Journal of plant physiology最新文献

{"title":"KAR1-dormancy release in Avena fatua caryopses includes increased AfMAN gene expression and ENDO-β-MANNANASE activity in the coleorhiza and radicle","authors":"Anna Orłowska,&nbsp;Jan Kępczyński","doi":"10.1016/j.jplph.2024.154363","DOIUrl":"10.1016/j.jplph.2024.154363","url":null,"abstract":"<div><div>KAR₁, at very low concentration (3x10⁻⁹ M) released dormancy in <em>Avena fatua</em> caryopses, which was expressed in almost complete emergence of coleorhiza (CE) and radicle (RE) just after three days of germination. The dormancy-releasing effect of KAR₁ was associated with an increased activity of ENDO-β-MANNANASE (MAN; EC 3.2.1.78) (hydrolase and transglycosylase) in coleorhiza and radicle before RE. The <em>MAN</em> genes, <em>MAN</em>1, <em>MAN2</em>, <em>MAN</em>3, <em>MAN</em>4, and <em>MAN5</em> were for the first time identified in the genome of <em>A. fatua</em>. KAR₁ induced expression of <em>AfMAN1-3</em> and <em>AfMAN5</em> in the coleorhiza and <em>AfMAN2</em> and <em>AfMAN3</em> in the radicle during caryopses germination. The increase in transcripts in the coleorhiza of <em>AfMAN1,5</em> after 8 h and <em>AfMAN3,5</em> after 12 h germination in the presence of KAR₁ is probably responsible for the increase in MAN activity determined after 18 h before RE. KAR₁ also increased <em>AfMAN</em>3 expression in radicle after 12 h which probably caused the increased MAN activity after 18 h. Therefore, release of caryopses dormancy by KAR₁ involves increasing expression of <em>MAN</em> genes and MAN activity both in the coleorhiza and radicle, which might facilitate the passage of the radicle through the coleorhiza. The work provides the first data on the contribution of MAN, present in coleorhiza and radicle, in the dormancy release of caryopses by KAR₁.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154363"},"PeriodicalIF":4.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142375595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of BpEXP family genes and functional characterization of the BpEXPA1 gene in the stems development of Betula platyphylla","authors":"Yao Chi,&nbsp;Zihan Wang,&nbsp;Shizhong Chen,&nbsp;Lin Feng,&nbsp;Meiqi Zhou,&nbsp;Yang Li,&nbsp;Ying Yu,&nbsp;Caiqiu Gao,&nbsp;Chao Wang","doi":"10.1016/j.jplph.2024.154361","DOIUrl":"10.1016/j.jplph.2024.154361","url":null,"abstract":"<div><div>Expansins (EXPs) are unique plant cell wall proteins with the ability to induce cell wall expansion and play potential roles in xylem development. In the present study, a total of 25 <em>BpEXP</em> genes were identified in <em>Betula platyphylla</em>. Results of bioinformatics analysis described that BpEXP gene family was highly conserved in the process of evolution. All these genes were clustered into four groups, EXPA (Expansin A), EXPB (Expansin B), EXLA (Expansin-like A) and EXLB (Expansin-like B), according to phylogenetic analysis and BpEXPA1 was highly homologous to PttEXP1 and PttEXP2. The results of RT-qPCR showed that <em>BpEXPA1</em> was expressed higher in stems and preferentially expressed in the first internodes, followed by apical buds and the third internodes, promoter expression analysis with GUS assay demonstrated that it was expressed in developing xylem, suggesting that <em>BpEXPA1</em> might be involved in the development of the primary stems of birch. Overexpression of <em>BpEXPA1</em> can promote cortex cell expansion and then enlarge the cortex cell area and layer, however inhibit the secondary cell wall deposition and result in the thinner cell wall and larger lumens of xylem fiber in transgenic plants. This study will provide information for investigating the regulation mechanism of <em>BpEXP</em> family genes and gene resources for birch genetics improvement.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154361"},"PeriodicalIF":4.0,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of element and hormone content in zygotic embryos of Pinus elliottii and P. elliottii × P. caribaea","authors":"Yang Liu ,&nbsp;Lei Xue ,&nbsp;Zhe Wang ,&nbsp;Xiaoliang Che ,&nbsp;Leping Deng ,&nbsp;Wei Xie ,&nbsp;Wenbing Guo","doi":"10.1016/j.jplph.2024.154359","DOIUrl":"10.1016/j.jplph.2024.154359","url":null,"abstract":"<div><div>Somatic embryogenesis is a crucial method for achieving clonal forestry in conifers. Understanding the development of zygotic embryos is essential not only for enhancing the efficiency and quality of somatic embryogenesis, but also for advancing