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1.
PLoS One ; 16(9): e0250678, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34473720

RESUMO

Apricot bud gall mite, Acalitus phloeocoptes (Nalepa), is a destructive arthropod pest that causes significant economic losses to apricot trees worldwide. The current study explores the ways to understand the mode of dispersal of A. phloeocoptes, the development and ultrastructure of apricot bud gall, and the role of phytohormones in the formation of the apricot bud galls. The results demonstrated that the starch granules in the bud axon were extended at the onset of the attack. During the later stages of the attack, the cytoplasm was found to deteriorate in infected tissues. Furthermore, we have observed that the accumulation of large amounts of cytokinin (zeatin, ZT) and auxin (indoleacetic acid, IAA) led to rapid bud proliferation during rapid growth period, while abscisic acid (ABA) controls the development of gall buds and plays a vital role in gall bud maturity. The reduction of gibberellic acid (GA3) content led to rapid lignification at the later phase of bud development. Overall, our results have revealed that the mechanism underlying the interaction of apricot bud gall with its parasite and have provided reliable information for designing valuable Apricot breeding programs. This study will be quite useful for pest management and will provide a comprehensive evaluation of ecology-based cost-effective control, life history and demographic parameters of A. phloeocoptes.


Assuntos
Ácaros/patogenicidade , Reguladores de Crescimento de Plantas/metabolismo , Prunus armeniaca/parasitologia , Amido/metabolismo , Ácido Abscísico/metabolismo , Animais , Citocininas/metabolismo , Feminino , Giberelinas/metabolismo , Interações Hospedeiro-Parasita , Ácidos Indolacéticos/metabolismo , Masculino , Melhoramento Vegetal , Prunus armeniaca/fisiologia
2.
Int J Mol Sci ; 22(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34445260

RESUMO

De novo shoot organogenesis (DNSO) is a procedure commonly used for the in vitro regeneration of shoots from a variety of plant tissues. Shoot regeneration occurs on nutrient media supplemented with the plant hormones cytokinin (CK) and auxin, which play essential roles in this process, and genes involved in their signaling cascades act as master regulators of the different phases of shoot regeneration. In the last 20 years, the genetic regulation of DNSO has been characterized in detail. However, as of today, the CK and auxin signaling events associated with shoot regeneration are often interpreted as a consequence of these hormones simply being present in the regeneration media, whereas the roles for their prior uptake and transport into the cultivated plant tissues are generally overlooked. Additionally, sucrose, commonly added to the regeneration media as a carbon source, plays a signaling role and has been recently shown to interact with CK and auxin and to affect the efficiency of shoot regeneration. In this review, we provide an integrative interpretation of the roles for CK and auxin in the process of DNSO, adding emphasis on their uptake from the regeneration media and their interaction with sucrose present in the media to their complex signaling outputs that mediate shoot regeneration.


Assuntos
Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Organogênese Vegetal , Reguladores de Crescimento de Plantas/metabolismo , Brotos de Planta/metabolismo , Brotos de Planta/citologia
3.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360972

RESUMO

Auxins and cytokinins create versatile regulatory network controlling virtually all aspects of plant growth and development. These hormonal systems act in close contact, synergistically or antagonistically, determining plant phenotype, resistance and productivity. However, the current knowledge about molecular interactions of these systems is still scarce. Our study with potato plants aimed at deciphering potential interactions between auxin and cytokinin signaling pathways at the level of respective gene expression. Potato plants grown on sterile medium with 1.5% (vegetation) or 5% (tuberization) sucrose were treated for 1 h with auxin or cytokinin. Effects of these two hormones on expression profiles of genes belonging to main signaling pathways of auxin and cytokinin were quantified by RT-qPCR. As a result, several signaling genes were found to respond to auxin and/or cytokinin by up- or down-regulation. The observed effects were largely organ-specific and depended on sucrose content. Auxin strongly reduced cytokinin perception apparatus while reciprocal cytokinin effect was ambiguous and sucrose-dependent. In many cases, functional clustering of genes of the same family was observed. Promoters in some clusters are enriched with canonic hormone-response cis-elements supporting their direct sensitivity to hormones. Collectively, our data shed new light on the crosstalk between auxin- and cytokinin signaling pathways.


