Hydrogen sulfide (H₂S), a novel gasotransmitter in both mammals and plants, plays important roles in plant development and stress responses. Leaf senescence represents the final stage of leaf development. The role of H₂S-producing enzyme L-cysteine desulfhydrase in regulating tomato leaf senescence is still unknown. In the present study, the effect of an L-cysteine desulfhydrase LCD1 on leaf senescence in tomato was explored by physiological analysis. LCD1 mutation caused earlier leaf senescence, whereas LCD1 overexpression significantly delayed leaf senescence compared with the wild type in 10-week tomato seedlings. Moreover, LCD1 overexpression was found to delay dark-induced senescence in detached tomato leaves, and the lcd1 mutant showed accelerated senescence. An increasing trend of H₂S production was observed in leaves during storage in darkness, while LCD1 deletion reduced H₂S production and LCD1 overexpression produced more H₂S compared with the wild-type control. Further investigations showed that LCD1 overexpression delayed dark-triggered chlorophyll degradation and reactive oxygen species (ROS) accumulation in detached tomato leaves, and the increase in the expression of chlorophyll degradation genes NYC1, PAO, PPH, SGR1, and senescence-associated genes (SAGs) during senescence was attenuated by LCD1 overexpression, whereas lcd1 mutants showed enhanced senescence-related parameters. Moreover, a correlation analysis indicated that chlorophyll content was negatively correlated with H₂O₂ and malondialdehyde (MDA) content, and also negatively correlated with the expression of chlorophyll degradation-related genes and SAGs. Therefore, these findings increase our understanding of the physiological functions of the H₂S-generating enzyme LCD1 in regulating leaf senescence in tomato.

High-temperature stress severely limits the growth, development, yield, and quality of garlic (Allium sativum L.), but the role of hormone signaling in its heat stress response remains unclear. This study examined changes in seven plant hormones and the expression of related genes in garlic leaves (‘Xusuan No. 6’) under heat stress (38 °C for 0, 2, 4, and 24 h). Growth-promoting hormones, auxin and gibberellic acid, significantly decreased within 2 h of heat stress, while stress-response hormones, including abscisic acid, jasmonic acid, salicylic acid, and ethylene, increased. KEGG pathway analysis revealed significant changes in genes related to hormone biosynthesis and signal transduction, such as NCED and PYR/PYL in the ABA pathway, LOX and OPR in JA biosynthesis, AUX and ARF in IAA signaling, and ERT and ERF in ethylene signaling. A protein–protein interaction network identified 15 hub genes potentially coordinating hormone regulation under heat stress. These findings provide a basis for functional validation of key hormone-related genes in the garlic heat-stress response and suggest potential genetic targets for the development of heat-tolerant garlic varieties.

In this study, a garlic DNA fingerprinting system based on single nucleotide polymorphisms (SNPs) was developed using representative cultivated garlic accessions. SNP markers were identified based on reduced-representation genome sequencing (GBS) data from 77 garlic accessions. A total of 26,701,817 raw SNPs were detected and subsequently filtered to obtain 7,006 high-quality candidate SNP loci. Among these, KASP primers were successfully designed for 4,297 loci, corresponding to an assay design success rate of 61.3%. Of these candidate loci, 30 generated reliable KASP genotyping results, from which 13 high-quality core SNP markers were finally selected through stepwise screening based on genotyping quality, marker polymorphism, and discriminatory ability. The average minor allele frequency (MAF), expected heterozygosity (He), and polymorphism information content (PIC) of these core markers were 0.235, 0.281, and 0.227, respectively. Based on these 13 core SNP markers, an SNP-based DNA fingerprinting system for garlic was established. Genotyping analysis of the 77 accessions showed that 73 could be effectively distinguished, whereas 4 accessions remained unresolved. Overall, this core SNP marker set showed effective discriminatory power for most garlic accessions and provides a practical basis for germplasm identification, variety protection, and molecular breeding in garlic.

This study investigated the effects of four selenium fertilizers (nano-Se, EDTA-chelated Se, organic Se, and microbial Se) at three concentrations (50, 25, and 12.5 mg·L⁻¹) on garlic (Allium sativum L. cv. ‘Xusuan 918’) through foliar application during critical growth stages. Comprehensive evaluation combining agronomic traits, yield components, nutritional quality (soluble sugars, vitamin C), and selenium accumulation revealed distinct fertilizer-specific responses. Organic Se at 50 mg·L⁻¹ (O1) maximized vegetative growth (21.83% increased plant spread), while 25 mg·L⁻¹ microbial Se (M2) showed optimal yield enhancement (10.04% higher bulb dry weight vs. CK). Notably, 50 mg·L⁻¹ nano-Se (N1) achieved simultaneous improvement in nutritional quality and selenium biofortification (29-fold bulb Se enrichment). Principal component analysis integrated with membership function method identified N1 treatment (D-value = 0.571) as the most effective protocol for selenium-enriched garlic production, demonstrating the importance of fertilizer selection for crop-specific selenium management strategies.