RESUMO
Plant autophagy plays an important role in delaying senescence, nutrient recycling, and stress responses. Functional analysis of plant autophagy has almost exclusively focused on the proteins required for the core process of autophagosome assembly, but little is known about the proteins involved in other important processes of autophagy, including autophagy cargo recognition and sequestration. In this study, we report functional genetic analysis of Arabidopsis NBR1, a homolog of mammalian autophagy cargo adaptors P62 and NBR1. We isolated two nbr1 knockout mutants and discovered that they displayed some but not all of the phenotypes of autophagy-deficient atg5 and atg7 mutants. Like ATG5 and ATG7, NBR1 is important for plant tolerance to heat, oxidative, salt, and drought stresses. The role of NBR1 in plant tolerance to these abiotic stresses is dependent on its interaction with ATG8. Unlike ATG5 and ATG7, however, NBR1 is dispensable in age- and darkness-induced senescence and in resistance to a necrotrophic pathogen. A selective role of NBR1 in plant responses to specific abiotic stresses suggest that plant autophagy in diverse biological processes operates through multiple cargo recognition and delivery systems. The compromised heat tolerance of atg5, atg7, and nbr1 mutants was associated with increased accumulation of insoluble, detergent-resistant proteins that were highly ubiquitinated under heat stress. NBR1, which contains an ubiquitin-binding domain, also accumulated to high levels with an increasing enrichment in the insoluble protein fraction in the autophagy-deficient mutants under heat stress. These results suggest that NBR1-mediated autophagy targets ubiquitinated protein aggregates most likely derived from denatured or otherwise damaged nonnative proteins generated under stress conditions.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Autofagia/genética , Proteínas de Transporte , Estresse Fisiológico/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteína 5 Relacionada à Autofagia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Mutação , Fenótipo , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/metabolismo , Solubilidade , Ubiquitina/metabolismo , Proteínas Ubiquitinadas/metabolismoRESUMO
WRKY transcription factors are encoded by a large gene superfamily with a broad range of roles in plants. Recently, several groups have reported that proteins containing a short VQ (FxxxVQxLTG) motif interact with WRKY proteins. We have recently discovered that two VQ proteins from Arabidopsis (Arabidopsis thaliana), SIGMA FACTOR-INTERACTING PROTEIN1 and SIGMA FACTOR-INTERACTING PROTEIN2, act as coactivators of WRKY33 in plant defense by specifically recognizing the C-terminal WRKY domain and stimulating the DNA-binding activity of WRKY33. In this study, we have analyzed the entire family of 34 structurally divergent VQ proteins from Arabidopsis. Yeast (Saccharomyces cerevisiae) two-hybrid assays showed that Arabidopsis VQ proteins interacted specifically with the C-terminal WRKY domains of group I and the sole WRKY domains of group IIc WRKY proteins. Using site-directed mutagenesis, we identified structural features of these two closely related groups of WRKY domains that are critical for interaction with VQ proteins. Quantitative reverse transcription polymerase chain reaction revealed that expression of a majority of Arabidopsis VQ genes was responsive to pathogen infection and salicylic acid treatment. Functional analysis using both knockout mutants and overexpression lines revealed strong phenotypes in growth, development, and susceptibility to pathogen infection. Altered phenotypes were substantially enhanced through cooverexpression of genes encoding interacting VQ and WRKY proteins. These findings indicate that VQ proteins play an important role in plant growth, development, and response to environmental conditions, most likely by acting as cofactors of group I and IIc WRKY transcription factors.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Mapeamento de Interação de Proteínas , Fatores de Transcrição/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Botrytis/patogenicidade , DNA de Plantas/genética , Proteínas de Ligação a DNA/metabolismo , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fenótipo , Filogenia , Doenças das Plantas/imunologia , Imunidade Vegetal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas , Pseudomonas syringae/patogenicidade , Ácido Salicílico/farmacologia , Fator sigma/genética , Fator sigma/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Fatores de Transcrição/genética , Técnicas do Sistema de Duplo-HíbridoRESUMO
