The Plant Journal最新文献

Cold stress is a major abiotic stress factor that affects plant growth and development, leading to yield loss. Abscisic acid (ABA) plays important roles in mediating abiotic stress tolerance. The molecular mechanisms underlying crosstalk between cold tolerance and ABA signaling remain elusive. Here, we report the E3 ubiquitin ligase OsPUB9 as a critical regulator linking ABA signaling and cold stress response in rice. We demonstrate that OsPUB9 negatively regulates cold tolerance. Cold induces OsPUB9 expression, which promotes the degradation of OsICE1, a key transcription factor in cold signaling, thereby suppressing the expression of OsCBFs. Intriguingly, OsCBF3 binds the OsPUB9 promoter, establishing a feedback loop that upregulates OsPUB9 under cold stress to fine-tune OsICE1 stability. ABA induces OsPUB9 degradation whereas OsPUB9 modulates ABA signaling by ubiquitinating and degrading the phosphatase OsABI2 and the kinase SAPK10, which form a regulatory complex. OsPUB9 disrupts OsABI2-mediated dephosphorylation of SAPK10, enhancing SAPK10 activity. SAPK10 phosphorylates OsICE1, further linking ABA and cold pathways. Our results elucidate a dual role for OsPUB9 in balancing ABA signaling and cold response through posttranslational regulation of OsABI2, SAPK10, and OsICE1, offering novel targets for breeding climate-resilient rice varieties.

The NAC transcription factors (TFs) are among the largest TF families in plants and play essential roles in growth, development, and stress responses. However, few studies have investigated how NAC TFs regulate salt gland development of recretohalophytes. In this study, we identified LbNAC55, a TF whose expression is upregulated by salt, from Limonium bicolor (a typical recretohalophyte which serves as a model for studying development and salt secretion of plant salt glands). Overexpression of LbNAC55 in L. bicolor significantly increases salt gland density and the salt tolerance of the species, whereas silencing LbNAC55 results in reduced salt gland development and diminished salt tolerance. Furthermore, yeast two-hybrid screening revealed that LbFLZ13 interacts with LbNAC55. Silencing LbFLZ13 similarly decreased salt gland formation and salt tolerance. Further studies showed that the reduction in salt gland density induced by the simultaneous silencing of both LbNAC55 and LbFLZ13 was significantly lower than that caused by the silencing of either gene alone. These results demonstrate that the regulatory modules of LbNAC55-LbFLZ13 control the expression of genes involved in salt gland development and secretion. These findings provide a new perspective on salt gland development in halophytes.

Leaves are the primary source of photosynthesis in plants. Elucidating the mechanism of leaf shape variation is essential for plant development. In previous studies, we demonstrated that BoALG10, a member of the glycosyltransferase family, is responsible for the smooth-leaved trait in kale (Brassica oleracea var. acephala), but the underlying molecular mechanism remains unclear. Here, we performed quantitative N-glycoproteomics with the BoALG10 overexpression line and the corresponding wild type. A cupredoxin domain-containing protein Skewed5 (SKU5) specifically underwent N-glycosylation in the BoALG10 overexpression line. Site-directed mutagenesis of the N-glycosylation site Asn-444 affected BoSKU5 nuclear localization and protein function in maintaining smooth leaf margins. Transcriptome sequencing showed that the BoSKU5 mutation altered the expression of auxin signaling and cell wall modification-related genes. We then identified a transcription factor BoARF8, which interacted with the protein BoSKU5, through yeast two-hybrid library screening. BoARF8 promoted smooth leaf margin formation and positively regulated its target gene BoUIF1. The BoSKU5-BoARF8 complex further enhanced the activation of the BoARF8-BoUIF1 cascade. Moreover, BoUIF1 directly repressed the expression of BoCUC2, a leaf margin regulator. The BoSKU5/BoARF8-BoUIF1-BoCUC2 module illustrated the novel function of Skewed5 in leaf margin development. This will provide deeper insights into the genetic improvement in plants.

Nexine is an essential layer of the pollen wall. TRANSPOSABLE ELEMENT SILENCING VIA AT-HOOK (TEK), a member of the AT-HOOK MOTIF CONTAINING NUCLEAR-LOCALIZED (AHL) family, is a key regulator for nexine formation in Arabidopsis. In this study, we report that TEK interacts with TEOSINITE BRANCHED1-CYCLOIDEA-PCF 14 (TCP14) and TCP15 to regulate nexine formation. TCP14/15 are expressed in the anther cell layers including the tapetum. Although tcp14 tcp15 has no anther development defect, specifically repressing TCP15 and its homologs during the nexine formation stage in the pAMS::TCP15-SRDX transgenic plants leads to a defect in the nexine layer and complete sterility. Cell wall and other pollen wall formation-related genes are significantly enriched among downregulated genes in the transgenic line. This indicates that TCP14/15 and other TCP members are required for nexine formation. In addition, tek exhibits thermosensitive genic male sterility (TGMS) as its fertility was partially restored under low temperature (17°C), suggesting other AHL family members play a redundant role in nexine formation. AHL8 is localized in the tapetum and interacts with TCP14 and TCP15. Although the fertility of the ahl8 tek double mutant is similar to tek under 17°C, dominant suppression of AHL homologs in pAMS::AHL8-SRDX transgenic plants exhibits complete male sterility under 17°C. All these indicate that AHL8 and other AHLs play a redundant role in interacting with TCPs to regulate nexine formation. This work not only reveals the regulatory mechanism for nexine formation, but also provides a novel thermosensitive genic male sterile (TGMS) locus that may have potential applications in agriculture.

