Among abiotic stresses, heat stress is described as one of the major limiting factors of crop growth worldwide, as high temperatures elicit a series of physiological, molecular, and biochemical cascade events that ultimately result in reduced crop yield. There is growing interest among researchers in the use of beneficial microorganisms. Intricate and highly complex interactions between plants and microbes result in the alleviation of heat stress. Plant–microbe interactions are mediated by the production of phytohormones, siderophores, gene expression, osmolytes, and volatile compounds in plants. Their interaction improves antioxidant activity and accumulation of compatible osmolytes such as proline, glycine betaine, soluble sugar, and trehalose, and enriches the nutrient status of stressed plants. Therefore, this review aims to discuss the heat response of plants and to understand the mechanisms of microbe-mediated stress alleviation on a physio-molecular basis. This review indicates that microbes have a great potential to enhance the protection of plants from heat stress and enhance plant growth and yield. Owing to the metabolic diversity of microorganisms, they can be useful in mitigating heat stress in crop plants. In this regard, microorganisms do not present new threats to ecological systems. Overall, it is expected that continued research on microbe-mediated heat stress tolerance in plants will enable this technology to be used as an ecofriendly tool for sustainable agronomy.

Introduction: Drought has become more prevalent due to dramatic climate change worldwide. Consequently, the most compatible fungal communities collaborate to boost plant development and ecophysiological responses under environmental constraints. However, little is known about the specific interactions between non-host plants and endophytic fungal symbionts that produce growth-promoting and stress-alleviating hormones during water deficits.Methods: The current research was rationalized and aimed at exploring the influence of the newly isolated, drought-resistant, ACC deaminase enzyme-producing endophytic fungiTrichoderma gamsii(TP),Fusarium proliferatum(TR), and its consortium (TP+TR) from a xerophytic plantCarthamus oxycanthaL. onMoringa oleiferaL. grown under water deficit induced by PEG-8000 (8% osmoticum solution).Results: The current findings revealed that the co-inoculation promoted a significant enhancement in growth traits such as dry weight (217%), fresh weight (123%), root length (65%), shoot length (53%), carotenoids (87%), and chlorophyll content (76%) in comparison to control plants under water deficit. Total soluble sugars (0.56%), proteins (132%), lipids (43%), flavonoids (52%), phenols (34%), proline (55%), GA₃(86%), IAA (35%), AsA (170%), SA (87%), were also induced, while H₂O₂(-45%), ABA (-60%) and ACC level (-77%) was decreased by co-inoculation of TP and TR inM. oleiferaplants, compared with the non-inoculated plants under water deficit. The co-inoculum (TP+TR) also induced the antioxidant potential and enzyme activities POX (325%), CAT activity (166%), and AsA (21%), along with a lesser decrease (-2%) in water potential inM. oleiferaplants with co-inoculation under water deficit compared with non-inoculated control. The molecular analysis for gene expression unraveled the reduced expression of ethylene biosynthesis and signaling-related genes up to an optimal level, with an induction of antioxidant enzymatic genes by endophytic co-inoculation inM. oleiferaplants under water deficit, suggesting their role in drought stress tolerance as an essential regulatory function.Conclusion: The finding may alert scientists to consider the impacts of optimal reduction of ethylene and induction of antioxidant potential on drought stress tolerance inM. oleifera.Hence, the present study supports the use of compatible endophytic fungi to build a bipartite mutualistic symbiosis inM. oleiferanon-host plants to mitigate the negative impacts of water scarcity in arid regions throughout the world.

Today's world needs to control the industrial pollution through smarter ways. Presently, we observed the capacity of soil borne fungi to digest Synozol Red HF-6BN and Synozol Black B. Initially, 86 fungal strains were isolated from soil samples randomly collected from industrial sites. Among these, 31 isolates were capable of dye decolorization on solid media, with SN12f and SN13a isolates showed the highest decolorization capacity. The dye decolorization by both strains was higher (80-95%), when incubated for 120 h under optimized conditions of pH, concentration, nutrient source and temperature. The dye (Synozol red HF-6BN and Synozol black B) decolorization by SN12f isolate was maximum ((>)90%) at pH7, whereas the SN13a decolorized 90% of Synozol red HF-6BN and 89% of Synozol black B at pH3. The SN13a and SN12f isolates at 40 mg/L showed decolorization of 94.71%, 81.4% (for Synozol red HF-6BN) and 90.5%, 84.4% (Synozol black B), respectively. Our isolates also mitigated the toxic effect of azo dyes on the growth of phosphate solubilizing soil bacteria. In fact, the untreated effluent showed toxic effects on the growth of beneficial bacterial by developing zone of inhibition (16.5 mm around Aeromonas spp., 14.5 mm around Sailmonella while 14.25 mm around Citrobacter spp). However, the fungal treated dye was unable to develop zone of inhibition. Lactase activity was positive for both of fungal isolates after incubation on Bassnell Hass Medium (0.0733 U/mL for SN12f and 0.0439 U/mL SN13a). Using molecular approaches (ITS region), SN12f was identified as Aspergillus nidulans, while SN13a as Aspergillus fumigatus. The current study showed that local fungal flora can reclaim the contaminated soils and support the agro-friendly micro-flora.

