Tomato fruit susceptibility to fungal disease can be uncoupled from ripening by suppressing susceptibility factors

2020 ◽  
Author(s):  
Christian J. Silva ◽  
Casper van den Abeele ◽  
Isabel Ortega-Salazar ◽  
Victor Papin ◽  
Jaclyn A. Adaskaveg ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Crop Production ◽  
Tomato Fruit ◽  
Redox Homeostasis ◽  
Pectate Lyase ◽  
Defense Responses ◽  
Fungal Disease ◽  
Ripe Fruit ◽  
Susceptibility Factors ◽  
Increased Susceptibility

AbstractThe increased susceptibility of ripe fruit to fungal pathogens poses a substantial threat to crop production and marketability. Here, we coupled transcriptomic analyses with mutant studies to uncover critical processes associated with defenses and susceptibility in tomato (Solanum lycopersicum) fruit. Using unripe and ripe fruit inoculated with three fungal pathogens, we identified common pathogen responses reliant on chitinases, WRKY transcription factors, and reactive oxygen species detoxification. We established that the magnitude and diversity of defense responses do not significantly impact the interaction outcome, as susceptible ripe fruit mounted a strong defense response to pathogen infection. Then, to distinguish features of ripening that may be responsible for susceptibility, we utilized non-ripening tomato mutants that displayed different susceptibility patterns to fungal infection. Based on transcriptional and hormone profiling, susceptible tomato genotypes had losses in the maintenance of cellular redox homeostasis, while jasmonic acid accumulation and signaling coincided with defense activation in resistant fruit. We identified and validated a susceptibility factor, pectate lyase (PL). CRISPR-based knockouts of PL, but not polygalacturonase (PG2a), reduced susceptibility of ripe fruit by >50%. This study suggests that targeting specific genes that drive susceptibility is a viable strategy to improve the resistance of tomato fruit against fungal disease.HighlightIncreased susceptibility to fungal disease during tomato ripening is driven by the accumulation of susceptibility factors and not the lack of defense responses.

scholarly journals Inducing Fungus-Resistance into Plants through Biotechnology

2010 ◽  
Vol 2 (2) ◽  
pp. 14-21 ◽  
Author(s):  
Shabir Hussain WANI
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Hydrolytic Enzymes ◽  
Defense Responses ◽  
Stilbene Synthase ◽  
Fungal Disease ◽  
Plant Diseases ◽  
Fungal Cell ◽  
Oxidase Gene ◽  
Enhanced Resistance

Plant diseases are caused by a variety of plant pathogens including fungi, and their management requires the use of techniques like transgenic technology, molecular biology, and genetics. There have been attempts to use gene technology as an alternative method to protect plants from microbial diseases, in addition to the development of novel agrochemicals and the conventional breeding of resistant cultivars. Various genes have been introduced into plants, and the enhanced resistance against fungi has been demonstrated. These include: genes that express proteins, peptides, or antimicrobial compounds that are directly toxic to pathogens or that reduce their growth in situ; gene products that directly inhibit pathogen virulence products or enhance plant structural defense genes, that directly or indirectly activate general plant defense responses; and resistance genes involved in the hypersensitive response and in the interactions with virulence factors. The introduction of the tabtoxin acetyltransferase gene, the stilbene synthase gene, the ribosome-inactivation protein gene and the glucose oxidase gene brought enhanced resistance in different plants. Genes encoding hydrolytic enzymes such as chitinase and glucanase, which can deteriorate fungal cell-wall components, are attractive candidates for this approach and are preferentially used for the production of fungal disease-resistant plants. In addition to this, RNA-mediated gene silencing is being tried as a reverse tool for gene targeting in plant diseases caused by fungal pathogens. In this review, different mechanisms of fungal disease resistance through biotechnological approaches are discussed and the recent advances in fungal disease management through transgenic approach are reviewed.

scholarly journals The Fungal Effector Avr-Pita Suppresses Innate Immunity by Increasing COX Activity in Rice Mitochondria

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jingluan Han ◽  
Xiaoyu Wang ◽  
Fengpin Wang ◽  
Zhe Zhao ◽  
Gousi Li ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Host Plant ◽  
Fungal Pathogen ◽  
Defense Responses ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Molecular Pattern ◽  
Ros Accumulation ◽  
Ros Metabolism ◽  
Increased Susceptibility

