Acta Biologica Szegediensis

Mitigating salt stress in maize: A multifaceted role for a halotolerant Paenibacillus sp. isolate from arid saline Sebkha

Fri, 19 Jun 2026 00:00:00 +0000

Soil salinity severely limits crop productivity in arid regions. This study investigates a halotolerant Paenibacillus sp. isolate for mitigating salt stress in maize (Zea mays L.). The bacterium was characterized for key plant growth-promoting rhizobacteria (PGPR) traits, indole-3-acetic acid (IAA) production, phosphate solubilization, siderophore secretion, and ammonia release, under NaCl concentrations up to 900 mM. Its efficacy was tested in maize seed germination and seedling growth assays under four salinity levels (0-150 mM NaCl). The isolate maintained high IAA production and phosphate solubilization up to 600 mM NaCl and exhibited enhanced siderophore secretion with increasing salinity. Inoculation did not affect final germination percentages but alleviated germination delays under 100 mM NaCl. Crucially, bacterial inoculation significantly improved seedling growth under all salt stresses, with shoot length showing up to a fourfold increase at 150 mM NaCl compared to uninoculated controls. These results demonstrate that this Paenibacillus sp. confers substantial salt tolerance to maize during early development, highlighting its strong potential as a bioinoculant for sustainable agriculture in saline environments.

Plant Growth-Promoting Microorganisms as agents of biological control: Mechanisms and perspectives for sustainable plant protection

Fri, 19 Jun 2026 00:00:00 +0000

Plant growth-promoting microorganisms (PGPM), including plant growth-promoting bacteria (PGPB) and plant growth-promoting fungi (PGPF), can improve plant performance while simultaneously suppressing plant pathogens. Most PGPM colonize the rhizosphere, and some are also able to establish endophytic populations within plant tissues, where they contribute to plant health through direct antagonism, induced systemic resistance, improved nutrient acquisition, and phytohormone-related effects. These properties make PGPM attractive alternatives or complements to conventional pesticides in sustainable plant protection. This mini-review summarizes the principal mechanisms by which PGPM suppress pathogens, with particular emphasis on antimicrobial secondary metabolites, siderophore production, extracellular hydrolytic enzymes, mycoparasitism, mycophagy, and induced systemic resistance. In addition, nutrient mobilization and microbial phytohormone production are discussed as indirect but important contributors to disease reduction and plant vigor. Overall, PGPM-based approaches provide a multifunctional framework for sustainable plant protection by integrating direct pathogen suppression with improved plant performance and defense.

Effects of transplanting date and salinity stress on yield and yield-attributing traits of perilla (Perilla frutescens (L.) Britton)

Fri, 19 Jun 2026 00:00:00 +0000

Perilla (Perilla frutescens (L.) Britton) is a potential oilseed crop with high nutritional and medicinal value. Its productivity is strongly influenced by transplanting time and soil salinity. The objectives of the study are to determine the optimal transplanting time and to assess the impact of salinity on yield-attributing traits. Two separate experiments were conducted to fulfill the objectives. In the first experiment, seedlings were transplanted on three dates (August 1, August 26, and September 11) following a randomized complete block design with three replications. Importantly, transplanting of perilla seedlings on August 1 resulted in a significant delay in flowering and maturity, whereas plant height (PH), number of branches per plant (NBP), number of inflorescences per plant (NIP), and seed yield per plant (SYP) increased significantly compared to other transplanting dates. The second experiment was conducted under pot culture conditions where three salinity treatments, namely control, 10 dS m^-1, and 20 dS m^-1 were applied through irrigation water at the reproductive stage of plant growth and continued for three weeks. Imposition of salinity stress resulted in a significant decrease in days to maturity, PH, NBP, NIP, inflorescence length, 1000-seed weight, SYP, and SPAD values, while the highest negative effects were recorded at 20 dS m^-1 salinity. Overall, early August is the optimum transplanting time for maximizing yield in perilla, and both 10 and 20 dS m^-1 salinity stress had negative effects on yield-attributing traits, with stronger reductions at 20 dS m^-1. Further studies under field conditions will give more insight into the salinity tolerance of perilla for formulating sustainable management strategies.

