Journal of Experimental Botany最新文献_第7页

Arabidopsis KNS3 and its two homologs mediate endoplasmic reticulum-to-plasma membrane traffic of boric acid channels. 拟南芥 KNS3 及其两个同源物介导了硼酸通道从内质网到质膜的运输。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae380

Zhe Zhang, Shunsuke Nakamura, Arisa Yamasaki, Masataka Uehara, Shunsuke Takemura, Kohei Tsuchida, Takehiro Kamiya, Shuji Shigenobu, Katsushi Yamaguchi, Toru Fujiwara, Sumie Ishiguro, Junpei Takano

{"title":"Arabidopsis KNS3 and its two homologs mediate endoplasmic reticulum-to-plasma membrane traffic of boric acid channels.","authors":"Zhe Zhang, Shunsuke Nakamura, Arisa Yamasaki, Masataka Uehara, Shunsuke Takemura, Kohei Tsuchida, Takehiro Kamiya, Shuji Shigenobu, Katsushi Yamaguchi, Toru Fujiwara, Sumie Ishiguro, Junpei Takano","doi":"10.1093/jxb/erae380","DOIUrl":"https://doi.org/10.1093/jxb/erae380","url":null,"abstract":"Membrane proteins targeted to the plasma membrane are first transported from the endoplasmic reticulum (ER) to the Golgi apparatus. This study explored the mechanisms controlling plasma membrane trafficking of the boric acid channel AtNIP5;1 from the ER. Imaging-based screening using transgenic Arabidopsis identified six mutants in which GFP-NIP5;1 was localized in the ER in addition to the plasma membrane. Genetic mapping and whole-genome resequencing identified the responsible gene in four among the six mutants as KAONASHI3 (KNS3)/SPOTTY1/IMPERFECTIVE EXINE FORMATION. Among the plasma membrane-localized proteins tested, NIP5;1 and its homolog NIP6;1 were retained in the ER of the kns3 mutants. Our genetic analysis further discovered that two homologs of KNS3, KNSTH1 and KNSTH2, were also involved in the ER exit of NIP5;1. In Arabidopsis protoplasts and tobacco leaves, mCherry-fused KNS3 localized to the ER and Golgi, whereas KNSTH2 localized to the ER. The cytosolic C-terminal tail of KNS3 contains amino acids important for Golgi-to-ER trafficking. Furthermore, the ER-to-Golgi trafficking of KNS3 depended on KNSTH1 and KNSTH2, and the accumulation of these three proteins in Arabidopsis roots depended on each other. We propose that KNS3, KNSTH1, and KNSTH2 function as a cargo-receptor complex mediating the ER exit of NIP5;1.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":""},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142545829","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}

引用次数: 0

Roles of plastoglobules and lipid droplets in leaf neutral lipid accumulation during senescence and nitrogen deprivation. 质粒和脂滴在叶片衰老和缺氮过程中的中性脂质积累中的各自作用

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae301

Denis Coulon, Houda Nacir, Delphine Bahammou, Juliette Jouhet, Jean-Jacques Bessoule, Laëtitia Fouillen, Claire Bréhélin