forestry breeding programs. This study investigated dynamic changes of element and hormone contents during ZE development of <em>Pinus elliottii</em> and its hybrid <em>P. elliottii</em> × <em>P. caribaea</em>. Significant differences in embryo development speed among different clones were observed. Elemental analysis was conducted using inductively coupled plasma mass spectrometry (ICP-MS) and identified 68 elements, including major, minor, and beneficial elements. In both species, the contents of potassium (K), calcium (Ca), iron (Fe), boron (B) and five beneficial elements decreased during early ZE development, while phosphorus (P) and copper (Cu) increased. Significantly higher levels of K, Ca and Fe at the initial stage, and sulfur (S) and nickel (Ni) decreased at later stages were detected in <em>P. elliottii</em> than in the hybrid. For the other elements, except for very few significant differences at certain stages, most differences between the two species did not reach a significant level. The contents of endogenous hormones were determined and different accumulation patterns were detected in most hormones between the two species, except abscisic acid (ABA) which simultaneously decreased with developments by stage 8. Significant differences were found in indole-3-acetic acid (IAA) contents at most stages between species, while higher levels of total cytokinin (CK) at each stage were detected in the hybrid in comparison with those in <em>P. elliottii</em>. As a result, lower IAA to CK ratios in the hybrid than in <em>P. elliottii</em>. Methyl jasmonate (JA-me) and gibberellin A3 (GA3) contents showed a similar pattern and exhibited an M-shaped fluctuation in the hybrid. Furthermore, JA-me, GA3, gibberellin A4 (GA4) and brassinolide (BR) showed significantly higher levels in the hybrid than in <em>P. elliottii</em>. K-means clustering and correlation analyses were used to explore relationships between elements and hormones during embryo development, revealing complex interplay in both species. These data indicate different requirement in element and hormone contents for embryogenesis and suggest species-specific media composition for each step in somatic embryogenesis. The findings provide insights into their developmental processes and informing future research and applications in somatic embryogenesis and forestry breeding.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154359"},"PeriodicalIF":4.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of LED polarized and vortex light on growth and photosynthetic characteristics of pepper (Capsicum annuum L.)","authors":"Shujie Gai ,&nbsp;Yushuai Chen ,&nbsp;Yiyan Long ,&nbsp;Yichao Luo ,&nbsp;Xiaoni Yi ,&nbsp;Zixiang Zhao ,&nbsp;Xiaochun Li ,&nbsp;Zhi Zhou","doi":"10.1016/j.jplph.2024.154360","DOIUrl":"10.1016/j.jplph.2024.154360","url":null,"abstract":"<div><div>Most studies currently focus on traditional illuminant regulating plant growth, while less attention has been given to the LED internal luminescence. This study examined how polarized and vortex light affect the growth and photosynthetic traits of pepper plants, with LED light used as the control. The findings indicated that circular polarized light significantly increased the aboveground biomass of pepper. Additionally, both polarized and vortex light treatment significantly influenced the root development of pepper. In comparison to the control group, the chlorophyll content was highest under circular polarized light, while the Pn, Sc, Tr, and Ci values were highest under linear polarized light, and the enzyme activity of Rubisco was increased. Circular polarized light notably increased the activities of POD, CAT, and SOD, the activity of SOD reached its peak under the left vortex light. Moreover, the content of MDA was observed to be the lowest under linear and right vortex light treatments. The expressions of key genes for chlorophyll synthesis (<em>CaHEMA1</em> and <em>CaCAO</em>) and antioxidant enzyme synthesis (<em>CaPOD, CaSOD</em>, and <em>CaMDHAR</em>) were significantly altered under varying polarized light conditions, The latter genes, which play crucial roles in antioxidant enzyme activity, also showed significant variations in response to different polarized light treatments. In conclusion, polarized light significantly impacts the growth of pepper and is anticipated to be utilized for plant growth, setting the stage for future research in this area.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154360"},"PeriodicalIF":4.