Hsing-Fun Hsu, Ya-Chun Li, Yi-Hsuan Shen, Chang-Hsien Yang
The standout characteristic of the orchid perianth is the transformation of the upper median petal into a distinctively formed lip, which gives orchid flowers their typically zygomorphic symmetry and makes them the most popular ornamental plants worldwide. To study orchid flower development, two WUSCHEL-related homeobox (WOX) genes, PaWOX3 and PaWOX3B, were identified in Phalaenopsis. PaWOX3 and PaWOX3B mRNAs accumulate abundantly during early reproductive development and perianths of young buds, significantly decreasing in mature flowers and absent in vegetative leaves and roots. PaWOX3 and PaWOX3B virus-induced gene silencing (VIGS) knockdown in Phalaenopsis significantly reduces floral bud numbers, suggesting that PaWOX3/PaWOX3B may be involved in flower initiation. Transgenic Arabidopsis ectopically expressing repressor forms of PaWOX3/PaWOX3B and their Oncidium ortholog, OnPRS, exhibit lateral organ development defects, implicating these genes likely have function in regulating growth and differentiation for lateral organs. Neither PaWOX3, PaWOX3B single nor PaWOX3/PaWOX3B double VIGS Phalaenopsis altered the flower morphology. Interestingly, double silencing of PaWOX3 or PaWOX3B with OAGL6-2, which controlled the identity/formation of lips, altered the symmetry of 'BigLip' produced in OAGL6-2 VIGS. This result indicated that the levels of PaWOX3/PaWOX3B are still sufficient to maintain the symmetry for the OAGL6-2 VIGS 'BigLip'. However, the symmetry of the OAGL6-2 VIGS 'BigLip' cannot be maintained once the expression of PaWOX3 or PaWOX3B is further reduced. Thus, in addition to controlling lip identity, this study further found that OAGL6-2 could cooperate with functionally redundant PaWOX3/PaWOX3B in maintaining the symmetric axis of lip.
{"title":"PaWOX3 and PaWOX3B Regulate Flower Number and the Lip Symmetry of Phalaenopsis.","authors":"Hsing-Fun Hsu, Ya-Chun Li, Yi-Hsuan Shen, Chang-Hsien Yang","doi":"10.1093/pcp/pcae069","DOIUrl":"10.1093/pcp/pcae069","url":null,"abstract":"<p><p>The standout characteristic of the orchid perianth is the transformation of the upper median petal into a distinctively formed lip, which gives orchid flowers their typically zygomorphic symmetry and makes them the most popular ornamental plants worldwide. To study orchid flower development, two WUSCHEL-related homeobox (WOX) genes, PaWOX3 and PaWOX3B, were identified in Phalaenopsis. PaWOX3 and PaWOX3B mRNAs accumulate abundantly during early reproductive development and perianths of young buds, significantly decreasing in mature flowers and absent in vegetative leaves and roots. PaWOX3 and PaWOX3B virus-induced gene silencing (VIGS) knockdown in Phalaenopsis significantly reduces floral bud numbers, suggesting that PaWOX3/PaWOX3B may be involved in flower initiation. Transgenic Arabidopsis ectopically expressing repressor forms of PaWOX3/PaWOX3B and their Oncidium ortholog, OnPRS, exhibit lateral organ development defects, implicating these genes likely have function in regulating growth and differentiation for lateral organs. Neither PaWOX3, PaWOX3B single nor PaWOX3/PaWOX3B double VIGS Phalaenopsis altered the flower morphology. Interestingly, double silencing of PaWOX3 or PaWOX3B with OAGL6-2, which controlled the identity/formation of lips, altered the symmetry of 'BigLip' produced in OAGL6-2 VIGS. This result indicated that the levels of PaWOX3/PaWOX3B are still sufficient to maintain the symmetry for the OAGL6-2 VIGS 'BigLip'. However, the symmetry of the OAGL6-2 VIGS 'BigLip' cannot be maintained once the expression of PaWOX3 or PaWOX3B is further reduced. Thus, in addition to controlling lip identity, this study further found that OAGL6-2 could cooperate with functionally redundant PaWOX3/PaWOX3B in maintaining the symmetric axis of lip.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141432646","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}
Hybridization generates biodiversity, and wide hybridization plays a pivotal role in enhancing and broadening the useful attributes of crops. The hybridization barrier between wheat and rice, the two most important cereals, was recently overcome by in vitro production of allopolyploid wheat-rice hybrid zygotes, which can develop and grow into mature plants. In the study, genomic sequences and compositions of the possible hybrid plants were investigated through short- and long-read sequencing analyses and fluorescence in situ hybridization (FISH)-based visualization. The possible hybrid possessed whole wheat nuclear and cytoplasmic DNAs and rice mitochondrial (mt) DNA, along with variable retention rates of rice mtDNA ranging from 11% to 47%. The rice mtDNA retained in the wheat cybrid, termed Oryzawheat, can be transmitted across generations. In addition to mitochondrial hybridization, translocation of rice chromosome 1 into wheat chromosome 6A was detected in a F1 hybrid individual. OryzaWheat can provide a new horizon for utilizing inter-subfamily genetic resources among wheat and rice belonging to different subfamilies, Pooideae and Ehrhartoideae, respectively.