Histone variant His2Av is implicated in maintaining Piwi protein abundance in the Drosophila melanogaster female germline

Norbert Andrási, Katalin Fejes Tóth — Fri, 19 Jun 2026 00:00:00 +0000

The PIWI-interacting RNA (piRNA) pathway protects the germline from the deleterious effects of uncontrolled transposon expression in animals. Although the piRNA pathway and its components, such as Piwi, have been extensively studied, their regulation is not fully understood. We revealed a reduced mCherry-Piwi signal in Drosophila nurse cell nuclei and decreased mCherry-Piwi protein levels in His2Av depleted ovaries. In contrast, we did not detect any significant changes in piwi mRNA levels. Here, we report that His2Av is implicated in maintaining Piwi protein abundance in the Drosophila female germline, however its precise role remains to be elucidated.

Developing an experimental protocol to test Armillaria-specific genes for their potential role in pathogenicity and virulence

Boris Indic, György Sipos — Fri, 19 Jun 2026 00:00:00 +0000

Most Armillaria species are notorious fungal pathogens that cause substantial damage to woody plants in forestry and agriculture. Their pathogenic success is attributed to specialized gene families involved in host invasion and virulent activities in the plant tissues. This study aims to investigate the expression patterns of expanded genetically diversified gene families in two Armillaria species (A. borealis and A. ostoyae) using unique Armillaria-specific gene sets, involved in degrading monocyclic aromatics, previously identified through comparative genomics analysis of gene pools related to fungal bioremediation. By analyzing differential gene expression data from high- and low-virulent isolates grown under stem invasion conditions, comparing fresh, slowly decaying stems with autoclaved dead stems, several Armillaria genes were implicated as potential plant pathogenicity or virulence factors. In conclusion, systematic plant invasion experiments combined with differential gene expression profiling focusing on new gene variants specific to Armillaria species offer a reliable and feasible framework for predicting genes related to pathogenicity and distinguishing between pathogenicity genes and potential virulence effectors.

Antioxidant and antimicrobial activity of extracts from selected Allium species

Judit Krisch, Ildikó Bartháné Szalma, Zsolt Határ, Csilla Veres, Csaba Vágvölgyi — Fri, 19 Jun 2026 00:00:00 +0000

Allium vegetables are widely consumed and represent important dietary sources of organosulfur compounds and phenolics with potential antioxidant and antimicrobial relevance. In the present study, hydroethanolic extracts prepared from onion (Allium cepa; young/spring, summer, and mature stages), leek (Allium porrum), chive (Allium schoenoprasum), and ramson (Allium ursinum; selected plant parts) were comparatively evaluated in vitro. Lyophilized plant material was extracted with 50% ethanol/water. Antioxidant properties were determined by total phenolic content, DPPH radical scavenging activity, and FRAP reducing power. Antimicrobial activity was screened by agar well diffusion and quantified by broth dilution assays for bacteria and yeasts, while filamentous fungi were evaluated by a disc-based growth inhibition assay. Among the tested samples, ramson bulb exhibited the highest phenolic content (82.29 mg GAE/100 g fresh weight) and the strongest reducing power (FRAP-AS 603.78 µM and FRAP-Fe 670.87 µM per 100 g fresh weight), whereas the highest DPPH scavenging activity was recorded for ramson leaf (78.40%). In antibacterial assays, the lowest MIC/MBC against Escherichia coli (2.5/2.5 mg/mL) was observed for chive and ramson inflorescence extracts. Detectable activity against Serratia marcescens and Micrococcus luteus was restricted to ramson organs, with the inflorescence extract showing the highest potency (MIC/MBC 1.25/2.5 mg/mL). Overall, ramson plant parts and chive consistently showed the most pronounced bioactivities across the applied assays, indicating their relevance as candidates for further phytochemical characterization and application-oriented evaluation as natural sources of antioxidant and antimicrobial agents.