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Cadmium (Cd) and chromium (Cr) in agricultural soils is becoming a serious threat in tomato. The complete removal of these heavy metals (HMs) from contaminated soil is challenging. However, the use of plant endophytes might be beneficial. The pragmatic role of endophytic fungi Aspergillus flavus (Ch-01) in tomato under Cd and Cr stress was, therefore, investigated. A. flavus enhanced growth attributes in tomato seedlings under Cd and Cr stress. Besides, it remediated Cd and Cr toxicity by reducing their translocation from the roots to the upper part of the tomato plants. In fact, A. flavus associated plants developed tolerance against Cd and Cr toxicity via the expression of SlGSH1 and SlPCS1 genes. Both genes helped in metal chelation and mitigation of Cd and Cr toxicity. From the results, it is concluded that A. flavus is a plant growth promoting and HMs alleviating endophyte, hence it might be used as a biofertilizer. [ABSTRACT FROM AUTHOR]

Plants can be severely affected by heat stress due to rapid environmental changes. Use of endophytic fungi is a new tool to protect crops from the environmental stresses. Here we claim a potent endophyte isolated from Sonchus asper L. The aim was to explore the stress adaptive mechanism of sunflower and soybean mediated by Aspergillus niger (SonchL-7) under high temperature. Inoculation with A. niger boosted plant height, biomass and chlorophyl contents, while significantly curtailed the concentration of lipid peroxidation and reactive oxygen species (ROS) under thermal stress at 40°C. Moreover, the ROS-scavenging activities, like ascorbic acid oxidase (AAO), catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD) and peroxidase (POD) were augmented. Also, proline and phenolics were enhanced in the tested crops, while ABA concentration was significantly reduced. These positive results suggested that A. niger can be used as a heat-stress ameliorative tool for crops in the future. [ABSTRACT FROM AUTHOR]

Gibberellins (GAs) are well known for plant growth promotion. GAs production by fungi has received little attention, although substantial work has been carried out on other aspects of plant growth-promoting fungi (PGPF). We investigated GAs production and plant growth-promoting capacity of an endophytic fungus isolated from the roots of soil grown soybean plants. The endophytic fungus is reported as GAs producer and as PGPF for the first time in this study. Nine endophytic isolates were collected from the roots of soybean, and culture filtrates (CFs) obtained from their pure cultures were screened on Waito-C, a dwarf rice cultivar, for the presence of GAs. Of these, seven fungal isolates promoted shoot length as compared to control (distilled water), while one inhibited it. Three fungal isolates were selected on the basis of higher shoot elongation as compared to wild type Gibberella fujikuroi, which was used as positive control. The growth-prompting capacity of selected fungal isolates SB5-1, SB3-2, and SB3-3 was bio-assayed on soybean cv. Hwangkeumkong. Fungal isolate SB5-1 provided maximum plant height (31.6 cm), shoot length (21.1 cm), whole plant fresh biomass (2.41 g), shoot fresh biomass (1.99 g), and leaf area (24.37 cm2). The CF of isolate SB5-1 was analyzed for the presence of GAs, and it was found that all physiologically active GAs were present (GA1, 0.15 ng/ml, GA3, 1.2 ng/ml, GA4, 7.37 ng/ml, and GA7, 3.18 ng/ml) in conjunction with physiologically inactive GA5, GA9, GA15, GA19, GA20, and GA24. The fungal isolate SB5-1 was identified as a new strain of Cephalotheca sulfurea through molecular and phylogenetic approaches. [ABSTRACT FROM AUTHOR]

Abiotic stresses lead to excessive crop yield losses and are a major threat to agriculture. It is essential to equip crops with multi-stress tolerance to mitigate the adverse effects of abiotic stressors and meet the demands of the increasing global population. The association between plants and symbiotic microorganisms is involved in key functions at the ecosystem and plant levels, and the application of microbial plant biostimulants (MPBs) is a sustainable strategy to augment plant growth and productivity, even under abiotic stress conditions. Several different microorganisms can be used as MPBs to enhance plant growth and produce progressive and reproducible effects on crops. In the present review, we assessed the current knowledge on the use of MPBs, discuss the diversity and characteristics of MPBs, and provide a meticulous assessment of the possible applications of MPBs in abiotic stress relief in crops. [ABSTRACT FROM AUTHOR]

