit cultivars during ripening by comparing ethylene-treated fruit to the control. A total of 36 primary metabolites (20 amino acids, 9 fatty acids, 4 organic acids, and 3 sugars) were identified to be altered significantly during the ripening of both cultivars. Significant changes in secondary metabolites such as total phenols, flavonoids, and vitamin C were also observed during the ripening of both cultivars. Moreover, antioxidant activity assays showed that ripening either maintains or increases the antioxidant activity of kiwifruit cultivars. These findings could assist the fruit industry in developing metabolic markers for indication of the optimum kiwifruit ripening quality and postharvest decisions for storage, distribution, and marketing.


Assuntos
Actinidia , Antioxidantes , Actinidia/química , Antioxidantes/análise , Etilenos/metabolismo , Frutas/química , Ouro/análise
10.
Plant Cell Rep ; 41(4): 1075-1085, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35201411

RESUMO

KEY MESSAGE: Arabidopsis CPR5 is involved in regulation of ethylene signaling via two different ways: interacting with the ETR1 N-terminal domains, and controlling nucleocytoplasmic transport of ethylene-related mRNAs. The ETR1 receptor plays a predominant role in ethylene signaling in Arabidopsis thaliana. Previous studies showed that both RTE1 and CPR5 can directly bind to the ETR1 receptor and regulate ethylene signaling. RTE1 was suggested to promote the ETR1 receptor signaling by influencing its conformation, but little is known about the regulatory mechanism of CPR5 in ethylene signaling. In this study, we presented the data showing that both RTE1 and CPR5 bound to the N-terminal domains of ETR1, and regulated ethylene signaling via the ethylene receptor. On the other hand, the research provided evidence indicating that CPR5 could act as a nucleoporin to regulate the ethylene-related mRNAs export out of the nucleus, while RTE1 or its homolog (RTH) had no effect on the nucleocytoplasmic transport of mRNAs. Nuclear qRT-PCR analysis and poly(A)-mRNA in situ hybridization showed that defect of CPR5 restricted nucleocytoplasmic transport of mRNAs. These results advance our understanding of the regulatory mechanism of CPR5 in ethylene signaling.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Transporte Ativo do Núcleo Celular , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana/genética , Mutação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/genética
11.
Plant Cell Rep ; 41(4): 979-993, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35226115

RESUMO

KEY MESSAGE: Lower ethylene production in sugarcane results in plants with higher stature, expression of growth-promoting genes, higher photosynthetic rate, and increased antioxidant compounds. The hormone ethylene is involved in critical processes in sugarcane, such as the growth and accumulation of sucrose. The lack of mutants for ethylene biosynthesis or signaling genes makes it difficult to understand the role of this phytohormone throughout sugarcane development. This study aimed to evaluate the physiology and development of sugarcane plants with low ethylene production. To achieve this goal, we used RNA interference to silence three genes, ScACS1, ScACS2, and ScACS3, encoding 1-aminocyclopropane-1-carboxylic acid synthases (ACS), responsible for a limiting step of the ethylene biosynthesis pathway. Sugarcane plants with reduced ethylene levels presented increased growth, faster germination of lateral gems, and activation of non-enzymatic antioxidant mechanisms. We observed an augmentation in the expression of ScACO5, which encodes the final enzyme regulating ethylene biosynthesis, and ScERF1, encoding a transcription factor, linked to the ethylene response. The increase in plant height was correlated with higher expression of ScPIF3, ScPIF4, and ScPIF5, which encode for transcription factors related to growth induction. Interestingly, there was also an increase in the expression of the ScGAI gene, which encodes a DELLA protein, a growth repressor. The final content of sucrose in the stems was not affected by the low levels of ethylene, although the rate of CO2 assimilation was reduced. This study reports for the first time the impacts of low endogenous production of ethylene in sugarcane and provides helpful insights on the molecular mechanisms behind ethylene responses.


