The CmABF1-CmBt/CmBr Module Regulates Cucurbitacin B Biosynthesis to Promote Cold Tolerance of Oriental Melon Seedlings.

The brassinosteroid-responsive transcription factor CmBEEL1 through integrating ICE1 cascade and ROS homeostasis enhances cold tolerance in Chrysanthemum.

It is concluded that overexpression of CmBEEL1 is sufficient to enhance cold tolerance in chrysanthemum via the ICE1 cascade and ROS homeostasis via the ICE1 cascade and ROS homeostasis.

Abscisic acid–regulated stability of CmABF1 and CmBRM modulates salt tolerance in chrysanthemum via epigenetic regulation of CmHSFA4

It is shown that salt stress–induced ABA accumulation up-regulates Heat Shock Factor 4 (CmHSFA4), a gene that is known to enhance chrysanthemum salt tolerance, and an ABA-SnRK2.2-ABF1/BRM signaling module that integrates phosphorylation-dependent protein stabilization and degradation with histone methylation dynamics to fine-tune salt stress–responsive gene expression in chrysanthemum is revealed.

Genome-Wide Identification of the CmTIFY Gene Family and Analysis of Its Expression Patterns under Cold Stress (Cucumis melo L.)

Genome-Wide Identification of the CmABF Gene Family in Melon (Cucumis melo L.) and Their Response to Ozone and ABA

Melon (Cucumis melo L.) is a globally significant horticultural crop whose fruit quality and postharvest shelf life are profoundly influenced by oxidative stress. Abscisic acid (ABA)-responsive element binding factors (ABFs), which represent the Group A subfamily of the basic leucine zipper (bZIP) transcription factor family, serve as pivotal components in the ABA signaling pathway. These factors play essential roles in regulating plant responses to abiotic stress as well as fruit development and maturation processes. In this study, a total of nine CmABF gene family members (CmABF1–CmABF9) were successfully identified within the melon genome using genome-wide identification techniques. Bioinformatic analysis indicated that all CmABF proteins contain a conserved bZIP domain. Physicochemical property analysis revealed that most of these proteins are unstable hydrophilic proteins and all are localized to the cell nucleus. Phylogenetic analysis categorized the CmABF family into three distinct evolutionary branches (Groups A, B, and C), exhibiting high conservation with homologous genes in Arabidopsis thaliana, Solanum tuberosum, and other species. Promoter analysis demonstrated that CmABF genes are rich in hormone-responsive elements (such as abscisic acid-responsive element (ABRE) and gibberellin-responsive element (GARE)) and stress-responsive elements (such as MYB binding sites (MBS) and anaerobic-response element (ARE)). To investigate their responses to oxidative stress and ABA signaling, we analyzed the expression patterns of these genes in melon fruit at 0, 7, 14, 21, 28, and 35 days of postharvest storage under ozone (O3, an oxidative stressor), exogenous abscisic acid (ABA), and the ABA synthesis inhibitor nordihydroguaiaretic acid (NDGA) using RNA-seq and qRT-PCR. The results showed that ozone treatment significantly induced the up-regulation of CmABF9 while inhibiting the early expression of CmABF2 and CmABF4. ABA treatment generally promoted the transcription of family members during the late stages of storage (35 d). NDGA treatment suppressed the expression of CmABF2 and CmABF4 during the early storage stage (7 d), while markedly increasing their expression levels at later storage stages (28 d and 35 d), suggesting a compensatory feedback response under endogenous ABA deficiency. Furthermore, protein–protein interaction predictions indicated potential close interactions between CmABF proteins and SnRK2 protein kinases. This study provides a theoretical basis for elucidating the molecular mechanisms of the CmABF family in regulating postharvest oxidative stress in melon and provides candidate gene resources for molecular breeding aimed at enhancing resistance and extending the shelf life of melon fruit.

The CmABI5-CmKN1 module regulates seasonal growth and flowering in response to chilling in chrysanthemum.

Perennial plants have evolved complex regulatory networks that allow them to perceive environmental changes and trigger adaptive growth responses. Many perennial herbs exhibit a rosette growth habit during winter, and then undergo extension growth/stem elongation growth and flowering in the following spring. However, the mechanisms underlying this seasonal transition are still not well understood. Here, using the perennial herb chrysanthemum (Chrysanthemum morifolium), we identified CmKN1, a class I KNOTTED (KN1)-like homeobox transcription factor, that mediates extension growth and flowering competence in response to prolonged chilling exposure. The rosette growth of chrysanthemum rhizomes in late autumn coincides with downregulation of CmKN1 expression. Overexpression of CmKN1 promotes premature rhizome extension growth and flowering, whereas the kn1 heterozygous mutant shows suppression of these processes. Furthermore, seasonal growth regulation involves the abscisic acid (ABA) signaling pathway. Shoot apices in the rosette state accumulate higher levels of ABA than those in the extension growth state. Notably, in response to ABA, CmKN1 expression is downregulated by CmABI5. Our results demonstrated that the CmABI5-CmKN1 module mediates extension growth and flowering competence in response to chilling, thereby facilitating the perennial growth habit of chrysanthemum.

The ethylene-responsive transcription factor CsESR1 positively regulates cucumber ( Cucumis sativus L.) Trichomes

Trichomes are multicellular, non-glandular structures that play important roles in plant development, and provide protection against harmful ultraviolet radiation, insect damage and excessive water loss through transpiration. However, the regulation of trichome formation in cucumber remains incompletely understood. Although the phenotype of gl2 have been identified, no fine mapping and candidate gene for it has been determined so far. In this study, CsGL2 was mapped to a 72.5-kb region on chromosome 2, and via fine-mapping, an ethylene-responsive transcription factor ESR1, was identified as the candidate gene. We generated a CRISPR/Cas9 knockout mutant CsGL2  CRwhich was phenotypically resembled the natural gl2 mutant, demonstrating that CsESR1 is CsGL2. We further investigated whether CsGL2 interacts with CsGL1 and CsGL3, two known regulators of trichome development. Our results showed that CsGL2 directly binds to the promoter of CsGL1 and regulates its expression. Moreover, CsGL1 directly interacts with the CsGL3 protein. Genetic analysis demonstrated that CsGL3 is epistatic to CsGL1 and CsGL2, respectively. In conclusion, this study identified CsGL2 as a novel regulator of trichome development in cucumber, which is the first report of an ethylene-responsive transcription factor involved in cucumber trichome development. Furthermore, we elucidate the functional relationships among CsGL2, CsGL1 and CsGL3, providing new insights into the molecular network governing trichome development in cucumber.