Gibberellins are considered to play an important role in modulating plant–pathogen interactions. In order to find this, we studied the effect of GA4 on the interactions of Bipolaris sorokiniana (Scc.) (BIPOL) with Triticum aestivum. After inoculating the roots of hydroponically grown T. avestivum with BIPOL, the GA4 level shot up by 26%. The increased level of GA4 elicited a hypersensitive response (HR) in the T. aestivum seedlings. The elicitation in HR was confirmed through measurement of HR-inducing signaling compounds (i.e. c-di-GMP, cAMP, phosphatidic acid, pure and esterified oxo-phytodeinoic acid, and jasmonic acid). The concentration of HR-inducing signaling compounds in the treated T. aestivum seedlings was 31% higher compared to the control seedlings. Moreover, the induced HR response lowered the indole-3-acetic acid (IAA) level by 15% and the transzeatin (TZn) level by 22%. However, the application of 10 mM uniconazole through aerial spray inhibited GA4 biosynthesis in T. aestivum seedlings. Also, BIPOL colonized the roots of T. aestivum seedlings after uniconazole treatment and promoted seedling growth through increased relative growth rate (14%) and net assimilation rate (27%). [ABSTRACT FROM AUTHOR]

Medicinal herbs provide prime source of primary health care in the northern mountainous parts of Pakistan in the Himalayas, Hindu-Kush and Karakorum mountain ranges. However, with the introduction of allopathic drags, the use of crude drugs from medicinal plants is on the decline and subsequently, the pertinent traditional knowledge may be lost in the near future. During the present study traditional knowledge of 126 medicinal herbs was documented from Swat Kohistan. Most of these herbs are used locally while some are sold to other parts of Pakistan. [ABSTRACT FROM AUTHOR]

In this study, an endophytic fungus, Aspergillus niger CSR3, was isolated from Cannabis sativa. The culture filtrate (CF) was initially screened for growth-promoting activities such as the presence of siderophores, phosphate solubilization, and the production of indole acetic acid (IAA) and gibberellins and was further assayed for its ability to promote the growth of mutant waito-C rice. Nearly all plant growth attributes examined (root-shoot length, biomass, and chlorophyll content) were significantly enhanced by treatment with CSR3. This growth promotion action was due to the presence of various types of gibberellins (GAs) and IAA in the endophyte CF. Moreover, the presence of GA pathway genes (P50-1, P450-3, P450-4, ggs2, and des) was confirmed by means of semi-quantitative RT-PCR. Finally, the application of CSR3 spore suspension with uniconazole and yucasin on maize seedlings revealed that, similar to exogenous IAA and GA3, CSR3 has the potential to alleviate the inhibitory effect of these inhibitors. [ABSTRACT FROM AUTHOR]

Beneficial bacterialiving in the rhizosphere pose several implications on plant growth promotion and are highly desirable for sustainable agriculture. In the current study, we explored the ameliorative capacity ofLeifsonia xyliSE134, a plant growth-promoting rhizobacteria (PGPR), against copper (Cu) stress on tomato grown under elevated Cu levels of 50 and 100 mM. Initially,L. xyliSE134 modulated innate gibberellins (GAs) and indole-3-acetic acid (IAA) metabolism in response to elevated Cu toxicity. The IAA contents increased, whereas that of bioactive GAs decreased in relation to Cu concentration gradient in the broth media. Furthermore, exposure to elevated Cu caused detrimental effects on the physiological attributes as revealed by attenuated shoot length, root length, stem diameter, shoot dry weight, root dry weight, and chlorophyll content in non-inoculated tomatoes as compared toL. xyliSE134 inoculated plants. The growth rescuing effect ofL. xyliSE134 may be attributed to the modulation of endogenous amino acids contents in plants, such as glutamic acid, threonine, phenylalanine, glycine, proline, and arginine. Moreover,L. xyliSE134 inoculation stimulated total polyphenol and flavonoid content, reduced super oxide dismutase activity, strongly inhibited Cu, and increased phosphorus and iron content in plants grown under elevated Cu stress. In the absence of Cu toxicity,L. xyliSE134 significantly enhanced amino acid content, improved total flavonoids, and increased phosphorus content, thus resulting in higher plant growth. [ABSTRACT FROM PUBLISHER]

This study explores Banana pseudo-stem fiber (BPSF) derived from BPF cultivars that are common in Nigeria. The four cultivars are known locally as Agbagba, Omini, Panbola, and Paranta. This study characterized these cultivars to gain insight into their physical, thermal and microstructural properties. The BPSFs were obtained after manual BPS retting and treated with a 2 wt. % sodium hydroxide solution to improve the fiber quality. Data from the characterization revealed the agbagba cultivar to give the highest percentage recovery (3%) and thermal stability at elevated temperatures with a residual char of 14%. The percentage of cellulose, lignin, hemicellulose, and ash content were determined by chemical composition analysis. FTIR spectroscopy showed a lower lignin and hemicellulose absorption band in the agbagba cultivar while scanning electron microscopy supported the FTIR results. Agabagba’s crystallinity index (XRD) of 61.7% was higher than other cultivars, and X-ray fluorescence (XRF) and a biodegradation test also showed that only agbagba cultivar contained calcium and had the strongest resilience to microbial attack under simulated soil conditions. Agbagba BPSF may be a viable reinforcement in bio-fiber polymer composites needing high strength due to its balanced qualities that have been demonstrated in comparison to other cultivars. [ABSTRACT FROM AUTHOR]

