生命科学最新文献

Flower color change, a common phenomenon that is important in pollination ecology, has intrigued scientists for decades. While previous flower color studies have mainly focused on color diversity among different plant species, our focus is on unraveling the mechanism of post-anthesis color change (PACC) and the molecular basis for its presence and absence, respectively, in two closely related species of Lotus, Lotus filicaulis and Lotus japonicus MG20. Metabolomic analysis reveals anthocyanins as the key metabolites responsible for the observed PACC. Differential expression of anthocyanin biosynthetic and transport genes causes the variation in PACC between the two Lotus species. Crucially, the significant upregulation of a functionally characterized MYB regulator, LfPAP1, is linked to the accumulation of anthocyanins and visible color alterations in L. filicaulis flowers. Notably, we uncover a nucleotide polymorphism in the initiation codon of LjPAP1. Although this mutation does not affect transcription, we show that it has a major effect in attenuating protein translation, reducing its capacity to activate anthocyanin biosynthesis, and leading to a failure of PACC in L. japonicus MG20. Our study sheds light on mechanisms of PACC phenomenon and highlights the potential for mutations in initiation sequences to generate phenotypic differences between species in evolution.

Polystyrene micro- and nanoplastics (MNPs) are increasingly found in terrestrial environments, posing risks across the food web. However, the potential impacts of MNPs transfer on plant-insect interactions remains largely unknown. In this study, consumption of willow plants (Salix maizhokunggarensis) exposed to 10.0 mg/L MNPs for 21 days inhibited survival and reduced body weight in Plagiodera versicolora larvae unlike those exposed to lower concentrations or shorter durations (0.1, 1.0 and 10.0 mg/L MNPs for 7 or 14 days). MNPs exposure increased lignin content and leaf thickness in willows, leading to decreased leaf consumption and increased mouthpart wear in P. versicolora larvae. Transcriptome and gut microbiota analyses revealed significant downregulation of genes related to digestion, intestinal homoeostasis, immunity, and growth/development along with profound alterations in gut microbiota composition. Notably, the abundance of the pathogenic bacterium Pseudomonas increased significantly. The gut barrier was disrupted, allowing gut bacteria to translocate into the haemolymph, accelerating larval mortality. Overall, MNPs altered plant physiology, making willow plants unsuitable for herbivore consumption and indirectly influenced herbivore survival by modulating gut bacteria. These findings offer novel insights into the cascading ecological effects and risks of MNPs, highlighting potential impacts on plant-herbivore interactions, biodiversity, and ecosystem health in terrestrial ecosystems.

Trait-based approaches offer valuable perspectives for vegetation classification, but functional traits struggle to capture resource allocation among competing plants, showing limitations across scales. This study aimed to introduce plant architecture to enhance trait-based vegetation classification. Based on a forest transect survey along China's eastern coast from 2021 to 2023, data from 32 plots of coastal dwarf forests (CDF), characterized primarily by reduced plant height, and normal noncoastal dwarf forests (NCDF) were obtained. Their community characteristics were quantified, and classification and clustering models assessed the advantages of plant architecture in distinguishing these communities. The results indicated plant architecture traits are more critical for distinguishing different community types than leaf-based functional traits. Additionally, plant architecture traits are effective in clustering plant associations within the same community type. Because plant architectural traits are closely linked to habitat, phylogeny and community structure, providing a comprehensive description of vegetation. In contrast, traditional plant functional traits primarily reflect habitat information related to soil nutrients. Our findings underscore the importance of plant architecture in optimizing trait-based vegetation classification and suggest that variations in the plasticity of plant architecture traits may support the classification of CDF as a distinct vegetation unit.

Small RNAs are involved in diverse cellular processes, including plant immunity to pathogens. Here, we report that miR158a negatively regulates plant immunity to the oomycete pathogen Phytophthora parasitica in Arabidopsis thaliana. By performing real-time quantitative PCR, transient expression, and RNA ligase-mediated 5' rapid amplification of cDNA ends assays, we demonstrate that miR158a downregulates AtTN7 expression by cleaving its 3'-untranslated region. AtTN7 positively affects plant immunity and encodes a truncated intracellular nucleotide-binding site and leucine-rich repeat receptor containing the Toll/interleukin-1 receptor. AtTN7 can degrade oxidized forms of nicotinamide adenine dinucleotide (NAD+). Further genetic and molecular analyses reveal that the Enhanced Disease Susceptibility 1-Phytoalexin Deficient 4-Activated Disease Resistance 1 complex is required for AtTN7-mediated immunity. ADR1-dependent Ca²⁺ influx is crucial for activating salicylic acid signaling to condition AtTN7-triggered immunity. Our study uncovers the immune roles and regulatory mechanisms of miR158a and its target AtTN7. Both miR158a-downregulation and AtTN7-overexpression lead to enhanced plant resistance to P. parasitica without affecting plant growth phenotypes, suggesting their application potentials and the utilization of miRNAs in identifying novel immune genes for the development of plant germplasm resources with enhanced disease resistance.

The transition from vegetative to reproductive growth is essential for the flowering process of plants. In summer chrysanthemum, CmBBX8 exploits prominence function in floral transition by activating the expression of CmFTL1. However, how CmBBX8 induces CmFTL1 during the photoperiod inductive cycles remains unknown. Here, we show that CmBBX8 interacts with the SGS3-like protein CmFDM2, and the CmFDM2 overexpression strains presented early flowering, while knockdown strains delayed flowering. Additionally, CmFDM2 could bind to the CmFTL1 promoter and activate the expression of CmFTL1, and associate with chromatin remodeling factor CmSWI3B, and CmBBX8 induces flowering dependent on CmFDM2 and CmSWI3B. CmFDM2 also partially depends on CmSWI3B. The CmSWI3B knockdown strains exhibited a significant late flowering phenotype. Interestingly, CmBBX8 also interacts with CmSWI3B. Moreover, the level of H3K27me3 at the CmFTL1 locus was reduced when CmBBX8 and CmFDM2/CmSWI3B occupied the locus to promote chrysanthemum flowering during the photoperiod inductive cycles, which was accompanied by the increasing level of CmFTL1 transcripts. Thus, our work provides novel insights into the gradually increasing level of CmFTL1 for the floral transition through CmBBX8 recruiting chromatin modifiers CmFDM2/CmSWI3B.

