Plant Physiology最新文献

The thylakoid membrane remodeling protein VIPP1 forms bundled oligomers in tobacco chloroplasts

IF 7.4 1区生物学

Plant Physiology Pub Date : 2025-04-08 DOI: 10.1093/plphys/kiaf137

Sarah W Gachie, Alexandre Muhire, Di Li, Akihiro Kawamoto, Noriko Takeda-Kamiya, Yumi Goto, Mayuko Sato, Kiminori Toyooka, Ryo Yoshimura, Tsuneaki Takami, Lingang Zhang, Genji Kurisu, Toru Terachi, Wataru Sakamoto

{"title":"The thylakoid membrane remodeling protein VIPP1 forms bundled oligomers in tobacco chloroplasts","authors":"Sarah W Gachie, Alexandre Muhire, Di Li, Akihiro Kawamoto, Noriko Takeda-Kamiya, Yumi Goto, Mayuko Sato, Kiminori Toyooka, Ryo Yoshimura, Tsuneaki Takami, Lingang Zhang, Genji Kurisu, Toru Terachi, Wataru Sakamoto","doi":"10.1093/plphys/kiaf137","DOIUrl":"https://doi.org/10.1093/plphys/kiaf137","url":null,"abstract":"The thylakoid membrane (TM) serves as the scaffold for oxygen-evolving photosynthesis, hosting the protein complexes responsible for the light reactions and ATP synthesis. Vesicle Inducing Protein in Plastid 1 (VIPP1), a key protein in TM remodeling, has been recognized as essential for TM homeostasis. In vitro studies of cyanobacterial VIPP1 demonstrated its ability to form large homo-oligomers (&gt; 2 MDa) manifesting as ring-like or filament-like assemblies associated with membranes. Similarly, VIPP1 in Chlamydomonas reinhardtii assembles into rods that encapsulate liposomes or into stacked spiral structures. However, the nature of VIPP1 assemblies in chloroplasts, particularly in Arabidopsis, remains uncharacterized. Here, we expressed Arabidopsis thaliana VIPP1 fused to GFP (AtVIPP1-GFP) in tobacco (Nicotiana tabacum) chloroplasts and performed transmission electron microscopy (TEM). A purified AtVIPP1-GFP fraction was enriched with long filamentous tubule-like structures. Detailed TEM observations of chloroplasts in fixed resin-embedded tissues identified VIPP1 assemblies in situ that appeared to colocalize with GFP fluorescence. Electron tomography demonstrated that the AtVIPP1 oligomers consisted of bundled filaments near membranes, some of which appeared connected to the TM or inner chloroplast envelope at their contact sites. The observed bundles were never detected in wild-type Arabidopsis but were observed in Arabidopsis vipp1 mutants expressing AtVIPP1-GFP. Taken together, we propose that the bundled filaments are the dominant AtVIPP1 oligomers that represent its static state in vivo.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"38 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143805690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Diphthamide formation in Arabidopsis requires DPH1-interacting DPH2 for light and oxidative stress resistance

IF 7.4 1区生物学

Plant Physiology Pub Date : 2025-04-07 DOI: 10.1093/plphys/kiaf128

Hongliang Zhang, Nadežda Janina, Koray Ütkür, Thirishika Manivannan, Lei Zhang, Lizhen Wang, Christopher Grefen, Raffael Schaffrath, Ute Krämer