{"title":"Wheat Cybrid Plants, OryzaWheat, Regenerated from Wheat-Rice Hybrid Zygotes via in Vitro Fertilization System Possess Wheat-Rice Hybrid Mitochondria.","authors":"Tety Maryenti, Shizuka Koshimizu, Nonoka Onda, Takayoshi Ishii, Kentaro Yano, Takashi Okamoto","doi":"10.1093/pcp/pcae074","DOIUrl":"10.1093/pcp/pcae074","url":null,"abstract":"<p><p>Hybridization generates biodiversity, and wide hybridization plays a pivotal role in enhancing and broadening the useful attributes of crops. The hybridization barrier between wheat and rice, the two most important cereals, was recently overcome by in vitro production of allopolyploid wheat-rice hybrid zygotes, which can develop and grow into mature plants. In the study, genomic sequences and compositions of the possible hybrid plants were investigated through short- and long-read sequencing analyses and fluorescence in situ hybridization (FISH)-based visualization. The possible hybrid possessed whole wheat nuclear and cytoplasmic DNAs and rice mitochondrial (mt) DNA, along with variable retention rates of rice mtDNA ranging from 11% to 47%. The rice mtDNA retained in the wheat cybrid, termed Oryzawheat, can be transmitted across generations. In addition to mitochondrial hybridization, translocation of rice chromosome 1 into wheat chromosome 6A was detected in a F1 hybrid individual. OryzaWheat can provide a new horizon for utilizing inter-subfamily genetic resources among wheat and rice belonging to different subfamilies, Pooideae and Ehrhartoideae, respectively.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11369819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141898111","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}
Qi Guo, Shayan Sarkar, Tracy Punshon, Ryan Tappero, J Bronwyn Barkla, Kendal D Hirschi
Research on elemental distribution in plants is crucial for understanding nutrient uptake, environmental adaptation, and optimizing agricultural practices for sustainable food production. Plant trichomes, with their self-contained structures and easy accessibility, offer a robust model system for investigating elemental repartitioning. Transport proteins, such as the four functional cation exchangers (CAXs) in Arabidopsis, are low-affinity, high-capacity transporters primarily located on the vacuole. Mutants in these transporters have been partially characterized, with one of the phenotypes of the CAX1 mutant being altered tolerance to low-oxygen conditions. A simple visual screen demonstrated trichome density and morphology in cax1 and quadruple CAX (cax1-4: qKO) mutants remained unaltered. Here we used SXRF (Synchrotron X-Ray Fluorescence) to show that trichomes in CAX-deficient lines accumulated high levels of chlorine, potassium, calcium, and manganese. Proteomic analysis on isolated Arabidopsis trichomes. showed changes in protein abundance in response to changes in element accumulation. The CAX mutants showed an increased abundance of plasma membrane ATPase and vacuolar H-pumping proteins, and proteins associated with water movement and endocytosis, while also showing changes in proteins associated with the regulation of plasmodesmata. These findings advance our understanding of the integration of CAX transport with elemental homeostasis within trichomes and shed light on how plants modulate protein abundance under conditions of altered elemental levels.