The development of rice fertility is a complex process, which is precisely regulated by numerous genes. In this study, we cloned and characterized OsPAIP11, a PABP-interacting protein that functions as an auxiliary factor in translation initiation. The ospaip11 exhibited multiple defects, including impaired callose synthesis, delayed tapetum apoptosis, and abnormal pollen wall development, which are essentially consistent with the phenotype of the allelic mutant dcet1. Subcellular localization analysis revealed that OsPAIP11 is localized in both the cytoplasm and nucleus. Interestingly, further investigation demonstrated that the RRM2 domain of OsPAIP11 exhibits transcriptional activation activity. Moreover, OsPAIP11 directly binds to the promoter of the callose synthesis-related genes GLUCAN SYNTHASE-LIKE 5 (OsGSL5) and OsGAMYB, thereby regulating their transcription and influencing callose biosynthesis during pollen development. Additionally, OsPAIP11 also interacts with the translation initiation factor and auxiliary factors. These findings suggest that OsPAIP11 modulates male fertility primarily by regulating the transcription of callose synthesis-related genes and may also participate in the translation process.

BIN2-LIKE1 genes encode glycogen synthase kinase 3-like (GSK3-LIKE) proteins that suppress brassinosteroid (BR) signaling, with crucial effects on plant architecture and agronomic traits. We isolated a gain-of-function gene (BnaC04.BIL1^Mut) in Brassica napus that may improve crop production by increasing planting density, enhancing lodging resistance, and facilitating mechanized harvest. To explore strategies for exploiting BnaC04.BIL1^Mut for genetic improvement, we analyzed its function along with key upstream genes (BnaHY5) and downstream transcription factor genes (BnaBZR1). BnaC04.BIL1^Mut overexpression resulted in a compact dwarf architecture with severely decreased biomass. By contrast, knocking out BnaC04.BIL1^Mut restored normal plant growth. BnaC04.BIL1^Mut interacts with BnaHY5 homologs to form complexes that lead to increased inhibition of kinase activity, thereby further adversely affecting plant growth. Knocking out two BnaHY5 homologs significantly alleviated the negative effects caused by BnaC04.BIL1^Mut overexpression. BnaC04.BIL1^Mut selectively interacted with two BnaBZR1 proteins (BnaC06.BZR1 and BnaCnn.BZR1) to negatively regulate plant architecture and BR signaling. The Thr187Ser substitution in BnaC04.BIL1 was predicted to alter the three-dimensional structure, enhancing selective BnaC04.BIL1-BZR1 interactions and severely inhibiting plant growth. BnaA07.BZR1 and BnaCnn.BZR1 overexpression promoted B. napus growth and improved the growth of BnaC04.BIL1^Mut-overexpressing plants without altering the compact growth habit. Our results may be useful for designing effective approaches for generating an ideal plant architecture (characterized by moderate biomass, compact plant, and enhanced lodging resistance) through appropriately regulated BR signaling via the modification of key upstream and downstream genes in B. napus.

Ferns are the second most diverse vascular plant lineage after angiosperms and have been a key ecological component of Earth's biodiversity for more than 380 million years. Importantly, ferns are sister to seed plants, providing a critical outgroup for understanding the evolution of seed plant features. Ferns are remarkably resilient to abiotic and biotic stresses due to a long evolutionary history with adaptations to diverse habitats, stresses, and herbivores. As a result, ferns produce a multitude of secondary metabolites with unique bioactivities; these chemicals are potentially linked to the adaptation of ferns to herbivory, various abiotic and biotic stresses, and changing environments. Assembled reference genomes and the identification of key metabolic compounds of multiple ferns have already made significant contributions to human health and well-being. Here, we review the recent scientific advances in fern research, including evolution, stress resistance, metabolites and medicinal utilization, and comparative multi-omics applications. We propose that integrated investigations involving ecological, physiological, and molecular techniques will facilitate the future research translation of fern resources in diverse areas including soil remediation, biopesticides, and medicine. Advances in our understanding of fern molecular biology will provide new insights into the evolution of land plants and promote the utilization of ferns for heightened environmental restoration, crop protection and human health.

Drought stress severely limits crop productivity in Brassica napus, yet strategies to enhance drought tolerance without compromising yield remain elusive. Here, we identify BnNAC038 as a negative regulator of drought responses in Brassica napus. CRISPR/Cas9-generated bnnac038 mutants exhibited improved drought survival, reduced water loss, and enhanced stomatal closure under drought conditions compared to wild-type (WT) plants. RNA-sequencing (RNA-seq) and DNA affinity purification sequencing (DAP-seq) analyses revealed that BnNAC038 directly represses drought-responsive genes, including BnSnRK2.6 (a key ABA signaling kinase), and genes involved in photosynthesis (BnPPC2) and gluconeogenesis (BnPGK). Field trials demonstrated that bnnac038 plants exhibit enhanced photosynthesis, accumulate more sucrose and glucose under drought, and exhibit increased biomass and seed yield compared to WT. Genetic interaction studies further showed that BnSnRK2.6 acts downstream of BnNAC038 to mediate drought tolerance. Our results indicate that targeted editing of BnNAC038 enhances drought tolerance while minimizing yield loss, providing a new strategy for developing drought-resilient Brassica napus varieties with minimal yield penalty.