Abstract Background Avr-Pita was the first effector identified in the blast fungus (Magnaporthe oryzae)–rice (Oryza sativa) pathosystem. However, the molecular mechanism underlying its effects on the host plant has remained a long-standing mystery. Results Here, we report that ectopically expressing Avr-Pita in rice enhances susceptibility to M. oryzae and suppresses pathogen-associated molecular pattern (PAMP)-triggered defense responses. Avr-Pita targets the host mitochondria and interacts with the cytochrome c oxidase (COX) assembly protein OsCOX11, a key regulator of mitochondrial reactive oxygen species (ROS) metabolism in rice. Overexpressing Avr-Pita or OsCOX11 increased COX activity and decreased ROS accumulation triggered by the fungal PAMP chitin. OsCOX11-overexpressing plants showed increased susceptibility to M. oryzae, whereas OsCOX11-knockdown plants showed resistance to M. oryzae. Conclusions Taken together, these findings suggest that the fungal pathogen M. oryzae delivers the effector Avr-Pita to the host plant, where it enhances COX activity thus decreasing ROS accumulation. Therefore, this effector suppresses host innate immunity by perturbing ROS metabolism in the mitochondria.

scholarly journals Isolation and Characterization of Root-Associated Bacterial Endophytes and Their Biocontrol Potential against Major Fungal Phytopathogens of Rice (Oryza sativa L.)

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 172
Author(s):  
Maqsood Ahmed Khaskheli ◽  
Lijuan Wu ◽  
Guoqing Chen ◽  
Long Chen ◽  
Sajid Hussain ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Fungal Pathogens ◽  
Oryza Sativa L ◽  
Defense Responses ◽  
Growth And Yield ◽  
Bacterial Endophytes ◽  
16S Rrna Sequence ◽  
Resistance Response ◽  
Isolation And Characterization ◽  
Fungal Phytopathogens

Rice (Oryza sativa L.) is a major cereal food crop worldwide, and its growth and yield are affected by several fungal phytopathogens, including Magnaporthe oryzae, Fusarium graminearum, F. moniliforme, and Rhizoctonia solani. In the present study, we have isolated and characterized root-associated bacterial endophytes that have antifungal activities against rice fungal phytopathogens. A total of 122 root-associated bacterial endophytes, belonging to six genera (Bacillus, Fictibacillus, Lysinibacillus, Paenibacillus, Cupriavidus, and Microbacterium) and 22 species were isolated from three rice cultivars. Furthermore, the 16S rRNA sequence-based phylogeny results revealed that Bacillus was the most dominant bacterial genera, and that there were 15 different species among the isolates. Moreover, 71 root-associated endophytes showed antagonistic effects against four major fungal phytopathogens, including M. oryzae, F. graminearum, F. moniliforme, and R. solani. Additionally, the biochemical, physiological, and PCR amplification results of the antibiotic-related genes further supported the endophytes as potential biocontrolling agents against the rice fungal pathogens. Consequently, the findings in this study suggested that the isolated bacterial endophytes might have beneficial roles in rice defense responses, including several bioactive compound syntheses. The outcomes of this study advocate the use of natural endophytes as an alternative strategy towards the rice resistance response.

Manipulating fruit chloroplasts as a strategy to improve fruit quality

2013 ◽  
Author(s):  
Alan B. Bennett ◽  
Arthur A. Schaffer ◽  
Ilan Levin ◽  
Marina Petreikov ◽  
Adi Doron-Faigenboim
Keyword(s):  
Chloroplast Development ◽  
Tomato Fruit ◽  
Soluble Sugar ◽  
Fruit Size ◽  
Soluble Solids ◽  
Nucleotide Polymorphisms ◽  
Ripe Fruit ◽  
Green Fruit ◽  
Functional Alleles ◽  
Sugar Levels