研究植物体内的元素分布对于了解养分吸收、环境适应以及优化农业实践以实现可持续粮食生产至关重要。植物毛状体具有自成一体的结构,易于接近,为研究元素再分配提供了一个强大的模型系统。转运蛋白,如拟南芥中的四种功能性阳离子交换体(CAXs),是一种低亲和性、高容量的转运体,主要位于液泡上。这些转运体的突变体已有部分特征,其中 CAX1 突变体的表型之一是对低氧条件的耐受性发生了改变。简单的视觉筛选表明,cax1 和四重 CAX(cax1-4: qKO)突变体的毛状体密度和形态没有改变。在这里,我们利用同步辐射 X 射线荧光(SXRF)显示,CAX 缺失株系的毛状体积累了大量的氯、钾、钙和锰。对分离的拟南芥毛状体进行的蛋白质组分析表明,蛋白质丰度的变化与元素积累的变化有关。CAX突变体的质膜ATP酶和液泡H-泵蛋白以及与水运动和内吞相关的蛋白丰度增加,同时与质膜调控相关的蛋白也发生了变化。这些发现加深了我们对CAX转运与毛状体内部元素平衡相结合的理解,并揭示了植物在元素水平改变的条件下如何调节蛋白质丰度。
{"title":"Proteomic Insights into Trichome Responses to Elevated Elemental Stress in Cation Exchanger (CAX) Mutants.","authors":"Qi Guo, Shayan Sarkar, Tracy Punshon, Ryan Tappero, J Bronwyn Barkla, Kendal D Hirschi","doi":"10.1093/pcp/pcae097","DOIUrl":"https://doi.org/10.1093/pcp/pcae097","url":null,"abstract":"<p><p>Research on elemental distribution in plants is crucial for understanding nutrient uptake, environmental adaptation, and optimizing agricultural practices for sustainable food production. Plant trichomes, with their self-contained structures and easy accessibility, offer a robust model system for investigating elemental repartitioning. Transport proteins, such as the four functional cation exchangers (CAXs) in Arabidopsis, are low-affinity, high-capacity transporters primarily located on the vacuole. Mutants in these transporters have been partially characterized, with one of the phenotypes of the CAX1 mutant being altered tolerance to low-oxygen conditions. A simple visual screen demonstrated trichome density and morphology in cax1 and quadruple CAX (cax1-4: qKO) mutants remained unaltered. Here we used SXRF (Synchrotron X-Ray Fluorescence) to show that trichomes in CAX-deficient lines accumulated high levels of chlorine, potassium, calcium, and manganese. Proteomic analysis on isolated Arabidopsis trichomes. showed changes in protein abundance in response to changes in element accumulation. The CAX mutants showed an increased abundance of plasma membrane ATPase and vacuolar H-pumping proteins, and proteins associated with water movement and endocytosis, while also showing changes in proteins associated with the regulation of plasmodesmata. These findings advance our understanding of the integration of CAX transport with elemental homeostasis within trichomes and shed light on how plants modulate protein abundance under conditions of altered elemental levels.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142111315","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}
Diurnal gene expression is a pervasive phenomenon occurring across all kingdoms of life, orchestrating adaptive responses to daily environmental fluctuations and thus enhancing organismal fitness. Our understanding of the plant circadian clock is primarily derived from studies in Arabidopsis and direct comparisons are difficult due to differences in gene family sizes. To this end, the identification of functional orthologs based on diurnal and tissue expression is necessary. The diurnal.plant.tools database constitutes a repository of gene expression profiles from 17 members of the Archaeplastida lineage, with built-in tools facilitating cross-species comparisons. In this database update, we expand the dataset with diurnal gene expression from 4 agriculturally significant crop species and Marchantia, a plant of evolutionary significance. Notably, the inclusion of diurnal gene expression data for Marchantia enables researchers to glean insights into the evolutionary trajectories of the circadian clock and other biological processes spanning from algae to angiosperms. Moreover, integrating diurnal gene expression data with datasets from related gene co-expression databases, such as CoNekt-Plants and CoNekt-Stress, which contain gene expression data for tissue and perturbation experiments, provides a comprehensive overview of gene functions across diverse biological contexts. This expanded database serves as a valuable resource for elucidating the intricacies of diurnal gene regulation and its evolutionary underpinnings in plant biology.