Stomata are fundamental to plant-water relations and represent promising targets to enhance crop water-use efficiency and climate resilience. Here, we investigated stomatal density (SD) variation in 269 apple accessions across 3 years (2019-2021), which demonstrated significant differences between accessions but consistency over time. We selected 2 subsets of 20 accessions, each with contrasting SD: high stomatal density (HSD; 370-500 mm^-2) and low stomatal density (LSD; 192-316 mm^-2). SD groups were compared in stomatal function, leaf physiology and crop productivity across two seasons (2021-2022). LSD had lower stomatal conductance (g_s) and higher intrinsic water-use efficiency in both years (p < 0.05). Hotter and drier conditions in 2022 reduced g_s similarly in both groups (-22% HSD, -21% LSD), but also created a difference in net carbon assimilation (A_net) that was not present in 2021 (HSD + 1.7 μmol CO₂ m^-2 s^-1, p < 0.05). LSD constraints on A_net were reflected in carbon isotope discrimination (δ¹³C, p < 0.001) and annual decline in fruit yield (-35%, p < 0.001). Our results demonstrate the suitability of SD as a trait to improve WUE, but also identifies a trade-off between water savings and productivity, which requires consideration for breeding.

In the accumulation response, chloroplasts move toward weak blue light (BL) to maximize photosynthetic efficiency; in the avoidance response, they move away from strong BL to reduce photodamage. The BL receptor kinase phototropin (phot) mediates these chloroplast relocation responses, and the chloroplast relocation response requires phot kinase activity. Upon receiving BL, phot undergoes autophosphorylation; however, the molecular mechanisms that regulate chloroplast relocation through phot autophosphorylation remain unclear. In this study, we conducted biochemical experiments using phot in the liverwort Marchantia polymorpha and revealed that phot employs cis-autophosphorylation under weak BL and both cis- and trans-autophosphorylation under strong BL. Inhibiting trans-autophosphorylation reduced phot autophosphorylation and suppressed the avoidance response, but not the accumulation response. These findings suggest that phot employs two modes of autophosphorylation to alternate between the accumulation and avoidance responses in plants.

Food security is fundamental to human capacity building and is crucial for sustainable global development. As the global population continues to surge, the demand for food production is increasingly strained, struggling to keep pace with nutritional needs. This challenge is exacerbated by climate change effects, including extreme weather events and natural disasters, leading to significant losses in both crop yield and arable land. In this article, we delve into the innovative strategies employed by plant researchers to enhance crop resilience and productivity. These efforts have led to the development of new crop varieties that boast adaptability to varying climatic conditions, improved resistance to diseases and herbicides, and significantly increased yields. Alongside genetic advancements, the article also highlights sustainable and smart agricultural practices that are pivotal in augmenting crop productivity. These practices include optimizing water resource management during irrigation and integrating modern informational and intelligent technologies in farmland management. By synthesizing these technological and methodological advances, this article proposes a comprehensive approach to addressing the pressing issues of food security. These solutions not only aim to meet the immediate food demands but also foster long-term sustainability in agricultural practices.

Acer rubrum, a famous ornamental tree, produces bright red-coloured leaves because of the temperature decline from summer to autumn. This process's molecular mechanism is elusive, so we have investigated how anthocyanin biosynthesis is induced in A. rubrum leaves under low temperatures. The results of low-temperature treatment under light and dark conditions showed that the low-temperature promoted anthocyanin accumulation in A. rubrum is light-dependent. The transcriptome analysis showed that ArMYB89 was significantly highly expressed in leaves of A. rubrum growing under low temperatures with light conditions. The findings from the Dap-seq analysis, yeast one hybridisation, electrophoretic mobility shift assay and luciferase reporter assay indicated that the ArMYB89 transcription factor binds directly to the promoter of ArUGT52 and stimulates its transcription. The co-expression of ArUGT52 with ArMYB89 significantly induced anthocyanin levels under low temperatures with light conditions. Enzyme activity analysis showed that ArUGT52 could convert Cyanidins and Pelargonidins into Cyanidin-3-O-glucoside and Pelargonidin 3-glucoside, which are considered the main anthocyanins in red colour leaves of A. rubrum. The results of yeast two hybridisation, pulldown assay and bimolecular fluorescence complementation experiment showed an interaction between COP1 and ArMYB89, while in vivo and in vitro protein ubiquitination assay demonstrated that ArCOP1 ubiquitinates ArMYB89. Notably, co-expression of ArCOP1 with ArMYB89 significantly reduced anthocyanin levels, while the virus-induced gene silencing of ArCOP1 significantly induced anthocyanin levels under low temperatures with light conditions. In conclusion, this work revealed the molecular mechanism regulating anthocyanin accumulation in the A. rubrum leaves under low temperatures.

Outside Front Cover: The cover image is based on the article Metabolic and Molecular Insights Into Nicotiana benthamiana Trichome Exudates: An Ammunition Depot for Plant Resistance Against Insect Pests by Jun-Xia Wang et al., https://doi.org/10.1111/pce.15135.