Environmental and Experimental Botany最新文献

{"title":"Absorption and partitioning mechanism of nitrogen oxides by typical greening species of tree in Beijing","authors":"Shaowei Lu ,&nbsp;Mengxue Wang ,&nbsp;Jiaxing Fang ,&nbsp;Junjie Zhang ,&nbsp;Xiaotian Xu ,&nbsp;Bin Li ,&nbsp;Qin Zhang ,&nbsp;Chen Liu ,&nbsp;Na Zhao ,&nbsp;Shaoning Li","doi":"10.1016/j.envexpbot.2024.106028","DOIUrl":"10.1016/j.envexpbot.2024.106028","url":null,"abstract":"<div><div>In this study, we analyzed the uptake of nitrogen dioxide (NO₂) and its processes of distribution in various organs of different typical greening species of trees and the differences in its uptake by these different species using the ¹⁵N stable isotope tracer method under the gradient of three NO₂ concentration treatments, namely, low, medium and high. These experiments were conducted using one-time artificial fumigation to provide necessary data and theoretical support for the selection and application of species of greening trees in urban gardens. The treatments of fumigation with different concentrations of NO₂ showed that the leaves of the six species of trees had the highest content of ¹⁵N. The organs that were the most effective at taking up ¹⁵N were the leaves in broadleaf trees and the branches in conifers. The content of ¹⁵N per unit of the leaves (0.0058–2.0486 μg/g) increased in parallel with the concentration of fumigant and then was rapidly transported to various organs in the tree. This caused different degrees of changes in other organs. The total content of ¹⁵N per unit was higher in the broadleaf species (0.0129–2.3171 μg/g) than in the conifers (0.0296–0.1260 μg/g). The leaves of broadleaf trees were the most effective at taking up ¹⁵N (0.0054–1.3228 %) under medium and high concentrations of fumigant with the exception of ginkgo. The ability of each organ of the other broadleaf species was leaves&gt;branches&gt;trunks&gt;roots, and the branches of conifers were the most effective parts of the trees at taking up NO₂ under three concentrations of fumigants (0.0789–0.4005 %). The highest rate of distribution of ¹⁵N was found in the leaves (48.14–99.53 %) in all six species under different concentrations of fumigant, and the distribution in the other organs varied to different degrees.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106028"},"PeriodicalIF":4.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen regulated reactive oxygen species metabolism of leaf and grain under elevated temperature during the grain-filling stage to stabilize rice substance accumulation","authors":"Yufei Zhao ,&nbsp;Yigong Zhao ,&nbsp;Yuxuan Peng ,&nbsp;Yiqian Sun ,&nbsp;Dengying Zhang ,&nbsp;Chen Zhang ,&nbsp;Xuan Ran ,&nbsp;Yingying Shen ,&nbsp;Wenzhe Liu ,&nbsp;Yanfeng Ding ,&nbsp;She Tang","doi":"10.1016/j.envexpbot.2024.106037","DOIUrl":"10.1016/j.envexpbot.2024.106037","url":null,"abstract":"<div><div>Rational additional nitrogen is an important agronomic measure to cope with the adverse effects of warming on rice production. However, the mechanism by which nitrogen mitigated the adverse impact of substance accumulation due to elevated temperature is poorly clarified. Therefore, in this study, a field warming experiment during grain filling and 60 kg·ha⁻¹ of additional nitrogen was established. Under elevated temperature, panicle temperature was higher and increased more substantially than leaf temperature. However, nitrogen application did not significantly reduce the leaf, panicle, and canopy temperatures. Additional nitrogen under elevated temperature delayed the decline of chlorophyll, maintained leaf photosynthesis, and prolonged grain-filling period to alleviate the decrease of starch due to warming. Hydrogen peroxide (H₂O₂) was sensitive to elevated temperature in leaves and grains. However, application of nitrogen under elevated temperature improved the activity of antioxidant enzymes to mitigate the increase of H₂O₂, resulting in a 30.31 % and 45.33 % decrease of H₂O₂ in leaves and grains compared to elevated temperature, respectively. Elevated temperature promoted the expression of heat-responsive genes, especially <em>HSP16.9</em> and <em>HSP26.7</em>, which were consistently increased in response to warming at 5–30d after flowering. In addition, the expression of <em>HSP16.9</em> at 5d and 10d after flowering and <em>HSP26.7</em> at 10d after flowering was further increased with nitrogen application under elevated temperature. Therefore, HSP may be the key regulator of grain response to warming with additional nitrogen under elevated temperature. In conclusion, the relevant results revealed the physiological mechanism of nitrogen to guarantee substance accumulation and provided new ideas for cultivation measures to protect against the likely scenario of global warming.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"229 ","pages":"Article 106037"},"PeriodicalIF":4.