Assuntos
Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Transdução de Sinais , Solanum tuberosum/metabolismo , Genes de Plantas , Desenvolvimento Vegetal , Solanum tuberosum/genética , Solanum tuberosum/crescimento & desenvolvimento , Sacarose/metabolismo
4.
Sci Rep ; 11(1): 14592, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272422

RESUMO

Banana, one of the most important staple fruit among global consumers is highly sterile owing to natural parthenocarpy. Identification of genetic factors responsible for parthenocarpy would facilitate the conventional breeders to improve the seeded accessions. We have constructed Protein-protein interaction (PPI) network through mining differentially expressed genes and the genes used for transgenic studies with respect to parthenocarpy. Based on the topological and pathway enrichment analysis of proteins in PPI network, 12 candidate genes were shortlisted. By further validating these candidate genes in seeded and seedless accession of Musa spp. we put forward MaAGL8, MaMADS16, MaGH3.8, MaMADS29, MaRGA1, MaEXPA1, MaGID1C, MaHK2 and MaBAM1 as possible target genes in the study of natural parthenocarpy. In contrary, expression profile of MaACLB-2 and MaZEP is anticipated to highlight the difference in artificially induced and natural parthenocarpy. By exploring the PPI of validated genes from the network, we postulated a putative pathway that bring insights into the significance of cytokinin mediated CLAVATA(CLV)-WUSHEL(WUS) signaling pathway in addition to gibberellin mediated auxin signaling in parthenocarpy. Our analysis is the first attempt to identify candidate genes and to hypothesize a putative mechanism that bridges the gaps in understanding natural parthenocarpy through PPI network.


Assuntos
Frutas/genética , Musa/genética , Partenogênese , Proteínas de Plantas/genética , Mapas de Interação de Proteínas , Transdução de Sinais , Citocininas/metabolismo , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Musa/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Sementes/genética
5.
Nat Commun ; 12(1): 4321, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34262040

RESUMO

Symmetry establishment is a critical process in the development of multicellular organs and requires careful coordination of polarity axes while cells actively divide within tissues. Formation of the apical style in the Arabidopsis gynoecium involves a bilateral-to-radial symmetry transition, a stepwise process underpinned by the dynamic distribution of the plant morphogen auxin. Here we show that SPATULA (SPT) and the HECATE (HEC) bHLH proteins mediate the final step in the style radialisation process and synergistically control the expression of adaxial-identity genes, HOMEOBOX ARABIDOPSIS THALIANA 3 (HAT3) and ARABIDOPSIS THALIANA HOMEOBOX 4 (ATHB4). HAT3/ATHB4 module drives radialisation of the apical style by promoting basal-to-apical auxin flow and via a negative feedback mechanism that finetune auxin distribution through repression of SPT expression and cytokinin sensitivity. Thus, this work reveals the molecular basis of axes-coordination and hormonal cross-talk during the sequential steps of symmetry transition in the Arabidopsis style.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas de Homeodomínio/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Transporte Biológico , Citocininas/metabolismo , Retroalimentação Fisiológica , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Ácidos Indolacéticos/metabolismo
6.
Plant Mol Biol ; 106(6): 555-567, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275101