{"title":"Diurnal.plant.tools in 2024: expanding to Marchantia polymorpha and four angiosperms.","authors":"Qiao Wen Tan, Emmanuel Tan, Marek Mutwil","doi":"10.1093/pcp/pcae099","DOIUrl":"https://doi.org/10.1093/pcp/pcae099","url":null,"abstract":"<p><p>Diurnal gene expression is a pervasive phenomenon occurring across all kingdoms of life, orchestrating adaptive responses to daily environmental fluctuations and thus enhancing organismal fitness. Our understanding of the plant circadian clock is primarily derived from studies in Arabidopsis and direct comparisons are difficult due to differences in gene family sizes. To this end, the identification of functional orthologs based on diurnal and tissue expression is necessary. The diurnal.plant.tools database constitutes a repository of gene expression profiles from 17 members of the Archaeplastida lineage, with built-in tools facilitating cross-species comparisons. In this database update, we expand the dataset with diurnal gene expression from 4 agriculturally significant crop species and Marchantia, a plant of evolutionary significance. Notably, the inclusion of diurnal gene expression data for Marchantia enables researchers to glean insights into the evolutionary trajectories of the circadian clock and other biological processes spanning from algae to angiosperms. Moreover, integrating diurnal gene expression data with datasets from related gene co-expression databases, such as CoNekt-Plants and CoNekt-Stress, which contain gene expression data for tissue and perturbation experiments, provides a comprehensive overview of gene functions across diverse biological contexts. This expanded database serves as a valuable resource for elucidating the intricacies of diurnal gene regulation and its evolutionary underpinnings in plant biology.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142111313","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}
Conventional plant gene editing requires laborious tissue-culture-mediated transformation, which restricts the range of applicable plant species. In this study, we developed a heritable and tissue-culture-free gene editing method in Nicotiana benthamiana using tobacco ringspot virus (TRSV) as a vector for in planta delivery of Cas9 and single-guide RNA (sgRNA) to shoot apical meristems. Agrobacterium-mediated inoculation of the TRSV vector induced systemic and heritable gene editing in NbPDS. Transient downregulation of RNA silencing enhanced gene editing efficiency, resulting in an order of magnitude increase (0.8% to 13.2%) in the frequency of transgenerational gene editing. While the TRSV system had a preference for certain sgRNA sequences, co-inoculation of a TRSV vector carrying only Cas9 and a tobacco rattle virus vector carrying sgRNA successfully introduced systemic mutations with all five tested sgRNAs. Extensively gene-edited lateral shoots occasionally grew from plants inoculated with the virus vectors, of which the transgenerational gene editing frequency ranged up to 100%. This virus-mediated heritable gene editing method makes plant gene editing easy, requiring only the inoculation of non-transgenic plants with a virus vector(s) to obtain gene-edited individuals.
{"title":"Heritable Tissue-Culture-Free Gene Editing in Nicotiana benthamiana through Viral Delivery of SpCas9 and sgRNA.","authors":"Tetsuya Yoshida, Masayuki Ishikawa, Seiichi Toki, Kazuhiro Ishibashi","doi":"10.1093/pcp/pcae100","DOIUrl":"https://doi.org/10.1093/pcp/pcae100","url":null,"abstract":"<p><p>Conventional plant gene editing requires laborious tissue-culture-mediated transformation, which restricts the range of applicable plant species. In this study, we developed a heritable and tissue-culture-free gene editing method in Nicotiana benthamiana using tobacco ringspot virus (TRSV) as a vector for in planta delivery of Cas9 and single-guide RNA (sgRNA) to shoot apical meristems. Agrobacterium-mediated inoculation of the TRSV vector induced systemic and heritable gene editing in NbPDS. Transient downregulation of RNA silencing enhanced gene editing efficiency, resulting in an order of magnitude increase (0.8% to 13.2%) in the frequency of transgenerational gene editing. While the TRSV system had a preference for certain sgRNA sequences, co-inoculation of a TRSV vector carrying only Cas9 and a tobacco rattle virus vector carrying sgRNA successfully introduced systemic mutations with all five tested sgRNAs. Extensively gene-edited lateral shoots occasionally grew from plants inoculated with the virus vectors, of which the transgenerational gene editing frequency ranged up to 100%. This virus-mediated heritable gene editing method makes plant gene editing easy, requiring only the inoculation of non-transgenic plants with a virus vector(s) to obtain gene-edited individuals.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142111314","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}
Yoshiko Yamamoto-Negi, Takeshi Higa, Aino Komatsu, Kanta Sasaki, Kimitsune Ishizaki, Ryuichi Nishihama, Eiji Gotoh, Takayuki Kohchi, Noriyuki Suetsugu
Chloroplasts accumulate on the cell surface under weak light conditions to efficiently capture light but avoid strong light to minimize photodamage. The blue light receptor phototropin regulates the chloroplast movement in various plant species. In Arabidopsis thaliana, phototropin mediates the light-induced chloroplast movement and positioning via specialized actin filaments on the chloroplasts, chloroplast-actin filaments. KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT (KAC) and CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1) are pivotal for chloroplast-actin-based chloroplast movement and positioning in land plants. However, the mechanisms by which KAC and CHUP1 regulate chloroplast movement and positioning remain unclear. In this study, we characterized KAC and CHUP1 orthologs in the liverwort Marchantia polymorpha, MpKAC and MpCHUP1, respectively. Their knockout mutants, Mpkack° and Mpchup1k°, impaired the light-induced chloroplast movement. Although Mpchup1k° showed mild chloroplast aggregation, Mpkack° displayed severe chloroplast aggregation, suggesting the greater contribution of MpKAC to the chloroplast anchorage to the plasma membrane. Analysis of the subcellular localization of the functional MpKAC-Citrine indicated that MpKAC-Citrine formed a punctate structure on the plasma membrane. Structure-function analysis of MpKAC revealed that a deletion of the conserved C-terminal domain abrogates the targeting to the plasma membrane and its function. A deletion of the N-terminal motor domain retained the plasma membrane targeting but abrogates the formation of punctate structure and showed severe defect in the light-induced chloroplast movement. Our findings suggest that the formation of the punctate structure on the plasma membrane of MpKAC is essential for chloroplast movement.
