The Plant Journal最新文献

The hypothesis that small peptides in the CLAVATA3/EMBRYO SURROUNDING REGION-RELATED (CLE) family are responsible for stomatal regulation under soil drying was tested in grapevine (Vitis vinifera L.). Potted Cabernet Sauvignon grapevines were subjected to water stress by withholding irrigation over a 10-day period followed by 6 days of holding stress and 10 days of recovery. Soil drying resulted in declines in leaf (Ψ_L) and stem (Ψ_S) water potentials and root and leaf hydraulic conductances. Near-complete stomatal closure occurred within 10 days of withholding water. Extending the duration of dry soil over an additional week had no additional effect on stomatal conductance (g_s), but decreased Ψ_L and Ψ_S. Xylem sap abscisic acid (ABA) increased during peak water stress and declined during extended stress. Transcripts of CLE1, CLE3 and CLE6 followed the same patterns as ABA and its transcript NCED1, increasing as the soil dried and decreasing upon soil rehydration. Gene expression of CLE9 increased in both roots and leaves in response to soil drying, but, in contrast to the other CLE peptides, it remained high in the roots even after the vines recovered from water stress. The results indicate that CLE9 may be a key root-to-shoot signal of soil drying in grapevine. Together with the putative regulation of leaf ABA by CLE peptides, stomatal regulation is suggested to be indirectly controlled by root and leaf CLE9 under soil drying. An overall model of hydraulic and chemical signalling in grapevine under water stress that incorporates the role of CLE peptides is proposed.

Rice (Oryza sativa L.), originating from tropical and subtropical regions, is a cold-sensitive and water-demanding crop whose yield and quality are severely compromised by chilling injury or water deficits during growth and development. In this study, we systematically characterized Cold and Drought Resistance 1 (OsCDR1), a nucleus-localized transcription activator belonging to the bZIP transcription factor family. OsCDR1 overexpression enhances rice tolerance to cold and drought stress, whereas knockout mutants of OsCDR1 exhibit reduced resistance to low temperatures and drought conditions. Furthermore, OsCDR1 positively regulates abscisic acid (ABA) signaling in rice, and mediates ABA-regulated drought tolerance responses in rice. Integrated RNA-seq and CUT&Tag analyses demonstrated that OsCDR1 coordinates with ABA-dependent (PIP2;2) and -independent genes (DREB1J). OsCDR1 specifically binds to the G-box cis-element in the promoters of PIP2;2 and DREB1J, thereby activating their transcription and regulating the abiotic stress responses in rice. Protein interaction analysis revealed that OsCDR1 interacts with the kinase OsMPK9 in vivo and in vitro, and a dual-luciferase reporter assay showed that OsMPK9 and OsCDR1 regulate the transcription of DREB1J and PIP2;2 in the same functional pathway. Overexpression of OsMPK9 inhibits ABA responses in rice and reduces cold and drought tolerance. Our findings establish the OsMPK9–OsCDR1 module as a critical hub connecting ABA signaling to abiotic stress resilience, providing new insights for breeding crops.

Plants have evolved intricate mechanisms to balance growth and defense through complex signaling networks. Previous studies have focused on aerial parts or crop yield, but little is known about the regulation of root growth under pathogen attack. Here, we report that the SERINE RICH ENDOGENOUS PEPTIDE12 (SCOOP12) immune signaling peptide regulates root meristem development via the receptor-like kinase MALE DISCOVERER 1-INTERACTING RECEPTOR-LIKE KINASE 2 (MIK2) and the MAPK cascade in Arabidopsis. We demonstrated that SCOOP12 treatment reduced the number of root meristematic cells by suppressing the expression of key molecular regulators, including PLETHORA1 (PLT1) and PLT2, which are essential for maintaining root stem cell niche (SCN) activity. Physiological and cell biological experiments revealed that MIK2 and MPK6 are required for SCOOP12-mediated root growth regulation, as the mik2 and mpk6 mutants presented reduced sensitivity to SCOOP12-induced effects. Further biochemical evidence indicates that MPK6 directly phosphorylates PLT1 and PLT2. The plt1-4 plt2-2 double mutant also presented diminished responses to SCOOP12, confirming the central role of PLT1/2 in this regulatory network. Our work elucidated a molecular pathway through which SCOOP12 modulates root meristem activity, providing insights into the trade-off between plant growth and immunity.

Global biodiversity is facing threats from climate change, habitat fragmentation, and anthropogenic activities—pressures that particularly endanger endemic and narrowly distributed species. In this study, the high-quality chromosome-level genomes of two ecologically divergent maples were assembled: the endangered and range-restricted Acer tsinglingense (791.40 Mb) and its widespread congener Acer davidii (1291.99 Mb). Phylogenomic analysis indicates that the two species diverged ~16.3 million years ago, with A. tsinglingense showing notable gene family expansions in secondary metabolite pathways. Notably, the 3-ketoacyl-CoA synthase gene family, which is involved in nervonic acid biosynthesis, underwent significant expansion and tandem duplication in A. tsinglingense, exhibiting high expression in buds. Population genomic analysis revealed that, compared with the widely distributed A. davidii, A. tsinglingense possesses lower genetic diversity, higher harmful mutation load, and signatures of a severe population bottleneck during the Late Pleistocene. Genome–environment association analysis further identified climate-adaptive genomic variations linked to five key environmental factors and projected potential genomic offsets under future climate scenarios. The southern lineage of A. tsinglingense exhibited greater climate sensitivity and genomic vulnerability under strong selective pressures, underscoring its importance as a conservation priority. Our research reveals that metabolic specializations in A. tsinglingense (such as the synthesis of nervonic acid) may confer competitive advantages in specific habitats. However, factors including its restricted distribution, historical population bottlenecks, and accumulated genetic load severely constrain its evolutionary potential to cope with rapid climate change. These findings emphasize the importance of elucidating the genomic basis and mechanisms of endangerment in metabolically specialized and threatened plant species to inform effective conservation strategies.

N⁶-methyladenosine (m⁶A) modification occurs prevalently in eukaryotic mRNAs and is a key epitranscriptomic mechanism regulating plant development and stress responses. The m⁶A mark is interpreted by ‘readers’ that recognize and bind to m⁶A-modified RNAs. Recent studies highlight Evolutionarily Conserved C-terminal region (ECT) proteins as m⁶A readers in various plant species. However, the functions of many ECT proteins remain unknown. Therefore, this study aims to determine the role of ECT10 as an m⁶A reader and to evaluate its function in drought stress response in Arabidopsis. The electrophoretic mobility shift assay demonstrated that ECT10 specifically binds to m⁶A-modified RNAs but not to m⁵C-modified RNAs in vitro. The expression of ECT10 decreased markedly under drought stress conditions. The ect10 loss-of-function mutant exhibited reduced sensitivity to drought stress. Complementation lines expressing the native ECT10 in the ect10 mutant background restored the wild-type phenotype, while lines expressing the mutant mECT10, harboring substitutions at two critical amino acid residues, failed to rescue the phenotype. ECT10 regulated the expression of several m⁶A-modified positive or negative regulators of the drought stress response by modulating their stability through direct binding to these m⁶A-modified transcripts in planta. Collectively, these findings establish ECT10 as a novel m⁶A reader crucial for drought stress response by modulating mRNA stability.