RESUMO

KEY MESSAGE: Root-specific expression of a cytokinin-degrading CKX gene in maize roots causes formation of a larger root system leading to higher element content in shoot organs. The size and architecture of the root system is functionally relevant for the access to water and soil nutrients. A great number of mostly unknown genes are involved in regulating root architecture complicating targeted breeding of plants with a larger root system. Here, we have explored whether root-specific degradation of the hormone cytokinin, which is a negative regulator of root growth, can be used to genetically engineer maize (Zea mays L.) plants with a larger root system. Root-specific expression of a CYTOKININ OXIDASE/DEHYDROGENASE (CKX) gene of Arabidopsis caused the formation of up to 46% more root dry weight while shoot growth of these transgenic lines was similar as in non-transgenic control plants. The concentration of several elements, in particular of those with low soil mobility (K, P, Mo, Zn), was increased in leaves of transgenic lines. In kernels, the changes in concentration of most elements were less pronounced, but the concentrations of Cu, Mn and Zn were significantly increased in at least one of the three independent lines. Our data illustrate the potential of an increased root system as part of efforts towards achieving biofortification. Taken together, this work has shown that root-specific expression of a CKX gene can be used to engineer the root system of maize and alter shoot element composition.


Assuntos
Proteínas de Arabidopsis/genética , Citocininas/metabolismo , Proteínas de Membrana/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Folhas de Planta/genética , Raízes de Plantas/genética , Zea mays/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Cobre/metabolismo , Regulação da Expressão Gênica de Plantas , Engenharia Genética/métodos , Manganês/metabolismo , Proteínas de Membrana/metabolismo , Minerais/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transgenes/genética , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Zinco/metabolismo
7.
Sci Rep ; 11(1): 12381, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34117332

RESUMO

Zoysia japonica is a commonly used turfgrass species around the world. Seed germination is a crucial stage in the plant life cycle and is particularly important for turf establishment and management. Experiments have confirmed that melatonin can be a potential regulator signal in seeds. To determine the effect of exogenous melatonin administration and explore the its potential in regulating seed growth, we studied the concentrations of several hormones and performed a transcriptome analysis of zoysia seeds after the application of melatonin. The total antioxidant capacity determination results showed that melatonin treatment could significantly improve the antioxidant capacity of zoysia seeds. The transcriptome analysis indicated that several of the regulatory pathways were involved in antioxidant activity and hormone activity. The hormones concentrations determination results showed that melatonin treatment contributed to decreased levels of cytokinin, abscisic acid and gibberellin in seeds, but had no significant effect on the secretion of auxin in early stages. Melatonin is able to affect the expression of IAA (indoleacetic acid) response genes. In addition, melatonin influences the other hormones by its synergy with other hormones. Transcriptome research in zoysia is helpful for understanding the regulation of melatonin and mechanisms underlying melatonin-mediated developmental processes in zoysia seeds.


Assuntos
Genes de Plantas , Germinação , Melatonina/farmacologia , Poaceae/efeitos dos fármacos , Ácido Abscísico/metabolismo , Citocininas/genética , Citocininas/metabolismo , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Poaceae/genética , Poaceae/crescimento & desenvolvimento , Transcriptoma
8.
Int J Mol Sci ; 22(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34072151

RESUMO

Sound waves affect plants at the biochemical, physical, and genetic levels. However, the mechanisms by which plants respond to sound waves are largely unknown. Therefore, the aim of this study was to examine the effect of sound waves on Arabidopsis thaliana growth. The results of the study showed that Arabidopsis seeds exposed to sound waves (100 and 100 + 9k Hz) for 15 h per day for 3 day had significantly longer root growth than that in the control group. The root length and cell number in the root apical meristem were significantly affected by sound waves. Furthermore, genes involved in cell division were upregulated in seedlings exposed to sound waves. Root development was affected by the concentration and activity of some phytohormones, including cytokinin and auxin. Analysis of the expression levels of genes regulating cytokinin and auxin biosynthesis and signaling showed that cytokinin and ethylene signaling genes were downregulated, while auxin signaling and biosynthesis genes were upregulated in Arabidopsis exposed to sound waves. Additionally, the cytokinin and auxin concentrations of the roots of Arabidopsis plants increased and decreased, respectively, after exposure to sound waves. Our findings suggest that sound waves are potential agricultural tools for improving crop growth performance.


