Integration of breeding innovations and epigenetic modifications offers the potential to boost productivity and promote sustainable agricultural practices, particularly in tomato production, which accounts for 16 % of global vegetable production. They are susceptible to various stress factors, Both abiotic (light, temperature, water, humidity, nutrients) and biotic (pests, diseases), which can impact fruit quality and reduce yield quantity by 50-70 %leading to food insecurity and economic losses. Climatic factors impact the traditional farming of tomatoes in the open field; innovative technologies aim to tackle the adverse effects of both abiotic and biotic stress factors. It highlights advancements in crop productivity and stress tolerance, including increased phytochemicals biosynthesis, improved water use efficiency, and soil salinity tolerance. However, challenges like photooxidative damage and downregulation of anthocyanin biosynthetic genes persist. This review provides highlights of promising technologies to mitigate the impact of stress factors on open field tomato production, highlighting both qualitative and quantitative losses. Besides sustainable systematic solutions, such as agroforestry systems, the advantages of using beneficial microbial endophytes, nanomaterials, and exogenous phytohormones in agriculture are discussed.
Heavy metal (HM) pollution in agricultural soils threatens plant growth and food security, underscoring the urgency for sustainable and eco-friendly solutions. This study investigates the potential of endophytic fungi, Fusarium proliferatum SL3 and Aspergillus terreus MGRF2, in mitigating nickel (Ni) and cadmium (Cd) stress in Solanum lycopersicum (tomato). These fungi were evaluated for their plant growth-promoting traits, including the production of indole-3-acetic acid (IAA) and siderophores, offering a sustainable strategy for alleviating HM toxicity. Inoculation with SL3 and MGRF2 significantly reduced metal accumulation in plant tissues by enhancing metal immobilization and modifying root architecture. Microscopic analysis revealed that fungi protected root epidermal cells from Ni- and Cd-induced damage, preserving cellular integrity and preventing plasmolysis. Fungal-treated plants exhibited improved growth and biomass, with SL3 demonstrating superior Cd stress mitigation and MGRF2 excelling under Ni stress. Photosynthetic pigment levels, including chlorophyll-a and carotenoids, were restored, highlighting the role of fungi in maintaining photosynthetic efficiency. Antioxidant activity was also modulated, as reduced glutathione (GSH) levels and increased flavonoid production were observed, contributing to enhanced oxidative stress management. Hormonal profiling revealed that fungal inoculation balanced stress-induced hormonal disruptions, with lower abscisic acid (ABA) levels and improved salicylic acid (SA) and gibberellic acid (GA) pathways. These changes facilitated better stress adaptation, enhanced nutrient uptake, and improved physiological performance. qRT-PCR analysis further revealed differential gene expression patterns, while antioxidant enzyme activity strengthened the plants' defense against HMinduced oxidative damage. Multivariate analyses highlighted shoot and root traits as critical indicators of resilience, with fungal inoculation driving substantial improvements. These findings demonstrate the potential of SL3 and MGRF2 as eco-friendly bioinoculants, offering a sustainable and cost-effective approach to reducing HMs toxicity in contaminated soils while enhancing crop productivity. This work highlights the promising role of plant-microbe interactions in advancing sustainable agriculture and addressing the challenges posed by heavy metal pollution.
To feed the nearly 10 billion people by the year 2050, agricultural activities and yield must be enhanced substantially, maintaining soil health and overpowering the expected adverse effects of climate change. High soil salinity is one of the major concerns in future farming, as salinity is a prominent abiotic stress that significantly impacts plants inhabiting arid and semiarid environments worldwide. The increasing levels of soil salinity are proving detrimental to agriculture, the general productivity of the ecosystem, and the economy at large. Excessive salt accumulation in plants leads to an osmotic imbalance, resulting in a decrease in photosynthesis, formation of reactive oxygen species, DNA damage, hormonal instability, and decreased water and mineral uptake. To mitigate the adverse impacts of salt stress, along with diverse physiological mechanisms, plants have developed symbiotic associations with endophytic microorganisms that reside within the plant tissues and help the plants in many ways. Endophytes have been found to alleviate the effects of salinity stress by diverse mechanisms-synthesis of osmolytes, and antioxidant enzymes such as catalase, superoxide dismutase, and peroxidase; synthesis and modulation of phytohormones such as ethylene, indole-3-acetic acid, gibberellin, abscisic acid, etc.; promotion of siderophore production and exopolysaccharide formation; carrying out nitrogen fixation, and increasing phosphate solubilization. In this review, the effects of salinity stress on plants, and the mechanisms by which endophytic microorganisms help the plants to withstand such stress are discussed at length. The application of tailored endophytic microbial consortia holds the key to future food security through sustainable agriculture.
