Tomato Plant Proteins Actively Responding to Fungal Applications and Their Role in Cell Physiology

Proteomics of Reproductive Development, Fruit Ripening, and Stress Responses in Tomato

The fruits of the tomato crop (Solanum lycopersicum L.) are increasingly consumed by humans worldwide. Due to their rich nutritional quality, pharmaceutical properties, and flavor, tomato crops have gained a salient role as standout crops among other plants. Traditional breeding and applied functional research have made progress in varying tomato germplasms to subdue biotic and abiotic stresses. Proteomic investigations within a span of few decades have assisted in consolidating the functional genomics and transcriptomic research. However, due to the volatility and dynamicity of proteins in the regulation of various biosynthetic pathways, there is a need for continuing research in the field of proteomics to establish a network that could enable a more comprehensive understanding of tomato growth and development. With this view, we provide a comprehensive review of proteomic studies conducted on the tomato plant in past years, which will be useful for future breeders and researchers working to improve the tomato crop.

The effect of circular soil biosolarization treatment on the physiology, metabolomics, and microbiome of tomato plants under certain abiotic stresses

Soil biosolarization (SBS) is an alternative technique for soil pest control to standard techniques such as soil fumigation and soil solarization (SS). By using both solar heating and fermentation of organic amendments, faster and more effective control of soilborne pathogens can be achieved. A circular economy may be created by using the residues of a given crop as organic amendments to biosolarize fields that produce that crop, which is termed circular soil biosolarization (CSBS). In this study, CSBS was employed by biosolarizing soil with amended tomato pomace (TP) residues and examining its impact on tomato cropping under conditions of abiotic stresses, specifically high salinity and nitrogen deficiency. The results showed that in the absence of abiotic stress, CSBS can benefit plant physiological performance, growth and yield relative to SS. Moreover, CSBS significantly mitigated the impacts of abiotic stress conditions. The results also showed that CSBS impacted the soil microbiome and plant metabolome. Mycoplana and Kaistobacter genera were found to be positively correlated with benefits to tomato plants health under abiotic stress conditions. Conversely, the relative abundance of the orders RB41, MND1, and the family Ellin6075 and were negatively correlated with tomato plants health. Moreover, several metabolites were significantly affected in plants grown in SS- and CSBS-treated soils under abiotic stress conditions. The metabolite xylonic acid isomer was found to be significantly negatively correlated with tomato plants health performance across all treatments. These findings improve understanding of the interactions between CSBS, soil ecology, and crop physiology under abiotic stress conditions.

Phenology forcing model to estimate phenology shifting ability of extreme environmental events

The current study considered the climate extreme index (CEI) values originated from extreme environmental events (EEEs) by following the National Oceanic and Atmospheric Administration (NOAA) guidelines. The EEEs were fractionated into six sub-categories (i.e., high temperature, low temperature, high precipitation, low precipitation, drought, and wind), and the combined impact of CEIs was utilized to develop an algorithm for the estimation of the phenology sensitivity index (P _Si ). Finally, the CEIs, and the P _Si were undergone the development of the phenology forcing (P^F ) model. The developed model showed a high sensitivity at the CEI value of as low as ≥1.0. Furthermore, the uncertainty index varied between 0.03 and 0.07, making a parabolic curvature at increasing CEIs (1.0-15.0). The current study precisely estimates the tendency of EEEs for phenology change. It will assist in policy-making and planning crop cultivation plans for achieving sustainable development goal 2 (SDG2) of the Food and Agriculture Organization (FAO).