Assuntos
Arabidopsis/fisiologia , Arabidopsis/efeitos da radiação , Desenvolvimento Vegetal/efeitos da radiação , Som , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Citocininas/genética , Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas , Fenótipo , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Sementes/efeitos da radiação
9.
Plant Cell Rep ; 40(8): 1331-1343, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34086069

RESUMO

Aluminium (Al) is one of the most abundant metals in earth crust, which becomes toxic to the plants growing in acidic soil. Phytohormones like ethylene, auxin, cytokinin, abscisic acid, jasmonic acid and gibberellic acid are known to play important role in regulating Al toxicity tolerance in plants. Exogenous applications of auxin, cytokinin and abscisic acid have shown significant effect on Al-induced root growth inhibition. Moreover, ethylene and cytokinin act synergistically with auxin in responding against Al toxicity. A number of studies showed that phytohormones play vital roles in controlling root responses to Al toxicity by modulating reactive oxygen species (ROS) signalling, cell wall modifications, organic acid exudation from roots and expression of Al responsive genes and transcription factors. This review provides a summary of recent studies related to involvement of phytohormone signalling and cross-talk with other pathways in regulating response against Al toxicity in plants.


Assuntos
Alumínio/toxicidade , Reguladores de Crescimento de Plantas/metabolismo , Plantas/efeitos dos fármacos , Plantas/metabolismo , Ácido Abscísico/metabolismo , Ciclopentanos/metabolismo , Citocininas/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
10.
J Plant Physiol ; 262: 153448, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34058643

RESUMO

The halophyte ice plant (Mesembryanthemum crystallinum) converts its mode of photosynthesis from C3 to crassulacean acid metabolism (CAM) during severe water stress. During the transition to CAM, the plant induces CAM-related genes and changes its diurnal stomatal behavior to take up CO2 efficiently at night. However, limited information concerning this signaling exists. Here, we investigated the changes in the diurnal stomatal behavior of M. crystallinum during its shift in photosynthesis using a detached epidermis. M. crystallinum plants grown under C3 conditions opened their stomata during the day and closed them at night. However, CAM-induced plants closed their stomata during the day and opened them at night. Quantitative analysis of endogenous phytohormones revealed that trans-zeatin levels were high in CAM-induced plants. In contrast, the levels of jasmonic acid (JA) and JA-isoleucine were severely reduced in CAM-induced plants, specifically at night. CAM induction did not alter the levels of abscisic acid; however, inhibitors of abscisic acid synthesis suppressed CAM-induced stomatal closure. These results indicate that M. crystallinum regulates the diurnal balance of cytokinin and JA during CAM transition to alter stomatal behavior.


Assuntos
Metabolismo Ácido das Crassuláceas , Mesembryanthemum/metabolismo , Reguladores de Crescimento de Plantas/fisiologia , Estômatos de Plantas/fisiologia , Plantas Tolerantes a Sal/metabolismo , Ácido Abscísico/metabolismo , Ritmo Circadiano , Metabolismo Ácido das Crassuláceas/fisiologia , Ciclopentanos/metabolismo , Citocininas/metabolismo , Citocininas/fisiologia , Regulação da Expressão Gênica de Plantas , Mesembryanthemum/fisiologia , Oxilipinas/metabolismo , Epiderme Vegetal/metabolismo , Folhas de Planta/metabolismo , Estômatos de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Plantas Tolerantes a Sal/fisiologia
11.
Plant Physiol ; 185(3): 1166-1181, 2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33793921

