https://jpmb-gabit.sanru.ac.ir/ Journal of Plant Molecular Breeding en daily 1 Sun, 01 Jun 2025 00:00:00 +0330 Sun, 01 Jun 2025 00:00:00 +0330 https://jpmb-gabit.sanru.ac.ir/article_720851.html Phytohormones, also known as plant growth regulators, regulate various physiological processes in plants, including germination, growth, and response to biotic and abiotic stresses. Plant diseases, caused by pathogens such as fungi, bacteria, and viruses, often alter hormonal pathways, leading to the simultaneous induction of antagonistic and synergistic hormones in plants. In resistant varieties, however, the hormonal responses follow a more sequential pattern. Plant hormone signaling pathways are primarily polarized along two antagonistic axes: the salicylic acid (SA) and jasmonic acid (JA) pathways on one side, and the ethylene pathway on the other. In addition to SA, JA, and ethylene, other growth regulators, such as auxins, brassinosteroids, cytokinins, and abscisic acid (ABA), also play significant roles in plant responses to biotic stress and are increasingly recognized for their importance in plant-pathogen interactions.  Pathogens can modulate hormone biosynthesis and signaling to suppress plant defenses and alter the cellular environment, promoting their infection and proliferation. In this article, we will review the latest advances in understanding the function and regulation of plant hormones, the modulation of plant defense responses, and their synergistic and the crosstalk between phytohormones and defense pathways. https://jpmb-gabit.sanru.ac.ir/article_721545.html Drought and heat stresses present significant challenges in agriculture production. This study evaluated CIMMYT-Mexico Core Germplasm (CIMCOG) under drought, heat, and their combined stress over two growing seasons. The germplasm was genotyped with a 35K Axiom® SNP Array to identify associations with the studied traits under these environmental conditions. The Best Linear Unbiased Predictors (BLUPs) of each line were used to calculate marker-trait associations using 16063 SNP markers with a mixed linear model (MLM). For genome-wide association mapping (GWAM), the highest number of associations was obtained for test weight (32), followed by grain hardness (17). In the case of grain yield, six SNPs were detected in association with the trait only under heat stress conditions. When applying a P-value threshold of <0.001, GWAM identified several significant associations: 11 under normal conditions, 31 under drought stress, 10 under heat stress, and 10 under combined drought-heat stress. These associations were distributed across most wheat chromosomes. The identified SNPs explained between 18% and 35.2% of the phenotypic variance. Notably, six SNPs were shared between heat and combined drought-heat stress conditions. These findings provide valuable insights for breeding programs aimed at enhancing wheat tolerance to abiotic stresses. https://jpmb-gabit.sanru.ac.ir/article_722457.html Bacterial spot, caused by Xanthomonas perforans, significantly threatens global tomato production. Traditional control methods have proven inadequate, necessitating innovative approaches. This study assessed nitric oxide (NO) pretreatment at 0.5, 1, and, 2 mM concentrations to induce abiotic resistance against X. perforans in greenhouse-grown tomatoes. Results indicated that NO pretreatment enhanced plant growth, biomass, and defense mechanisms under both normal and pathogen-stressed conditions. Specifically, NO regulated physiological processes such as lipid peroxidation, chlorophyll content, and fluorescence parameters. It also modulated key enzymes like NADPH oxidase and phenylalanine ammonia lyase (PAL), bolstering antioxidant defenses by scavenging reactive oxygen species, thereby reducing oxidative damage and improving stress tolerance. Additionally, NO induced sugar accumulation, increasing energy reserves during stress, and elevated amino acid content, facilitating defense protein synthesis. Notably, NO pretreatment significantly reduced disease severity by upregulating defense-related genes, including non-expressor of pathogenesis-related genes (NPR), PAL, and peroxidase (POD). Overall, NO pretreatment improved plant health, decreased pathogen proliferation, and increased biomass, highlighting its potential as an environmentally friendly strategy for