Assuntos
Saccharum , Antioxidantes/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Saccharum/genética , Saccharum/metabolismo , Sacarose/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Plant Physiol ; 189(1): 66-83, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35148400

RESUMO

Anthocyanin production in apple (Malus domestica) fruit and their consequent coloration can be induced by high-light treatment. The hormone ethylene is also essential for this coloration, but the regulatory relationships that link ethylene and light with anthocyanin-associated coloration are not well defined. In this study, we observed that high-light treatment of apple fruit increased anthocyanin accumulation more than moderate-light treatment did and was the main contributor of induced ethylene production and activation of anthocyanin biosynthesis. A transcriptome study of light-treated apple fruit suggested that a long noncoding RNA (lncRNA), MdLNC610, the corresponding gene of which is physically located downstream from the 1-aminocyclopropane-1-carboxylate oxygenase (ACO) ethylene biosynthesis gene MdACO1, likely affects anthocyanin biosynthesis under high-light treatment. Expression and promoter ß-glucuronidase reporter analyses further showed that MdLNC610 upregulates expression of MdACO1 and so likely participates in high-light-induced ethylene biosynthesis. Overexpression of MdACO1 and MdLNC610 in apple fruit and calli indicated that a major increase in MdLNC610 expression activates MdACO1 expression, thereby causing an increase in ethylene production and anthocyanin levels. These results suggest that MdLNC610 participates in the regulation of high-light-induced anthocyanin production by functioning as a positive regulator to promote MdACO1 expression and ethylene biosynthesis. Our study provides insights into the relationship between mRNA and lncRNA networks in the ethylene biosynthetic pathway and anthocyanin accumulation in apple fruit.


Assuntos
Malus , RNA Longo não Codificante , Antocianinas/metabolismo , Etilenos/metabolismo , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Malus/genética , Malus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
13.
Plant Physiol ; 189(1): 315-328, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35171288

RESUMO

DNA methylation plays an important role in regulating tomato (Solanum lycopersicum) fruit ripening. Although SlDML2, a DNA demethylase (DML) gene, is critically involved in tomato fruit ripening, little is known about genes that regulate its expression. Using yeast one-hybrid screening, we identified a High Mobility Group A protein, named SlHMGA3, and demonstrated its binding activity to the AT-rich region of the SlDML2 promoter. We produced slhmga3 tomato mutants using CRISPR/Cas9 and observed that slhmga3 fruit reached the breaker stage much later than fruit from the wild-type. We further demonstrated that at the initiation stage of fruit ripening, the increased expression of SlDML2 and ethylene biosynthetic and signaling genes was significantly delayed in slhmga3 fruit, along with delays in ethylene production and demethylation and activation of ripening-associated transcription factor genes. Our results demonstrate that SlHMGA3 plays a role in enhancing SlDML2 expression, and its effects on tomato fruit ripening are largely through DNA demethylation of ripening-associated transcription factor genes.


Assuntos
Lycopersicon esculentum , DNA/metabolismo , Etilenos/metabolismo , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
New Phytol ; 234(4): 1262-1277, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35182082

RESUMO

Ethylene (ETH) controls climacteric fruit ripening and can be triggered by osmotic stress. However, the mechanism regulating ETH biosynthesis during fruit ripening and under osmotic stress is largely unknown in apple (Malus domestica). Here, we explored the roles of SnRK2 protein kinases in ETH biosynthesis related to fruit ripening and osmoregulation. We identified the substrates of MdSnRK2-I using phosphorylation analysis techniques. Finally, we identified the MdSnRK2-I-mediated signaling pathway for ETH biosynthesis related to fruit ripening and osmoregulation. The activity of two MdSnRK2-I members, MdSnRK2.4 and MdSnRK2.9, was significantly upregulated during ripening or following mannitol treatment. Overexpression of MdSnRK2-I increased ETH biosynthesis under normal and osmotic conditions in apple fruit. MdSnRK2-I phosphorylated the transcription factors MdHB1 and MdHB2 to enhance their protein stability and transcriptional activity on MdACO1. MdSnRK2-I also interacted with MdACS1 and increased its protein stability through two phosphorylation sites. The increased MdACO1 expression and MdACS1 protein stability resulted in higher ETH production in apple fruit. In addition, heterologous expression of MdSnRK2-I or manipulation of SlSnRK2-I expression in tomato (Solanum lycopersicum) fruit altered fruit ripening and ETH biosynthesis. We established that MdSnRK2-I functions in fruit ripening and osmoregulation, and identified the MdSnRK2-I-mediated signaling pathway controlling ETH biosynthesis.