{"title":"Roles of plastoglobules and lipid droplets in leaf neutral lipid accumulation during senescence and nitrogen deprivation.","authors":"Denis Coulon, Houda Nacir, Delphine Bahammou, Juliette Jouhet, Jean-Jacques Bessoule, Laëtitia Fouillen, Claire Bréhélin","doi":"10.1093/jxb/erae301","DOIUrl":"10.1093/jxb/erae301","url":null,"abstract":"Upon abiotic stress or senescence, the size and/or abundance of plastid-localized plastoglobules and cytosolic lipid droplets, both compartments devoted to neutral lipid storage, increase in leaves. Meanwhile, plant lipid metabolism is also perturbed, notably with the degradation of thylakoidal monogalactosyldiacylglycerol (MGDG) and the accumulation of neutral lipids. Although these mechanisms are probably linked, they have never been jointly studied, and the respective roles of plastoglobules and lipid droplets in the plant response to stress are totally unknown. To address this question, we determined and compared the glycerolipid composition of both lipid droplets and plastoglobules, followed their formation in response to nitrogen starvation, and studied the kinetics of lipid metabolism in Arabidopsis leaves. Our results demonstrated that plastoglobules preferentially store phytyl-esters, while triacylglycerols (TAGs) and steryl-esters accumulated within lipid droplets. Thanks to a pulse-chase labeling approach and lipid analyses of the fatty acid desaturase 2 (fad2) mutant, we showed that MGDG-derived C18:3 fatty acids were exported to lipid droplets, while MGDG-derived C16:3 fatty acids were stored within plastoglobules. The export of lipids from plastids to lipid droplets was probably facilitated by the physical contact occurring between both organelles, as demonstrated by our electron tomography study. The accumulation of lipid droplets and neutral lipids was transient, suggesting that stress-induced TAGs were remobilized during the plant recovery phase by a mechanism that remains to be explored.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6542-6562"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141590501","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}

引用次数: 0

Proximity driven plastid-nucleus relationships are facilitated by tandem plastid-ER dynamics. 串联质粒-ER动态促进了近距离驱动的质粒-核关系。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae313

Thomas Kadanthottu Kunjumon, Puja Puspa Ghosh, Laura M J Currie, Jaideep Mathur

{"title":"Proximity driven plastid-nucleus relationships are facilitated by tandem plastid-ER dynamics.","authors":"Thomas Kadanthottu Kunjumon, Puja Puspa Ghosh, Laura M J Currie, Jaideep Mathur","doi":"10.1093/jxb/erae313","DOIUrl":"10.1093/jxb/erae313","url":null,"abstract":"Peri-nuclear clustering (PNC) of chloroplasts has largely been described in senescent and pathogen- or reactive oxygen species-stressed cells. Stromules, tubular plastid extensions, are also observed under similar conditions. Coincident observations of PNC and stromules associate the two phenomena in facilitating retrograde signaling between chloroplasts and the nucleus. However, PNC incidence in non-stressed cells under normal growth and developmental conditions, when stromules are usually not observed, remains unclear. Using transgenic Arabidopsis expressing different organelle-targeted fluorescent proteins, we show that PNC is a dynamic subcellular phenomenon that continues in the absence of light and is not dependent on stromule formation. PNC is facilitated by tandem plastid-endoplasmic reticulum (ER) dynamics created through membrane contact sites between the two organelles. While PNC increases upon ER membrane expansion, some plastids may remain in the peri-nuclear region due to their localization in ER-lined nuclear indentions. Moreover, some PNC plastids may sporadically extend stromules into ER-lined nuclear grooves. Our findings strongly indicate that PNC is not an exclusive response to stress caused by pathogens, high light, or exogenous H2O2 treatment, and does not require stromule formation. However, morphological and behavioral alterations in ER and concomitant changes in tandem, plastid-ER dynamics play a major role in facilitating the phenomenon.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6275-6294"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11523032/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141734316","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}

引用次数: 0

The MADS-domain transcription factor DAL10 is a direct target of putative DAL1-mediated age pathway in conifers. DAL10 是针叶树假定的 DAL1 介导的年龄途径的直接靶标。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae329

Hui Zhang, Peiyi Wang, Yitong Song, Huanhuan Zhao, Quan Zuo, Xi Chen, Fangxu Han, Hongmei Liu, Yumeng Nie, Meiqin Liu, Meina Guo, Shihui Niu

