Nematodes in horticulture: an overview.

Herein, we integrated information about the damage and losses caused by these pathogens in horticulture. Resistant genotypes seem to be the best alternative and, due to wide horticulture aspect, the focus is especially for life sustaining horticultural, such as banana, cassava, potato, and sugar beet. In addition, it was also provided evidence regarding how studies have been conducted on new strategies for resistance and control, such as the elucidation of effector?s functions. Nematode effectors studies, focus on the development of new resistant plant genotypes, is an auspicious strategy against this parasites

Temporal gene expression analysis of effector candidates of Phakopsora pachyrhizi across the infection cycle.

Phakopsora pachyrhizi is the causer of the Asian soybean rust, the most aggressive foliar disease that attacks the soybean plants in cultivated areas. To design effective breeding strategies for durable disease resistance it is important to understand the molecular basis of this plant-pathogen interaction. In particular, the characterization of the secreted effector proteins can help the breeding programs. Our recent analysis of the P. pachyrhizi secretome has revealed the presence of potential effectors genes. In this work, the temporal expression of 58 effector candidate genes were characterized from spores, germinated spores and infected soybean leaves at 0, 6, 12, 24, 36, 48, 72, 96, 192 and 240 hours after inoculation (hai) using RT-qPCR. Expression analysis showed differential temporal gene expression of these candidate effectors. Clustering analysis revealed three main clusters with coordinated expression of candidates across the infection cycle. The first has candidates expressed in specific steps of infection and almost sequences have the common motifs Y/F/WxC frequently found in haustoria-producing rust fungi effectors. The second cluster has candidates expressed during initial steps of infection that matches germ tube and appressorium formation (0 – 24 hai) and almost sequences have ?3 cysteine residues, other common features of the effectors. Third cluster has candidates expressed only in contact with the host, suggesting that these candidates are host-induced. The sequences in this cluster have the CFEM domain associated with pathogenicity. Functional analyses are in progress with more promising candidates effectors to validate the potential effectors from soybean rust

Diversidade genética de isolados monouredinias de Phakopsora pachyrhizi coletados em diferentes regiões do Brasil.

O objetivo deste trabalho foi avaliar a diversidade genética de isolados monourediniais do fungo Phakopsora pachyrhizi coletados em diferentes regiões produtoras de soja no Brasil, por meio da análise das sequências da região do espaçador interno transcrito 1 (ITS1)

Sensitivity of Cercospora spp. from soybean to quinone outside inhibitors and methyl benzimidazole carbamate fungicides in Brazil.

Artigo de acesso aberto

Time Course RNA-seq Reveals Soybean Responses against Root-Lesion Nematode and Resistance Players.

Pratylenchus brachyurus causes serious damage to soybean production and other crops worldwide. Plant molecular responses to RLN infection remain largely unknown and no resistance genes have been identified in soybean. In this study, we analyzed molecular responses to RLN infection in moderately resistant BRSGO (Chapadões—BRS) and susceptible TMG115 RR (TMG) Glycine max genotypes. Differential expression analysis revealed two stages of response to RLN infection and a set of differentially expressed genes (DEGs) in the first stage suggested a pattern-triggered immunity (PTI) in both genotypes. The divergent time-point of DEGs between genotypes was observed four days post-infection, which included the activation of mitogen-activated protein kinase (MAPK) and plant–pathogen interaction genes in the BRS, suggesting the occurrence of an effector-triggered immunity response (ETI) in BRS. The co-expression analyses combined with single nucleotide polymorphism (SNP) uncovered a key element, a transcription factor phytochrome-interacting factor (PIF7) that is a potential regulator of moderate resistance to RLN infection. Two genes for resistance-related leucine-rich repeat (LRR) proteins were found as BRS-specific expressed genes. In addition, alternative splicing analysis revealed an intron retention in a myo-inositol oxygenase (MIOX) transcript, a gene related to susceptibility, may cause a loss of function in BRS

Food Legumes and Rising Temperatures: Effects, Adaptive Functional Mechanisms Specific to Reproductive Growth Stage and Strategies to Improve Heat Tolerance

Ambient temperatures are predicted to rise in the future owing to several reasons associated with global climate changes. These temperature increases can result in heat stress- a severe threat to crop production in most countries. Legumes are well-known for their impact on agricultural sustainability as well as their nutritional and health benefits. Heat stress imposes challenges for legume crops and has deleterious effects on the morphology, physiology, and reproductive growth of plants. High-temperature stress at the time of the reproductive stage is becoming a severe limitation for production of grain legumes as their cultivation expands to warmer environments and temperature variability increases due to climate change. The reproductive period is vital in the life cycle of all plants and is susceptible to high-temperature stress as various metabolic processes are adversely impacted during this phase, which reduces crop yield. Food legumes exposed to high-temperature stress during reproduction show flower abortion, pollen and ovule infertility, impaired fertilization, and reduced seed filling, leading to smaller seeds and poor yields. Through various breeding techniques, heat tolerance in major legumes can be enhanced to improve performance in the field. Omics approaches unravel different mechanisms underlying thermotolerance, which is imperative to understand the processes of molecular responses toward high-temperature stress

Molecular soybean-pathogen interactions

Soybean hosts a wide variety of pathogens that cause significant yield losses. The importance of soybean as a major oilseed crop has led to research focused on its interactions with pathogens, such as Soybean mosaic virus, Pseudomonas syringae, Phytophthora sojae, Phakopsora pachyrhizi, and Heterodera glycines. Pioneering work on soybean's interactions with these organisms, which represent the five major pathogen groups (viruses, bacteria, oomycetes, fungi, and nematodes), has contributed to our understanding of the molecular mechanisms underlying virulence and immunity. These mechanisms involve conserved and unique features that validate the need for research in both soybean and homologous model systems. In this review, we discuss identification of effectors and their functions as well as resistance gene-mediated recognition and signaling. We also point out areas in which model systems and recent advances in resources and tools have provided opportunities to gain deeper insights into soybean-pathogen interactions