Silicon assisted ameliorative effects of iron nanoparticles against cadmium stress: Attaining new equilibrium among physiochemical parameters, antioxidative machinery, and osmoregulators of Phaseolus lunatus

Currently, producing safe agricultural commodities from the crop plants cultivated in the soil with increasing heavy metal toxicity is a gigantic challenge in front of researchers. Heavy metals are absorbed and translocated in the crop plants and then transferred to every downstream consumer of the food chain, including humans, causing serious disorders and ailments. The current research presents a combined schematic application of iron nanoparticles (Fe-NPs) and/or silicon (Si), to mitigate cadmium (Cd) stress in Lima bean (Phaseolus lunatus). It was noted that Cd-induced toxicity curtailed growth, antioxidative machinery, glyoxalase system and nutrient uptake of the plants. Furthermore, the physiochemical features of Cd stressed plants, including carotenoids, chlorophyll, photochemical quenching, photosynthetic efficiency, and leaf relative water contents, were improved by the combined application of Si and Fe-NPs. Moreover, higher levels of malondialdehyde (MDA), methylglyoxal (MG), hydrogen peroxide (H₂O₂), and electrolyte leakage (EL) were observed in Cd stressed plants. Nevertheless, the independent treatment or combined application of Si and/or Fe-NPs attenuated the adversative effects of Cd on the aforementioned growth attributes. Furthermore, Si and Fe-NPs defended plants from the injurious effects of MG by improving the activities of the glyoxalase enzyme. The Si and Fe-NPs reduced Cd contents but at the same time improved uptake and accumulation of nutrients in treated plants exposed to the Cd regime. This study highlights that Si and Fe-NPs have enormous potential to mitigate Cd-induced phytotoxicity by declining Cd uptake and improving the growth attributes of plants if applied in combination.

Consequences of LED Lights on Root Morphological Traits and Compounds Accumulation in Sarcandra glabra Seedlings

This study evaluated the effects of different light spectra (white light; WL, blue light; BL and red light; RL) on the root morphological traits and metabolites accumulation and biosynthesis in Sarcandra glabra. We performed transcriptomic and metabolomic profiling by RNA-seq and ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS), respectively. When morphological features were compared to WL, BL substantially increased under-ground fresh weight, root length, root surface area, and root volume, while RL inhibited these indices. A total of 433 metabolites were identified, of which 40, 18, and 68 compounds differentially accumulated in roots under WL (WG) vs. roots under BL (BG), WG vs. roots under RL (RG), and RG vs. BG, respectively. In addition, the contents of sinapyl alcohol, sinapic acid, fraxetin, and 6-methylcoumarin decreased significantly in BG and RG. In contrast, chlorogenic acid, rosmarinyl glucoside, quercitrin and quercetin were increased considerably in BG. Furthermore, the contents of eight terpenoids compounds significantly reduced in BG. Following transcriptomic profiling, several key genes related to biosynthesis of phenylpropanoid-derived and terpenoids metabolites were differentially expressed, such as caffeic acid 3-O-methyltransferase) (COMT), hydroxycinnamoyl-CoA shikimate hydroxycinnamoyl transferase (HCT), O-methyltransferase (OMT), and 1-deoxy-D-xylulose-5-phosphate synthetase (DXS). In summary, our findings showed that BL was suitable for growth and accumulation of bioactive metabolites in root tissue of S. glabra. Exposure to a higher ratio of BL might have the potential to improve the production and quality of S. glabra seedlings, but this needs to be confirmed further.

Magnetic Field Stimulation Effect on Germination and Antioxidant Activities of Presown Hybrid Seeds of Sunflower and Its Seedlings

Magnetic field biostimulation plays a significant role in enhancing the germination of seeds and increasing the metabolic rate. The low magnetic field effect for long exposure time and its effect on antioxidant profiling have not been studied. Therefore, in the recent findings, the static magnetic field’s impact on sunflower seeds subjected to the magnetic field at varying intensity (millitesla) for different exposure times was examined. The effectiveness of magnetic biostimulation on presown sunflower seeds, growth parameters of seedlings (biomass, root and shoot length, fresh and dry weight of roots, shoots, leaf, and height of plants), and antioxidant activities were also studied. It has been revealed that magnetic treatment at 50 mT/45 min greatly influenced the growth parameters, including mean germination growth (100 ± 0.02) and final emergence rate. Concerning the antioxidant parameters, seed variety FH620 at 500 µg/µL concentration showed significant results compared to other varieties. FTIR was employed to determine the conformational changes and functional groups of organic compounds from sunflower seedlings. Tocopherol analysis by HPLC showed that magnetic treatment at 50 mT/45 min had a higher concentration of vitamin E compared to the control group. These modifications indicated that magnetic field induction enhanced seeds’ inner energy that led to seedlings’ growth and development enhancement. Besides, magnetic field pretreatment has been shown to have a beneficial influence on sunflower seeds and their bioactive compounds. Future studies should be focused on growth characteristics at the field level and yield attributes.

