Plant, Cell & Environment最新文献

The application of microbial inoculants holds promise for the sustainable restoration of abandoned mine sites by affecting soil nutrients and microbial communities. However, the responses of plant microbial communities to microbial inoculants in mine restoration remain largely unknown. To bridge this knowledge gap, we conducted a 4-year field experiment at an abandoned carbonate mine site to assess the impacts of microbial inoculants on the soil-plant microbiome. Our findings revealed that microbial inoculants significantly changed roots, fine root bacterial and fungal communities. Further, no significant correlations were observed between the soil-plant nutrient content (Z-score) and microbial alpha diversity. However, a significantly positive correlation was found between the relative abundance of the keystone ecological cluster (Module #1) and soil-plant nutrient content. The application of microbial inoculants also increased complexity, albeit decreased stability of plant microbiome networks, alongside a reduction in stochastic assembly. Conversely, they decreased the complexity but increased the stability of soil microbiome networks, accompanied by an increase in stochastic assembly. Notably, the number of specifically enriched microbiome functional traits of roots and root nodules under the microbial inoculant treatments surpassed that of the control. In summary, our findings underscored the potential of microbial inoculants to enhance soil-plant functionality at abandoned mine restoration sites.

Warm temperatures accelerate plant growth, but the underlying molecular mechanism is not fully understood. Here, we show that increasing the temperature from 22°C to 28°C rapidly activates proliferation in the apical shoot and root meristems of wild-type Arabidopsis seedlings. We found that one of the central regulators of cell proliferation, the cell cycle inhibitor RETINOBLASTOMA-RELATED (RBR), is suppressed by warm temperatures. RBR became hyper-phosphorylated at a conserved CYCLIN-DEPENDENT KINASE (CDK) site in young seedlings growing at 28°C, in parallel with the stimulation of the expressions of the regulatory CYCLIN D/A subunits of CDK(s). Interestingly, while under warm temperatures ectopic RBR slowed down the acceleration of cell proliferation, it triggered elongation growth of post-mitotic cells in the hypocotyl. In agreement, the central regulatory genes of thermomorphogenic response, including PIF4 and PIF7, as well as their downstream auxin biosynthetic YUCCA genes (YUC1-2 and YUC8-9) were all up-regulated in the ectopic RBR expressing line but down-regulated in a mutant line with reduced RBR level. We suggest that RBR has both canonical and non-canonical functions under warm temperatures to control proliferative and elongation growth, respectively.

Plant organs harbour diverse components that connect their physiology to the whole organism. The turnover of metabolites may be higher in some organs than in others, triggering differential growth patterns throughout the organism. We revealed that Solanum lycopersicum exhibits more coordinated growth and physiology across the entire plant compared to wild tomato species. Specifically, young leaves of S. lycopersicum develop more slowly than mature leaves, whereas wild species do not exhibit this pattern. Wild tomato Solanum pennellii displays young leaves with higher photosynthetic rates than mature leaves. Consequently, sucrose metabolism in S. pennellii is quite similar between young and mature leaves, while expression patterns of circadian clock genes differ significantly between leaves of different ages. Additionally, we demonstrated that introducing alleles related to tomato domestication into the wild tomato Solanum pimpinellifolium promotes coordinated growth between young and mature leaves, resulting in similar patterns to those observed in S. lycopersicum. Collectively, S. lycopersicum appears to exhibit more coordinated regulation of growth and metabolism, and understanding this process is likely fundamental to explaining its elevated harvest index.

Nitrogen is a crucial macroelement essential for plant growth and development. In Arabidopsis Thaliana, classical phytohormones such as auxin and cytokinin orchestrate local and systemic signalling networks coordinate plant growth and development in response to nitrogen deficiency. Nowadays, emerging signalling pathways involving small peptides like CLAVATA3/EMBRYO SURROUNDINGR REGION (CLE) and C-TERMINALLY ENCODED PEPTIDE (CEP) and their corresponding kinase receptors, also regulate Arabidopsis' adaptation to nitrogen scarcity. Unlike Arabidopsis, which adapts to nitrogen deficiency by changing root development, legumes have the unique ability to form nitrogen-fixing root nodules through symbiotic interactions with soil rhizobia. During the symbiotic nodulation in Medicago, CLE and CEP peptides and their receptors consist of an autoregulatory network governing the number of nodules in accordance with the soil nitrogen level. Additionally, other plant peptides, such as phytosulfokine (PSK) and root meristem growth factors (RGF), have been identified as new regulators of leguminous root nodule development under nitrogen-limited condition. However, the precise mechanism by which these peptides coordinate nitrogen deficiency response and the development of nitrogen-fixing organs remains to be fully elucidated. This review summarises the adaptive strategies of dicotyledons to nitrogen deficiency, with a particular focus on the regulation of Medicago nitrogen-fixing nodule development by the peptides.