managing bacterial diseases and activating specific resistance responses in tomato plants. https://jpmb-gabit.sanru.ac.ir/article_722456.html Based on the transcriptome data of Ilex cornuta, the SSR loci were identified and profiled for I. cornuta unigenes by using MicroSAtellite (MISA) software. A total of 31335 SSR loci were detected on 24964 Unigene sequences in 124003 Unigenes with a length greater than 500 bp. The frequency of SSR loci was 20.13 %, the frequency of occurrence was 25.27 %, and the average distribution distance was 2.62 kb in I. cornuta. A total of 77 repeat motif types were present in the transcriptome of this species. The major repeat types were single nucleotide (52.91%) and dinucleotide (39.47%), while the dominant repeat motifs were (A/T)n and (AG/CT)n, accounting for 50.11% and 28.11% of the total number of SSR loci, respectively. The lengths of the SSR motifs of I. cornuta were distributed between 10 and 92 bp with an average length of 13.81 bp, among which the number of SSRs with a length of 10 bp was the largest, with 5847, accounting for 18.66% of the total number of SSR loci. The study provides a theoretical foundation for SSR-based genetic diversity analysis and characterization of genetic resources in I. cornuta, while supporting future conservation efforts and molecular-assisted breeding programs. https://jpmb-gabit.sanru.ac.ir/article_724113.html Green synthesis of gold nanoparticles (AuNPs) is increasingly popular due to their broad potential applications. Hence, this research reports the synthesis of AuNPs by reducing of HAuCl4 using an aqueous extract of Haplophyllum canaliculatum Boiss as both a reducing and stabilizing agent. In addition, the antioxidant activity of as-prepared AuNPs was investigated. The physicochemical properties of AuNPs were characterized by UV-visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). The UV-Vis spectra displayed a surface plasmon resonance band at 523 nm, which confirmed the formation of AuNPs. Also, the FESEM image revealed  that the particle sizes of the AuNPs ranged from 15 to 25 nm. In addition, the Debye-Scherrer equation showed a particle size of 16.4 nm from the XRD result. Furthermore, the biosynthesized AuNPs exhibited significant antioxidant activity (P< 0.05) against DPPH free radicals’ scavenger in a concentration-dependent manner . The IC50 value of the AuNPs was obtained as  44.42 µg mL-1. The antioxidant activity of the AuNPs likely stems from secondary metabolites of the H. canaliculatum extract, such as quinoline alkaloids. These findings offer a promising approach for developing biosynthesized AuNPs for potential pharmaceutical applications. https://jpmb-gabit.sanru.ac.ir/article_726294.html Grass pea is a legume with great potential for use in both human food and animal feed. This study was performed to determine the tolerance of ten grass pea genotypes in cadmium stress condition, based on dry matter accumulation at callus and seedling stages under in vitro conditions. The calli and seedlings were exposed to various cadmium concentrations (0, 12.5, 25, and 50 µM). Callus cultures were grown on MS medium supplemented with 2,4-D (2 mg/L), and the seedlings were grown with BAP (15 mg/L). Both calli and seedlings survived at 50 µM cadmium, while 25 µM had no significant effect on their growth . At 25 µM cadmium, callus and seedling root growth were reduced by 50.41% and 35.27%, respectively. Hence, callus was less tolerant to cadmium than seedlings, likely due to its higher cadmium accumulation The present study suggests that grass pea exhibits high tolerance to cadmium, and can also surviving low to moderate concentrations of cadmium at seedling and callus stages. Tolerant callus lines may serve as valuable sources for regenerating cadmium-tolerant plants, which should be further evaluated for their detoxification potential at the adult growth stages. https://jpmb-gabit.sanru.ac.ir/article_726563.html The HSP70 gene family in the Blueberry (Vaccinium darrowii) genome was identified and analyzed using a bioinformatics approach. First, using the HSP70 sequences of the model plant Arabidopsis thaliana and BLASTP and SMART tools, fifty HSP70 genes were identified in the blueberry genome and their structural and biophysical properties (such as molecular weight and isoelectric point) were investigated. The