The Original Objectives were modified and two were eliminated to reflect the experimental results: Objective 1 - Identify additional genetic variability in SlGLK2 and IPin wild, traditional and heirloom tomato varieties Objective 2 - Determine carbon balance and horticultural characteristics of isogenic lines expressing functional and non-functional alleles of GLKsand IP Background: The goal of the research was to understand the unique aspects of chloroplasts and photosynthesis in green fruit and the consequences of increasing the chloroplast capacity of green fruit for ripe fruit sugars, yield, flavor and nutrient qualities. By focusing on the regulation of chloroplast formation and development solely in fruit, our integrated knowledge of photosynthetic structures/organs could be broadened and the results of the work could impact the design of manipulations to optimize quality outputs for the agricultural fruit with enhanced sugars, nutrients and flavors. The project was based on the hypothesis that photosynthetic and non-photosynthetic plastid metabolism in green tomato fruit is controlled at a basal level by light for minimal energy requirements but fruit-specific genes regulate further development of robust chloroplasts in this organ. Our BARD project goals were to characterize and quantitate the photosynthesis and chloroplast derived products impacted by expression of a tomato Golden 2- like 2 transcription factor (US activities) in a diverse set of 31 heirloom tomato lines and examine the role of another potential regulator, the product of the Intense Pigment gene (IP activities). Using tomato Golden 2-like 2 and Intense Pigment, which was an undefined locus that leads to enhanced chloroplast development in green fruit, we sought to determine the benefits and costs of extensive chloroplast development in fruit prior to ripening. Major conclusions, solutions, achievements: Single nucleotide polymorphisms in the promoter, coding and intronicSlGLK2 sequences of 20 heirloom tomato lines were identified and three SlGLK2 promoter lineages were identified; two lineages also had striped fruit variants. Lines with striped fruit but no shoulders were not identified. Green fruit chlorophyll and ripe fruit soluble sugar levels were measured in 31 heirloom varieties and fruit size correlates with ripe fruit sugars but dark shoulders does not. A combination of fine mapping, recombinant generation, RNAseq expression and SNP calling all indicated that the proposed localization of a single locus IP on chr 10 was incorrect. Rather, the IP line harbored 11 separate introgressions from the S. chmielewskiparent, scattered throughout the genome. These introgressions harbored ~3% of the wild species genome and no recombinant consistently recovered the IP parental phenotype. The 11 introgressions were dissected into small combinations in segregating recombinant populations. Based on these analyses two QTL for Brix content were identified, accounting for the effect of increased Brix in the IP line. Scientific and agricultural implications: SlGLK2 sequence variation in heirloom tomato varieties has been identified and can be used to breed for differences in SlGLK2 expression and possibly in the green striped fruit phenotype. Two QTL for Brix content have been identified in the S. chmielewskiparental line and these can be used for increasing soluble solids contents in breeding programs. 

scholarly journals Peach Brown Rot: Still in Search of an Ideal Management Option

Agriculture ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 125 ◽  
Author(s):  
Vitus Ikechukwu Obi ◽  
Juan José Barriuso ◽  
Yolanda Gogorcena
Keyword(s):  
Fungal Pathogens ◽  
Crop Production ◽  
Control Strategies ◽  
Brown Rot ◽  
Management Option ◽  
Management Options ◽  
Pests And Diseases ◽  
Resistant Varieties ◽  
Rot Disease ◽  
Post Harvest Loss

The peach is one of the most important global tree crops within the economically important Rosaceae family. The crop is threatened by numerous pests and diseases, especially fungal pathogens, in the field, in transit, and in the store. More than 50% of the global post-harvest loss has been ascribed to brown rot disease, especially in peach late-ripening varieties. In recent years, the disease has been so manifest in the orchards that some stone fruits were abandoned before harvest. In Spain, particularly, the disease has been associated with well over 60% of fruit loss after harvest. The most common management options available for the control of this disease involve agronomical, chemical, biological, and physical approaches. However, the effects of biochemical fungicides (biological and conventional fungicides), on the environment, human health, and strain fungicide resistance, tend to revise these control strategies. This review aims to comprehensively compile the information currently available on the species of the fungus Monilinia, which causes brown rot in peach, and the available options to control the disease. The breeding for brown rot-resistant varieties remains an ideal management option for brown rot disease control, considering the uniqueness of its sustainability in the chain of crop production.

scholarly journals JAZ repressors of metabolic defense promote growth and reproductive fitness inArabidopsis

2018 ◽  
Vol 115 (45) ◽  
pp. E10768-E10777 ◽  
Author(s):  
Qiang Guo ◽  
Yuki Yoshida ◽  
Ian T. Major ◽  
Kun Wang ◽  
Koichi Sugimoto ◽  
...  
Keyword(s):  
Gene Family ◽  
Fungal Pathogens ◽  
Defense Responses ◽  
Protein Profiling ◽  
Metabolic Effects ◽  
Repressor Proteins ◽  
Acid Protein ◽  
Jaz Proteins ◽  
Physiological Tasks ◽  
Amino Acid Protein