Peach Leaf Curl Disease, caused by Taphrina deformans, is characterized by reddish hypertrophic and hyperplasic leaf areas. To comprehend the biochemical imbalances caused by the fungus, dissected symptomatic (C) and asymptomatic areas (N) from leaves with increasing disease extension were analyzed by an integrated approach including metabolomics, lipidomics, proteomics, and complementary biochemical techniques. Drastic metabolic differences were identified in C areas with respect to either N areas or healthy leaves, including altered chloroplastic functioning and composition, which differs from the typical senescence process. In C areas, alteration in redox-homoeostasis proteins and in triacylglycerols content, peroxidation and double bond index were observed. Proteomic data revealed induction of host enzymes involved in auxin and jasmonate biosynthesis and an upregulation of phenylpropanoid and mevalonate pathways and downregulation of the plastidic methylerythritol phosphate route. Amino acid pools were affected, with upregulation of proteins involved in asparagine synthesis. Curled areas exhibited a metabolic shift towards functioning as a sink tissue importing sugars, probably from N areas, and producing energy through fermentation and respiration and reductive power via the pentose phosphate route. Identifying the metabolic disturbances leading to disease symptoms is a key step in designing strategies to prevent or delay the progression of the disease.

Cold stress can limit the growth and development of grapevines, which can ultimately reduce productivity. However, the mechanisms by which grapevines respond to cold stress are not yet fully understood. Here, we characterized an APETALA2/ethylene response factor (AP2/ERF) which was shown to be a target gene of our previously identified VaMYB4a from Amur grape. We further investigated the molecular interactions between VaMYB4a and VaERF054-like transcription factors in grapes and their role in cold stress tolerance. Our results demonstrated that VaMYB4a directly binds to and activates the VaERF054-like gene promoter, leading to its enhanced expression. Moreover, we also explored the influence of ethylene precursors and inhibitors on VaERF054-like expression and grape cold tolerance. Our findings indicate that VaERF054-like contribute to cold tolerance in grapes through modulation of the ethylene pathway and the CBF signal pathway. Overexpression of VaERF054-like in Vitis vinifera 'Chardonnay' calli and transgenic grape lines resulted in increased freezing stress tolerance, confirming its role in the cold stress response. We further confirmed the interaction between VaMYB4a and VaERF054-like in vivo and in vitro. The co-transformation of VaMYB4a and VaERF054-like in grape calli demonstrates a synergistic interaction, enhancing the cold tolerance through a regulatory feedback mechanism. Our finding provides new insights into grape cold tolerance mechanisms, potentially contributing to the development of cold-resistant grape varieties.

Phenotypic plasticity is the property of a genotype to produce different phenotypes under different environmental conditions. Understanding genetic and environmental factors behind phenotypic plasticity helps answer some longstanding biology questions and improve phenotype prediction. In this study, we investigated the phenotypic plasticity of flowering time and plant height with a set of diverse sorghum lines evaluated across 14 natural field environments. An environmental index was identified to quantitatively connect the environments. Reaction norms were then obtained with the identified indices for genetic dissection of phenotypic plasticity and performance prediction. Genome-wide association studies (GWAS) detected different sets of loci for reaction-norm parameters (intercept and slope), including 10 new genomic regions in addition to known maturity (Ma1) and dwarfing genes (Dw1, Dw2, Dw3, Dw4 and qHT7.1). Cross-validations under multiple scenarios showed promising results in predicting diverse germplasm in dynamic environments. Additional experiments conducted at four new environments, including one from a site outside of the geographical region of the initial environments, further validated the predictions. Our findings indicate that identifying the environmental index enriches our understanding of gene-environmental interplay underlying phenotypic plasticity, and that genomic prediction with the environmental dimension facilitates prediction-guided breeding for future environments.

Actin depolymerizing factors (ADFs), like other actin-binding proteins (ABPs), are modified by phosphorylation to regulate the dynamics of the actin filaments, thereby functioning in various processes throughout the plant lifecycle. In this study, we found that the Arabidopsis thaliana cytoplasmic kinase AGC1.7 interacts with ADF7 in vitro and in vivo. AGC1.7 phosphorylates ADF7 at its Ser-6, Ser-103 and Ser-104 residues in vitro, while replacing these residues with alanine promotes ADF7-mediated actin depolymerization in vitro. Expression of the phosphorylation-mimetic mutant protein ADF7^S6/103/104D driven by the pollen-specific LAT52 promoter fully rescues the defects in germination rate, silique length and seeds per silique in both adf7-2 and agc1.5 agc1.7 (agcdm) mutants. Our data establish a model whereby AGC1.7-mediated ADF7 phosphorylation plays an important role in pollen germination and pollen tube growth.

Salt stress is the main factor limiting the large-scale cultivation of Shanxin poplar; therefore, improving its salt tolerance is crucial. In this study, we identified and characterized a CRF gene (PdbCRF5) in Shanxin poplar. Compared with the wild-type poplar, the Shanxin poplar overexpressing PdbCRF5 were more sensitive to salt stress. The PdbCRF5-silenced plants exhibited improved salt tolerance. ChIP‒PCR, EMSA, and Y1H confirmed that PdbCRF5 can regulate the expression of the PdbbZIP61 by binding to ABRE element. Further analysis revealed that the overexpression of PdbbZIP61 can reduce cell damage by increasing ROS scavenging, and on the other hand, overexpression of PdbbZIP61 can improve the salt tolerance of Shanxin poplar by regulating the expression of the PdbNCED genes to increase the ABA content. In addition, we also demonstrated that PdbCRF5 can inhibit the expression of the PdbbZIP61 in combination with PdbCRF6. The overexpression of PdbCRF6 also reduced the salt tolerance of Shanxin poplar. Therefore, we found that PdbCRF5 negatively regulates the salt tolerance of Shanxin poplar by inhibiting the PdbbZIP61, indicating that PdbCRF5 plays an important role in the tolerance of Shanxin poplar to salt stress and is an important candidate gene for gene editing and breeding in forest trees.