{"title":"The MADS-domain transcription factor DAL10 is a direct target of putative DAL1-mediated age pathway in conifers.","authors":"Hui Zhang, Peiyi Wang, Yitong Song, Huanhuan Zhao, Quan Zuo, Xi Chen, Fangxu Han, Hongmei Liu, Yumeng Nie, Meiqin Liu, Meina Guo, Shihui Niu","doi":"10.1093/jxb/erae329","DOIUrl":"10.1093/jxb/erae329","url":null,"abstract":"The optimal timing of the transition from vegetative growth to reproductive growth is critical for plant reproductive success, and the underlying regulatory mechanisms have been well studied in angiosperm model species, but relatively little in gymnosperms. DAL1, a MADS domain transcription factor (TF) that shows a conserved age-related expression profile in conifers, may be an age timer. However, how DAL1 mediates the onset of reproductive growth remains poorly understood. Here, we showed that PtDAL1 directly regulates PtDAL10 transcription by binding to its promoter region in vitro. Both in vitro and in Nicotiana benthamiana PtDAL1 forms ternary complexes with PtDAL10 and PtMADS11, two potential candidate regulators of the vegetative to reproductive transition in Chinese pine (Pinus tabuliformis). In new shoots PtDAL10 was progressively induced with age and was also expressed in male and female cones. Overexpression of PtDAL10 rescued the flowering of ft-10 and soc1-1-2 mutants in Arabidopsis. We provide insights into the molecular components associated with PtDAL1, which integrates the vegetative to reproductive phase transition into age-mediated progressive development of the whole plant in conifers.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6462-6475"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141855657","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}

引用次数: 0

Combined transcriptome and metabolome analysis identifies triterpenoid-induced defense responses in Myzus persicae Sülzer-infested peach. 结合转录组和代谢组分析，确定三萜类化合物诱导的受桃螨侵染的防御反应。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae339

Lei Pan, Rui Huang, Zhenhua Lu, Wenyi Duan, Shihang Sun, Lele Yan, Guochao Cui, Liang Niu, Zhiqiang Wang, Wenfang Zeng

{"title":"Combined transcriptome and metabolome analysis identifies triterpenoid-induced defense responses in Myzus persicae Sülzer-infested peach.","authors":"Lei Pan, Rui Huang, Zhenhua Lu, Wenyi Duan, Shihang Sun, Lele Yan, Guochao Cui, Liang Niu, Zhiqiang Wang, Wenfang Zeng","doi":"10.1093/jxb/erae339","DOIUrl":"10.1093/jxb/erae339","url":null,"abstract":"Piercing/sucking insects such as green peach aphid (GPA) (Myzus persicae) cause direct damage by obtaining phloem nutrients and indirect damage by spreading plant viruses. To investigate the response of peach trees (Prunus persica) to aphids, the leaf transcriptome and metabolome of two genotypes with different sensitivities to GPA were studied. The gene expression of aphid-susceptible plants infested with aphids was similar to that of control plants, whereas the gene expression of aphid-resistant plants infested with aphids showed strong induced changes in gene expression compared with control plants. Furthermore, gene transcripts in defense-related pathways, including plant-pathogen interaction, MAPK signaling, and several metabolic pathways, were strongly enriched upon aphid infestation. Untargeted secondary metabolite profiling confirmed that aphid infestation induced larger changes in aphid-resistant than in aphid-susceptible peaches. Consistent with transcriptomic alterations, nine triterpenoids showed highly significant GPA-induced accumulation in aphid-resistant peaches, whereas triterpenoid abundance remained predominantly unchanged or undetected in aphid-susceptible peaches. Furthermore, some types of transcription factors (including WRKYs, ERFs, and NACs) were strongly induced upon GPA infestation in aphid-resistant, but not in aphid-susceptible peaches. These results suggested that the accumulation of specialized triterpenoids and the corresponding pathway transcripts may play a key role in peach GPA resistance.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6644-6662"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141901939","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}

引用次数: 0

The emerging role of cysteine-rich peptides in pollen-pistil interactions. 富半胱氨酸肽在花粉与雌蕊相互作用中的新作用。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae322

