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1.
Plant Commun ; 3(3): 100321, 2022 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-35576161

RESUMO

Paraquat (PQ) is the third most used broad-spectrum nonselective herbicide around the globe after glyphosate and glufosinate. Repeated usage and overreliance on this herbicide have resulted in the emergence of PQ-resistant weeds that are a potential hazard to agriculture. It is generally believed that PQ resistance in weeds is due to increased sequestration of the herbicide and its decreased translocation to the target site, as well as an enhanced ability to scavenge reactive oxygen species. However, little is known about the genetic bases and molecular mechanisms of PQ resistance in weeds, and hence no PQ-resistant crops have been developed to date. Forward genetics of the model plant Arabidopsis thaliana has advanced our understanding of the molecular mechanisms of PQ resistance. This review focuses on PQ resistance loci and resistance mechanisms revealed in Arabidopsis and examines the possibility of developing PQ-resistant crops using the elucidated mechanisms.


Assuntos
Arabidopsis , Herbicidas , Arabidopsis/genética , Produtos Agrícolas/genética , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Paraquat/toxicidade , Plantas Daninhas/genética
2.
Front Plant Sci ; 11: 271, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32211015

RESUMO

As sessile organisms, plants must be highly adaptable to the changing environment by modifying their growth and development. Plants rely on their underground part, the root system, to absorb water and nutrients and to anchor to the ground. The root is a highly dynamic organ of indeterminate growth with new tissues produced by root stem cells. Plants have evolved unique molecular mechanisms to fine-tune root developmental processes, during which phytohormones play vital roles. These hormones often relay environmental signals to auxin signaling that ultimately directs root development programs. Therefore, the crosstalk among hormones is critical in the root development. In this review, we will focus on the recent progresses that jasmonic acid (JA) and ethylene signaling are integrated into auxin in regulating root development of Arabidopsis thaliana and discuss the key roles of transcription factors (TFs) ethylene response factors (ERFs) and homeobox proteins in the crosstalk.

3.
PLoS Genet ; 12(9): e1006332, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27676073

RESUMO

Oxidative stress is unavoidable for aerobic organisms. When abiotic and biotic stresses are encountered, oxidative damage could occur in cells. To avoid this damage, defense mechanisms must be timely and efficiently modulated. While the response to oxidative stress has been extensively studied in plants, little is known about how the activated response is switched off when oxidative stress is diminished. By studying Arabidopsis mutant paraquat tolerance3, we identified the genetic locus PARAQUAT TOLERANCE3 (PQT3) as a major negative regulator of oxidative stress tolerance. PQT3, encoding an E3 ubiquitin ligase, is rapidly down-regulated by oxidative stress. PQT3 has E3 ubiquitin ligase activity in ubiquitination assay. Subsequently, we identified PRMT4b as a PQT3-interacting protein. By histone methylation, PRMT4b upregulates the expression of APX1 and GPX1, encoding two key enzymes against oxidative stress. On the other hand, PRMT4b is recognized by PQT3 for targeted degradation via 26S proteasome. Therefore, we have identified PQT3 as an E3 ligase that acts as a negative regulator of activated response to oxidative stress and found that histone modification by PRMT4b at APX1 and GPX1 loci plays an important role in oxidative stress tolerance.

4.
5.
PLoS Genet ; 12(1): e1005760, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26745809

RESUMO

The gaseous phytohormone ethylene participates in the regulation of root growth and development in Arabidopsis. It is known that root growth inhibition by ethylene involves auxin, which is partially mediated by the action of the WEAK ETHYLENE INSENSITIVE2/ANTHRANILATE SYNTHASE α1 (WEI2/ASA1), encoding a rate-limiting enzyme in tryptophan (Trp) biosynthesis, from which auxin is derived. However, the molecular mechanism by which ethylene decreases root growth via ASA1 is not understood. Here we report that the ethylene-responsive AP2 transcription factor, ETHYLENE RESPONSE FACTOR1 (ERF1), plays an important role in primary root elongation of Arabidopsis. Using loss- and gain-of-function transgenic lines as well as biochemical analysis, we demonstrate that ERF1 can directly up-regulate ASA1 by binding to its promoter, leading to auxin accumulation and ethylene-induced inhibition of root growth. This discloses one mechanism linking ethylene signaling and auxin biosynthesis in Arabidopsis roots.


Assuntos
Antranilato Sintase/biossíntese , Proteínas de Arabidopsis/biossíntese , Fatores de Terminação de Peptídeos/biossíntese , Reguladores de Crescimento de Plantas/biossíntese , Raízes de Plantas/crescimento & desenvolvimento , Antranilato Sintase/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Fatores de Terminação de Peptídeos/genética , Reguladores de Crescimento de Plantas/genética , Raízes de Plantas/genética , Transdução de Sinais
6.
J Integr Plant Biol ; 57(12): 1017-30, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25752924

