The Plant Journal最新文献

Flowering is a crucial developmental process in angiosperms. However, the underlying mechanisms remain to be elucidated. In this study, we identify INDETERMINATE DOMAIN (IDD) transcription factors (TFs), IDD14, IDD15, and IDD16, as redundant negative regulators of flowering time in Arabidopsis. The idd14-1 idd15-5 idd16-1 triple mutant displays early flowering, while the gain-of-function mutation in idd14-1D results in delayed flowering under long-day conditions. Gene expression analysis shows that the florigen gene FLOWERING LOCUS T (FT) is activated in idd14-1 idd15-5 idd16-1 but suppressed in idd14-1D. Further analyses show that IDD14 could directly bind to the promoter of FT to suppress its expression. Moreover, IDDs interact with DELLAs in vitro and in vivo, and DELLAs enhance the inhibition ability of IDD14 on FT. Genetic and physiological analyses further support that IDDs regulate flowering through their dependence on FT and are partially involved in DELLA-mediated flowering time regulation. Taken together, our findings suggest that a subfamily of IDD TFs may function as new components of DELLA-mediated gibberellin signaling to negatively modulate flowering time by repressing the expression of FT.

Fruit ripening is a complex process involving physiological and biochemical changes that are influenced by multiple factors. NAC transcription factors play roles in regulating plant growth, development, and responses to plant hormones, and have been implicated in playing regulatory roles in the ripening of several fruits. However, the mechanisms whereby NACs regulate ripening and quality formation in the climacteric fruit apricot (Prunus armeniaca L.) remain unclear. In this study, we identified ripening-associated PaNAC64 from apricot fruit by WGCNA and RT-qPCR analysis and showed that it is upregulated during fruit ripening and is highly expressed at fruit maturity. Expression experiments confirmed that PaNAC64 can promote fruit ripening and the development of fruit quality attributes. PaNAC64 is not induced by exogenous ABA but its expression is significantly enhanced by ethylene. Through correlation analysis, we found that PaCYP707A is negatively correlated with PaNAC64. Experiments confirmed that PaNAC64 directly inhibits the transcription of PaCYP707A, thereby suppressing the hydroxylation-mediated inactivation of ABA, leading to the accumulation of endogenous ABA, which in turn promotes ethylene synthesis and fruit ripening. Our study demonstrates the importance of the interactions between transcription factors, ABA and ethylene in the regulation of apricot fruit ripening, quality formation, and post-harvest storage.

Drought is one of the most severe abiotic stresses leading to reduced crop yield. Stomatal closure mediated by abscisic acid (ABA) signaling is a critical drought resistance mechanism in plants. Previously, we identified a drought-responsive apple transcription factor, MdWRKY75, from the drought transcriptome, which positively regulates apple drought resistance. Overexpression of MdWRKY75 results in smaller stomatal apertures than wild-type (WT) plants, elevated ABA content, and increased expression of ABA signaling pathway genes, whereas RNA interference (RNAi) lines exhibit the opposite effect. Furthermore, MdWRKY75 binds to the promoter of ABA signaling pathway gene C2-domain ABA-related 4 (MdCAR4) and positively regulates its expression. MdCAR4-RNAi plants are less drought-tolerant than WT plants, with lower stomatal aperture and ABA content, while MdCAR4 overexpression enhances drought resistance and rescues the drought-sensitive phenotype of MdWRKY75-Ri3. In addition, MdCAR4 interacts with ABA receptor family member MdPYL3/4.2/5/6, enhancing their localization to the plasma membrane. Finally, MdPYL3/4.2/5/6 also positively regulates ABA-mediated stomatal closure and drought tolerance, and their overexpression rescues the drought-sensitive phenotype of MdCAR4-Ri5. Our findings demonstrate that the MdCAR4-MdPYLs interaction module, regulated by MdWRKY75, promotes ABA signaling and enhances apple drought resistance by increasing the plasma membrane localization of ABA receptors.