Plant immune responses mediated by the hormone jasmonoyl-l-isoleucine (JA-Ile) are metabolically costly and often linked to reduced growth. Although it is known that JA-Ile activates defense responses by triggering the degradation of JASMONATE ZIM DOMAIN (JAZ) transcriptional repressor proteins, expansion of theJAZgene family in vascular plants has hampered efforts to understand how this hormone impacts growth and other physiological tasks over the course of ontogeny. Here, we combined mutations within the 13-memberArabidopsis JAZgene family to investigate the effects of chronic JAZ deficiency on growth, defense, and reproductive output. A higher-order mutant (jazdecuple,jazD) defective in 10JAZgenes (JAZ1–7,-9,-10, and-13) exhibited robust resistance to insect herbivores and fungal pathogens, which was accompanied by slow vegetative growth and poor reproductive performance. Metabolic phenotypes ofjazDdiscerned from global transcript and protein profiling were indicative of elevated carbon partitioning to amino acid-, protein-, and endoplasmic reticulum body-based defenses controlled by the JA-Ile and ethylene branches of immunity. Resource allocation to a strong defense sink injazDleaves was associated with increased respiration and hallmarks of carbon starvation but no overt changes in photosynthetic rate. Depletion of the remaining JAZ repressors injazDfurther exaggerated growth stunting, nearly abolished seed production and, under extreme conditions, caused spreading necrotic lesions and tissue death. Our results demonstrate that JAZ proteins promote growth and reproductive success at least in part by preventing catastrophic metabolic effects of an unrestrained immune response.

scholarly journals The Effect of Low Temperature on Phosphate Esterification and Cell Membrane Permeability in Tomato Fruit and Cabbage Leaf Tissue

1964 ◽  
Vol 17 (1) ◽  
pp. 147 ◽  
Author(s):  
TL Lewis ◽  
M Workman
Keyword(s):  
Low Temperature ◽  
Tomato Fruit ◽  
Chilling Injury ◽  
Leaf Tissue ◽  
Cell Membrane Permeability ◽  
Energy Deficit ◽  
Chilling Temperature ◽  
Tomato Fruits ◽  
Threefold Increase ◽  
Increased Susceptibility

Exposure to O�C for 4 weeks caused a threefold increase in cell membrnno permeability of mature-green tomato fruits (susceptible to chilling injury) hut had no effect on that of cabbage leaves (not susceptible). While tomato fruits chilled for 12 days lost two-thirds of their capacity to esterify phosphate at 20�0, a steady rise in this capacity occurred during chilling of cabbage leaves for 5 weeks. In tomato fruits the rate of phosphate esterification at the chilling temperature fell in 12 days to about one-half of the rate at the commencement of chilling .. It is suggested that the characteristic symptoms of chilling injury in mature-green tomato fruits, viz. increased susceptibility to fungal attack and loss of the capacity to ripen normally. may result from an energy deficit caused by a chilling. induced reduction in the phosphorylative capacity of the tissue.

scholarly journals Comparative Proteomics Reveals the Potential Targets of BcNoxR, a Putative Regulatory Subunit of NADPH Oxidase of Botrytis cinerea

2016 ◽  
Vol 29 (12) ◽  
pp. 990-1003 ◽  
Author(s):  
Hua Li ◽  
Zhanquan Zhang ◽  
Chang He ◽  
Guozheng Qin ◽  
Shiping Tian
Keyword(s):  
Nadph Oxidase ◽  
Botrytis Cinerea ◽  
Proteomic Analysis ◽  
Fungal Pathogens ◽  
Molecular Mechanisms ◽  
Quantitative Polymerase Chain Reaction ◽  
Tomato Fruit ◽  
Polymerase Chain Reaction Analysis ◽  
Regulatory Subunit ◽  
Wild Type

The NADPH oxidase (NOX) complex has been shown to play a crucial role in stress response and in the virulence of various fungal pathogens. The underlying molecular mechanisms of NOX, however, remain largely unknown. In the present study, a comparative proteomic analysis compared changes in protein abundance in wild-type Botrytis cinerea and ΔbcnoxR mutants in which the regulatory subunit of NOX was deleted. The ΔbcnoxR mutants exhibited reduced growth, sporulation, and impaired virulence. A total of 60 proteins, representing 49 individual genes, were identified in ΔbcnoxR mutants that exhibited significant differences in abundance relative to wild-type. Reverse transcription-quantitative polymerase chain reaction analysis demonstrated that the differences in transcript levels for 36 of the genes encoding the identified proteins were in agreement with the proteomic analysis, while the remainder exhibited reverse levels. Functional analysis of four proteins that decreased abundance in the ΔbcnoxR mutants indicated that 6-phosphogluconate dehydrogenase (BcPGD) played a role in the growth and sporulation of B. cinerea. The Δbcpgd mutants also displayed impaired virulence on various hosts, such as apple, strawberry, and tomato fruit. These results suggest that NOX can influence the expression of BcPGD, which has an impact on growth, sporulation, and virulence of B. cinerea.