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diethyl ether anaesthesia does not block local touch response in Arabidopsis thaliana","authors":"Martin Hřivňacký ,&nbsp;Marek Rác ,&nbsp;Ondřej Vrobel ,&nbsp;Petr Tarkowski ,&nbsp;Andrej Pavlovič","doi":"10.1016/j.jplph.2024.154358","DOIUrl":"10.1016/j.jplph.2024.154358","url":null,"abstract":"<div><div>Plants can sense and respond to non-damaging mechanical stimulation such as touch, rain, or wind. Mechanical stimulation induces an increase of cytosolic calcium ([Ca²⁺]_cyt), accumulation of phytohormones from the group of jasmonates (JAs) and activation of gene expression, which can be JAs-dependent or JAs-independent. Response to touch shares similar properties with reactions to stresses such as wounding or pathogen attack, and regular mechanical stimulation leads to changes in growth and development called thigmomorphogenesis. Previous studies showed that well-known seismonastic plants such as Venus flytrap (<em>Dionaea muscipula</em>) or sensitive plant (<em>Mimosa pudica</em>) lost their touch-induced motive responses during exposure to general volatile anaesthetic (GVA) diethyl ether. Here, we investigated the effect of diethyl ether anaesthesia on touch response in <em>Arabidopsis thaliana</em>. We monitored [Ca²⁺]_cyt level, accumulation of JAs and expression of touch-responsive genes. Our results showed that none of the investigated responses was affected by diethyl ether. However, diethyl ether alone increased [Ca²⁺]_cyt and modulated JAs-independent touch-responsive genes, thus partially activating touch response non-specifically. Together with our previous studies, we concluded that GVA diethyl ether cannot block the local rise of [Ca²⁺]_cyt but only its systemic propagation dependent on GLUTAMATE LIKE RECEPTOR 3s (GLR3s) channels.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154358"},"PeriodicalIF":4.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phloretin inhibits the growth of Arabidopsis shoots by inducing chloroplast damage and programmed cell death","authors":"Dijana Smailagić ,&nbsp;Jelena Dragišić Maksimović ,&nbsp;Marija Marin ,&nbsp;Sofija Stupar ,&nbsp;Slavica Ninković ,&nbsp;Nevena Banjac ,&nbsp;Mariana Stanišić","doi":"10.1016/j.jplph.2024.154354","DOIUrl":"10.1016/j.jplph.2024.154354","url":null,"abstract":"<div><div>Phloretin is a key secondary metabolite produced by apple trees. Known for its strong antioxidant properties, this dihydrochalcone has been extensively studied in animals but less so in plants. Recently, we identified phloretin as a phytotoxic allelochemical that inhibits growth in the model plant Arabidopsis by disrupting auxin metabolism and distribution in the roots. In this study, we found that phloretin significantly hinders the growth of Arabidopsis seedlings' aerial parts after a short-term treatment (10 days) and causes their decay after long-term exposure (28 days). These effects result from ultrastructural damage in the mesophyll cells of the leaves, including chloroplast displacement and swelling, lesions, and alterations in thylakoid and cell wall organization. Interestingly, phloretin-treated plants showed a decrease in malondialdehyde levels and antioxidant enzyme activities, while hydrogen peroxide and proline levels remained unchanged. This suggests that phloretin-induced chlorosis and seedling decay are not due to oxidative stress but rather to severe chloroplast structural damage, leading to inefficient photosynthesis, starch degradation, starvation, and activation of micro- and macroautophagic processes for self-preservation. Ultimately, these processes result in programmed cell death. These new insights into the phytotoxic effects of phloretin on Arabidopsis shoots could pave the way for future research into phloretin as a potential multitarget bioherbicide and enhance our understanding of autoallelopathy in apple trees.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154354"},"PeriodicalIF":4.