Disease resistance is a highly desirable crop trait in the sustainable agricultural industry. Endophytic fungi with gibberellins-secreting potential are now widely known for their ability to stimulate plant growth, but their role in promoting disease resistance in plants has rarely been reported. We have studied the role ofPenicillium citrinumLWL4 andAspergillus terreusLWL5 in time-dependent manner on sunflower (Helianthus annuusL.) growth, disease resistance and their capacity for the regulation of hormone signaling networks involved in plant defense against the stem rot caused bySclerotium rolfsiifor 3, 6 and 12 days after treatment (DAT). Our results show that plant growth characteristics (i.e. shoot length, shoot diameter, shoot fresh/dry weight, transpiration, stomatal conductance, photosynthesis and chlorophyll content) were promoted in fungi-treated plants with or without the disease caused bySclerotium rolfsiias compared to their respective controls in 3, 6 and 12 DAT. The negative impacts of stem rot in endophyte-treated diseased plants were greatly reduced in comparison to control diseased plants shown by low disease severity in 3, 6 and 12 DAT. Similarly, fungal endophytes in diseased plants relieved the biotic stress in time-dependent manner (3, 6 and 12 DAT) as shown by low level of endogenous salicylic acid and jasmonic acid contents and were significantly higher in control diseased plants. Furthermore, we observed that thePenicillium citrinumLWL4 association had a greater positive effect on sunflower plants thanAspergillus terreusLWL5. It was concluded that inoculation with fungal endophytes reprogramed plant growth during disease incidence by regulating responses associated with host plant defense. Management strategies involving endophytic symbiosis can help achieve sustainability in agriculture in an eco-friendly manner by reducing excessive fungicide use. [ABSTRACT FROM AUTHOR]

Plant growth and gibberellins (GAs) biosynthesis are two separate but linked processes, involving many genes but fewer have been reported for their role in plant growth and development. Due to little information on the genes involved in such processes, the known plant growth promoting and GAs producing fungal endophytePenicillium citrinumKACC43900 was used as potential tool to obtain a blueprint of the putative growth promoting and GAs synthesizing proteins. For proteomic analysis, the seedlings ofGlehnia littoraliswere treated with culture filtrate ofP. citrinumKACC43900, which revealed significant differences between 2 dimensional gel electrophoresis profile of the crude protein extracts of the treated and control samples. Matrix-assisted laser desorption/ionization analysis of the 56 selected spots led to the identification of 41 proteins. A significant number (31.5%) of these highly expressed proteins were associated with plant growth regulation, including beta-expansin EXPB4, ent-kaur 16-ene synthase, gibberellin 3-oxidase, and cytochrome P450 family proteins. Proteins involved in regulating energy metabolism and intracellular redox conditions, such as glyceraldehyde-3-phosphate dehydrogenase and ribulose-1,5-bisphospahate carboxylase/oxygenase, were also expressed. It was concluded that culture filtrate ofP. citrinumKACC43900 altered the gene expression pattern of hostG. littoralis. Current study highlighted the importance of proteomics as a starting tool for any post-genomic research. [ABSTRACT FROM AUTHOR]

The leaf leachate of Inula falconeri Hook. f. has been reported to carry allelopathic potential. To analyse its further effects, it was fractionated into five subfractions, i.e. hexane, chloroform, ethyl acetate, n-butanol, and water. The hexane subfraction had the highest specific activity compared with the other four fractions and presented 100% inhibitory effect to germination of lettuce seeds. Chloroform subfraction presented a dose-response effect, and the ethyl acetate subfraction exhibited insignificant inhibitory effect, while n-butanol and water subfractions presented stimulatory effects. Elemental analysis through energy-dispersive X-ray spectroscopy (EDX) showed the composition of 15 different elements with carbon, oxygen, and potassium showing highest weight percentages. In the case of hexane subfraction, highest percentages of silver (1.22%), cadmium (1.44%), manganese (0.71%), and chromium (0.70%) were observed, compared with other subfractions. Chloroform subfraction has high proportions of copper (0.63%), nickel (0.45%), iron (0.37%), calcium (0.22%), and cobalt (0.08%). In the case of ethyl acetate subfraction oxygen (49.66%) and sodium (0.33%) percentage was the highest of all the subfractions, while the other elements were observed in lesser amounts than in other subfractions. The n-butanol subfraction has recorded highest weight of zinc (0.79%) compared with other subfractions while in water subfraction significant amounts of other elements were not observed. To investigate the behaviour of these subfractions against plant pathogens, hexane subfraction (concentration gradients of 1.25, 2.5, and 5 mg/disc) demonstrated significant zones of inhibition against Alternaria alternata and Rhizoctonia solani while only an insignificant effect against Fusarium oxysporum. Thus, using active natural inhibitors of plant pathogens reveals broader perspectives and interests in avoiding losses to cash crops in the local area. [ABSTRACT FROM AUTHOR]