OBJECTIVE: To compare therapeutic effects of internal fixation with volar locking plate in treating extension and flexion type of distal radius fracture (DRF). METHODS: From January 2015 to June 2018, 103 patients with DRF were retrospectively analyzed. According to original fracture displacement direction, patients were divided into extension fracture(Colles) group and flexion fracture (Smith) group. In Colles fracture group, there were 24 males and 44 females aged from 20 to 79 years old with an average of (59.0±13.4) years old;according to AO classification, 9 patients of type A2, 13 patients of type A3, 16 patientsof type C1, 17 patients of type C2 and 13 patients of type C3;the time from injury to operation ranged from 2 to 9 days with an average of (3.9±0.8) days. In Smith fracture group, there were 15 males and 20 females, aged from 27 to 87 years old with an average of (60.1±15.3) years old;according to AO classification, 4 patienst of A2, 7 patients of A3, 14 patients of C1, 5 patients of C2 and 5 patients of C3;the time from injury to operation ranged from 2 to 6 days with an average of (4.1±0.9) days. Operation time, fracture healing time and postoperative complications were recorded between two groups. Disabilities of arm, shoulder and hand (DASH) score at 6 and 8 weeks, 6 and 8 months were used to evaluate functional recovery of affected limbs during each follow up. Volar tilt, radial inclination and radius height were measured at 8 months after operation. Mayo score was measured at 8 months after operation to evaluate recovery of limb function. RESULTS: All patients were followed up for 8 to 30 months with an average of (14.8±4.3) months, and no difference in follow up between two groups (P> 0.05). There were no statistical differences in operation time, fracture healing time and postoperative complications between two groups(P>0.05). DASH score at 6 and 12 weeks in Colles fracture group were (37.24±5.08) and (19.68±4.55), while in Smith fracture group were (39.05±4.79) and (23.44±4.21);Colles fracture group was better than that of Smith fracture group (P<0.001);while there were no differences in DASH score at 6 and 8 months between two groups (P>0.05). Volar tilt of Smith fracture group (11.1±3.1)° was better than that of Colles fracture group (8.6±4.1) °, and there were no significant difference in radial inclination and radius height between two groups(P>0.05). Also there was no significant difference in Mayo score between two group(P>0.05). CONCLUSION: Patients with Colles fracture and Smith fracture could receive good reduction and fixation through volar locking plate. The radiographic parameters of both groups recovered satisfactorily after operation. Recovery of volar tilt of Smith fracture group is better than that of Colles fracture group, and early recovery function of Colles fracture group is better than that of Smith group, but there is no significant difference in long-term wrist joint function and incidence of postoperative complications between two groups.
Assuntos
Fraturas do Rádio , Adulto , Idoso , Idoso de 80 Anos ou mais , Placas Ósseas , Feminino , Fixação Interna de Fraturas , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas do Rádio/cirurgia , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento , Articulação do Punho , Adulto JovemRESUMO
To research the mechanism of soybean reproductive development, we identified a number of flower development related genes in soybean by microarray hybridization. A gene predominately expressed in soybean flowers was chosen for further analysis. Through bioinformatic and RT-PCR approaches, the full-length gene was cloned from soybean flowers. The results of BLAST searching indicated that this gene encoded for an aldehyde dehydrogenase and was named as GmALDH3-1. GmALDH3-1 contains a complete open reading frame of 1485 bp in length, which encodes for a peptide of 494 amino acids. The product encoded by GmALDH3-1 shows 83% similarity and 68% identity with Populus tomentosa PtALDH3, respectively, and 39% and 59% with human ALDH3B. Phylogenetic analysis shows that GmALDH3-1 and other ALDH3 subfamily members are grouped into the same branch and GmALDH3-1 is close to PtALDH3 and Arabidopsis AtALDH3F1. Real-time RT-PCR analysis demonstrated that the highest expression level of GmALDH3-1 occurred in flowers, but the expression of this gene was almost undetectable in leaves and roots. We further analyzed GmALDH3-1 expression during the course of seed development based on publicly available microarray data and found that GmALDH3-1 was highly expressed in the seed endothelium, epidermis, outer integument, and hilum.