RESUMO

Interactions between plant hormones and environmental signals are important for the maintenance of root growth plasticity under ever-changing environmental conditions. Here, we demonstrate that arsenate (AsV), the most prevalent form of arsenic (As) in nature, restrains elongation of the primary root through transcriptional regulation of local auxin biosynthesis genes in the root tips of Arabidopsis (Arabidopsis thaliana) plants. The ANTHRANILATE SYNTHASE ALPHA SUBUNIT 1 (ASA1) and BETA SUBUNIT 1 (ASB1) genes encode enzymes that catalyze the conversion of chorismate to anthranilate (ANT) via the tryptophan-dependent auxin biosynthesis pathway. Our results showed that AsV upregulates ASA1 and ASB1 expression in root tips, and ASA1- and ASB1-mediated auxin biosynthesis is involved in AsV-induced root growth inhibition. Further investigation confirmed that AsV activates cytokinin signaling by stabilizing the type-B ARABIDOPSIS RESPONSE REGULATOR1 (ARR1) protein, which directly promotes the transcription of ASA1 and ASB1 genes by binding to their promoters. Genetic analysis revealed that ASA1 and ASB1 are epistatic to ARR1 in the AsV-induced inhibition of primary root elongation. Overall, the results of this study illustrate a molecular framework that explains AsV-induced root growth inhibition via crosstalk between two major plant growth regulators, auxin and cytokinin.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Antranilato Sintase/efeitos dos fármacos , Antranilato Sintase/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Arseniatos/farmacologia , Regulação da Expressão Gênica de Plantas , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
12.
Int J Mol Sci ; 22(7)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810428

RESUMO

Cytokinins are a class of phytohormones, signalling molecules specific to plants. They act as regulators of diverse physiological processes in complex signalling pathways. It is necessary for plants to continuously regulate cytokinin distribution among different organs, tissues, cells, and compartments. Such regulatory mechanisms include cytokinin biosynthesis, metabolic conversions and degradation, as well as cytokinin membrane transport. In our review, we aim to provide a thorough picture of the latter. We begin by summarizing cytokinin structures and physicochemical properties. Then, we revise the elementary thermodynamic and kinetic aspects of cytokinin membrane transport. Next, we review which membrane-bound carrier proteins and protein families recognize cytokinins as their substrates. Namely, we discuss the families of "equilibrative nucleoside transporters" and "purine permeases", which translocate diverse purine-related compounds, and proteins AtPUP14, AtABCG14, AtAZG1, and AtAZG2, which are specific to cytokinins. We also address long-distance cytokinin transport. Putting all these pieces together, we finally discuss cytokinin distribution as a net result of these processes, diverse in their physicochemical nature but acting together to promote plant fitness.


Assuntos
Membrana Celular/metabolismo , Citocininas/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Homeostase , Interações Hidrofóbicas e Hidrofílicas , Cinética , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Transdução de Sinais/fisiologia , Termodinâmica
13.
Int J Mol Sci ; 22(8)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923687

RESUMO

TaCKX gene family members (GFMs) play essential roles in the regulation of cytokinin during wheat development and significantly influence yield-related traits. However, detailed function of most of them is not known. To characterize the role of TaCKX2.2 genes we silenced all homoeologous copies of both TaCKX2.2.1 and TaCKX2.2.2 by RNAi technology and observed the effect of silencing in 7 DAP spikes of T1 and T2 generations. The levels of gene silencing of these developmentally regulated genes were different in both generations, which variously determined particular phenotypes. High silencing of TaCKX2.2.2 in T2 was accompanied by slight down-regulation of TaCKX2.2.1 and strong up-regulation of TaCKX5 and TaCKX11, and expression of TaCKX1, TaCKX2.1, and TaCKX9 was comparable to the non-silenced control. Co-ordinated expression of TaCKX2.2.2 with other TaCKX GFMs influenced phytohormonal homeostasis. Contents of isoprenoid, active cytokinins, their conjugates, and auxin in seven DAP spikes of silenced T2 plants increased from 1.27 to 2.51 times. However, benzyladenine (BA) and abscisic acid (ABA) contents were significantly reduced and GA3 was not detected. We documented a significant role of TaCKX2.2.2 in the regulation of thousand grain weight (TGW), grain number, and chlorophyll content, and demonstrated the formation of a homeostatic feedback loop between the transcription of tested genes and phytohormones. We also discuss the mechanism of regulation of yield-related traits.