Endophytic Fusarium oxysporum strain V5w2 has been suggested to offer the ecosystem service of suppressing Cosmopolites sordidus and other pests that attack tissue culture banana plants in agroecosystems. The effects of endophytic F. oxysporum V5w2 and nutrient supply on C. sordidus in potted tissue culture banana plants were investigated. In the screenhouse, rhizome damage by C. sordidus larvae was lower in F. oxysporum V5w2-inoculated plants than in non-inoculated ones. Banana plants inoculated with F. oxysporum V5w2 were larger and suffered less rhizome damage but with low chlorophyll content. Weights of C. sordidus larvae were not different between those reared on F. oxysporum V5w2-inoculated banana plants and the non-inoculated ones. Larval C. sordidus from nutrient-treated plants had lower weight than those that fed on plants that did not receive nutrients. In the field, fewer adult C. sordidus were found on F. oxysporum V5w2inoculated banana plants than on non-inoculated plants 12 h after insect release. The number of adult C. sordidus and their eggs did not vary between F. oxysporum V5w2-inoculated banana plants and controls at the end of the experiment. Adult C. sordidus did not discriminate between nutrient-treated banana plants and those without nutrient treatment. However, non-beneficial interactions between F. oxysporum V5w2 and plant-parasitic nematodes negate the chances of its application as an endophytic biological control agent. In conclusion, while F. oxysporum V5w2 is not quite viable for application as an endophytic biological control agent for C. sordidus and other banana pests, this fungus may still have some potential to offer alternative ecosystem services through the provisioning of pest-inhibitive organic compounds.
The phyllosphere is an important but underestimated habitat for a variety of microorganisms, with limited knowledge about leaf endophytes as a crucial component of the phyllosphere microbiome. In this study, we investigated the mechanisms of communities and co-occurrence networks of leaf endophytes in response to forest thinning in a temperate forest. As we expected, contrasting responses of fungal and bacterial endophytes were observed. Specifically, the diversity of leaf endophytic fungi and the complexity of their co-occurrence networks increased significantly with thinning intensity, whereas the complexity of endophytic bacterial co-occurrence networks decreased. In particular, microbiota inhabiting damaged leaves seem to be more intensively interacting, showing an evident fungi-bacteria trade-off under forest thinning. In damaged leaves, besides the direct effects of thinning, thinning-induced changes in neighbor tree diversity indirectly altered the diversity of leaf fungal and bacterial endophytes via modifying leaf functional traits such as leaf dry matter content and specific leaf area. These findings provide new experimental evidence for the trade-offs between leaf endophytic fungi and bacteria under the different magnitudes of deforestation, highlighting their dependence on the presence or absence of leaf damage.
Soil salinity is one of the major environmental stresses that results in reduction of cultivable land and decreased productivity. In the present study, halotolerant and plant growth-promoting endophytic fungi were isolated from Catharanthus roseus, and their effect in mitigating salt stress in Vigna radiata was evaluated. An isolate CR7, identified to be Aspergillus terreus, showing plant growth promotion activities, viz. IAA production (23.43 +/- 0.79 mu g/ml), phosphate solubilization (133.63 +/- 6.40 mu g/ml), ACC deaminase activity (86.36 +/- 2.70 mu mol alpha-ketobutyrate/h/mg protein) etc. and ability to grow at 15% NaCl was selected for further in vivo studies. Colonization of CR7 was carried out in V. radiata which was subjected to different concentrations of salt (150, 200, and 250 mM NaCl). Under salt stress, A. terreus CR7 inoculated plants showed substantially improved root and shoot length, biomass, chlorophyll content, relative water content, phenolics, protein content, and DPPH scavenging activity. Endogenous IAA level was enhanced by 5.28-fold in treated plants at maximum salt stress. Inoculation of A. terreus CR7 affected oxidative stress parameters, exhibiting an increase in catalase and superoxide dismutase and reduction in proline, electrolyte leakage, and malondialdehyde content. Fluorescent microscopic analysis of roots revealed improved cell viability and decreased levels of glutathione and hydrogen peroxide under salt stress in treated plants. The isolate A. terreus CR7 also protected against DNA damage induced by salt stress which was evaluated using comet assay. A decrease in DNA tail length, tail moment, and olive tail moment to the extent of 19.87%, 19.76%, and 24.81%, respectively, was observed in A. terreus CR7-colonized plants under salt stress. It can be concluded that A. terreus CR7 can be exploited for alleviating the impact of salt stress in crop plants.
Drought is one of the environmental stresses that threaten food availability. It results in decreased crop yields and developments and diminishes overall plant health. Chemical solutions for alleviating drought stress may be harmful to the environment. Using an alternative, microorganisms help counter the effects of drought stress. Endophytes have a mutualistic relationship with the host as they provide protection and get nutrients. Fungal endophytes assist plants in countering the damaging results of drought stress by producing phytohormones and growth-promoting compounds that promote root and shoot growth and enhance crop productivity. Inoculating maize plants with endophytic fungi like Fusarium oxysporum and Penicillium sp. have a higher chance of surviving drought stress. These organisms can increase root length, allowing moisture to reach deeper into the soil. This review explores endophytic fungi's roles in alleviating drought stress's consequences on plants. More investigations should be carried out on the favourable effects of fungal endophytes in the mitigation of drought stress through pot and field inoculation.
Permafrost soils contain c. 1980 Pg carbon (C; Schuur et al., 2015), more than twice the size of the atmospheric C pool. Thawing permafrost, subsequent changes in hydrological conditions and resulting microbial decomposition of previously frozen organicCis one of the most significant potential feedbacks from terrestrial ecosystems to the atmosphere in a changing climate (Schuur et al., 2008; Hugelius et al., 2012; Hope& Schaefer, 2016): such changes are now occurring at a dramatic pace over large regions of the Northern Hemisphere.