{"title":"Diphthamide formation in Arabidopsis requires DPH1-interacting DPH2 for light and oxidative stress resistance","authors":"Hongliang Zhang, Nadežda Janina, Koray Ütkür, Thirishika Manivannan, Lei Zhang, Lizhen Wang, Christopher Grefen, Raffael Schaffrath, Ute Krämer","doi":"10.1093/plphys/kiaf128","DOIUrl":"https://doi.org/10.1093/plphys/kiaf128","url":null,"abstract":"Diphthamide is a post-translationally modified histidine residue of eukaryotic TRANSLATION ELONGATION FACTOR 2 (eEF2) and the target of diphtheria toxin in human cells. In yeast and mammals, the 4Fe-4S cluster-containing proteins Dph1 and Dph2 catalyze the first biosynthetic step of diphthamide formation. Here, we identify Arabidopsis (Arabidopsis thaliana) DPH2 and show that it is required for diphthamide biosynthesis, localizes to the cytosol and interacts physically with AtDPH1. Arabidopsis dph2 mutants form shorter primary roots and smaller rosettes than the wild type, similar to dph1 mutants which we characterized previously. Additionally, increased ribosomal -1 frameshifting error rates and attenuated TARGET OF RAPAMYCIN (TOR) kinase activity in dph2 mutants also phenocopy the dph1 mutant. Beyond the known heavy-metal hypersensitivity and heat shock tolerance of dph1, we show here that both dph1 and dph2 mutants are hypersensitive to elevated light intensities and oxidative stress, and that wild-type Arabidopsis seedlings accumulate diphthamide-unmodified eEF2 under oxidative stress. Both mutants share the deregulation of 1,186 transcripts associated with several environmental and hormone responses. AtDPH1 and AtDPH2 do not complement the corresponding mutants of Saccharomyces cerevisiae. In summary, DPH2 and DPH1 interact to function inter-dependently in diphthamide formation, the maintenance of translational fidelity, wild-type growth rates and TOR kinase activation, and they contribute to mitigating damage from elevated light intensities and oxidative stress. Under oxidative stress, a dose-dependent loss of diphthamide could potentiate downstream effects in a feed-forward loop. This work advances our understanding of translation and its interactions with growth regulation and stress responses in plants.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"10 2 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143805711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Nodule organogenesis in Medicago truncatula requires local stage-specific auxin biosynthesis and transport.

IF 6.5 1区生物学

Plant Physiology Pub Date : 2025-04-04 DOI: 10.1093/plphys/kiaf133

Ting Ting Xiao, Sophia Müller, Defeng Shen, Jieyu Liu, Kelvin Adema, Amber van Seters, Henk Franssen, Ton Bisseling, Olga Kulikova, Wouter Kohlen

{"title":"Nodule organogenesis in Medicago truncatula requires local stage-specific auxin biosynthesis and transport.","authors":"Ting Ting Xiao, Sophia Müller, Defeng Shen, Jieyu Liu, Kelvin Adema, Amber van Seters, Henk Franssen, Ton Bisseling, Olga Kulikova, Wouter Kohlen","doi":"10.1093/plphys/kiaf133","DOIUrl":"https://doi.org/10.1093/plphys/kiaf133","url":null,"abstract":"The importance of auxin in plant organ development, including root nodule formation, is well known. The spatiotemporal distribution pattern of auxin during nodule development has been illustrated using auxin reporter constructs. However, our understanding of how this pattern is established and maintained remains elusive. Here, we studied how the auxin gradient is associated with the spatiotemporal expression patterns of known auxin biosynthesis and transport genes at different stages of nodule development in Medicago (Medicago truncatula). In addition, we examined the Medicago PIN-FORMED10 (MtPIN10) expression pattern and polar positioning on the cell membrane during nodule primordium development to investigate auxin flux. RNA interference and the application of auxin biosynthesis inhibitors were used to demonstrate the importance of auxin biosynthesis and transport at the initial stages of nodulation. Our results show that upon rhizobium inoculation before the first cell divisions, a specific subset of Medicago YUCCA (MtYUC) and MtPIN genes, as well as Medicago LIKE AUXIN RESISTANT2 (MtLAX2), are expressed in the pericycle and contribute to the creation of an auxin maximum. Overall, we demonstrate that the dynamic spatiotemporal expression of both MtYUC and MtPIN genes results in specific auxin outputs during the different stages of nodule primordia and nodule meristem formation.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