Assuntos
Grão Comestível/genética , Genes de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Triticum/genética , Ácido Abscísico/metabolismo , Clorofila/metabolismo , Citocininas/metabolismo , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas , Homeostase , Ácidos Indolacéticos/metabolismo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
14.
Int J Mol Sci ; 22(7)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33805045

RESUMO

The bulbil is an important vegetative reproductive organ in triploid Lilium lancifolium whose development is promoted by cytokinins. Type-B response regulators (RRs) are critical regulators that mediate primary cytokinin responses and promote cytokinin-induced gene expression. However, the function of cytokinin type-B Arabidopsis RRs (ARRs) in regulating bulbil formation is unclear. In this study, we identified five type-B LlRRs, LlRR1, LlRR2, LlRR10, LlRR11 and LlRR12, in L. lancifolium for the first time. The five LlRRs encode proteins of 715, 675, 573, 582 and 647 amino acids. All of the regulators belong to the B-I subfamily, whose members typically contain a conserved CheY-homologous receiver (REC) domain and an Myb DNA-binding (MYB) domain at the N-terminus. As transcription factors, all five type-B LlRRs localize at the nucleus and are widely expressed in plant tissues, especially during axillary meristem (AM) formation. Functional analysis showed that type-B LlRRs are involved in bulbil formation in a functionally redundant manner and can activate LlRR9 expression. In summary, our study elucidates the process by which cytokinins regulate bulbil initiation in L. lancifolium through type-B LlRRs and lays a foundation for research on the molecular mechanism of bulbil formation in the lily.


Assuntos
Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas , Lilium/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Ligação a DNA/metabolismo , Perfilação da Expressão Gênica , Inativação Gênica , Lilium/crescimento & desenvolvimento , Meristema/crescimento & desenvolvimento , Conformação Molecular , Peptídeos/química , Fenótipo , Domínios Proteicos , Transdução de Sinais
15.
Plant Physiol ; 185(4): 1708-1721, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33793932

RESUMO

Shoot branching is an important aspect of plant architecture because it substantially affects plant biology and agricultural performance. Sugars play an important role in the induction of shoot branching in several species, including potato (Solanum tuberosum L.). However, the mechanism by which sugars affect shoot branching remains mostly unknown. In the present study, we addressed this question using sugar-mediated induction of bud outgrowth in potato stems under etiolated conditions. Our results indicate that sucrose feeding to detached stems promotes the accumulation of cytokinin (CK), as well as the expression of vacuolar invertase (VInv), an enzyme that contributes to sugar sink strength. These effects of sucrose were suppressed by CK synthesis and perception inhibitors, while CK supplied to detached stems induced bud outgrowth and VInv activity in the absence of sucrose. CK-induced bud outgrowth was suppressed in vinv mutants, which we generated by genome editing. Altogether, our results identify a branching-promoting module, and suggest that sugar-induced lateral bud outgrowth is in part promoted by the induction of CK-mediated VInv activity.


Assuntos
Citocininas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/metabolismo , Sacarose/metabolismo , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Variação Genética , Genótipo , Israel , Mutação , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo
16.
PLoS Genet ; 17(4): e1009537, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33901177

RESUMO

Morphogenesis and differentiation are important stages in organ development and shape determination. However, how they are balanced and tuned during development is not fully understood. In the compound leaved tomato, an extended morphogenesis phase allows for the initiation of leaflets, resulting in the compound form. Maintaining a prolonged morphogenetic phase in early stages of compound-leaf development in tomato is dependent on delayed activity of several factors that promote differentiation, including the CIN-TCP transcription factor (TF) LA, the MYB TF CLAU and the plant hormone Gibberellin (GA), as well as on the morphogenesis-promoting activity of the plant hormone cytokinin (CK). Here, we investigated the genetic regulation of the morphogenesis-differentiation balance by studying the relationship between LA, CLAU, TKN2, CK and GA. Our genetic and molecular examination suggest that LA is expressed earlier and more broadly than CLAU and determines the developmental context of CLAU activity. Genetic interaction analysis indicates that LA and CLAU likely promote differentiation in parallel genetic pathways. These pathways converge downstream on tuning the balance between CK and GA. Comprehensive transcriptomic analyses support the genetic data and provide insights into the broader molecular basis of differentiation and morphogenesis processes in plants.


