Small heat shock proteins play a pivotal role in maintaining protein homeostasis under abiotic stress conditions and are indispensable for plant viability. In the present study, a comprehensive characterization of this gene family in Allium sativum was conducted through genome-wide sequence identification, phylogenetic reconstruction, conserved motif analysis, promoter cis-element profiling, transcriptomic investigation, quantitative real-time PCR, subcellular localization, and yeast-based functional assays. A total of 114 small heat shock protein genes were identified across eight chromosomes and subsequently classified into ten phylogenetic subgroups. All encoded proteins conserved the α-crystallin domain, whereas their exon–intron architectures and promoter elements responsive to environmental stress or phytohormones exhibited considerable diversity. The predicted proteins range from 130 to 364 amino acids, with isoelectric points (pI) spanning 3.97 to 9.95 and GRAVY values from −1.131 to −0.014, indicating predominantly hydrophilic characteristics. Subcellular localization analysis revealed a broad distribution across the cytoplasm, chloroplasts, mitochondria, and other compartments, with the majority (74 proteins) localized in the cytoplasm. Synteny analysis uncovered two segmentally duplicated gene pairs (AsHSP20-80/31, and AsHSP20-81/32), both showing strong purifying selection (Ka/Ks = 0.0459 and 0.2545, respectively), suggesting functional conservation. Expression profiling demonstrated predominant transcript accumulation in bulbs and floral organs, with significant induction under heat, salinity, and jasmonic acid treatments. qRT–PCR validation further confirmed that several candidate genes, notably AsHSP20-94 and AsHSP20-79, were strongly and consistently upregulated across multiple stress conditions, underscoring their roles as core stress-responsive regulators. Subcellular localization experiments demonstrated that representative proteins are targeted to the cytoplasm, nucleus and chloroplasts. Furthermore, heterologous expression of AsHSP20-79 in yeast conferred marked thermotolerance. Collectively, these findings reveal extensive expansion and functional divergence of the small heat shock protein gene family in garlic and provide valuable candidate genes for improving stress resilience in this important crop species.

Allium mongolicum Regel is a valuable desert plant, yet its functional genomic research is hindered by low genetic transformation efficiency due to monocot regeneration recalcitrance and dense tissue structures. This study established a dual genetic transformation platform for A. mongolicum, encompassing in vivo transient expression and stable hairy root induction. By evaluating various infiltration methods, vacuum impregnation was identified as the optimal transient strategy and was successfully applied to localize the candidate proteins AmJAZ2 and AmSWEET14 to the nucleus and plasma membrane, respectively. For stable transformation, shortened stems were utilized as the optimal target explants. An orthogonal experimental design was employed to optimize key parameters, including Agrobacterium density, acetosyringone concentration, vacuum parameters, and co-cultivation duration. GFP fluorescence and PCR analysis confirmed the stable integration and expression of the transgene in the induced hairy roots. In conclusion, this study establishes preliminary, species-specific genetic transformation protocols for A. mongolicum, providing a baseline technical reference that may support subsequent exploratory research on the molecular biology and secondary metabolism of this species.

Jasmonate ZIM-domain (JAZ) proteins are pivotal repressors in the jasmonate (JA) signaling pathway, yet their specific roles in garlic (Allium sativum) remain largely unexplored. In this study, 28 AsJAZ genes were identified through a genome-wide analysis. The expansion of this family was primarily driven by whole-genome duplication events, with a significant majority (71.43%) of members belonging to a lineage-specific clade, Subfamily E. While AsJAZ proteins harbor conserved TIFY and Jas domains, they exhibit diverse gene structures and subcellular localization patterns. Notably, AsJAZ17 is strictly localized to the nucleus, whereas AsJAZ16 shows a nucleocytoplasmic distribution, suggesting potential functional compartmentalization within the family. Transcriptomic and qRT–PCR analyses revealed that most AsJAZ genes are responsive to heat, salt, and methyl jasmonate (MeJA) treatments. Protein–protein interaction (PPI) modeling and yeast two-hybrid (Y2H) assays confirmed that AsJAZ17 physically interacts with the MYC2 transcription factor, identifying it as a key regulator within the conserved COI1-JAZ-MYC2 signaling module. Functional validation demonstrated that overexpression of AsJAZ17 in Arabidopsis significantly enhances salt tolerance. This improvement is attributed to an optimized growth-defense trade-off and a reinforced antioxidant defense system, as evidenced by the increased activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), which collectively maintain reactive oxygen species (ROS) homeostasis under stress. These findings provide comprehensive insights into the evolutionary and functional landscape of the garlic JAZ family and identify AsJAZ17 as a promising candidate gene for molecular breeding to improve abiotic stress resilience in Allium crops.