A galactolipase activated by high light helps cells acclimate to stress in cyanobacteria

IF 7.4 1区生物学

Plant Physiology Pub Date : 2025-04-04 DOI: 10.1093/plphys/kiaf130

Nobuyuki Takatani, Makoto Uenosono, Yuya Senoo, Kazutaka Ikeda, Makiko Aichi, Tatsuo Omata

{"title":"A galactolipase activated by high light helps cells acclimate to stress in cyanobacteria","authors":"Nobuyuki Takatani, Makoto Uenosono, Yuya Senoo, Kazutaka Ikeda, Makiko Aichi, Tatsuo Omata","doi":"10.1093/plphys/kiaf130","DOIUrl":"https://doi.org/10.1093/plphys/kiaf130","url":null,"abstract":"In the cyanobacterium Synechococcus elongatus PCC 7942, high-light (HL) stress activates deacylation of the four major lipid classes in the membrane. To investigate the mechanism and the physiological relevance of the HL-activated lipid deacylation, we searched for lipase genes of S. elongatus by measuring in vitro lipase activity of recombinant proteins expressed in Escherichia coli. Three genes (lipB, lipC, and lipD) were identified as lipase genes out of 14 candidates, and lipB was found to be conserved in most cyanobacteria. His-tagged LipB protein showed acyl-hydrolyzing activity against galactolipids in vitro. In a strain deficient in acyl-acyl carrier protein synthetase and hence defective in the recycling of free fatty acids (FFA), HL-induced accumulation of FFA and lysogalactolipids was reduced by 45% by lipB inactivation, verifying that LipB is a lipase involved in the HL-induced deacylation of galactolipids. Deficiency of lipB in the WT background had no impact on PSII photoinhibition or its subsequent recovery; however, unlike WT cells, ΔlipB cells failed to quickly resume growth when irradiated with strong light (2,000 µmol photons m-2 s-1). The HL sensitivity of growth due to lipB deficiency was more pronounced under nitrogen-limiting conditions. The phenotype was rescued by wild-type LipB expression but not by inactive LipB variant expression. These results suggest that the deacylation of galactolipids by LipB helps cells acclimate to HL conditions by regulating factors other than PSII activity.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"18 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Multiscale Imaging Locates Thermogenic Tissues and Reveals the Role of Ca2+ in Floral Thermogenesis

IF 7.4 1区生物学

Plant Physiology Pub Date : 2025-04-04 DOI: 10.1093/plphys/kiaf131

Miao Yu, Siqin Wang, Lingdie Kong, Mengsha Huang, Jin Zhang, Jing Li, Ruohan Wang

{"title":"Multiscale Imaging Locates Thermogenic Tissues and Reveals the Role of Ca2+ in Floral Thermogenesis","authors":"Miao Yu, Siqin Wang, Lingdie Kong, Mengsha Huang, Jin Zhang, Jing Li, Ruohan Wang","doi":"10.1093/plphys/kiaf131","DOIUrl":"https://doi.org/10.1093/plphys/kiaf131","url":null,"abstract":"Floral thermogenesis is an ancient feature that facilitates mutualism between flowers and pollinators. Yet localization of specific thermogenic tissues within floral organs has received little attention. Here, we integrated infrared (IR) thermal imaging and micro X-ray fluorescence (μ-XRF) to localize the thermogenic tissues in the lotus (Nelumbo nucifera Gaertn.) receptacle. IR imaging preliminarily identified the primary thermogenic tissues of the receptacle as the carpels and epidermis. The calcium distribution visualized by μ-XRF complemented the results of IR imaging, indicating that the thermogenic tissues include the epidermis and the upper parts of the carpels. This ensures that heat reaches the chamber formed by the petals and receptacle over the shortest distance, thereby minimizing heat loss. Additionally, we observed a higher rate of Ca2+ transport from the apoplast to the cytosol and upregulation of genes associated with mitochondrial calcium uniporters (MCU) at the thermogenesis initiation stage as compared to the pre-thermogenic stage. Increasing the cytosolic Ca2+ (cCa2+) concentration reversed the inhibition of alternative respiratory pathways, further illustrating the close relationship between Ca2+ concentration and thermogenesis. Our research not only presents a precise method for identifying thermogenic tissues in plants but also demonstrates the evolutionary efforts of lotus to maximize energy utilization efficiency.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"16 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143775396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Ceratostigma willmottianum mineralizes atmospheric CO2 into CaCO3 in a high-calcium environment