results showed that these genes have high structural and functional diversity and are present in different cellular organelles including the nucleus, mitochondria, chloroplast, and endoplasmic reticulum, which indicates their multiple roles in response to environmental stresses such as heat, drought, salinity, and oxidative stress. Analysis of the regulatory elements of the genes' promoters showed that various motifs such as TC-rich repeats, LTR, and ABRE play a role in regulating gene expression under stress conditions. Also, the expression patterns of HSP70 genes change under the influence of environmental stresses and some genes show increased expression in response to stress. The phylogenetic tree of HSP70 genes shows a division into 14 groups and the presence of intraspecific duplications. Analysis of protein motifs also revealed the presence of conserved and functionally specific sequences that are involved in processes such as ATP binding and hydrolysis and stress response. These findings provide a basis for genetic modification and improvement of Blueberry resistance to environmental stresses. https://jpmb-gabit.sanru.ac.ir/article_729343.html Heat shock proteins (HSPs) are integral to plant responses to stress, with HSP100 constituting a significant family involved in protein disaggregation and thermotolerance. This studty investigated the members of HSP100 gene family in Phaseolus vulgaris, Pisum sativum, Glycine max, and Oryza sativa, disclosing variations in gene number (ranging from 8 to 17 members), molecular weight (between 101 and 119 kDa), exon count (ranging 3 to 12), and isoelectric point (from 5.83 to 8.81). Phylogenetic analysis sparated HSP100 family members into four main groups, that each groupshowed specific subcellular localizations (nucleus, chloroplast, mitochondria, and cytoplasm-nucleus). Predictions of phosphorylation sites indicated interspecies variability in members of HSP100 family. Prediction of duplication events in P. vulgaris revealed that segmental duplication events have more occurred in HSP100 family members. Expression analyses disclosed that PHAVU-008g035600g and PHAVU-001g243900g are more linked to responsive to salinity stress. Interaction networks revealed that HSP100s association with SCF ubiquitin ligase components, esterases, CLP proteases, and HSP21, all enriched in ATP-dependent activities. Our findings revealed a deeper understanding of the evolutionary and expression diversity of HSP100 proteins within the plant species. https://jpmb-gabit.sanru.ac.ir/article_732637.html Foxtail millet (Setaria italica L.), a vital crop in semi-arid regions, exhibits strong tolerance to environmental stresses. To investigate genetic diversity and trait relationships, an experiment was conducted with 128 foxtail millet genotypes from Iranian indigenous, foreign, and hybrid cultivars. Stepwise regression analysis showed that Panicle weight (Pw), RDW, Panicle thickness (PT), and Chlorophyll (SPAD value) together explained 73% of the variation in total dry weight (TDW). The trait Panicle weight (Pw) had the highest direct effect on TDW (0.569), consistent with its strong positive correlation (0.785**). Genetic variation was highest for Flag leaf width (110.91), followed by panicle number (71.14). The highest heritability was observed for Flag leaf width (97.51%) and Peduncle thickness (76.88%), indicating these traits are less affected by environmental factors. Building on these findings, a subset of 25 genotypes selected for further evaluation under salinity stress. These genotypes were subjected to a hydroponic experiment with two conditions: a control (0 mM NaCl) and moderate salinity (60 mM NaCl). The study focused on assessing key physiological and biochemical responses, including Proline content and the activity of antioxidant enzymes Superoxide Dismutase (SOD) and Catalase (CAT). The results showed that genotype and condition had a highly significant effect on all three traits, with a significant interaction effect confirming that the genotypic response to salinity stress is not uniform. https://jpmb-gabit.sanru.ac.ir/article_732728.html Late embryogenesis abundant (LEA) proteins play crucial roles in lipid accumulation and plant defense under drought stress. We performed a comprehensive bioinformatics analysis of LEA protein sequences across oilseed species and