The use of plant endophytes to release salt stress is cheap and quick. In this respect, we have isolated an endophytic fungus (Trichoderma reesei) from Solanum surattense that promoted the wheat growth under salt stress. The results showed that the fungal inoculated wheat plants had higher chlorophyll a and b, carotenoids, reduced glutathione (GSH), ascorbate, peroxidase, catalase, weight of plant, flavonoids, total soluble protein, stomatal conductance, transpiration rate, and relative water contents. Also, T. reesei treated plants showed higher IAA, GA, Ca and K, while lower ABA, H2O2, phenol, sugar, proline, electrical conductivity, malondialdehyde (MDA), Na+ and Cl−. The results concluded that the integrative use of T. reesei might help the wheat plants to stand salt stress. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa (P. aeruginosa) is an aerobic gram-negative, non-spore forming, rod-shaped bacterium. It accelerates the decline in lung function and ultimately leads to increased mortality and morbidity rate. Survival and virulence of P. aeruginosa is due to its biofilm formation ability. The main aim of this study was to test the synergistic effect of silver nanoparticles (AgNPs) in combination with Polymyxin B against biofilms of P. aeruginosa. A total of 500 pus aspirations were collected and bacterial pathogens were identified. Biofilm formation was attained using a glass tube method and microtiter plate assay. The minimum inhibitory concentration of Polymyxin B was determined using agar well diffusion method. Silver nanoparticles were synthesized by chemical reduction method followed by determination of their anti-pseudomonal ability separately and in combination with Polymyxin B using microtiter plate assay. Our results showed that 120 out of 500 samples were Pseudomonas positive. The ratio of multidrug-resistant (MDR) in our collected Pseudomonas samples was 83% (25/30). Generally, the minimum inhibitory concentration (MIC) of Polymyxin B was 16 µg/mL and that of AgNPs was null. However, AgNPs showed great synergistic effect in combination with Polymyxin B. Synergistically, the efficacy of Polymyxin B was enhanced four times as compared to unaided Polymyxin B. [ABSTRACT FROM AUTHOR]

The association between microbes and plant roots involves a complex chemical dialogue featured by IAA and flavonoids in addition to other signals. Current study is focused on the role of IAA and flavonoids as essential elements of the chemical dialogue between an endophytic fungus and maize roots. The strain was isolated from the leaves of Withania somnifera and was identified as Aspergillus fumigatus greenish by 18S rDNA sequence. Culture filtrate of the strain contained phyotstimulant (IAA, ammonia and ACC) and signaling compounds including IAA, flavonoids and flavonols. The strain effectively colonized the maize roots and enhanced its growth. In order, to determine the effect of IAA and flavonoids on the ability of the endophyte to colonize maize roots, we inhibited the release of IAA and flavonoids in maize separately which reduced the colonization of endophyte in maize root to 66% and 55% of the untreated control. Similarly, application of IAA in combination with endophyte enhanced root colonization by 90% in zone of cell division, 66% in the zone of elongation and 30% in the zone of maturation. These findings determined that IAA and flavonoids are among the key players of the complex chemical dialogue between plant root and fungal endophyte. [ABSTRACT FROM AUTHOR]

The stimulation of seed germination by smoke and aqueous smoke extracts from the combustion of plant material has recently received a great deal of attention. This study was conducted to assess the effects of smoke on the weed speciesEchinochloa crus-galli(barnyard grass). Plant-derived smoke was produced fromBauhinia variegatausing a newly designed furnace and then applied to the weed species. The results showed that plant-derived smoke solution significantly increased the germination rate (70–92.3%), germination percentage (31–47%), fresh weight (30–69%), shoot and root length (10–14.9%, 35–44%), germination index (50–100%) and vigour index (114–157%) of barnyard grass relative to the control. Treatment with plant-derived smoke solution also significantly reduced the endogenous abscisic acid of seeds, whileα-amylase activity increased significantly compared to the control. Overall, these findings indicate that stimulation and quick emergence from a dormant soil seed bank of barnyard grass can be induced by plant-derived smoke solution followed by chemical control through known weedicide/herbicide treatments as an eco-friendly alternative method of weed control. [ABSTRACT FROM AUTHOR]