IF 7.4 1区生物学

Plant Physiology Pub Date : 2025-04-04 DOI: 10.1093/plphys/kiaf134

Cailei Liu, Ting Lei, Yunlong Wang, Lijuan Yang, Jiani Li, Qibing Chen, Long Guo, Yirui Li, Zian Zhao, Niting Wen, Yichen Yin, Suping Gao

{"title":"Ceratostigma willmottianum mineralizes atmospheric CO2 into CaCO3 in a high-calcium environment","authors":"Cailei Liu, Ting Lei, Yunlong Wang, Lijuan Yang, Jiani Li, Qibing Chen, Long Guo, Yirui Li, Zian Zhao, Niting Wen, Yichen Yin, Suping Gao","doi":"10.1093/plphys/kiaf134","DOIUrl":"https://doi.org/10.1093/plphys/kiaf134","url":null,"abstract":"Calcium carbonate (CaCO3) biomineralization is an ancient evolutionary feature of life that plays a key role in environmental adaptation. In plants, CaCO3 deposition is found in several taxa; however, current knowledge of its formation and ecological adaptive implication is limited. Here, we used the chalk gland plant Ceratostigma willmottianum to gain insight into CaCO3 biomineralization. We found that secretion crystals are mainly composed of CaCO3 (&gt; 90%), and the chalk gland consists of sixteen cells with four secretory pores on the surface. CaCO3 accumulation was highly dependent on atmospheric carbon dioxide (CO2) and independent of soil dissolved inorganic carbon (DIC). CaCO3 accumulation occurred mainly during the day, with diurnal variations in the carbon source, mainly atmospheric CO2 during the day and metabolic CO2 at night. Hydration of CO2 to bicarbonate (HCO3) occurred within the leaves, and the reaction rate was controlled by the activity of extracellular carbonic anhydrases (CAs). C. willmottianum showed a high tolerance to calcium stress, potentially related to enhanced calcium compartmentalization and CaCO3 excretion in the chalk gland under high-calcium environments. The conversion of atmospheric CO2 into CaCO3 by C. willmottianum may represent an ecological adaptation of plants to high-calcium environments. These results provide cases and theoretical references for studying CaCO3 biomineralization mechanisms and plant calcium adaptation.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"37 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

MIZU-KUSSEI 1 regulates root hydrotropism and cytokinin signal transduction by interacting with cytokinin receptors.

