生命科学最新文献

Flowering represents a pivotal developmental transition stage in the life cycle of a plant, and the occurrence of flowering at the optimal time is critical for reproductive success. WRKY transcription factors play a vital role in a signaling network that governs a multitude of plant processes. Here, a gene, GhWRKY46, that was differentially expressed in early and late maturing materials was identified via association analysis, and it was specifically expressed in flower buds. Under natural light and temperature conditions, compared to Jin668, the flowering time of OE-GhWRKY46 plants was advanced by approximately 6 days, while the flowering time of CR-GhWRKY46 plants was delayed by approximately 8 days. Transcriptomic data indicated that overexpression or knockout of GhWRKY46 resulted in the activation or repression, respectively, of the photoperiod gene CO-Like and genes related to bud differentiation. Combined RNA-seq and DAP-seq analysis revealed that three genes, namely, GhCOL4, GhCOL2 and GhFPF1-like, may be expressed downstream of GhWRKY46. Dual-luciferase assays and electrophoretic mobility shift assays (EMSAs) demonstrated that GhWRKY46 could directly bind to the W-box and promote the expression of these genes. Similarly, GhFT was also found to be activated by GhWRKY46. Both in vivo and in vitro biochemical analyses demonstrated that GhWRKY46 interacted with GhGAI, and GhGAI could interfere with the transcriptional activation of GhWRKY46, which in turn inhibited the expression of GhCOL4, GhCOL2, GhFPF1-like, and GhFT. In conclusion, this study accurately predicted the GhWRKY46 binding motif, which is important for the construction of regulatory networks of the WRKY family in other crops and introduces a novel regulatory module for the flowering regulation pathway in cotton.

How plants adapt to shade and perform specific morphogenesis is one of the secrets of the kingdom, and unravelling the underlying molecular mechanisms is crucial. Scanning electron microscope results have revealed that a low R/FR ratio (indicating shade conditions) inhibited the cell wall thickness of parenchyma cells and sieve tube cells of Moso bamboo (Phyllostachys edulis). Xyloglucan Endotransglucosylase/hydrolase3 (PheXTH3) was identified as a circadian rhythm gene responsive to a low R/FR ratio by qRT-PCR analysis, and it showed peak activity in the vascular system. PheXTH3 enhanced interfascicular fibre cell wall thickening and lignin accumulation in stable transgenic Arabidopsis thaliana lines. A low R/FR ratio downregulated PheXTH3 expression, subsequently suppressing cell wall thickening in vessel and interfascicular fibre cells. Both Yeast One-Hybrid experiments and Dual-LUC assays revealed that WOX3b1, AP2-39, and XTH3 may form a regulatory pathway. Collectively, we proposed a WOX3b1-AP2-39-XTH3 molecular pathway mediated by the ratio of low R/FR, which may regulate the thickening of cell wall in Moso bamboo.

The ubiquitin-proteasome pathway modulates protein stability, which impacts plant responses to abiotic stresses, such as drought. Our previous study reported that the pepper GRAS-type transcription factor CaGRAS1 plays a positive role in drought resistance. However, the mechanism by which drought stress affects CaGRAS1 protein stability remains unknown. Here, we identified Capsicum annuum CaGRAS1-Interacting RING-type E3 ligase 1 (CaGIR1) through yeast two-hybrid analysis. The interaction between these two proteins was confirmed by both in vitro and in vivo assays, and interaction occurred in both the nucleus and cytoplasm, consistent with their subcellular localisation. In ubiquitination assays, CaGIR1 was shown to have ubiquitin E3 ligase activity, which is dependent on its RING domain. CaGIR1 also directly ubiquitinated CaGRAS1 in vitro and in vivo, and CaGRAS1 protein stability negatively correlated with CaGIR1 expression levels. In contrast to CaGRAS1, CaGIR1 was found to play a negative role in drought resistance. Phenotypic assays revealed that the silencing of CaGIR1 in pepper resulted in enhanced drought resistance through the modulation of stomatal responses and drought-responsive marker gene expression, whereas CaGIR1 overexpression led to the opposite results in Arabidopsis. Overall, our findings suggest that CaGIR1 negatively modulates ABA and drought responses by triggering CaGRAS1 protein degradation.

