Ali Mokhtassi-Bidgoli

The tolerance to cryoprotectant equilibration and the necessary cellular dehydration during equilibrium or quasi-equilibrium cooling that facilitates avoidance of intracellular ice is fundamentally connected to the ability of cells to transport water across the plasma membrane. Because of this, the relationship between the rate of water transport and post-thaw motility in bovine sperm has long been hypothesized, but has not been definitively established. Previous studies suggested that variability in bull sperm water permeability might explain post-thaw motility. Here we used a stopped-flow technique in which sperm were abruptly exposed to hypoosmotic and hyperosmotic media (220 mOsm/kg and 445 mOsm/kg final osmolalities, respectively) to critically evaluate this hypothesis and determine whether there is a relationship between the water permeability of fresh semen and the post-thaw motility rates in bull semen from various ejaculates, breeds, and age groups. We also evaluated additional possible predictive metrics of kinetic volume responses to anisosmotic medium, including the time to achieve 10%, 50% and 90% equilibrium volume (T10, T50, T90) in both hypoosmotic and hyperosmotic media. The total motility in the first of two ejaculates (Ejaculate 1) collected from each bull within a 10–15-minute interval was approximately 6.3% higher, and its progressive motility was about 8.1% higher than that of Ejaculate 2. Holstein bulls showed significantly higher total motility than Jersey bulls. No significant differences in either total or progressive motility of post-thaw bull semen were detected across the age groups of 12–24 months, 25–38 months, 40–57 months, and 69–116 months. Direct association analyses identified only weak relationships between water permeability and post-thaw motility, and none remained statistically significant after adjustment for multiple comparisons. The available sample size provided 80% power to detect absolute correlations of approximately 0.30 or greater. However, significant volume rectification was observed, with water permeability under hyperosmotic conditions being approximately 2% to 42% higher than under hypoosmotic conditions, depending on ejaculate number, breed, and age group. Principal component analysis indicated that L _p under hypoosmotic conditions, followed by L _p under hyperosmotic conditions, contributes most strongly to the separation of samples. Overall, the present paper demonstrates that both log-logistic and linear models provide reliable estimators of L _p . Although L _p was not a robust predictor of post-thaw motility under the freezing conditions examined, these modeling approaches provide a quantitative framework for future studies investigating sperm osmotic behavior during cryopreservation.

Ninety isolates of Macrophomina phaseolina (Tassi) Goid. were obtained from charcoal rot‐diseased sesame ( Sesamum indicum L.) stems collected from 11 sesame‐growing provinces in Iran. Colony growth rates on potato dextrose agar at 30°C ranged from 0.56 to 1.86 mm h ⁻¹ (mean = 1.62 mm h ⁻¹ ). Chlorate phenotypes comprised 48.9% feathery (F; sensitive), 28.9% restricted (R; sensitive) and 22.2% dense (D; resistant). Aerial mycelium intensity varied from low to high, predominantly low, while microsclerotial production intensity differed significantly at 48, 72 and 96 h post‐inoculation. All isolates were pathogenic on sesame cv. Naz Tak‐Shakheh and were classified as showing moderate (33.3%), low (20.0%) or high virulence (46.7%) based on stem lesion indices and area under the disease progress curve. Five rep‐PCR primers generated 83 scorable loci (average 16.6 per primer), of which 91.1% were polymorphic (PIC = 0.34). UPGMA clustering based on Jaccard's coefficient separated the isolates into four major groups; however, genetic grouping was not significantly associated with virulence, chlorate phenotype or morphological traits. Therefore, the rep‐PCR clustering was interpreted mainly as evidence of high genetic heterogeneity rather than strong pathogenic or phenotypic specialization.

Saffron (Crocus sativus L.) is increasingly challenged by viral infections, yet the physiological links between viral stress and defense-associated metabolic responses remain insufficiently resolved. This study examined whether cucumber mosaic virus (CMV) and turnip mosaic virus (TuMV) are associated with coordinated changes in antioxidant defense, phenylpropanoid-related metabolism, gas-exchange traits, and flower biomass in saffron grown under controlled greenhouse conditions. Sixteen biochemical and physiological traits were quantified, including catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), total phenolics, flavonoids, Trolox-equivalent antioxidant capacity, vitamin C, proline, carbohydrate content, stomatal conductance, intercellular CO2 concentration, vapor pressure deficit at leaf level, leaf temperature, Ci/Ca, and flower dry weight. Principal component analysis showed that antioxidant enzymes, non-enzymatic antioxidants, and secondary-metabolite traits were positively associated with the major axis of variation, whereas carbohydrate content, stomatal conductance, vapor pressure deficit, and flower dry weight were negatively associated. Hierarchical clustering further separated virus-infected plants from mock controls and highlighted coordinated enrichment of antioxidant and phenylpropanoid-associated traits under infection. Together, the trait pattern supports a physiology-based interpretation in which CMV and TuMV infection are associated with oxidative-defense activation, PAL-linked phenylpropanoid reprogramming, and a defense-growth tradeoff in saffron. These findings provide a physiology-centered framework for understanding how viral infection alters functional traits in this economically important non-model crop.