Assuntos
Lycopersicon esculentum , Malus , Etilenos/metabolismo , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Malus/genética , Malus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
Plant Physiol ; 188(4): 2166-2181, 2022 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35088866

RESUMO

Histone deacetylase enzymes participate in the regulation of many aspects of plant development. However, the genome-level targets of histone deacetylation during apple (Malus domestica) fruit development have not been resolved in detail, and the mechanisms of regulation of such a process are unknown. We previously showed that the complex of ethylene response factor 4 (MdERF4) and the TOPLESS co-repressor (MdTPL4; MdERF4-MdTPL4) is constitutively active during apple fruit development (Hu et al., 2020), but whether this transcriptional repression complex is coupled to chromatin modification is unknown. Here, we show that a histone deacetylase (MdHDA19) is recruited to the MdERF4-MdTPL4 complex, thereby impacting fruit ethylene biosynthesis. Transient suppression of MdHDA19 expression promoted fruit ripening and ethylene production. To identify potential downstream target genes regulated by MdHDA19, we conducted chromatin immunoprecipitation (ChIP) sequencing of H3K9 and ChIP-quantitative polymerase chain reaction assays. We found that MdHDA19 affects ethylene production by facilitating H3K9 deacetylation and forms a complex with MdERF4-MdTPL4 to directly repress MdACS3a expression by decreasing the degree of acetylation. We demonstrate that an early-maturing-specific acetylation H3K9ac peak in MdACS3a and expression of MdACS3a were specifically up-regulated in fruit of an early-maturing, but not a late-maturing, cultivar. We provide evidence that a C-to-G mutation in the ethylene-responsive element binding factor-associated amphiphilic repression motif of MdERF4 reduces the repression of MdACS3a by the MdERF4-MdTPL4-MdHDA19 complex. Taken together, our results reveal that the MdERF4-MdTPL-MdHDA19 repressor complex participates in the epigenetic regulation of apple fruit ripening.


Assuntos
Malus , Epigênese Genética , Etilenos/metabolismo , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Histonas/genética , Histonas/metabolismo , Malus/metabolismo , Proteínas de Plantas/metabolismo
17.
Plant Cell ; 34(4): 1273-1288, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35021223

RESUMO

Primary root growth in cereal crops is fundamental for early establishment of the seedling and grain yield. In young rice (Oryza sativa) seedlings, the primary root grows rapidly for 7-10 days after germination and then stops; however, the underlying mechanism determining primary root growth is unclear. Here, we report that the interplay of ethylene and gibberellin (GA) controls the orchestrated development of the primary root in young rice seedlings. Our analyses advance the knowledge that primary root growth is maintained by higher ethylene production, which lowers bioactive GA contents. Further investigations unraveled that ethylene signaling transcription factor ETHYLENE INSENSITIVE3-LIKE 1 (OsEIL1) activates the expression of the GA metabolism genes GIBBERELLIN 2-OXIDASE 1 (OsGA2ox1), OsGA2ox2, OsGA2ox3, and OsGA2ox5, thereby deactivating GA activity, inhibiting cell proliferation in the root meristem, and ultimately gradually inhibiting primary root growth. Mutation in OsGA2ox3 weakened ethylene-induced GA inactivation and reduced the ethylene sensitivity of the root. Genetic analysis revealed that OsGA2ox3 functions downstream of OsEIL1. Taken together, we identify a molecular pathway impacted by ethylene during primary root elongation in rice and provide insight into the coordination of ethylene and GA signals during root development and seedling establishment.