{"title":"A kinesin-like protein, KAC, is required for light-induced and actin-based chloroplast movement in Marchantia polymorpha.","authors":"Yoshiko Yamamoto-Negi, Takeshi Higa, Aino Komatsu, Kanta Sasaki, Kimitsune Ishizaki, Ryuichi Nishihama, Eiji Gotoh, Takayuki Kohchi, Noriyuki Suetsugu","doi":"10.1093/pcp/pcae101","DOIUrl":"https://doi.org/10.1093/pcp/pcae101","url":null,"abstract":"<p><p>Chloroplasts accumulate on the cell surface under weak light conditions to efficiently capture light but avoid strong light to minimize photodamage. The blue light receptor phototropin regulates the chloroplast movement in various plant species. In Arabidopsis thaliana, phototropin mediates the light-induced chloroplast movement and positioning via specialized actin filaments on the chloroplasts, chloroplast-actin filaments. KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT (KAC) and CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1) are pivotal for chloroplast-actin-based chloroplast movement and positioning in land plants. However, the mechanisms by which KAC and CHUP1 regulate chloroplast movement and positioning remain unclear. In this study, we characterized KAC and CHUP1 orthologs in the liverwort Marchantia polymorpha, MpKAC and MpCHUP1, respectively. Their knockout mutants, Mpkack° and Mpchup1k°, impaired the light-induced chloroplast movement. Although Mpchup1k° showed mild chloroplast aggregation, Mpkack° displayed severe chloroplast aggregation, suggesting the greater contribution of MpKAC to the chloroplast anchorage to the plasma membrane. Analysis of the subcellular localization of the functional MpKAC-Citrine indicated that MpKAC-Citrine formed a punctate structure on the plasma membrane. Structure-function analysis of MpKAC revealed that a deletion of the conserved C-terminal domain abrogates the targeting to the plasma membrane and its function. A deletion of the N-terminal motor domain retained the plasma membrane targeting but abrogates the formation of punctate structure and showed severe defect in the light-induced chloroplast movement. Our findings suggest that the formation of the punctate structure on the plasma membrane of MpKAC is essential for chloroplast movement.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142111312","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}
Plants maintain nutrient homeostasis by controlling the activities and abundance of nutrient transporters. In Arabidopsis thaliana, the borate (B) transporter BOR1 plays a role in the efficient translocation of B under low-B conditions. BOR1 undergoes polyubiquitination in the presence of sufficient B and is then transported to the vacuole via multivesicular bodies (MVBs) to prevent B accumulation in tissues at a toxic level. A previous study indicated that BOR1 physically interacts with µ subunits of adaptor protein complexes AP-3 and AP-4, both involved in vacuolar sorting pathways. In this study, we investigated the roles of AP-3 and AP-4 subunits in BOR1 trafficking in Arabidopsis. The lack of AP-3 subunits did not affect either vacuolar sorting or polar localization of BOR1-GFP, whereas the absence of AP-4 subunits resulted in a delay in high-B-induced vacuolar sorting without affecting polar localization. Super-resolution microscopy revealed a rapid sorting of BOR1-GFP into AP-4-positive spots in the trans-Golgi network (TGN) upon high-B supply. These results indicate that AP-4 is involved in sequestration of ubiquitinated BOR1 into a TGN-specific subdomain "vacuolar-trafficking zone," and is required for efficient sorting to MVB and vacuole. Our findings elucidate the rapid vacuolar sorting process facilitated by AP-4 in plant nutrient transporters.