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inducible tolerance to low Ca:Mg in serpentine ecotype of Erythranthe guttata","authors":"Emily Palm ,&nbsp;Werther Guidi Nissim ,&nbsp;Giacomo Colasurdo ,&nbsp;Elizabeth Van Volkenburgh","doi":"10.1016/j.jplph.2024.154355","DOIUrl":"10.1016/j.jplph.2024.154355","url":null,"abstract":"<div><div>In serpentine soils, the low level of calcium relative to magnesium (Ca:Mg) is detrimental to the growth of most plant species. Ecotypic variation in <em>Erythranthe guttata</em> allows for some populations to maintain high photosynthetic rates and biomass despite low Ca:Mg. In this study, the mechanism of tolerance was investigated by treating hydroponically grown plants with either high (1.0) or low (0.02) Ca:Mg growth solutions and assaying excised leaf discs for rates of photosynthesis and disc expansion, and for starch, Ca²⁺ and Mg²⁺ ion concentrations. Low Ca:Mg in the assay solutions reduced both photosynthesis and leaf disc expansion after one week of treatment. However, serpentine tissues show stable photosynthetic rates after one week and a recovery in leaf tissue expansion after two weeks exposure to low Ca:Mg conditions. Values for non-serpentine tissues continued to decline. Increased growth of low Ca:Mg treated discs supplied with exogenous sucrose suggests that growth in serpentine-exposed tissues is limited by availability of carbon products from photosynthesis. Serpentine leaves had higher vacuole Mg concentrations than non-serpentine leaves after three weeks of treatment with low Ca:Mg. The combination of elevated starch concentrations, reduced growth and lower vacuolar Mg concentrations in leaves of non-serpentine plants grown in low Ca:Mg indicate an inefficient use of carbon resources and starch degradation as an observed response to Mg toxicity. Together, these results suggest that serpentine <em>E. guttata</em> exhibits an inducible tolerance to low Ca:Mg through gradual compartmentalization of magnesium to maintain the production and metabolism of photosynthates necessary for growth.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154355"},"PeriodicalIF":4.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogen sulfide alleviates cadmium stress in germinating carrot seeds by promoting the accumulation of proline","authors":"Miao Sun ,&nbsp;Huan-Xuan Qiao ,&nbsp;Tao Yang ,&nbsp;Peng Zhao ,&nbsp;Jun-Hao Zhao ,&nbsp;Jia-Ming Luo ,&nbsp;Hai-Ye Luan ,&nbsp;Xiang Li ,&nbsp;Sheng-Cai Wu ,&nbsp;Ai-Sheng Xiong","doi":"10.1016/j.jplph.2024.154357","DOIUrl":"10.1016/j.jplph.2024.154357","url":null,"abstract":"<div><div>Carrot (<em>Daucus carota</em> L.), a widely cultivated economically vegetable from the <em>Apiaceae</em> family, is grown globally. However, carrots can be adversely impacted by cadmium (Cd) pollution in the soil due to its propensity to accumulate in the fleshy root, thus impeding carrot growth and posing health hazards to consumers. Given the potential of hydrogen sulfide (H₂S) to improve plant resistance against Cd stress, we treated germinating carrot seeds with varying concentrations of sodium hydrosulfide (NaHS), aiming to alleviate the toxic impacts of Cd stress on carrot seed germination. The results revealed that carrot seeds treated with a concentration of 0.25 mM NaHS displayed better seed germination-associated characteristics compared to seeds treated with NaHS concentrations of 0.1 mM and 0.5 mM. Further investigation revealed a rise in the expression levels of <em>L-cysteine desulfhydrase</em> and <em>D-cysteine desulfhydrase</em>, along with enhanced activity of L-cysteine desulfhydrase and D-cysteine desulfhydrase among the NaHS treatment group, thereby leading to H₂S accumulation. Moreover, NaHS treatment triggered the expression of <em>pyrroline-5-carboxylate synthase</em> and <em>pyrroline-5-carboxylate reductase</em> and promoted the accumulation of endogenous proline, while the contents of soluble sugar and soluble protein increased correspondingly. Interestingly, since the application of exogenous proline did not influence the accumulation of endogenous H₂S, suggesting that H₂S served as the upstream regulator of proline. Histochemical staining and biochemical indices revealed that NaHS treatment led to elevated antioxidant enzyme activity, alongside a suppression of superoxide anion and hydrogen peroxide generation. Furthermore, high performance liquid chromatography analysis revealed that NaHS treatment reduced Cd²⁺ uptake, thereby promoting germination rate, seed vitality, and hypocotyl length of carrot seeds under Cd stress. Overall, our findings shed light on the application of NaHS to enhance carrot resistance against Cd stress and lay a foundation for exploring the regulatory role of H₂S in plants responding to Cd stress.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154357"},"PeriodicalIF":4.