Scientific public engagement activities and participation in bioscience discussions need to be open to everyone, as they play a significant role in connecting the general public to research and breaking down barriers of scientific skepticism. In a society increasingly shaped by scientific progress, it is crucial that everyone, regardless of their background or ability, feels empowered to participate in these conversations. However, this is not usually the case for blind or low-vision communities who are often excluded, in part due to scientific outreach events being historically limited to visual imagery. To break down such barriers, we organized a multisensory exhibition as part of the Cambridge Festival 2024. The initiative was inspired by Monash Sensory Science, a targeted outreach program designed to engage individuals who are blind, have low vision or diverse needs. Our aim was to use novel, tactile and informative models to explore the role of the immune system in the central nervous system health and disease, focusing on two inflammation models: traumatic brain injury and multiple sclerosis. In Sensory Science, we fostered the involvement of the blind and low-vision community through tactile scientific posters, resin and plaster brain models, and interactive experiences involving heat, sound, tactile poetry and photography. The Sensory Science exhibition held during March 2024 not only promoted equality but also reminded us that true innovation lies in the collective efforts of a diverse and inclusive community.

Legume plants commonly associate with both arbuscular mycorrhizal (AM) fungi and rhizobia and thus enhance the acquisition of phosphorus (P) and nitrogen (N) nutrition. Inoculation with AM fungi can promote nodulation and N₂ fixation of legume plants; however, the underlying mechanisms remain poorly understood. Here, root exudates collected from AM-colonised soybean plants showed greater accumulation of the specific flavonoids (daidzein and genistein) and phenolic acids (benzoic acid and p-Hydroxybenzoic acid), and significantly promoted nodulation. Furthermore, the exudates from AM-colonised roots and the derived specific flavonoids and phenolic acids effectively increased rhizobial growth, chemotaxis, biofilm formation. Addition of the specific synthetic root exudates enhanced nodulation and N₂ fixation, and expression of the core nodulation genes in soybean. Overexpression of a phenylalanine ammonia-lyase gene, GmPAL2.4 markedly upregulated the expression of the genes related to the biosynthesis of daidzein, genistein, benzoic acid, and p-Hydroxybenzoic acid, and increased accumulation of these specific flavonoids and phenolic acids in the transgenic plants, thus enhancing nodulation and N₂ fixation. In summary, we demonstrated a crucial role of specific flavonoids and phenolic acids induced by AM symbiosis in promoting rhizobium-host symbiosis. This offers a pathway for improving symbiotic efficiency through the use of specific synthetic compounds.

Limonium bicolor is a typical recretohalophyte with specialised salt glands that secrete excessive Na⁺ out of the plant. The detailed mechanisms of salt gland development and salt resistance are largely unclear. Here, we investigated the function of the importin-β protein LbSAD2 from L. bicolor. Lines with silenced LbSAD2 expression showed significantly lower salt gland density, salt-secretion ability and salt resistance, whereas LbSAD2 overexpression lines had a greater number of salt glands with an abnormal distribution in the abaxial and leaf adaxial surfaces. A previously uncharacterised hydrophobic protein, Lb2G12077, can bind to the LbSAD2 promoter to inhibit the transcription of LbSAD2 verified by a yeast one-hybrid, electrophoretic mobility shift and dual-luciferase reporter assay. Further functional validation revealed that Lb2G12077 demoted salt gland development and salt resistance of L. bicolor. Moreover, a yeast two-hybrid, bimolecular fluorescence complementation and GST pull-down assays indicated that the hypothetical protein Lb2G12567 interacts with LbSAD2, whose silenced lines also showed significantly reduced salt gland density, salt-secretion ability and salt resistance, suggesting Lb2G12567 played a similar positive role in salt resistance. The current LbSAD2 pathway sheds light on salt gland development and salt resistance in L. bicolor, laying the foundation for increasing salt tolerance in crops.