Functional and Structural Analysis of a Novel Acyltransferase from Pathogenic Phytophthora melonis

This investigation characterizes an acyltransferase enzyme responsible for the pathogenicity of Phytophthora melonis. The protein was characterized in vitro for its physicochemical properties. The biochemical characterization, including thermal and pH stability, revealed the 35 °C temperature and 7.0 pH as the optimum conditions for the enzyme. Applying the Tween-80 solution enhanced the activity up to 124.9%. Comprehensive structural annotation revealed two domains, A (ranging from residues 260 to 620) and B (ranging from 141 to 219). Domain A had transglutaminase (T-Gase) elicitor properties, while B possessed antifreeze features. Rigorous sequence characterization of the acyltransferase tagged it as a low-temperature-resistant protein. Further, the taxonomic distribution analysis of the protein highlighted three genera in Oomycetes, i.e., Pythium, Phytophthora, and Plasmopara, bearing this protein. However, some taxonomic groups other than Oomycetes (i.e., archaea and bacteria) also contained the protein. Functional studies of structurally analogous proteins spanned 10 different taxonomic groups. These revealed TGase elicitors (10%), phytopathogen effector proteins RxLR (4%), transporter family proteins (3%), and endonucleases (1%). Other analogues having one percent of their individual share were HIV tat-specific factor 1, protocadherin fat 4, transcription factor 1, and 3-hydroxyisobutyrate dehydrogenase. Because the plant infection by P. melonis is a complex process regulated by a profusion of extracellular signals secreted by both host plants and the pathogen, this study will be of help in interpreting the cross-talk in the host-pathogen system.

Benzenedicarboxylic acid upregulates O48814 and Q9FJQ8 for improved nutritional contents of tomato and low risk of fungal attack

BACKGROUND

Tomato is an important food item and a cocktail of phytonutrients. In the current study, metabolites from a non-pathogenic fungal species Penicillium oxalicum have been exploited to obtain nutritionally augmented tomato fruits from the plants to better withstand against Alternaria alternata infection.

RESULTS

Initially, bioactivity-guided assay and chromatographic analyses identified the bioactive metabolites of P. oxalicum [benzenedicarboxylic acid (BDA) and benzimidazole]. Then, ≥3 times elevated quantities of vitamins and other nutritional elements (protein, fat, fibers, and carbohydrates) were achieved by the foliar application of BDA. The maximum increase (625.81%) was recorded in riboflavin contents; however, thiamine showed the second highest enhancement (542.86%). Plant metabolites analysis revealed that jasmonic acid contents were boosted 121.53% to significantly enhance guaiacyl lignin defenses along with the reduction in coumarin contents. The protein profile analysis explored three most actively responding protein species toward BDA applications, (i) palmitoyltransferase protein Q9FLM3; (ii) serine/threonine-protein kinase O48814; and (iii) E3 ubiquitin-protein ligase Q9FJQ8. The O48814 improved plant defenses; whereas, Q9FJQ8 protein was negatively regulating cysteine-type endopeptidase activity and assisted plant to resist schedule alterations. Tomato cultivar with more active innate metabolism was found to be more responsive toward BDA. Furthermore, the bioactive compounds were enriched by using the two-step extraction method of ethyl acetate and chloroform, respectively.

CONCLUSION

Penicillium oxalicum a non-pathogenic fungal species, produced BDA, induced nutritional contents in tomato and protected it against Alternaria alternata. The current study is the first report on the bioactivity of BDA and benzimidazole concerning the nutritional enhancement and plant defense improvement. © 2019 Society of Chemical Industry.