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methyl salicylate induces endogenous jasmonic acid and salicylic acid in 'Nam Dok Mai' mango to maintain postharvest ripening and quality","authors":"Ngoc X.B. Nguyen ,&nbsp;Treenut Saithong ,&nbsp;Panida Boonyaritthongchai ,&nbsp;Mantana Buanong ,&nbsp;Saowalak Kalapanulak ,&nbsp;Chalermchai Wongs-Aree","doi":"10.1016/j.jplph.2024.154356","DOIUrl":"10.1016/j.jplph.2024.154356","url":null,"abstract":"<div><div>Salicylic acid (SA) and jasmonic acid (JA) are indispensable phytohormones whose interaction influences the ripening process in plants. Methyl salicylate (MeSA) and methyl jasmonate (MeJA) have been utilized to elevate the endogenous levels of SA and JA in horticultural products after harvest. However, their ability to preserve mango is uncertain. Individually and combined effects of exogenous MeSA and MeJA on mango ripening quality were investigated. 'Nam Dok Mai' mangoes were fumigated with MeSA, MeJA, and MeSA plus MeJA (MeSAJA) prior to storage for 6 d at 25 °C and 80–85% relative humidity (RH). Fruit ripening attributes, respiration rate, ethylene (ET) production, total phenolics (TP), and malondialdehyde (MDA) were assessed. Endogenous SA and JA levels were measured, as were the activities of lipoxygenase (LOX) and phenylalanine ammonia-lyase (PAL), and the expression of related genes <em>MiPAL, MiICS, and MiLOX</em>. Individual application of MeSA or MeJA preserved the mango quality by reducing ET production, respiration rate, and MDA levels while raising TP shortly after treatment. The ripening quality mirrored the induced SA and JA levels and correlated with the high expression of biosynthetic-related genes (<em>MiPAL</em>, <em>MiICS</em>, and <em>MiLOX</em>). Individual treatments stimulated SA and JA biosynthesis, demonstrating that these phytohormones are functionally connected and interdependent. When combined, MeSAJA caused a tradeoff response and distinct phenotypic outcomes compared to the individual treatments. As a result, MeSA fumigation is a practical method for preserving mango quality after harvest.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154356"},"PeriodicalIF":4.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular simulation reveals that pathogenic mutations in BTB/ANK domains of Arabidopsis thaliana NPR1 circumscribe the EDS1-mediated immune regulation","authors":"P. Raghuraman,&nbsp;SeonJoo Park","doi":"10.1016/j.jplph.2024.154345","DOIUrl":"10.1016/j.jplph.2024.154345","url":null,"abstract":"<div><div>The NPR1 (nonexpressor of pathogenesis-related genes 1) is a key regulator of the salicylic-acid-mediated immune response caused by pathogens in <em>Arabidopsis thaliana.</em> Mutations C150Y and H334Y in the BTB/ANK domains of NPR1 inhibit the defense response, and transcriptional co-activity with enhanced disease susceptibility 1 (EDS1) has been revealed experimentally. This study examined the conformational changes and reduced NPR1–EDS1 interaction upon mutation using a molecular dynamics simulation. Initially, ^BTBC150Y_NPR1 and ^ANKH334Y_NPR1 were categorized as pathological mutations rather than others based on sequence conservation. A distant ortholog was used to map the common residues shared among the wild-type because the mutations were highly conserved. Overall, 179 of 373 residues were determining the secondary structures and fold versatility of conformations. In addition, the mutational hotspots Cys150, Asp152, Glu153, Cys155, His157, Cys160, His334, Arg339 and Lys370 were crucial for oligomer-to-monomer exchange. Subsequently, the atomistic simulations with free energy (MM/PB(GB)SA) calculations predicted structural displacements engaging in the N-termini _α5133-178_α7 linker connecting the central ANK regions (_α13260–290_α14 and _α18320–390_α22), where prominent long helices (α5₁₆) and short helices (α3₁₀) replaced with β-turns and loops disrupting hydrogen bonds and salt bridges in both mutants implicating functional regulation and activation. Furthermore, the mutation repositions the intact stability of multiple regions (_L13C149-N356_α20^BTB/ANK-_α17W301-E357_α21^{N−ter/coiled-coil}) compromising a dynamic interaction of NPR1–EDS1. By unveiling the transitions between the distinct functions of mutational perception, this study paves the way for future investigation to orchestrate additive host-adapted transcriptional reprogramming that controls defense-related regulatory mechanisms of NPR1s in plants.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":"303 ","pages":"Article 154345"},"PeriodicalIF":4.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}