Jiao Xue, Qian Du, Fangfang Yang, Li-Yu Chen

{"title":"The emerging role of cysteine-rich peptides in pollen-pistil interactions.","authors":"Jiao Xue, Qian Du, Fangfang Yang, Li-Yu Chen","doi":"10.1093/jxb/erae322","DOIUrl":"10.1093/jxb/erae322","url":null,"abstract":"Unlike early land plants, flowering plants have evolved a pollen tube that transports a pair of non-motile sperm cells to the female gametophyte. This process, known as siphonogamy, was first observed in gymnosperms and later became prevalent in angiosperms. However, the precise molecular mechanisms underlying the male-female interactions remain enigmatic. From the landing of the pollen grain on the stigma to gamete fusion, the male part needs to pass various tests: how does the stigma distinguish between compatible and incompatible pollen? what mechanisms guide the pollen tube towards the ovule? what factors trigger pollen tube rupture? how is polyspermy prevented? and how does the sperm cell ultimately reach the egg? Successful male-female communication is essential for surmounting these challenges, with cysteine-rich peptides (CRPs) playing a pivotal role in this dialogue. In this review, we summarize the characteristics of four distinct classes of CRPs, systematically review recent progress in the role of CRPs in four crucial stages of pollination and fertilization, consider potential applications of this knowledge in crop breeding, and conclude by suggesting avenues for future research.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6228-6243"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141912917","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}

引用次数: 0

Non-specific phospholipase C3 is involved in endoplasmic reticulum stress tolerance in Arabidopsis. 非特异性磷脂酶 C3 参与拟南芥内质网胁迫耐受性的研究

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae303

Anh H Ngo, Artik Elisa Angkawijaya, Yuki Nakamura, Kazue Kanehara

{"title":"Non-specific phospholipase C3 is involved in endoplasmic reticulum stress tolerance in Arabidopsis.","authors":"Anh H Ngo, Artik Elisa Angkawijaya, Yuki Nakamura, Kazue Kanehara","doi":"10.1093/jxb/erae303","DOIUrl":"10.1093/jxb/erae303","url":null,"abstract":"Non-specific phospholipase C (NPC) is an emerging family of lipolytic enzymes unique to plants and bacteria that play crucial roles in growth and stress responses. Among six copies of NPC isoforms found in Arabidopsis, the role of NPC3 remains elusive to date. Here, we show that NPC3 is a functional non-specific phospholipase C involved in tolerance to tunicamycin (TM)-induced endoplasmic reticulum (ER) stress through the synthesis of phosphocholine (PCho), a reaction product of NPC3. The npc3 mutant exhibited reduced sensitivity to TM treatment. Recombinant NPC3 possessed pronounced phospholipase C activity that hydrolyses phosphatidylcholine (PC). The hyposensitivity of npc3 to TM treatment was complemented by exogenous PCho, suggesting that NPC3-catalysed PCho production is involved in TM-induced ER stress tolerance. NPC3 was localized at the ER and was predominantly expressed in the roots, and it was further induced by TM-induced ER stress. Intriguingly, npc3 mutants showed a markedly reduced PCho content in shoots under ER stress. Our results indicate that ER stress induces NPC3 to produce PCho, which is involved in TM-induced ER stress tolerance.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6489-6499"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017695","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}

引用次数: 0

Correction to: Revisiting FR13A for submergence tolerance: beyond the SUB1A gene. 更正：重新审视 FR13A 的耐淹性：超越 SUB1A 基因。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae397

引用次数: 0

Jasmonate/ethylene- and NaWRKY6/3-regulated Alternaria resistance depends on ethylene response factor 1B-like in Nicotiana attenuata. 野生烟草的 JA/乙烯和 NaWRKY6/3 调控的 Alternaria 抗性取决于乙烯响应因子 1B-like。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae320

Lan Ma, Na Song, Qing Duan, Wenwen Du, Xiang Li, Wenjie Jia, Guangfen Cui, Jihua Wang, Jinsong Wu

