Key message: HanMYB1 was found to play positive roles in the modulation of anthocyanins metabolism based on the integrative analysis of different color cultivars and the related molecular genetic analyses. As a high value ornamental and edible crop with various colors, sunflowers (Helianthus annuus L.) provide an ideal system to understand the formation of flower color. Anthocyanins are major pigments in higher plants, which is associated with development of flower colors and ability of oxidation resistance. Here, we performed an integrative analysis of the transcriptome and flavonoid metabolome in five sunflower cultivars with different flower colors. According to differentially expressed genes and differentially accumulated flavonoids, these cultivars could be grouped into yellow and red. The results showed that more anthocyanins were accumulated in the red group flowers, especially the chrysanthemin. Some anthocyanins biosynthesis-related genes like UFGT (UDP-glycose flavonoid glycosyltransferase) also expressed more in the red group flowers. A MYB transcriptional factor, HanMYB1, was found to play vital positive roles in the modulation of anthocyanins metabolism by the integrative analysis. Overexpressed HanMYB1 in tobacco could deepen the flower color, increase the accumulation of anthocyanins and directly active the express of UFGT genes. Our findings indicated that the MYB transcriptional factors provide new insight into the dynamic regulation of the anthocyanin biosynthesis in facilitating sunflower color formation and anthocyanin accumulation.

Seed aging is a key issue that affects the preservation of germplasm resources and crop production. At present, the anti-aging properties of perilla seeds and the mechanisms of differences among varieties have not been clearly reported. This study aims to analyze the mechanisms of changes in storage substances and hormone levels in different varieties of perilla during the artificial aging process. The results show that seed aging can significantly reduce the activity of antioxidant enzymes in perilla seeds, decrease the contents of storage nutrients such as soluble proteins, soluble sugars, and oil content, reduce the accumulation of unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid, and significantly decrease the contents of endogenous Gibberellic acid (GA₃) and Indole-3-acetic acid (IAA). Meanwhile, the levels of hydrogen peroxide (H₂O₂) and Malondialdehyde (MDA) increased significantly, while the contents of saturated fatty acids such as palmitic acid and stearic acid rose, and the contents of endogenous Abscisic acid (ABA), Jasmonic acid (JA), Salicylic acid (SA), and Trans-zeatin riboside (TZR) were significantly upregulated. There are significant genotype differences in the tolerance of different perilla varieties to seed aging. The sensitivity of Shiban Perill (S23014) to aging stress is significantly higher than that of Qisu No. 2 (S23017). This study has confirmed that seed aging has adverse effects on the germination of perilla seeds by down-regulating the activity of antioxidant enzymes, reducing the accumulation of storage nutrients, and disrupting the balance of endogenous hormones. The research results provide an important theoretical basis for the preservation of perilla seed germplasm resources and the selection of anti-aging varieties.

The CLE (CLAVATA3/EMBRYO SURROUNDING REGION-related) small peptides constitute a large supergene family in plants and are extensively involved in plant stress responses and the regulation of growth and development. Light, water, gravity, and mechanical trauma play critical roles in maintaining normal plant growth and development; however, there have been no reports as to whether CLE genes are involved in the responses of sesame to these forms of stress. In this study, the CLE gene family in Zhongzhi No. 13 was systematically identified. Stress induction was performed using light and gravity, and the expression patterns in various tissues and organs were analyzed by means of transcriptome sequencing. Concurrently, the water stress response published in the NCBI database was queried and analyzed. The results showed that a total of 12 SiCLE genes exist in the genome of Zhongzhi No. 13, distributed on six chromosomes. Each gene encodes a signal peptide at its N-terminus and a conserved motif at its C-terminus. The majority of SiCLE genes exhibit a single-exon structure. The SiCLE genes encode proteins ranging from 72 to 133 amino acids in length. Most of these proteins are basic, hydrophobic, and unstable. An analysis of promoter cis-acting elements revealed that the majority of SiCLE gene family members harbor response elements associated with light, phytohormones, stress, and growth and development. Transcriptome analysis revealed that SiCLE4, SiCLE5, SiCLE8, and SiCLE10 exhibit differential expression under water stress, light stress, and gravity stress/mechanical damage conditions. These results provide a solid foundation for future investigations aimed at elucidating the biological roles of the CLE gene family in both abiotic stress responses and the regulation of growth and development.