Garlic (Allium sativum L.) is an important vegetable and is cultivated and consumed worldwide for its economic and medicinal values. Garlic cloves, the major reproductive and edible organs, are derived from the axillary meristems. KNOTTED-like homeobox (KNOX) proteins, such as SHOOT MERISTEM-LESS (STM), play important roles in axillary meristem formation and development. However, the KNOX proteins in garlic are still poorly known. Here, 10 AsKNOX genes, scattered on 5 of the 8 chromosomes, were genome-wide identified and characterized based on the newly released garlic genome. The typical conserved domains of KNOX proteins were owned by all these 10 AsKNOX homologs, which were divided into two Classes (Class I and Class II) based on the phylogenetic analysis. Prediction and verification of the subcellular localizations revealed the diverse subcellular localization of these 10 AsKNOX proteins. Cis-element prediction, tissue expression analysis, and expression profilings in responding to exogenous GA₃ and 6-BA showed the potential involvement of AsKNOX genes in the gibberellin and cytokinin signaling pathways. Overall, the results of this work provided a better understanding of AsKNOX genes in garlic and laid an important foundation for their further functional studies.

Garlic has a strong ability of selenium (Se) accumulation and is one of the best target crops for Se biofortification. Arbuscular mycorrhizal fungi (AMF) inoculation might enhance the nutritional qualities and the absorption ability of exogenous Se in plants. However, little is known about the exogenous Se application and AMF inoculation on garlic. Here, we evaluated the effects of different concentrations of exogenous Se on the growth, nutritional quality, and selenium enrichment of garlic. The results demonstrated that significantly higher Se content of garlic bulb was found in exogenous Se treated plants, and the Se accumulation was improved with the increasing of Se supply. Low application of exogenous Se appreciably improved the yield and the contents of soluble sugar and allicin in garlic bulbs, but the opposite was observed at high Se concentration. Furthermore, AMF inoculation significantly reduced the inhibition effect of high concentration Se on garlic. AMF supply was effective in improving the growth and nutritional indicators of garlic, which promoted the exogenous Se utilization rate when combined with 10 mg/L exogenous Se treatment. The results will provide a more theoretical basis for the production of high-quality selenium enrichment garlic.

Sexual differentiation is an important developmental phenomenon in cucurbits that directly affects fruit yield. The natural existence of multiple flower types in melon offers an inclusive structure for studying the molecular basis of sexual differentiation. The current study aimed to identify and characterize the molecular network involved in sex determination and female development in melon. Male and female pools separated by the F₂ segregated generation were used for sequencing. The comparative multi-omics data revealed 551 DAPs and 594 DEGs involved in multiple pathways of melon growth and development, and based on functional annotation and enrichment analysis, we summarized four biological process modules, including ethylene biosynthesis, flower organ development, plant hormone signaling, and ubiquitinated protein metabolism, that are related to female development. Furthermore, the detailed analysis of the female developmental regulatory pathway model of ethylene biosynthesis, signal transduction, and target gene regulation identified some important candidates that might have a crucial role in female development. Two CMTs ((cytosine-5)-methyltransferase), one AdoHS (adenosylhomocysteinase), four ACSs (1-aminocyclopropane-1-carboxylic acid synthase), three ACOs (ACC oxidase), two ARFs (auxin response factor), four ARPs (auxin-responsive protein), and six ERFs (Ethylene responsive factor) were identified based on various female developmental regulatory models. Our data offer new and valuable insights into female development and hold the potential to offer a deeper comprehension of sex differentiation mechanisms in melon.

Background: C2H2 zinc finger proteins (C2H2-ZFPs) are one of the largest transcription factor families in plants and play vital roles in plant organ development and patterning, seed germination, and fruit ripening, as well as responses to biotic and abiotic stresses. Although widely studied in many species, the genome-wide characterization of the C2H2-ZFP family in watermelon (Citrullus lanatus) remains lacking. Methods: In this study, we identified 96 ClZFP genes in the watermelon genome and analyzed their chromosomal positions, gene structures, conserved motifs, and expression profiles. A tissue-specific expression analysis of 12 representative ClZFP genes revealed diverse and organ-preferential expression profiles, indicating functional differentiation during development. Results: Under abiotic stress treatments, four genes were significantly downregulated under drought, while one gene was strongly induced; six genes were inhibited and three genes were activated under low temperature; and most tested genes were upregulated at 72 h under salt stress, with one gene continuously induced throughout the treatment period. Key ClZFP members such as ClZFP36 and ClZFP72 showed specific and strong induction under drought and salt stress, respectively. Conclusions: These results indicate that ClZFPs may be involved in the tolerance of watermelon to various abiotic stresses. This study not only clarifies the evolutionary and expression characteristics of the ClZFP family in watermelon but also provides candidate genes for the genetic improvement of stress tolerance in cucurbit crops.