scholarly journals Side effects of triazoles on treated crops

2021 ◽  
Author(s):  
Michal Jakl ◽  
Sanja Ćavar Zeljković ◽  
Ishak Kovač ◽  
Kateřina Bělonožníková ◽  
Jana Jaklová Dytrtová
Keyword(s):  
Oxidative Stress ◽  
Side Effects ◽  
Fungal Pathogens ◽  
Crop Production ◽  
Growth Parameters ◽  
Target Species ◽  
Fruit Peel ◽  
Biochemical Processes ◽  
Basic Plant ◽  
Cherry Tomatoes

Triazolic fungicides are widely applied in crop production to protect plants against fungal pathogens. However, they may influence the biochemical processes in plants and other non-target species. This paper is aimed at the effect of triazoles (namely tebuconazole, cyproconazole, and penconazole) single/mixed applications on the phenolics production in tomato (Solanum lycopersicum L.) fruit peel, amount of chlorophyll a and b in tomato leaves as well as on basic plant growth parameters. For this purpose, cherry tomatoes were planted in the pot experiment and foliarly-treated weekly, with the same total triazoles dose of 3.52 μmol per plant (in mixtures of 1.71 or 1.17 μmol of each in two or three components, respectively). The treatments increased the weight of fruits in the 1 harvest about 43%, however, this effect was not observed in the next harvest. Increased oxidative stress in the triazoles presence was observed, based on the elevated production of antioxidant phenolics in the 1 harvest. Most alarming is the decrease of the weight of thin stems and foliage and the concentration of chlorophyll a (b) in leaves in all triazoles-treated variants. The non-target impacts on plant biochemical processes (related to the phenolics or chlorophylls production and functionality) were confirmed.

scholarly journals Physical Characteristics of Mature Green and Ripe Tomato Fruit Tissue of Normal and Firm Genotypes

1996 ◽  
Vol 121 (3) ◽  
pp. 380-383 ◽  
Author(s):  
E.V. Wann
Keyword(s):  
Cell Wall ◽  
Stress Relaxation ◽  
Tomato Fruit ◽  
Physical Characteristics ◽  
Tissue Elasticity ◽  
Ripe Fruit ◽  
Fruit Tissue ◽  
Relaxation Analysis ◽  
Fruit Samples ◽  
Mutant Lines

Tissue firmness of ripe tomatoes is controlled by cell wall integrity of the fruit tissue and by the enzymatic softening that normally occurs during ripening. This study was conducted to determine the physical characteristics of cells and tissues of mature green (MG) and ripe fruit that might account for differences in firmness between `Rutgers' (normal), `Flora-Dade' (Firm), and two mutant lines called high-pigment (T4065 hp) and dark-green (T4099 dg), both of which possess extra firm fruit. Fruit samples were tested for resistance to a force applied to whole fruit and to sections of the pericarp tissue and by stress-relaxation analysis. Determinations were also made of cell density and cell wall content within the pericarp tissue. Fruit of mutant lines had firmer tissue than either `Rutgers' or `Flora-Dade' at MG or ripe. Whole fruit compression measurements showed that T4099 dg was firmer than T4065 hp or `Rutgers' at MG and firmer than `Flora-Dade' and `Rutgers' when ripe. Whole fruit of `Flora-Dade' were significantly firmer than `Rutgers' at MG and ripe. Firmness measured by compressive strength also showed that mutant lines had firmer pericarp tissue than the wild types at both MG and ripe stages. Stress-relaxation analysis showed that MG fruit of T4099 dg had greater tissue elasticity than `Rutgers' or `Flora-Dade'. Ripe fruit of both mutant lines had more tissue elasticity than wild types. There were no apparent differences among the genotypes due to tissue relaxation. From these analyses, tissue elasticity appears to be a significant parameter in determining tissue firmness in the tomato genotypes used in this study. Firmness and textural quality of ripe tomatoes appeared to be dependent on elasticity of the pericarp tissue and on the level of enzymatic softening during ripening.

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