Ethylene-responsive transcription factors (ERFs) were widely found to participate in cold response in plants. But the underlying regulatory mechanism of each cold-induced ERFs remains to be elucidated. Previously, we identified VaERF057 as a cold-induced gene in Vitis amurensis, a cold-hardy wild Vitis species. Here we found that overexpression of VaERF057 (VaERF057-OE) enhanced the freezing tolerance of V. amurensis roots. While VaERF057 knockdown tissues show decreased cold tolerance than control. DAP-seq combined with transcriptome data (VaERF057-OE roots) allowed to identify VaFBA1 (fructose-1,6-bisphosphate aldolase) as a downstream target of VaERF057. VaERF057 can bind to the VaFBA1 promoters and activate its expression. VaERF057-OE roots show increased expression of VaFBA1 and high content of soluble sugar than the control, whereas VaERF057 knockdown tissues showed opposite changes. Results from OE and knockdown material also support the role of VaFBA1 in regulating soluble sugar content and cold tolerance in grapevines. Furthermore, cold-induced expression of VaERF057 was found to be regulated by ethylene-insensitive3-1 (VaEIN3.1). Overexpression of VaEIN3.1 enhanced the transcription of VaERF057 and VaFBA1, the content of soluble sugar and cold tolerance in grapevine. VaEIN3.1 knockdown tissues show opposite trends when compared to VaEIN3.1-OE lines. Together, these results suggested a positive contribution of VaEIN3.1-VaERF057-VaFBA1 module in response to cold stress in grapevine.

Hypoxia is one of the main challenges in apple (Malus domestica) cultivation. However, breeding hypoxia-tolerant cultivars demands a thorough understanding of the responses of apple trees to low oxygen supply. Studies have indicated that N⁶-methyladenosine (m⁶A) reader regulates plant stress response by binding to their corresponding mRNA targets with m⁶A modification. The present study investigated the function and mechanism of apple m⁶A reader MhYTP2 under hypoxia stress. Here, we found that the overexpression of MhYTP2 improved hypoxia resistance in apple. Previous RNA immunoprecipitation sequencing (RIP-seq) results identified the mRNA of Ethylene Response Factor 54 (ERF54) as a direct target of MhYTP2; electronic mobility shift assays (EMSA) further verified this finding. Further transcription inhibition assays demonstrated that MhYTP2 increased MdERF54 mRNA stability. Under hypoxia stress, MdERF54 increased the activities of pyruvate decarboxylase (PDC), lactate dehydrogenase (LDH), and alcohol dehydrogenase (ADH) the key enzymes in anaerobic respiration pathway, activated the ethylene signalling pathway, increased the chlorophyll content of plant leaves and photosynthetic rates, enhanced the adaptability of roots, reduced the damage to biofilm and antioxidant system, and enhanced the antioxidant capacity. Thus, our results elucidated the molecular mechanisms by which the MhYTP2-MdERF54 module influences the response of the apple to hypoxia stress.

Climate change projections predict warming and increased weather variability, mainly in polar regions, altering freeze-thaw patterns. However, the effects of rising temperatures and more frequent freeze-thaw events on the water and CO₂ management of Antarctic plants remain unclear. To address this, we conducted a laboratory experiment to investigate how growth temperature (5°C and 15°C) and successive freeze-thaw cycles influence the hydraulic and photosynthetic performance of Deschampsia antarctica (D. antarctica) and Colobanthus quitensis (C. quitensis). Our results showed that warmer conditions improved hydraulic and photosynthetic performance in both species, driven by anatomical adjustments in leaf xylem vessels. Additionally, plants exposed to successive freeze-thaw cycles exhibited a coordinated decline in whole-plant hydraulic conductivity and leaf gas exchange, regardless of growth temperature. The magnitude of changes (%) in photosynthetic traits after freeze-thaw cycles varied between species, with D. antarctica showing similar responses at both growth temperatures, while C. quitensis experienced more pronounced changes at the lower temperature. Overall, these findings suggest that while Antarctic plants benefit from warmer temperatures, repeated freeze-thaw events could disrupt their hydraulic balance and limit photosynthesis, particularly under natural environmental conditions.