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Foliar flavonoids across an elevation gradient: Plasticity in response to UV, and links with floral pigmentation patterning","authors":"Matthew H. Koski ,&nbsp;Elizabeth Leonard ,&nbsp;Nishanth Tharayil","doi":"10.1016/j.envexpbot.2024.106036","DOIUrl":"10.1016/j.envexpbot.2024.106036","url":null,"abstract":"<div><div>Metabolites produced in the flavonoid biosynthetic pathway (FBP) mitigate abiotic stress caused by factors such as ultraviolet (UV) light. Testing whether constitutive flavonoid production or flavonoid plasticity differ between populations spanning ecological gradients can reveal whether geographic patterns are consistent with local adaptation. Abiotic induction of flavonoids can occur in leaves as well as flowers where flavonoids influence UV color patterns perceived by pollinators. Assessing how foliar flavonoids are associated with floral color phenotypes can shed light on how pleiotropy affects biochemical phenotypes across tissues. We exposed <em>Argentina anserina</em> (Rosaceae) plants from alpine and lower elevation populations to low and high levels of UV and measured foliar and petal flavonoid production using UHPLC coupled mass spectrometry. We associated foliar flavonoid abundance with petal flavonoid abundance, and the size of the UV absorbing petal area (‘UV bullseye’). We found that total foliar flavonoids increased in response to UV due to flavonol upregulation, but only one class of flavonols, fisetin, exhibited stronger plasticity in alpine populations. Alpine populations tended to increase the quercetin-kaempferol ratio more than low elevation populations when exposed to higher UV, a signature of photoprotection and radical scavenging. Relationships between foliar flavonoids and the floral UV bullseye differed between alpine and low elevation populations. Previous work showed kaempferol glycosides contributed to variation in UV bullseye size at high elevation, while non-kaempferols spanning multiple FBP branches were associated with bullseye size at low elevation. Here, we found that alpine plants with less foliar kaempferol and greater kaempferol allocation to petals than leaves had larger floral UV-bullseyes, suggesting that floral UV patterning may be shaped by a biochemical tradeoff between tissues. Overall, nuanced elevational differences in flavonoid plasticity revealed by detailed metabolite classification provided support for local adaptation. Additionally, our study highlights that flavonoid production in leaves could influence the evolution of flavonoid-based floral phenotypes.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106036"},"PeriodicalIF":4.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors determining the invasion pattern of Ageratina adenophora Spreng. in Kumaun Himalaya India","authors":"Bhawna Negi ,&nbsp;Kavita Khatri ,&nbsp;Surendra Singh Bargali ,&nbsp;Kiran Bargali","doi":"10.1016/j.envexpbot.2024.106027","DOIUrl":"10.1016/j.envexpbot.2024.106027","url":null,"abstract":"<div><div>Factors such as topography, soil composition, and nutrient availability significantly influence the density patterns of <em>Ageratina adenophora</em>. Understanding these dynamics addresses a gap in our knowledge of the species' adaptive mechanisms in mountainous regions. Furthermore, the impact of habitat features along road corridors on the population dynamics of invasive plants remains underexplored, particularly regarding the effects of disturbance levels, light availability, and soil properties on their establishment. A species-specific rapid ecological assessment was conducted using stratified random sampling, with parallel transects of 50 × 2 m established in triplicates at 20 m intervals. This resulted in 43 main transects across the identified plots and 67 parallel transects in adjacent habitats. The number of individuals of <em>A. adenophora</em> and its clumps were recorded from each quadrat. Chemical and physical parameters of soil were measured for soil collected from 0 to 15 cm depth. Linear Mixed Model analysis revealed a significant negative effect of elevation (p&lt;0.05) on the density of clumped individuals (Estimate: −0.31, t-value: −3.05), total individuals (Estimate: −0.27, t-value: −2.61), and clump number (Estimate: −0.30, t-value: −4.78). Western aspect also showed a significant decrease (p&lt;0.05) in clumped individuals (Estimate: −1.83, t-value: −2.80), total individuals (Estimate: −2.24, t-value: −3.47), and clump number (Estimate: −0.81, t-value: −1.97). Total <em>A. adenophora</em> density was highest near settlements (133 ind. m², Estimate: 1.19) and grasslands (103 ind. m², Estimate: 1.16), but lowest in broadleaf forests (26 ind. m²). Density decreased significantly with increasing distance from road verges (Estimate: −0.24, t-value: −2.34). Soil moisture content positively influenced total individuals (Estimate: 0.19, t-value: 2.75), clumped individuals (Estimate: 0.23, t-value: 3.20), clump numbers (Estimate: 0.05, t-value: 1.09), and individuals per clump (Estimate: 0.37, t-value: 3.28). Available nitrogen positively influenced non-clumped individuals (Estimate: 0.17, t-value: 2.04) but negatively affected individuals per clump (Estimate: −0.25, t-value: −2.21), indicating that lower nitrogen levels correlate with higher individual density per clump. Hence, effective restoration efforts are needed including soil improvement, invasive species removal and control, and the planting of native species.