Cyanobacteria are photosynthetic prokaryotes with great potential in green biomanufacturing and basic research. Despite decades of pioneering achievements, the application of advanced genome editing tools, particularly CRISPR-based systems, has remained limited in cyanobacteria. In this study, we developed pCyABE, a new adenine base editor for efficient and precise A·T to G·C editing in cyanobacteria. This system utilizes a TadA-Cas9 nickase fusion and functions without double-strand breaks or donor templates. We demonstrated its high editing efficiency in Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120, highlighting its broad usability. pCyABE supports multiplex editing and enables start codon disruption for gene functional studies. Furthermore, this tool exhibits low off-target activity and can be effectively removed via sucrose counterselection. In conclusion, pCyABE provides a versatile and efficient genome editing platform that significantly expands the genetic toolbox for cyanobacterial research and biotechnology applications.

Strong seed dormancy is crucial for preventing pre-harvest sprouting (PHS) in cereal crops. However, the underlying molecular mechanism in wheat remains unclear. Here, we identified a gibberellin (GA)-stimulated regulator gene, TaGASR25, which negatively modulates wheat seed dormancy. Further analyses showed that TaC3HC4, a member of the C3HC4-type zinc finger family, enhances TaGASR25 transcription and interacts with TaGASR25 in the nucleus to negatively regulate wheat seed dormancy through crosstalk with the GA and abscisic acid (ABA) pathways. Marker-trait association analyses revealed that the A/G (−1317 bp) and CGG/GA- (−1645 bp) mutations in the TaGASR25 promoter were significantly associated with differences in seed dormancy among wheat varieties, with A and CGG associated with strong dormancy. Collectively, our findings uncover a novel TaC3HC4-TaGASR25 module regulating seed dormancy and provide promising targets and molecular markers for the molecular breeding of PHS-resistant wheat varieties.

Upland cotton (Gossypium hirsutum) and sea-island cotton (Gossypium barbadense) are the two most widely cultivated cotton species, differing in their fiber quality and environmental adaptability. Small secreted peptides (SSPs) are key signaling molecules that regulate plant development and stress responses, yet their genome-wide diversity and functional roles in cotton remain largely uncharacterized. Here, leveraging high-quality genome assemblies, we systematically identified 2629 and 2331 SSPs in G. hirsutum and G. barbadense, respectively. Transcriptomic analyses revealed distinct species SSP expression dynamics: Expressed SSPs number declined during fiber and ovule development in G. hirsutum, but increased in G. barbadense, implicating SSPs in the superior fiber traits of the latter. Under abiotic stress, G. hirsutum displayed a predominantly downregulated SSPs profile, whereas G. barbadense maintained a more balanced transcriptional response, suggesting divergent stress adaptation strategies. Among the differentially expressed SSPs, we identified and characterized GDRP (Gossypium Drought and Salt Resistance Peptide), a novel peptide strongly induced by both drought and salt stress. Exogenous application of GDRP significantly enhanced stress tolerance by reducing oxidative damage, improving water-use efficiency, and promoting stomatal closure. VIGS (Virus-Induced Gene Silencing) experiments have demonstrated that GhGDRP6 acts as a positive regulatory factor for drought tolerance. Mechanistically, GDRP activated abscisic acid (ABA) signaling by upregulating GhPYL4 and GhNACs, and repressing GhPP2Cs and GhPIP2;7, key negative regulators of ABA-mediated drought responses. Furthermore, GDRP induced the phosphorylation of GhMPK3 and GhMPK6, two central kinases in the MAPK signaling cascade. Virus-induced gene silencing of GhMPK3 or GhMPK6 abolished GDRP-mediated drought tolerance, confirming a MAPK3/6-dependent mechanism. Collectively, this study provides the first genome-wide SSP atlas in cotton and uncovers GDRP as a previously uncharacterized peptide that modulates ABA and MAPK signaling to enhance abiotic stress resilience. These findings lay the foundation for peptide-based crop improvement strategies targeting stress tolerance and yield stability in cotton.