examined their expression dynamics in Arabidopsis thaliana. Protein properties, conserved motifs, subcellular localization, and interaction networks were characterized using UniProt, MEME, SMART, WoLF PSORT, and STRING databases, alongside 3D structural modeling. Our results revealed that most LEA proteins possess high surface charge and hydrophilic, intrinsically disordered domains, supporting their role in cellular protection. Nuclear localization and motif conservation suggest regulatory functions, while interaction analyses showed strong associations with heat shock proteins (HSPs), heat shock factors (HSFs), and seed storage proteins such as CRU3 and SESA. Expression profiling indicated rapid induction of LEA genes following cold and drought stress, with elevated levels during key developmental stages including seed, leaf, cotyledon, and flower formation. The LEA gene expression peaks between 12 and 24 hours after cold stress in stems and within the first hour after drought onset. These findings underscore the multifunctional nature of LEA proteins in stress adaptation and reproductive success, offering v.aluable insights for improving oilseed resilience through targeted genetic strategies https://jpmb-gabit.sanru.ac.ir/article_735719.html Powdery mildew is a highly destructive and common disease in barley (Hordeum vulgare L). Therefore, developing stable resistance against it poses a significant challenge for plant breeders. Identifying gene locations that control specific resistance to powdery mildew is a top priority for barley breeders. In the current study, 111 QTL controlling powdery mildew disease were collected from previous research and their information was analysed. RIL, DH, and BC populations were used to prepare a genetic map. Finally, a consensus genetic map was created based on SSR, AFLP, CAPS, EST, DArT, SAP, RAPD, RFLP, IFLP, RGA, STS, and SNP markers using concatenation profiles. The total length of the consensus map was 2124.43 cm. Through Meta-QTL (MQTL) analysis 47 QTLs were successfully projected onto the consensus genetic map leading to the identification of 23 stable MQTL (MQTLs) and 311 candidate genes associated with powdery mildew resistance. Among these MQTL2.1 MQTL5.2 and MQTL5.4 exhibited the highest resistance effects with R² values ranging from 23% to 28%. The identified candidate genes and MQTLs provide valuable genomic resources for marker-assisted selection (MAS) and genomic selection (GS) programs. For practical breeding applications we recommend utilizing the markers MWG2033 Bmag0218 ABC321 MWG2135 AWBMS70 and Scssr10148 to accelerate the development of powdery mildew-resistant barley cultivars https://jpmb-gabit.sanru.ac.ir/article_735726.html This study investigated the phenotypic diversity in 55 loquat genotypes collected from four regions of the South Caspian Sea, Iran. Descriptive statistics revealed wide variability in key traits, including fruit weight (3–35 g), flesh thickness (2–9 mm), seed number (1–10), total soluble solids (3–17.5 °Brix), and leaf area (19.5–286 cm²). Pearson’s correlation analysis showed several significant associations among fruit and vegetative traits, notably, a strong positive correlation existed between one-year-old and current-year shoot thickness (r=0.733**). Fruit length and diameter were positively correlated with fruit weight, flesh thickness, and flavor index, but negatively correlated with titratable acidity. Factor analysis extracted six principal factors with eigenvalues greater than one, explaining 81% of the total variance. The first factor (38.17%) was mainly associated with fruit yield and quality traits, whereas the second factor (16.94%) reflected leaf and external fruit characteristics. Cluster analysis grouped the genotypes into two main clusters at a linkage distance of 15. Savadkuh–Behshahr genotypes showed stronger vegetative growth, while Juybar–Sari genotypes exhibited superior fruit characteristics. The clustering pattern corresponded well with the geographic origin, indicating the influence of environmental and climatic conditions on phenotypic variation. Overall, the results revealed that fruit- and leaf-related traits are the most discriminative factors among loquat genotypes, providing a valuable basis for selecting elite parents in breeding and regional orchard development programs in northern Iran.