RESUMO

Root architecture is crucial for plants to absorb water and nutrients. We previously reported edt1 (edt1D) mutant with altered root architecture that contributes significantly to drought resistance. However, the underlying molecular mechanisms are not well understood. Here we report one of the mechanisms underlying EDT1/HDG11-conferred altered root architecture. Root transcriptome comparison between the wild type and edt1D revealed that the upregulated genes involved in jasmonate biosynthesis and signaling pathway were enriched in edt1D root, which were confirmed by quantitative RT-PCR. Further analysis showed that EDT1/HDG11, as a transcription factor, bound directly to the HD binding sites in the promoters of AOS, AOC3, OPR3, and OPCL1, which encode four key enzymes in JA biosynthesis. We found that the jasmonic acid level was significantly elevated in edt1D root compared with that in the wild type subsequently. In addition, more auxin accumulation was observed in the lateral root primordium of edt1D compared with that of wild type. Genetic analysis of edt1D opcl1 double mutant also showed that HDG11 was partially dependent on JA in regulating LR formation. Taken together, overexpression of EDT1/HDG11 increases JA level in the root of edt1D by directly upregulating the expressions of several genes encoding JA biosynthesis enzymes to activate auxin signaling and promote lateral root formation.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Ciclopentanos/metabolismo , Mutação/genética , Oxilipinas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Fatores de Transcrição/genética , Regulação para Cima/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Vias Biossintéticas/genética , Fluorescência , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Redes Reguladoras de Genes , Genes de Plantas , Proteínas de Fluorescência Verde/metabolismo , Ácidos Indolacéticos/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Reprodutibilidade dos Testes , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Transcriptoma/genética
7.
Nat Commun ; 5: 5833, 2014 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-25524530

RESUMO

Jasmonic acid (JA) is well known to promote lateral root formation but the mechanisms by which JA signalling is integrated into the pathways responsible for lateral root formation, and how it interacts with auxin in this process remains poorly understood. Here, we report that the highly JA-responsive ethylene response factor 109 (ERF109) mediates cross-talk between JA signalling and auxin biosynthesis to regulate lateral root formation in Arabidopsis. erf109 mutants have fewer lateral roots under MeJA treatments compared with wild type whereas ERF109 overexpression causes a root phenotype that resembles those of auxin overproduction mutants. ERF109 binds directly to GCC-boxes in the promoters of ASA1 and YUC2, which encode two key enzymes in auxin biosynthesis. Thus, our study reveals a molecular mechanism for JA and auxin cross-talk during JA-induced lateral root formation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Proteínas Repressoras/genética , Fatores de Transcrição/genética
8.
Mol Plant ; 7(11): 1653-1669, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25122697

RESUMO

Plant root system morphology is dramatically influenced by various environmental cues. The adaptation of root system architecture to environmental constraints, which mostly depends on the formation and growth of lateral roots, is an important agronomic trait. Lateral root development is regulated by the external signals coordinating closely with intrinsic signaling pathways. MADS-box transcription factors are known key regulators of the transition to flowering and flower development. However, their functions in root development are still poorly understood. Here we report that AGL21, an AGL17-clade MADS-box gene, plays a crucial role in lateral root development. AGL21 was highly expressed in root, particularly in the root central cylinder and lateral root primordia. AGL21 overexpression plants produced more and longer lateral roots while agl21 mutants showed impaired lateral root development, especially under nitrogen-deficient conditions. AGL21 was induced by many plant hormones and environmental stresses, suggesting a function of this gene in root system plasticity in response to various signals. Furthermore, AGL21 was found positively regulating auxin accumulation in lateral root primordia and lateral roots by enhancing local auxin biosynthesis, thus stimulating lateral root initiation and growth. We propose that AGL21 may be involved in various environmental and physiological signals-mediated lateral root development and growth.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Ácidos Indolacéticos/metabolismo , Proteínas de Domínio MADS/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Transdução de Sinais , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento
9.
J Exp Bot ; 65(15): 4285-95, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24821957

RESUMO

The gain-of-function mutant edt1 shows significantly enhanced drought tolerance and a well-developed root system including deeper primary roots and more lateral roots. To explore the molecular mechanisms underlying the improved root system of edt1, we performed transcriptome comparison between the wild-type and edt1 roots. One of the interesting findings from the analysis was that several gene families of cell-wall-loosening proteins were upregulated in the mutant roots, including expansins, extensins, xyloglucan endotransglucosylase/hydrolases (XTHs), pectin-related enzymes, and cellulases. Most of these genes contain HD-binding cis-elements in their promoters predominantly with the TTTAATTT sequence, which can be bound by HDG11 in vitro and in vivo. The coordinated expression of these gene families overlaps fast root elongation. Furthermore, overexpression of AtEXPA5, which was dramatically upregulated in edt1, resulted in longer primary roots because cells were more extended longitudinally. When combined by crossing the AtEXPA5-overexpression lines with one pectin methylesterase inhibitor family protein (PMEI) gene (At5g62360)- or one cellulase (CEL) gene (At2g32990)-overexpression lines, the primary roots of the progeny even exceeded both parents in length. Our results demonstrate that HDG11 directly upregulates cell-wall-loosening protein genes, which is correlated with altered root system architecture, and confirm that cell-wall-loosening proteins play important roles in coordinating cell-wall extensibility with root development. The results of transgene experiments showed that expansin works together with PMEI and CEL to generate synergistic effects on primary root elongation, suggesting that different cell-wall-loosening protein families may function in combination to generate optimal effects on root extensibility.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/fisiologia , Parede Celular/fisiologia , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/crescimento & desenvolvimento , Fatores de Transcrição/fisiologia , Proteínas de Arabidopsis/metabolismo , Crescimento Celular , Celulase/metabolismo , Proteínas de Plantas/fisiologia , Regulação para Cima
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