Assuntos
Giberelinas , Oryza , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Giberelinas/metabolismo , Giberelinas/farmacologia , Oryza/metabolismo , Plântula/metabolismo
18.
Plant Cell ; 34(4): 1250-1272, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35099538

RESUMO

Ethylene response factors (ERFs) are downstream components of ethylene-signaling pathways known to play critical roles in ethylene-controlled climacteric fruit ripening, yet little is known about the molecular mechanism underlying their mode of action. Here, we demonstrate that SlERF.F12, a member of the ERF.F subfamily containing Ethylene-responsive element-binding factor-associated Amphiphilic Repression (EAR) motifs, negatively regulates the onset of tomato (Solanum lycopersicum) fruit ripening by recruiting the co-repressor TOPLESS 2 (TPL2) and the histone deacetylases (HDAs) HDA1/HDA3 to repress the transcription of ripening-related genes. The SlERF.F12-mediated transcriptional repression of key ripening-related genes 1-AMINO-CYCLOPROPANE-1-CARBOXYLATE SYNTHASE 2 (ACS2), ACS4, POLYGALACTURONASE 2a, and PECTATE LYASE is dependent on the presence of its C-terminal EAR motif. We show that SlERF.F12 interacts with the co-repressor TPL2 via the C-terminal EAR motif and recruits HDAs SlHDA1 and SlHDA3 to form a tripartite complex in vivo that actively represses transcription of ripening genes by decreasing the level of the permissive histone acetylation marks H3K9Ac and H3K27Ac at their promoter regions. These findings provide new insights into the ripening regulatory network and uncover a direct link between repressor ERFs and histone modifiers in modulating the transition to ripening of climacteric fruit.


Assuntos
Lycopersicon esculentum , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Etilenos/metabolismo , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
19.
Plant Physiol ; 188(2): 1294-1311, 2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-34718759

RESUMO

Shade-intolerant plants rapidly elongate their stems, branches, and leaf stalks to compete with neighboring vegetation, maximizing sunlight capture for photosynthesis. This rapid growth adaptation, known as the shade-avoidance response (SAR), comes at a cost: reduced biomass, crop yield, and root growth. Significant progress has been made on the mechanistic understanding of hypocotyl elongation during SAR; however, the molecular interpretation of root growth repression is not well understood. Here, we explore the mechanisms by which SAR induced by low red:far-red light restricts primary and lateral root (LR) growth. By analyzing the whole-genome transcriptome, we identified a core set of shade-induced genes in roots of Arabidopsis (Arabidopsis thaliana) and tomato (Solanum lycopersicum) seedlings grown in the shade. Abiotic and biotic stressors also induce many of these shade-induced genes and are predominantly regulated by WRKY transcription factors. Correspondingly, a majority of WRKY genes were among the shade-induced genes. Functional analysis using transgenics of these shade-induced WRKYs revealed that their role is essentially to restrict primary root and LR growth in the shade; captivatingly, they did not affect hypocotyl elongation. Similarly, we also found that ethylene hormone signaling is necessary for limiting root growth in the shade. We propose that during SAR, shade-induced WRKY26, 45, and 75, and ethylene reprogram gene expression in the root to restrict its growth and development.


Assuntos
Adaptação Ocular/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Etilenos/metabolismo , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Mutação , Fatores de Transcrição
20.
Curr Opin Plant Biol ; 65: 102116, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34653952

RESUMO

In seed plants, 1-amino-cyclopropane-1-carboxylic acid (ACC) is the well-known precursor of the plant hormone ethylene. In nonseed plants, the current view is that ACC is produced but is inefficiently converted to ethylene. Distinct responses to ACC that are uncoupled from ethylene biosynthesis have been discovered in diverse aspects of growth and development in liverworts and angiosperms, indicating that ACC itself can function as a signal. Evolutionarily, ACC may have served as a signal before acquiring its role as the ethylene precursor in seed plants. These findings pave the way for unraveling a potentially conserved ACC signaling pathway in plants and have ramifications for the use of ACC as a substitute for ethylene treatment in seed plants.


Assuntos
Aminoácidos Cíclicos , Etilenos , Aminoácidos Cíclicos/metabolismo , Ácidos Carboxílicos , Etilenos/metabolismo , Plantas/metabolismo , Transdução de Sinais
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