{"title":"Jasmonate/ethylene- and NaWRKY6/3-regulated Alternaria resistance depends on ethylene response factor 1B-like in Nicotiana attenuata.","authors":"Lan Ma, Na Song, Qing Duan, Wenwen Du, Xiang Li, Wenjie Jia, Guangfen Cui, Jihua Wang, Jinsong Wu","doi":"10.1093/jxb/erae320","DOIUrl":"10.1093/jxb/erae320","url":null,"abstract":"Biosynthesis of the phytoalexins scopoletin and scopolin in Nicotiana species is regulated by upstream signals including jasmonate (JA), ethylene (ET), and NaWRKY3 in response to the necrotrophic fungus Alternaria alternata, which causes brown spot disease. However, how these signals are coordinated to regulate these phytoalexins remains unknown. By analyzing RNA sequencing data and RNAi, we identified NaERF1B-like (NaERF1B-L) as a key player in Nicotiana attenuata during A. alternata infection by regulating the transcripts of Feruloyl-CoA 6'-hydroxylase 1 (NaF6'H1), encoding a key enzyme for scopoletin biosynthesis, and NaVS1-like (NaVS1-L), a putative biosynthetic gene of the phytoalexin solavetivone. We further demonstrated that the synergistic induction of these two genes by JA and ET signaling is mediated by NaERF1B-L. Additionally, we found that the two closely related proteins, NaWRKY6 and NaWRKY3, physically interact to enhance NaERF1B-L expression by directly binding to and activating the NaERF1B-L promoter. Collectively, our current results demonstrate that NaERF1B-L plays a positive role in resistance to A. alternata by modulating phytoalexin biosynthesis through the integration of JA/ET and NaWRKY6/3 signaling. Our findings reveal a fine-tuned transcriptional regulatory hierarchy mediated by NaERF1B-L for brown spot disease resistance in wild tobacco.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6593-6608"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141751887","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}

引用次数: 0

The sound of lichens: ultrasonic acoustic emissions during desiccation question cavitation events in the hyphae. 地衣的声音：干燥过程中的超声波声发射，质疑菌丝中的空化事件。

IF 5.6 2区生物学

Journal of Experimental Botany Pub Date : 2024-10-30 DOI: 10.1093/jxb/erae318

Enrico Boccato, Francesco Petruzzellis, César Daniel Bordenave, Andrea Nardini, Mauro Tretiach, Stefan Mayr, Fabio Candotto Carniel

{"title":"The sound of lichens: ultrasonic acoustic emissions during desiccation question cavitation events in the hyphae.","authors":"Enrico Boccato, Francesco Petruzzellis, César Daniel Bordenave, Andrea Nardini, Mauro Tretiach, Stefan Mayr, Fabio Candotto Carniel","doi":"10.1093/jxb/erae318","DOIUrl":"10.1093/jxb/erae318","url":null,"abstract":"Lichens are a mutualistic symbiosis between a fungus and one or more photosynthetic partners. They are photosynthetically active during desiccation down to relative water contents (RWCs) as low as 30% (on dry mass). Experimental evidence suggests that during desiccation, the photobionts have a higher hydration level than the surrounding fungal pseudo-tissues. Explosive cavitation events in the hyphae might cause water movements towards the photobionts. This hypothesis was tested in two foliose lichens by measurements of ultrasonic acoustic emissions (UAEs), a method commonly used in vascular plants but never in lichens, and by measurements of PSII efficiency, water potential, and RWC. Thallus structural changes were characterized by low-temperature scanning electron microscopy. The thalli were silent between 380% and 30% RWCs, when explosive cavitation events should cause movements of liquid water. Nevertheless, the thalli emitted UAEs at ~5% RWC. Accordingly, the medullary hyphae were partially shrunken at ~15% RWC, whereas they were completely shrunken at <5% RWC. These results do not support the hypothesis of hyphal cavitation and suggest that the UAEs originate from structural changes at hyphal level. The shrinking of hyphae is proposed as an adaptation to avoid cell damage at very low RWCs.","PeriodicalId":15820,"journal":{"name":"Journal of Experimental Botany","volume":" ","pages":"6579-6592"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141751888","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}

引用次数: 0