IF 6.5 1区生物学

Plant Physiology Pub Date : 2025-04-04 DOI: 10.1093/plphys/kiaf129

Weihao Fu, Juan Shen, Liming He, Ling Wang, Jia Li, Jinke Chang

{"title":"MIZU-KUSSEI 1 regulates root hydrotropism and cytokinin signal transduction by interacting with cytokinin receptors.","authors":"Weihao Fu, Juan Shen, Liming He, Ling Wang, Jia Li, Jinke Chang","doi":"10.1093/plphys/kiaf129","DOIUrl":"https://doi.org/10.1093/plphys/kiaf129","url":null,"abstract":"Roots exhibit hydrotropism in response to moisture gradients to avoid drought stress. Several proteins have been reported to regulate this process, with MIZU-KUSSEI 1 (MIZ1) being identified as a pivotal regulator. Although most studies on the regulatory mechanisms of root hydrotropism have focused on MIZ1, the molecular mechanisms of MIZ1 are poorly understood. Here, we report that MIZ1 plays an essential role in regulating cytokinin signal transduction by interacting with the cytokinin receptors ARABIDOPSIS HISTIDINE KINASEs (AHKs) in Arabidopsis (Arabidopsis thaliana). The miz1-2 mutant exhibited a decreased response to cytokinins, whereas overexpressors of MIZ1 showed an increased response to cytokinins. The expression levels of two type-A Arabidopsis response regulators (ARRs) of cytokinins, ARR16 and ARR17, were downregulated, and their up-regulation by cytokinins was substantially attenuated in miz1-2 compared with those in Col-0. Overexpression of MIZ1 partially rescued the decreased response of the ahk2-5 ahk3-7 double mutant to cytokinins. MIZ1 can physically interact with AHKs, as revealed by yeast two-hybrid, bimolecular fluorescence complementation (BiFC), and co-immunoprecipitation (co-IP) assays. Mutants of cytokinin signal transduction, such as ahk2-5 ahk3-7 ahk4-2 and arr3 arr4 arr5 arr6 arr8 arr9 arr16-C arr17-C, showed a greatly reduced hydrotropic response, similar to miz1-2. Additionally, MIZ1 also regulates the homeostasis of cytokinins by controlling the expression of genes encoding their biosynthetic and catabolic enzymes. Our results reveal the critical role of MIZ1 in regulating the cytokinin signaling response, which is essential for the root hydrotropic response.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Vertical farming limitations and potential demonstrated by back-of-the-envelope calculations.

IF 6.5 1区生物学

Plant Physiology Pub Date : 2025-04-02 DOI: 10.1093/plphys/kiaf056

Samuel J Lovat, Εlad Noor, Ron Milo

{"title":"Vertical farming limitations and potential demonstrated by back-of-the-envelope calculations.","authors":"Samuel J Lovat, Εlad Noor, Ron Milo","doi":"10.1093/plphys/kiaf056","DOIUrl":"https://doi.org/10.1093/plphys/kiaf056","url":null,"abstract":"Improving food security and reducing the environmental footprint of food production is urgently needed to satisfy the growing global population in a time of climate, biodiversity and water pressures. Indoor vertical farming is largely independent of environmental conditions and is reported to reduce the land and water required for food production. However, vertical farming requires large amounts of energy. Based on the vertical farming energy cost, we derive from basic considerations a current minimum cost of ≈$10/kg dry plant matter. Vertical farming is therefore not currently competitive with dried cereals or pulses (e.g. wheat, rice and soybeans). We also show limited current competitiveness for products like tomatoes and lettuce, despite a low dry matter content. Whereas the environmental implications of vertical farming depend on the electricity source. Using the average newly installed electricity mix in recent years (predominantly solar and wind, with some coal, natural gas and bioenergy), vertical farming could substantially increase greenhouse gas emissions and has limited land benefits compared to conventional agriculture. Using exclusively electricity from photovoltaics, some environmental benefits could be achieved for crops with a low dry matter content like lettuce, but this is more limited for dried crops like wheat. The transparent calculations we provide here set out challenges for vertical farming and highlight that improvements in both the overall vertical farming energetic efficiency (≈1-2%), as well as low-impact electricity sources are needed in the future.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143773027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Increased chloroplast area in the rice bundle sheath through cell-specific perturbation of brassinosteroid signalling.