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106027"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Saline-alkaline conditions altered Bolboschoenus planiculmis carbon and nitrogen allocation tradeoffs","authors":"Jingyao Wang,&nbsp;Fengxue Shi,&nbsp;Liu Yang,&nbsp;Haibo Jiang,&nbsp;Yong Wang,&nbsp;Chunguang He","doi":"10.1016/j.envexpbot.2024.106032","DOIUrl":"10.1016/j.envexpbot.2024.106032","url":null,"abstract":"<div><div>Soil salinization is an important factor that limits global agricultural production, specifically limiting the effectiveness of nitrogen-carbon resources and inhibiting plant growth. However, previous observations have focused on resource allocation, and there is little information about the coordination of carbon-nitrogen acquisition, allocation, and regulatory processes. We performed glasshouse pot experiments under different saline-alkaline conditions, and we measured 66 above- and belowground functional traits of <em>Bolboschoenus planiculmis</em>, to examine carbon-nitrogen resource acquisition and allocation strategies and their driving processes. Saline-alkaline conditions shifted <em>B. planiculmis</em> root-leaf functional traits toward a more acquisitive phenotype. Under low saline-alkaline conditions, although the root-leaf economic strategy inhibited resource acquisition efficiency, the opportunistic carbon-nitrogen capture and allocation strategy contributed to the maintenance of normal growth. However, highly saline-alkaline conditions led to the early enrichment of carbon-nitrogen resources in the corm. Additionally, saline-alkaline conditions altered the importance of physiological and biochemical processes in the carbon and nitrogen allocation regulatory network. In summary, <em>B. planiculmis</em> uses an opportunistic resource acquisition strategy under saline-alkaline conditions and a salt-avoidance allocation strategy under highly saline-alkaline conditions. This approach enables the maintenance of growth dominance under saline-alkaline conditions via gradient resource utilization.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106032"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inoculation with multifunctional Bacillus sp. NEAU-DCB1-2 mitigates chromium toxicity in pakchoi (Brassica rapa ssp. chinensis) through a multi-level mechanism","authors":"Lifeng Guo ,&nbsp;Dandan Du ,&nbsp;Tingting Li ,&nbsp;Ling Ling ,&nbsp;Wenshuai Song ,&nbsp;Xiaoyan Yu ,&nbsp;Junlei Zhao ,&nbsp;Wensheng Xiang ,&nbsp;Junwei Zhao","doi":"10.1016/j.envexpbot.2024.106026","DOIUrl":"10.1016/j.envexpbot.2024.106026","url":null,"abstract":"<div><div>Soil chromium (Cr) accumulation is escalating, severely hindering plant growth and development. Plant growth-promoting bacteria (PGPB) have shown potential in enhancing plant tolerance to heavy metals. However, the role and mechanisms of Cr(VI)-reducing PGPB strains in improving the growth of pakchoi under Cr toxicity remain unclear. This study aimed to isolate a Cr(VI)-reducing PGPB strain from Cr-contaminated soil, evaluate its effect on pakchoi growth under Cr(VI) stress, and investigate the mechanisms involved. Our findings showed that <em>Bacillus</em> sp. NEAU-DCB1–2 effectively reduce Cr(VI) to Cr(III) and produced indole-3-acetic acid and siderophores. Under Cr(VI) stress, inoculation with NEAU-DC1–2 significantly promoted seed germination and early growth of pakchoi. In pot experiments, NEAU-DCB1–2 significantly increased biomass accumulation, plant height, and root length of Cr(VI)-treated pakchoi seedlings, while reducing the Cr(VI) content in root, shoot and soil. Moreover, NEAU-DCB1–2 greatly increased catalase, superoxide dismutase, peroxidase, and ascorbate peroxidase activities in seedlings under Cr(VI) stress, thereby reducing malondialdehyde content. Transcriptome analysis indicated substantial alterations in gene expression patterns after inoculation with NEAU-DCB1–2 under Cr(VI) stress. Further analyses revealed that NEAU-DCB1–2 mainly affected the responses of antioxidant system, metal chelation and transport, together with auxin, abscisic acid, and jasmonic acid signaling to Cr(VI) stress. Conclusively, the Cr(VI)-reducing PGPB strain NEAU-DCB1–2 significantly enhances the growth and Cr tolerance of pakchoi through multiple mechanisms, offering a valuable microbial resource for mitigating the adverse effects of heavy metal contamination in agricultural soils on the yield and safety of vegetable crops.