Assuntos
Diferenciação Celular/genética , Citocininas/genética , Giberelinas/metabolismo , Morfogênese/genética , Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Desenvolvimento Vegetal/genética , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Fatores de Transcrição/genética
17.
Int J Mol Sci ; 22(7)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33804877

RESUMO

Salinity provokes an imbalance of vegetative to generative growth, thus impairing crop productivity. Unlike breeding strategies, grafting is a direct and quick alternative to improve salinity tolerance in horticultural crops, through rebalancing plant development. Providing that hormones play a key role in plant growth and development and stress responses, we hypothesized that rootstock-mediated reallocation of vegetative growth and yield under salinity was associated with changes in the hormonal balance. To test this hypothesis, the hybrid pepper variety (Capsicum annuum L. "Gacela F1") was either non-grafted or grafted onto three commercial rootstocks (Creonte, Atlante, and Terrano) and plants were grown in a greenhouse under control (0 mM NaCl) and moderate salinity (35 mM NaCl) conditions. Differential vegetative growth versus fruit yield responses were induced by rootstock and salinity. Atlante strongly increased shoot and root fresh weight with respect to the non-grafted Gacela plants associated with improved photosynthetic rate and K+ homeostasis under salinity. The invigorating effect of Atlante can be explained by an efficient balance between cytokinins (CKs) and abscisic acid (ABA). Creonte improved fruit yield and maintained the reproductive to vegetative ratio under salinity as a consequence of its capacity to induce biomass reallocation and to avoid Na+ accumulation in the shoot. The physiological responses associated with yield stability in Creonte were mediated by the inverse regulation of CKs and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. Finally, Terrano limited the accumulation of gibberellins in the shoot thus reducing plant height. Despite scion compactness induced by Terrano, both vegetative and reproductive biomass were maintained under salinity through ABA-mediated control of water relations and K+ homeostasis. Our data demonstrate that the contrasting developmental and physiological responses induced by the rootstock genotype in salinized pepper plants were critically mediated by hormones. This will be particularly important for rootstock breeding programs to improve salinity tolerance by focusing on hormonal traits.


Assuntos
Ácido Abscísico/metabolismo , Capsicum/metabolismo , Citocininas/metabolismo , Estresse Salino , Capsicum/crescimento & desenvolvimento
18.
Nat Commun ; 12(1): 2378, 2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33888716

RESUMO

Structural variation in plant genomes is a significant driver of phenotypic variability in traits important for the domestication and productivity of crop species. Among these are traits that depend on functional meristems, populations of stem cells maintained by the CLAVATA-WUSCHEL (CLV-WUS) negative feedback-loop that controls the expression of the WUS homeobox transcription factor. WUS function and impact on maize development and yield remain largely unexplored. Here we show that the maize dominant Barren inflorescence3 (Bif3) mutant harbors a tandem duplicated copy of the ZmWUS1 gene, ZmWUS1-B, whose novel promoter enhances transcription in a ring-like pattern. Overexpression of ZmWUS1-B is due to multimerized binding sites for type-B RESPONSE REGULATORs (RRs), key transcription factors in cytokinin signaling. Hypersensitivity to cytokinin causes stem cell overproliferation and major rearrangements of Bif3 inflorescence meristems, leading to the formation of ball-shaped ears and severely affecting productivity. These findings establish ZmWUS1 as an essential meristem size regulator in maize and highlight the striking effect of cis-regulatory variation on a key developmental program.