In the present study, we have isolated endophytic fungi Gliocladium cibotii from Verbena officinalis L. and tested against Oryza sativa L. seedlings for growth promotion. The strain was used to help Glycine max L. and Helianthus annuus L. under thermal stress. Association of G. cibotii with G. max and H. annuus enhanced chlorophyll contents, total biomass and plant height. Also, G. cibotii significantly curtailed lipids peroxidation and ROS (reactive oxygen species) in host species exposed to heat stress (40ºC). Furthermore, the concentration of ROS-degrading enzymes, like ascorbic acid oxidase (AAO), catalase (CAT), glutathione reductase (GR), peroxidase (POD) and superoxide dismutase (SOD) were boosted in test crops, while concentration of proline and ABA were inhibited. The phenolics and nutritional value (total lipids, proteins and sugars) of experimental plants were also enhanced. The results conclude that G. cibotii can be used as a heat stress mitigating weapon for food crops in the future.

Industrial effluents result in water pollution and affect the biological activity of aquatic and terrestrial life. In this study, efficient fungal strains were isolated from the aquatic environment and identified as Aspergillus fumigatus (SN8c) and Aspergillus terreus (SN40b). The isolates were selected based on their potential to efficiently decolorize and detoxify Remazol brilliant blue (RBB) dye, which is extensively used in different industries. Initially, a total of 70 different fungal isolates were screened. Among these, 19 isolates demonstrated dye decolorization capabilities, and SN8c and SN40b revealed the highest decolorization capabilities in liquid medium. The maximum estimated decolorization for SN8c was 91.3% and for SN40b, 84.5% at 40 mg/L of RBB dye in the presence of glucose (1 gm/L), after 5 days of incubation at different levels of pH, temperature, nutrient source, and concentration. RBB dye decolorization using SN8c and SN40b isolates was at a maximum of 99% at pH 3–5, whereas minimum decolorization was recorded as 71.29% and 73.4% SN8c, respectively, at pH 11. The maximum decolorization of the dye was 93% and 90.9% in a defined glucose concentration of 1 gm/L, and a 63.01% decrease was recorded in the decolorization activity at a low level of glucose concentration (0.2 gm/L). Finally, the decolorization and degradation were detected using UV spectrometry and HPLC. Toxicity tests of pure dye and treated dye samples were checked against the seed germination of different plants and the larvae mortality of Artemia salina. This study revealed that indigenous aquatic fungal flora can recover contaminated sites and support aquatic and terrestrial life.

High temperature is one of the compelling ecological stresses faced by the plants owing to anthropogenic activities of mankind. Recently, endophytic fungi are considered to be a novel tool to counteract the consequences of thermal stress in crops. Owing to the problem, we isolated fungal endophytes from Dryopteris blanfordii and their growth favoring potential in rice seedlings. Endophytic fungi have the proficiency to secrete plant growth stimulating secondary metabolites that help the host plants to restore growth under harsh environments. The isolated Penicillium glabrum (DryR- 30) helped the host plant species, i.e. Glycine max L. and Helianthus annuus L. under thermal stress. P. glabrum associated with G. max and H. annuus exposed to 40ºC not only boosted their host growth attributes (total biomass, plant height and chlorophyll contents), but also significantly curtailed the synthesis of reactive oxygen species and lipids peroxidation. Moreover, the abscisic acid (ABA) and proline concentrations were significantly reduced, while the accumulation of ROS-degrading enzymes, such as catalase (CAT), peroxidase (POD), ascorbic acid oxidase (AAO), glutathione reductase (GR) and superoxide dismutase (SOD) were increased in P. glabrum-associated crops. Additionally, the protein, lipid and sugar contents in tested plants were also improved. These stirring findings suggest that P. glabrum can be applied to food crops as a thermal stress alleviation tool.