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106026"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-wide identification of shaker K+ channel gene family in sugar beet (Beta vulgaris L.) and function of BvSKOR in response to salt and drought stresses","authors":"Ya-Dan Hu ,&nbsp;Pan-Pan Ren ,&nbsp;Ming Wei ,&nbsp;Henri Batoko ,&nbsp;Guo-Qiang Wu","doi":"10.1016/j.envexpbot.2024.106034","DOIUrl":"10.1016/j.envexpbot.2024.106034","url":null,"abstract":"<div><div>Potassium (K⁺) is the most abundant cation in plants, which is absorbed by roots and distributed throughout the plants and within plant cells, and is involved in various cellular processes. Shaker K⁺ channel plays crucial roles in the absorption and distribution of K⁺ and in the response to abiotic stress in plants. Herein, a total of six shaker K⁺ channel genes, <em>BvKAT1</em>, <em>BvKAT3</em>, <em>BvAKT1</em>, <em>BvAKT2</em>, <em>BvAKT5</em>, and <em>BvSKOR</em>, were identified in the genome of sugar beet (<em>Beta vulgaris</em> L.). The coding domain sequences (CDS) of these genes ranged from 2232 to 2739 bp, and protein lengths were varied from 743 to 912 aa. The shaker K⁺ channel genes contained hormone-related and light responsiveness <em>cis</em>-acting regulatory elements. The phylogenetic analysis showed that BvSKOR was highly conserved and contained six transmembrane structures. The expression patterns of <em>BvSKOR</em> under salt and osmotic stress were analyzed by qRT-PCR, and found that the expression level of <em>BvSKOR</em> under low concentration salt and osmotic stress at short period of treatment were significantly higher than that of the control group. The function of <em>BvSKOR</em> was further verified in tobacco (<em>Nicotiana tabacum</em>), and the results showed that under salt and osmotic stress, the roots of transgenic plants were significantly stronger than those of wild type (WT) plants, and the relative water content (RWC), chlorophyll, proline, soluble sugar, soluble proteins contents and antioxidant enzyme activity were significantly higher than those of WT plants. These results indicated that overexpression of <em>BvSKOR</em> can significantly enhance the salt and drought tolerance in transgenic tobacco plants. This study could provide theoretical support and genetic resources for genetic improvement of crops stress resistance.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106034"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological, physiological, and biochemical responses of rice (Oryza sativa L.) varieties to drought stress via regulating respiration and ROS metabolism during germination","authors":"Yangmengfei She ,&nbsp;Xiaorong Bai ,&nbsp;Xuping Lu ,&nbsp;Weifang Min ,&nbsp;Tinglu Liao ,&nbsp;Lei Tian ,&nbsp;Peifu Li ,&nbsp;Chengke Luo","doi":"10.1016/j.envexpbot.2024.106031","DOIUrl":"10.1016/j.envexpbot.2024.106031","url":null,"abstract":"<div><div>Germination marks a pivotal and sensitive phase in the life cycle of crops, with drought stress, precipitated by water scarcity, posing a significant impediment to the germination process in rice. Despite this, the regulation mechanism of respiratory and reactive oxygen species (ROS) metabolism during rice germination under drought stress remains to be fully elucidated. This manuscript presents an integrative analysis encompassing morphological, physiological, biochemical, and molecular attributes of germinated seeds from a cultivated drought-sensitive rice variety (JN10) and a drought-resistant rice variety (NG36). Our findings revealed that drought stress adversely affected the germination of both rice varieties, with NG36 exhibiting a more rapid germination rate compared to JN10 under such stress conditions. This differential response was attributed to the heightened activities of key enzymes, elevated levels of metabolic intermediates, and upregulated expression of genes encoding enzymes involved in ROS and respiratory metabolic pathways in NG36. To further dissect the interplay between these metabolic pathways, we selected specific enzyme activities for detailed examination. Notably, a robust positive linear correlation was established among phosphofructokinase (PFK), α-ketoglutarate dehydrogenase (KGDH), citrate synthase (CS), and isocitrate dehydrogenase (ICDH) in NG36. This correlation underscores the pivotal role of glycolytic pathways, particularly the tricarboxylic acid (TCA) cycle, in conferring drought resistance to NG36 during the germination phase under drought stress. To encapsulate our findings, the results of this investigation suggest that the rice cultivar NG36 manifests a heightened degree of drought tolerance relative to JN10. This is primarily achieved through the adept modulation of its respiratory metabolic pathways and the stringent preservation of ROS homeostasis during the germination phase under conditions of water deficit. These revelations provide unprecedented insights into the intricate regulatory mechanisms that subserve rice's drought resistance, potentially paving the way for the development of novel strategies in the breeding of rice cultivars with improved drought resilience.