Adjuvants are widely employed to enhance herbicide performance, offering both economic and environmental benefits in weed management programmes. While most research has focused on surfactants, nitrogen‐based adjuvants, such as ammonium compounds, combined with herbicides like tribenuron‐methyl, also show promising potential. In a pot experiment conducted during 2021–2022, Sinapis arvensis (wild mustard) was used as the testing plant to evaluate the synergistic effects of various surfactants and ammonium sources, both individually and in combination, on the efficacy of tribenuron‐methyl. Treatments consisted of tribenuron‐methyl at 0, 0.3, 0.6 and 1.0 times the recommended rate (equivalent to 0, 4.5, 9 and 15 g a.i. ha ⁻¹ ), applied either alone or in combination with surfactants (castor oil ethoxylate [COE], lauryl alcohol ethoxylate [LAE], cocamidopropyl betaine [CPB] and sodium lauryl ether sulphate [SLES], all applied at 1 L ha ⁻¹ ) and ammonium sources (ammonium nitrate, ammonium sulphate and ammonium acetate, each at 1% [w/v], plus asparagine at 0.1% [w/v]). While surfactants and ammonium sources each independently enhanced herbicide efficiency, their combined application had a more pronounced effect, as evidenced by a greater number of treatments achieving significant reductions in effective doses. The simultaneous application of ammonium acetate with LAE or SLES reduced ED ₉₀ to 6 g a.i. ha ⁻¹ . Additionally, compared to adjuvant‐free control, co‐applying asparagine amino acid with SLES or ammonium acetate with CPB lowered ED ₉₀ values from 15 to 7.10 and 7.70 g a.i. ha ⁻¹ , respectively.

Pseudomonas spp. are bacteria known for their ability to degrade various pesticides, acting as natural biofilters. Despite their widespread use, the degradation of metribuzin—a herbicide commonly applied in agriculture—by these bacterial strains remains undocumented. This investigation aims to assess the capacity of Pseudomonas spp. to alleviate metribuzin-induced stress in different wheat cultivars under precisely controlled environmental conditions, offering insights into potential bioremediation strategies. This experiment was conducted as factorial in a completely randomized design with three replications. It included varying concentrations of metribuzin (0, 5, 10, 15, 20, and 30 mg/kg), bacterial treatments (control, P. fluorescens, and P. aeruginosa), and wheat cultivars (Pishtaz, Chamran, and Sivand). The evaluation focused on plant growth and biochemical responses, monitored at ten-day intervals starting 14 days after planting (DAP). A strong dose-dependent inhibition of plant growth was observed with increasing metribuzin concentrations. Growth reduction intensified at concentrations above 20 mg/kg, but near-complete inhibition (EC90) generally required higher concentrations, depending on cultivar and bacterial treatment. Pishtaz demonstrated the highest level of herbicide tolerance, with EC90 values in the non-inoculated treatment ranging from 23 to 107 mg/kg across growth stages. Increases in antioxidant enzyme activities and decreases in malondialdehyde levels were observed, indicating the stress mitigation capabilities of Pseudomonas spp. through biodegradation, which also led to enhanced plant growth and increased bacterial colony numbers in the soil. Variability in metribuzin sensitivity was observed among the cultivars, with Pishtaz being notably tolerant, Chamran semi-sensitive, and Sivand sensitive. P. fluorescens, in particular, showed a marked ability to reduce metribuzin’s detrimental effects, underscoring the potential of employing microbial strategies for managing pesticide stress in wheat cultivation.

Extended Abstract Introduction: Drought stress is one of the most important factors limiting plant growth worldwide, which causes yield reduction by disrupting physiological processes, including photosynthesis and water relations. The use of arbuscular mycorrhizal fungi along with phosphorus fertilizer can increase plant tolerance to drought by improving water and nutrient ...

The economic value of the saffron stigma is primarily due to three crucial apocarotenoids: crocin, picrocrocin, and safranal, which contribute to its color, flavor, and aroma. These compounds make saffron highly valuable in various industries. Plant viruses like the cucumber mosaic virus (CMV) and turnip mosaic virus (TuMV) are significant threats to agricultural crops worldwide, causing economic losses. To elucidate the influence of viral stress on the quality of saffron, morphological, physiological, biochemical, and molecular indexes were assessed. Under the stress of both viruses, typical viral symptoms appeared. The lowest contents of leaf pigments, flowering performance, petal anthocyanin, greenness, and photosynthesis properties were observed in plants infected with CMV and TuMV. According to high-performance liquid chromatography (HPLC) analysis, CMV inoculation led to the highest reduction in crocin and safranal content, while inducing the highest increase in picrocrocin compared to the mock treatment. Gene expression analysis involved in the biosynthesis of crucial secondary metabolites showed a high correlation with the content of each metabolite. CMV inoculation resulted in the lowest expression of CsALDH31l and the highest expression of CsUGT709G1 compared with the mock treatment. Our findings demonstrate the association between virus stress and changes in the metabolism of the saffron medicinal plant.