Genetic defense analysis of tomatoes in response to early blight disease, Alternaria alternata

Early blight disease of tomato is one of the most devastating biotic stresses worldwide, and in Iran, Alternaria alternata is one of the most predominant species causing the disease. In the current study, a diverse collection of 35 tomato genotypes and implication of 5 SlWRKYs and 7 PR genes as well as enzymatic activity were evaluated on resistant and susceptible cultivars through real-time polymerase chain reaction at transplanting and maturing stages and by measuring product formation using spectrophotometry. The results indicated that the expression of these antifungal genes in 14 genotypes at two growth stages after inoculation with A. alternata highly enhanced by 1-50-fold. There was also significant upregulation of WRKYs and PRs genes among the resistant tomato varieties in comparison to susceptible and control varieties at both stages. These findings demonstrate the varieties that showed increased or decreased SlWRKY1 expression also displayed similar changes in the expression of PR1 and PR2 genes. Furthermore, the differential expression patterns of SlWRKY1 and SlWRKY11 were consistent with PR7 and PDF1.2 expression patterns. The analysis of enzymatic activity of PR2 and PR3 proteins, β-1,3-glucanase, and chitinase showed the highest level of activity in resistant inoculated genotypes against A. alternata. Therefore, the current findings suggest the possible involvement of these transcription factors in the increased expression of PR genes in response to A. alternata infection.

Proteomic and physiological assessment of stress sensitive and tolerant variety of tomato treated with brassinosteroids and hydrogen peroxide under low-temperature stress

The aim of current investigation was to perform proteomics and physio-chemical studies to dissect the changes in contrasting varieties (S-22 and PKM-1) of Lycopersicon esculentum under low-temperature stress. Plant grown under variable low-temperature stress were analysed for their growth biomarkers, antioxidant enzyme activities, and other physiological parameters, which headed toward the determination of protein species responding to low-temperature and 24-epibrassinolide (EBL) concentrations. The plants grown under temperatures, 20/14, 12/7, and 10/3 °C recorded significantly lower growth biomarkers, SPAD chlorophyll, net photosynthetic rate and carbonic anhydrase activity in S-22 and PKM-1. Moreover, the combined effect of EBL and hydrogen peroxide (H₂O₂) significantly improved the parameters mentioned above and consecutively upgraded the different antioxidant enzymes (CAT and SOD) with higher accumulation of proline under stress and stress-free environments. Furthermore, proteomics study revealed that the maximum number of differentially expressed proteins were detected in S-22 (EBL + H₂O₂); while treatment with EBL + H₂O₂ + low temperature lost expression of 20 proteins. Overall, three proteins (O80577, Q9FJQ8, and Q9SKL2) took a substantial part in the biosynthesis of citrate cycle pathway and enhanced the growth and photosynthetic efficiency of tomato plants under low-temperature stress.

Proteomics survey of Solanaceae family: Current status and challenges ahead

Solanaceae is one of the major economically important families of higher plants and has played a central role in human nutrition since the dawn of human civilization. Therefore, researchers have always been interested in understanding the complex behavior of Solanaceae members to identify key transcripts, proteins or metabolites, which are potentially associated with major traits. Proteomics studies have contributed significantly to understanding the physiology of Solanaceae members. A compilation of all the published reports showed that both gel-based (75%) and gel-free (25%) proteomic technologies have been utilized to establish the proteomes of different tissues, organs, and organelles under normal and adverse environmental conditions. Among the Solanaceae members, most of the research has been focused on tomato (42%) followed by potato (28%) and tobacco (20%), owing to their economic importance. This review comprehensively covers the progress made so far in the field of Solanaceae proteomics including novel methods developed to isolate the proteins from different tissues. Moreover, key proteins presented in this review can serve as a resource to select potential targets for crop improvement. We envisage that information presented in this review would enable us to design the stress tolerant plants with enhanced yields.