Seed germination is a critical checkpoint for plant growth under unfavorable environmental conditions. In Arabidopsis (Arabidopsis thaliana), the abscisic acid (ABA) and gibberellic acid (GA) signaling pathways play important roles in modulating seed germination. However, the molecular links between salinity stress and ABA/GA signaling are not well understood. Herein, we showed that the expression of DIVARICATA1 (DIV1), which encodes a MYB-like transcription factor, was induced by GA and repressed by ABA, salinity, and osmotic stress in germinating seeds. DIV1 positively regulated seed germination in response to salinity stress by directly regulating the expression of DELAY OF GERMINATION 1-LIKE 3 (DOGL3) and GA-STIMULATED ARABIDOPSIS 4 (GASA4) and indirectly regulating the expression of several germination-associated genes. Moreover, NUCLEAR FACTOR-YC9 (NF-YC9) directly repressed the expression of DIV1 in germinating seeds in response to salinity stress. These results help reveal the function of the NF-YC9–DIV1 module and provide insights into the regulation of ABA and GA signaling in response to salinity stress during seed germination in Arabidopsis.

Postharvest fruit softening is a critical determinant of fruit shelf life, significantly influencing mechanical damage susceptibility, pathogen invasion, and consumer preference. Collectively, these factors lead to substantial losses in the fruit industry. The structural modifications of cell wall and cuticle during ripening primarily govern fruit softening. The objective of this review is to synthesize recent advances and provide a comprehensive analysis of the molecular mechanisms underlying this process. In this review, we provide a comprehensive analysis of cell wall composition and softening-associated cell wall remodeling proteins. We examine recent advances in manipulating single or multiple genes encoding cell wall-modifying proteins that influence fruit softening, and identify key transcription factors regulating the expression of these gene networks. This review synthesizes current understanding of the molecular mechanisms governing fruit ripening, providing a foundation for future research in postharvest biology.

Seed oil content and fatty acid (FA) composition collectively determine the quality and economic value of Brassica napus. Little is known about the role of R2R3-MYB transcription factors (TFs) in regulating FA biosynthesis in B. napus. Here, BnaC04.MYB89 was found to be expressed primarily in developing seeds. Overexpression of BnaC04.MYB89 consistently decreased FA levels, as evidenced by its effect in both the Arabidopsis thaliana myb89-1 mutant and B. napus seeds. RNA-seq of developing seeds at 30 DAP (days after pollination) revealed marked suppression of FA biosynthetic genes in BnaC04.MYB89-overexpressing plants compared to the K407 control. ChIP (Chromatin immunoprecipitation) analysis revealed that BnaC04.MYB89 directly inhibited the expression of BnaA03.BCCP1 and BnaC03.HD while indirectly regulating that of BnaA09.BADC1, BnaA03.BADC3, BnaA03.MOD1, and BnaA08.FAT8, thereby reducing seed FA accumulation. Collectively, these results elucidate the role for BnaC04.MYB89 and provide new insights into the transcriptional regulatory network controlling seed oil accumulation in B. napus.

This study aimed to identify fungal species causing fruit rot of chestnut (Castanea mollissima Blume) in Hebei Province, China and analyze the resistance differences among major cultivars. A total of 220 fungal isolates were obtained from healthy and diseased kernels, which were classified into six distinct genera: Diaporthe (48.6%), Talaromyces (22.3%), Alternaria (10.5%), Mucor (9.5%), Fusarium (5.5%), and Rhizopus (3.6%). Based on both morphological and molecular analyses, six representative isolates of the six genera were identified as Diaporthe eres Nitschke, Talaromyces rugulosus Samson, N. Yilmaz, Frisvad & Seifert, Alternaria alternata (Fr.) Keissl., Mucor circinelloides Tiegh., Fusarium proliferatum (Matsush.) Nirenberg, and Rhizopus stolonifer (Ehrenb.) Vuill. Among these, D. eres was first reported to cause fruit rot on C. mollissima in China. Moreover, disease resistance evaluation of major cultivars showed significant differences: YG, YSSF, and DBH exhibited strong resistance under both natural conditions (with 1.67% to 5.27% DI after 180 days storage) and artificial inoculation (with 32.96 ± 0.64 to 52.61 ± 0.55 DI); while YJ was highly susceptible (with 47.71% decay incidence and 70.50 ± 7.22 DI). Correlation analysis revealed that the disease index was negatively correlated with sucrose and sorbitol contents, but positively correlated with stachyose and fructose contents. This study advances the understanding of postharvest chestnut fruit rot and provides a theoretical basis for breeding resistant cultivars and developing control strategies to mitigate losses and ensure food safety.

Leaf senescence is a critically regulated developmental process that determines crop yield and quality. MYB and NAC transcription factors (TFs) are central regulators within this network, yet the crosstalk between these TF families and their connection to the gibberellin (GA) pathway remain poorly understood. This study revealed that overexpression of DIV1, a MYB-like TF, leads to significantly reduced chlorophyll content and precocious leaf senescence. Based on the public transcriptome profiling of DIV1-overexpression leaves, 37 senescence-associated differentially expressed genes (DEGs), including the highly upregulated NAC59 and NAC92, were identified. Molecular assays confirmed that DIV1 directly binds to the promoters of NAC59 and NAC92 and activates their transcription. Meanwhile, yeast two-hybrid and split-luciferase assays demonstrated that DIV1 physically interacts with the GA biosynthetic enzyme ent-kaurene oxidase (KO1) both in vitro and in vivo. The promoted senescence phenotype in DIV1-overexpression lines was rescued by treatment with paclobutrazol (PAC), a GA biosynthesis inhibitor. In summary, our findings reveal a dual mechanism whereby DIV1 integrates the GA pathway and NAC-mediated transcription to regulate leaf senescence. This work provides new insights into the coordination between MYB and NAC TFs during hormone-mediated senescence.