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106031"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of Polyethylene Terephthalate (PET) Microplastic stress on the composition and gene regulatory network of amino acid in Capsicum annuum","authors":"Yilan Cui ,&nbsp;Yueqin Zhang ,&nbsp;Mingzhu Guan,&nbsp;Youyang Fu,&nbsp;Xiao Yang,&nbsp;Mangu Hu,&nbsp;Rongchao Yang","doi":"10.1016/j.envexpbot.2024.106029","DOIUrl":"10.1016/j.envexpbot.2024.106029","url":null,"abstract":"<div><div>Polyethylene Terephthalate (PET) is a widely used plastic in daily life. The extensive accumulation of PET microplastics (PET-MPs) in the environment adversely affects plant growth in multiple ways. However, the impact of PET-MPs exposure on the plant metabolism and the underlying molecular mechanisms are largely unexplored. To address this gap, we employed metabolomics and transcriptomics combination analyses to investigate the effects of PET-MPs exposure, varying in particle size and concentration, on the amino acid content and composition in pepper, as well as the underlying genes regulatory network. A total of 282 amino acids and their derivatives were identified, including 8 essential amino acids. Significant changes in differentially accumulated amino acids (DAAs) and differentially expressed genes (DEGs) were observed across different treatments, indicating that PET-MPs exposure affects amino acid metabolism in peppers, with these effects closely related to the size and concentration of PET-MPs. Ten DAAs with significant variable importance were identified through OPLS-DA. Weighted gene co-expression network analysis (WGCNA) revealed that the red module was significantly correlated with most of the DAAs indicators, highlighting the essential roles of <em>HMSI</em>, <em>BCAT</em>, and 12 transcription factor (TF) genes in regulating amino acid synthesis under PET-MPs exposure. Furthermore, correlation and redundancy analysis (RDA) identified three candidate genes, <em>HSMI</em>, <em>PROC</em>, and <em>FHM</em>, involved in amino acid biosynthesis pathways. This study enhances our understanding of MPs pollution and provides novel insights into the impact of MPs on crop growth and nutrition.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106029"},"PeriodicalIF":4.5,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding cytokinin: Biosynthesis, signal transduction, growth regulation, and phytohormonal crosstalk under heavy metal stress","authors":"Asif Hussain Hajam,&nbsp;Mohd Soban Ali,&nbsp;Sumit Kumar Singh,&nbsp;Gausiya Bashri","doi":"10.1016/j.envexpbot.2024.106025","DOIUrl":"10.1016/j.envexpbot.2024.106025","url":null,"abstract":"<div><div>Anthropogenic activities have gradually led to heavy metal (HM) stress in plants, a growing concern threatening global food security. Hence, this issue requires significant efforts to mitigate the impact of HM stress on plants. Recently, phytohormones have gained attention as an approach to alleviate HM stress by enhancing plant tolerance through exogenous application and strategic modulation of endogenous biosynthesis and signaling pathways. Cytokinins (CKs) have emerged as key regulators in various physiological processes, particularly under HM stress, as they play a vital role in orchestrating adaptive responses by altering antioxidant defense systems, maintaining ion balance, and regulating stress-responsive gene expression. Moreover, CKs interact with other phytohormones, forming complex signaling networks that influence diverse aspects of biological processes. Understanding these interactions offers valuable insights into enhancing plant growth, development, and HM stress tolerance, particularly in contaminated areas. This review explores critical aspects of CK biosynthesis, transport, and signal transduction, as well as their roles in growth, development, and HM stress response. Additionally, it examines the crosstalk between CKs and other phytohormones, highlighting their potential to facilitate plant adaptations and gene expression, thus enhancing resilience under HM stress. This study integrates the mechanisms by which CKs modulate HM tolerance in plants, emphasizing their signaling dynamics under HM stress and novel interactions with other phytohormones. Furthermore, it addresses various aspects of these complex regulatory networks.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"228 ","pages":"Article 106025"},"PeriodicalIF":4.5,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}