{"title":"Rapid Vacuolar Sorting of the Borate Transporter BOR1 Requires the Adaptor Protein Complex AP-4 in Arabidopsis.","authors":"Akira Yoshinari, Yutaro Shimizu, Takuya Hosokawa, Akihiko Nakano, Tomohiro Uemura, Junpei Takano","doi":"10.1093/pcp/pcae096","DOIUrl":"https://doi.org/10.1093/pcp/pcae096","url":null,"abstract":"<p><p>Plants maintain nutrient homeostasis by controlling the activities and abundance of nutrient transporters. In Arabidopsis thaliana, the borate (B) transporter BOR1 plays a role in the efficient translocation of B under low-B conditions. BOR1 undergoes polyubiquitination in the presence of sufficient B and is then transported to the vacuole via multivesicular bodies (MVBs) to prevent B accumulation in tissues at a toxic level. A previous study indicated that BOR1 physically interacts with µ subunits of adaptor protein complexes AP-3 and AP-4, both involved in vacuolar sorting pathways. In this study, we investigated the roles of AP-3 and AP-4 subunits in BOR1 trafficking in Arabidopsis. The lack of AP-3 subunits did not affect either vacuolar sorting or polar localization of BOR1-GFP, whereas the absence of AP-4 subunits resulted in a delay in high-B-induced vacuolar sorting without affecting polar localization. Super-resolution microscopy revealed a rapid sorting of BOR1-GFP into AP-4-positive spots in the trans-Golgi network (TGN) upon high-B supply. These results indicate that AP-4 is involved in sequestration of ubiquitinated BOR1 into a TGN-specific subdomain \"vacuolar-trafficking zone,\" and is required for efficient sorting to MVB and vacuole. Our findings elucidate the rapid vacuolar sorting process facilitated by AP-4 in plant nutrient transporters.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142111328","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}
A diverse range of commensal bacteria inhabit the rhizosphere, influencing host plant growth and responses to biotic and abiotic stresses. While root-released nutrients can define soil microbial habitats, the bacterial factors involved in plant-microbe interactions are not well characterized. In this study, we investigated the colonization patterns of two plant disease biocontrol agents, Allorhizobium vitis VAR03-1 and Pseudomonas protegens Cab57, in the rhizosphere of Arabidopsis thaliana using Murashige and Skoog (MS) agar medium. VAR03-1 formed colonies even at a distance from the roots, preferentially in the upper part, while Cab57 colonized only the root surface. The addition of sucrose to the agar medium resulted in excessive proliferation of VAR03-1, similar to its pattern without sucrose, whereas Cab57 formed colonies only near the root surface. Overgrowth of both bacterial strains upon nutrient supplementation inhibited host growth, independent of plant immune responses. This inhibition was reduced in the VAR03-1 ΔrecA mutant, which exhibited increased biofilm formation, suggesting that some activities associated with the free-living lifestyle rather than the sessile lifestyle may be detrimental to host growth. VAR03-1 grew in liquid MS medium with sucrose alone, while Cab57 required both sucrose and organic acids. Supplementation of sugars and organic acids allowed both bacterial strains to grow near and away from Arabidopsis roots in MS agar. These results suggest that nutrient requirements for bacterial growth may determine their growth habitats in the rhizosphere, with nutrients released in root exudates potentially acting as a limiting factor in harnessing microbiota.