IF 6.5 1区生物学

Plant Physiology Pub Date : 2025-04-02 DOI: 10.1093/plphys/kiaf108

Lee Cackett, Leonie H Luginbuehl, Ross-William Hendron, Andrew R G Plackett, Susan Stanley, Lei Hua, Na Wang, Steven Kelly, Julian M Hibberd

{"title":"Increased chloroplast area in the rice bundle sheath through cell-specific perturbation of brassinosteroid signalling.","authors":"Lee Cackett, Leonie H Luginbuehl, Ross-William Hendron, Andrew R G Plackett, Susan Stanley, Lei Hua, Na Wang, Steven Kelly, Julian M Hibberd","doi":"10.1093/plphys/kiaf108","DOIUrl":"https://doi.org/10.1093/plphys/kiaf108","url":null,"abstract":"In the leaves of C3 species such as rice (Oryza sativa), mesophyll cells contain the largest compartment of photosynthetically active chloroplasts. In contrast, plants that use the derived and more efficient C4 photosynthetic pathway have a considerable chloroplast compartment in both bundle sheath and mesophyll cells. Accordingly, the evolution of C4 photosynthesis from the ancestral C3 state required an increased chloroplast compartment in the bundle sheath. Here, we investigated the potential to increase chloroplast compartment size in rice bundle sheath cells by manipulating brassinosteroid signalling. Treatment with brassinazole, a brassinosteroid biosynthesis inhibitor, raised leaf chlorophyll content and increased the number but decreased the area of chloroplasts in bundle sheath cells. Ubiquitous overexpression of the transcription factor-encoding BRASSINAZOLE RESISTANT 1 (OsBZR1) increased bundle sheath chloroplast area by up to 45%, but these plants became chlorotic. However, when OsBZR1 expression was driven by a bundle sheath-specific promoter, the negative effects on growth and viability were alleviated whilst chloroplast area still increased. In summary, we report a role for brassinosteroids in controlling chloroplast area and number in rice and conclude that cell-specific manipulation of brassinosteroid signalling can be used to manipulate the chloroplast compartment in rice bundle sheath cells.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Three Rho of Plants (ROP)-GTPase regulatory proteins control ROP-mediated alkaloid biosynthesis in Catharanthus roseus.

IF 6.5 1区生物学

Plant Physiology Pub Date : 2025-04-02 DOI: 10.1093/plphys/kiaf115

Anuj Sharma, Sruthi Mohan, Priyanka Gupta, Durgesh Parihar, Dinesh A Nagegowda

{"title":"Three Rho of Plants (ROP)-GTPase regulatory proteins control ROP-mediated alkaloid biosynthesis in Catharanthus roseus.","authors":"Anuj Sharma, Sruthi Mohan, Priyanka Gupta, Durgesh Parihar, Dinesh A Nagegowda","doi":"10.1093/plphys/kiaf115","DOIUrl":"https://doi.org/10.1093/plphys/kiaf115","url":null,"abstract":"Rho of Plants (ROP)-GTPase Regulatory Proteins (RGRPs) have been shown to control plant morphogenesis, development and immunity; however, their role in specialized metabolism remains unknown. Here, we demonstrate that specific RGRPs control monoterpene indole alkaloid (MIA) biosynthesis by interacting with distinct ROPs in Madagascar periwinkle (Catharanthus roseus). Among the five Guanine nucleotide Exchange Factors (GEFs), four GTPase-Activating Proteins (GAPs), and two GDP Dissociation Inhibitors (GDIs) identified in the C. roseus genome, only CrGEF1, CrGAP1, and CrGDI2 specifically interacted with CrROP3 and CrROP5. These RGRPs displayed distinct cytosolic and/or membrane localization patterns, with their transcripts predominantly expressed in aerial tissues. Functional studies revealed that CrGEF1 acts as a positive regulator of MIA biosynthesis, as silencing its gene led to a reduction in MIA production, while overexpression enhanced MIA levels. Conversely, CrGAP1 and CrGDI2 function as negative regulators, with silencing resulting in increased MIA production and overexpression causing reduced MIA levels. Notably, terminal truncated forms of these RGRPs showed interaction with CrROP3 or CrROP5 but failed to influence MIA biosynthesis, underscoring the importance of these domains in their regulatory functions. Overall, our findings uncover a mechanism by which distinct RGRPs coordinate with specific ROPs to regulate transcription factors and fine-tune MIA biosynthesis in C. roseus.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143773024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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