Assuntos
Proteínas de Homeodomínio/genética , Inflorescência/crescimento & desenvolvimento , Proteínas de Plantas/genética , Fatores de Transcrição/metabolismo , Zea mays/crescimento & desenvolvimento , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Citocininas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Inflorescência/citologia , Meristema/crescimento & desenvolvimento , Mutagênese , Mutação , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Locos de Características Quantitativas , RNA-Seq , Transdução de Sinais/genética , Células-Tronco , Fatores de Transcrição/genética , Zea mays/genética
19.
Int J Mol Sci ; 22(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920993

RESUMO

Polyamines (PAs) dramatically affect root architecture and development, mainly by unknown mechanisms; however, accumulating evidence points to hormone signaling and reactive oxygen species (ROS) as candidate mechanisms. To test this hypothesis, PA levels were modified by progressively reducing ADC1/2 activity and Put levels, and then changes in root meristematic zone (MZ) size, ROS, and auxin and cytokinin (CK) signaling were investigated. Decreasing putrescine resulted in an interesting inverted-U-trend in primary root growth and a similar trend in MZ size, and differential changes in putrescine (Put), spermidine (Spd), and combined spermine (Spm) plus thermospermine (Tspm) levels. At low Put concentrations, ROS accumulation increased coincidently with decreasing MZ size, and treatment with ROS scavenger KI partially rescued this phenotype. Analysis of double AtrbohD/F loss-of-function mutants indicated that NADPH oxidases were not involved in H2O2 accumulation and that elevated ROS levels were due to changes in PA back-conversion, terminal catabolism, PA ROS scavenging, or another pathway. Decreasing Put resulted in a non-linear trend in auxin signaling, whereas CK signaling decreased, re-balancing auxin and CK signaling. Different levels of Put modulated the expression of PIN1 and PIN2 auxin transporters, indicating changes to auxin distribution. These data strongly suggest that PAs modulate MZ size through both hormone signaling and ROS accumulation in Arabidopsis.


Assuntos
Arabidopsis/anatomia & histologia , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Meristema/anatomia & histologia , Putrescina/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arginina/farmacologia , Peróxido de Hidrogênio/metabolismo , Meristema/efeitos dos fármacos , Modelos Biológicos , Mutação/genética , NADPH Oxidases/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Fenótipo , Iodeto de Potássio/farmacologia , Transdução de Sinais/efeitos dos fármacos
20.
Plant Sci ; 307: 110880, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33902848

RESUMO

Auxin alone or supplemented with cytokinins and strigolactones were long considered as the main player(s) in the control of apical dominance (AD) and correlative inhibition of the lateral bud outgrowth, the processes that shape the plant phenotype. However, past decade data indicate a more sophisticated pathways of AD regulation, with the involvement of mobile carbohydrates which perform both signal and trophic functions. Here we provide a critical comprehensive overview of the current status of the AD problem. This includes insight into intimate mechanisms regulating directed auxin transport in axillary buds with participation of phytohormones and sugars. Also roles of auxin, cytokinin and sugars in the dormancy or sustained growth of the lateral meristems were assigned. This review not only provides the latest data on implicated phytohormone crosstalk and its relationship with the signaling of sugars and abscisic acid, new AD players, but also focuses on the emerging biochemical mechanisms, at first positive feedback loops involving both sugars and hormones, that ensure the sustained bud growth. Data show that sugars act in concert with cytokinins but antagonistically to strigolactone signaling. A complex bud growth regulating network is demonstrated and unresolved issues regarding the hormone-carbohydrate regulation of AD are highlighted.


Assuntos
Meristema/efeitos dos fármacos , Meristema/crescimento & desenvolvimento , Fenótipo , Desenvolvimento Vegetal/efeitos dos fármacos , Reguladores de Crescimento de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Ácido Abscísico/metabolismo , Citocininas/metabolismo
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