{"title":"Nutrient requirements shape the preferential habitat of Allorhizobium vitis VAR03-1, a commensal bacterium, in the rhizosphere of Arabidopsis thaliana.","authors":"Niarsi Merry Hemelda, Jiyuan Bao, Megumi Watanabe, Hidenori Matsui, Kazuhiro Toyoda, Yuki Ichinose, Yoshiteru Noutoshi","doi":"10.1093/pcp/pcae091","DOIUrl":"https://doi.org/10.1093/pcp/pcae091","url":null,"abstract":"<p><p>A diverse range of commensal bacteria inhabit the rhizosphere, influencing host plant growth and responses to biotic and abiotic stresses. While root-released nutrients can define soil microbial habitats, the bacterial factors involved in plant-microbe interactions are not well characterized. In this study, we investigated the colonization patterns of two plant disease biocontrol agents, Allorhizobium vitis VAR03-1 and Pseudomonas protegens Cab57, in the rhizosphere of Arabidopsis thaliana using Murashige and Skoog (MS) agar medium. VAR03-1 formed colonies even at a distance from the roots, preferentially in the upper part, while Cab57 colonized only the root surface. The addition of sucrose to the agar medium resulted in excessive proliferation of VAR03-1, similar to its pattern without sucrose, whereas Cab57 formed colonies only near the root surface. Overgrowth of both bacterial strains upon nutrient supplementation inhibited host growth, independent of plant immune responses. This inhibition was reduced in the VAR03-1 ΔrecA mutant, which exhibited increased biofilm formation, suggesting that some activities associated with the free-living lifestyle rather than the sessile lifestyle may be detrimental to host growth. VAR03-1 grew in liquid MS medium with sucrose alone, while Cab57 required both sucrose and organic acids. Supplementation of sugars and organic acids allowed both bacterial strains to grow near and away from Arabidopsis roots in MS agar. These results suggest that nutrient requirements for bacterial growth may determine their growth habitats in the rhizosphere, with nutrients released in root exudates potentially acting as a limiting factor in harnessing microbiota.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142056324","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}
Oxygenic phototrophs use chlorophylls (Chls) as photosynthetically active pigments. A variety of Chl molecules have been found in photosynthetic eukaryotes including green plants, algae, and cyanobacteria. Here we review their molecular structures with stereochemistry, occurrence in light-harvesting antennas and reaction centers, biosyntheses in the late stage, chemical stabilities, and visible absorption maxima in diethyl ether. The observed maxima are comparable to those of semisynthetic Chl analogs, methyl pyropheophorbides, in dichloromethane. The effects of their peripheral substituents and core π-conjugation on the maxima of the monomeric states are discussed. Notably, the oxidation along the molecular x-axis in Chl-a produces its accessory pigments, Chls-b/c, and introduction of an electron-withdrawing formyl group along the y-axis perpendicular to the x-axis affords far-red light absorbing Chls-d/f.
含氧光养生物使用叶绿素(Chls)作为光合作用活性色素。在光合真核生物(包括绿色植物、藻类和蓝藻)中发现了多种叶绿素分子。在此,我们回顾了它们的分子结构和立体化学特征、在光收集天线和反应中心中的存在、后期生物合成、化学稳定性以及在二乙醚中的可见吸收最大值。观察到的最大值与二氯甲烷中的半合成螯合态类似物甲基吡咯烷的最大值相当。本文讨论了外围取代基和核心π-共轭对单体态最大值的影响。值得注意的是,在 Chl-a 中,沿分子 x 轴的氧化作用会产生其附属色素 Chls-b/c,而沿与 x 轴垂直的 y 轴引入一个抽电子的甲酰基则会产生吸收远红光的 Chls-d/f。
{"title":"Chlorophyll Pigments and Their Synthetic Analogs.","authors":"Hitoshi Tamiaki, Saki Kichishima","doi":"10.1093/pcp/pcae094","DOIUrl":"https://doi.org/10.1093/pcp/pcae094","url":null,"abstract":"<p><p>Oxygenic phototrophs use chlorophylls (Chls) as photosynthetically active pigments. A variety of Chl molecules have been found in photosynthetic eukaryotes including green plants, algae, and cyanobacteria. Here we review their molecular structures with stereochemistry, occurrence in light-harvesting antennas and reaction centers, biosyntheses in the late stage, chemical stabilities, and visible absorption maxima in diethyl ether. The observed maxima are comparable to those of semisynthetic Chl analogs, methyl pyropheophorbides, in dichloromethane. The effects of their peripheral substituents and core π-conjugation on the maxima of the monomeric states are discussed. Notably, the oxidation along the molecular x-axis in Chl-a produces its accessory pigments, Chls-b/c, and introduction of an electron-withdrawing formyl group along the y-axis perpendicular to the x-axis affords far-red light absorbing Chls-d/f.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142036757","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}
Research on chlorophyll degradation has progressed significantly in recent decades. In the 1990s, the structure of linear tetrapyrrole, which is unambiguously a chlorophyll degradation product, was determined. From the 2000s until the 2010s, the major enzymes involved in chlorophyll degradation were identified, and the pheophorbide a oxygenase/phyllobilin pathway was established. This degradation pathway encompasses several steps: (1) initial conversion of chlorophyll b to 7-hydroxymethyl chlorophyll a; (2) conversion of 7-hydroxymethyl chlorophyll a to chlorophyll a; (3) dechelation of chlorophyll a to pheophytin a; (4) dephytylation of pheophytin a to pheophorbide a; (5) opening of the macrocycle to yield a red chlorophyll catabolite; and (6) conversion of red chlorophyll catabolite to phyllobilins. This pathway converts potentially harmful chlorophyll into safe molecules of phyllobilins, which are stored in the central vacuole of terrestrial plants. The expression of chlorophyll-degrading enzymes is mediated by various transcription factors and influenced by light conditions, stress, and plant hormones. Chlorophyll degradation is differently regulated in different organs and developmental stages of plants. The initiation of chlorophyll degradation induces the further expression of chlorophyll-degrading enzymes, resulting in the acceleration of chlorophyll degradation. Chlorophyll degradation was initially considered the last reaction in senescence; however, chlorophyll degradation plays crucial roles in enhancing senescence, degrading chlorophyll-protein complexes, forming photosystem II, and maintaining seed quality. Therefore, controlling chlorophyll degradation has important agricultural applications.
近几十年来,有关叶绿素降解的研究取得了重大进展。20 世纪 90 年代,确定了线性四吡咯的结构,它明确是叶绿素降解产物。从 2000 年代到 2010 年代,参与叶绿素降解的主要酶被确定,并建立了叶绿素加氧酶/叶绿素途径。这一降解途径包括几个步骤:(1) 将叶绿素 b 初步转化为 7- 羟甲基叶绿素 a;(2) 将 7- 羟甲基叶绿素 a 转化为叶绿素 a;(3) 将叶绿素 a 脱螯转化为叶绿素 a;(4) 将叶绿素 a 脱去乙酰基转化为叶绿素 a;(5) 打开大环,生成红叶绿素异构体;(6) 将红叶绿素异构体转化为叶绿素。这一途径可将潜在的有害叶绿素转化为安全的叶绿素分子,储存在陆生植物的中央液泡中。叶绿素降解酶的表达由各种转录因子介导,并受光照条件、胁迫和植物激素的影响。叶绿素降解在植物的不同器官和发育阶段受到不同的调控。叶绿素降解的启动会诱导叶绿素降解酶的进一步表达,从而加速叶绿素降解。叶绿素降解最初被认为是衰老的最后一个反应;然而,叶绿素降解在促进衰老、降解叶绿素-蛋白质复合物、形成光系统 II 和保持种子质量方面发挥着至关重要的作用。因此,控制叶绿素降解具有重要的农业应用价值。
{"title":"Chlorophyll Degradation and its Physiological Function.","authors":"Ayumi Tanaka, Hisashi Ito","doi":"10.1093/pcp/pcae093","DOIUrl":"https://doi.org/10.1093/pcp/pcae093","url":null,"abstract":"<p><p>Research on chlorophyll degradation has progressed significantly in recent decades. In the 1990s, the structure of linear tetrapyrrole, which is unambiguously a chlorophyll degradation product, was determined. From the 2000s until the 2010s, the major enzymes involved in chlorophyll degradation were identified, and the pheophorbide a oxygenase/phyllobilin pathway was established. This degradation pathway encompasses several steps: (1) initial conversion of chlorophyll b to 7-hydroxymethyl chlorophyll a; (2) conversion of 7-hydroxymethyl chlorophyll a to chlorophyll a; (3) dechelation of chlorophyll a to pheophytin a; (4) dephytylation of pheophytin a to pheophorbide a; (5) opening of the macrocycle to yield a red chlorophyll catabolite; and (6) conversion of red chlorophyll catabolite to phyllobilins. This pathway converts potentially harmful chlorophyll into safe molecules of phyllobilins, which are stored in the central vacuole of terrestrial plants. The expression of chlorophyll-degrading enzymes is mediated by various transcription factors and influenced by light conditions, stress, and plant hormones. Chlorophyll degradation is differently regulated in different organs and developmental stages of plants. The initiation of chlorophyll degradation induces the further expression of chlorophyll-degrading enzymes, resulting in the acceleration of chlorophyll degradation. Chlorophyll degradation was initially considered the last reaction in senescence; however, chlorophyll degradation plays crucial roles in enhancing senescence, degrading chlorophyll-protein complexes, forming photosystem II, and maintaining seed quality. Therefore, controlling chlorophyll degradation has important agricultural applications.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142036756","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}