Adenine base editors (ABEs) produce precise A-to-G conversion in the genomic target sites without causing double-strand breaks. However, the hyperactive adenosine deaminase TadA8e raises safety concerns on genome-wide off-target edits. We engineered 11 chimeric proteins for ABEs (CP-ABEs) by embedding hyperactive TadA8e within Cas9 nickase to minimise the sgRNA-independent off-target effects. Four CP-ABEs exhibited robust on-target activity with minimal sgRNA-independent off-target edits. Then we developed four chimeric high-fidelity ABEs (CH-ABEs) to minimise both sgRNA-dependent and sgRNA-independent off-target effects by employing high-fidelity Cas9 variants. The CH-ABEs achieved reductions of up to 7.0-fold and 79.4-fold in the respective off-target edits, while generating 22.0%-72.4% homozygous and biallelic rice mutants. Whole-genome and whole-transcriptome sequencing (WGS/WTS) confirmed the specificity of CH-ABEs. Incorporating Sniper2L into CH-ABEs further enhanced both specificity and on-target activity. Two PAM-less SpRY variants (SpRY-K2, SpRY-KK) expanded the targeting scope of CP-ABEs and boosted activity by 80.0%. Furthermore, we demonstrated that CP-ABE8e-RYKK could discriminate paralogous targets in rice and successfully applied it to create herbicide-resistant rice by precisely installing the OsALS-K591E mutation.
{"title":"Cas9-Embedding Hyperactive TadA8e Confers Efficient and Highly Specific A-To-G Base Editing in Rice.","authors":"Jianjian Hu,Xue Li,Yuhong Gao,Yifan Guo,Yini Liu,Chen Wang,Gencheng Xu,Chaoyue Du,Shijia Liu,Zhigang Zhao,Yihua Wang,Yufeng Wu,Xiaoou Dong,Chao Li,Jianmin Wan","doi":"10.1111/pbi.70511","DOIUrl":"https://doi.org/10.1111/pbi.70511","url":null,"abstract":"Adenine base editors (ABEs) produce precise A-to-G conversion in the genomic target sites without causing double-strand breaks. However, the hyperactive adenosine deaminase TadA8e raises safety concerns on genome-wide off-target edits. We engineered 11 chimeric proteins for ABEs (CP-ABEs) by embedding hyperactive TadA8e within Cas9 nickase to minimise the sgRNA-independent off-target effects. Four CP-ABEs exhibited robust on-target activity with minimal sgRNA-independent off-target edits. Then we developed four chimeric high-fidelity ABEs (CH-ABEs) to minimise both sgRNA-dependent and sgRNA-independent off-target effects by employing high-fidelity Cas9 variants. The CH-ABEs achieved reductions of up to 7.0-fold and 79.4-fold in the respective off-target edits, while generating 22.0%-72.4% homozygous and biallelic rice mutants. Whole-genome and whole-transcriptome sequencing (WGS/WTS) confirmed the specificity of CH-ABEs. Incorporating Sniper2L into CH-ABEs further enhanced both specificity and on-target activity. Two PAM-less SpRY variants (SpRY-K2, SpRY-KK) expanded the targeting scope of CP-ABEs and boosted activity by 80.0%. Furthermore, we demonstrated that CP-ABE8e-RYKK could discriminate paralogous targets in rice and successfully applied it to create herbicide-resistant rice by precisely installing the OsALS-K591E mutation.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"3 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145807960","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}
Amanda Lopes, Omar Sandoval‐Ibáñez, Stéphanie Arrivault, David Rolo, F. Vanessa Loiacono, Alexander Erban, Daniel Karcher, Stephan Obst, Stephanie Ruf, Joachim Kopka, Ralph Bock
Hyaluronic acid (HA) is a glycosaminoglycan composed of alternating units of N‐acetylglucosamine and glucuronic acid. High moisture retention, viscoelasticity and biocompatibility are unique features that make HA polymers attractive compounds for medical applications and aesthetic purposes. Current synthesis of HA polymers relies on microorganisms and requires supply of glucose in bioreactors to produce glucose‐6‐phosphate and fructose‐6‐phosphate as precursors for HA biosynthesis. By contrast, photosynthetic organisms generate glucose‐6‐phosphate and fructose‐6‐phosphate as autotrophic products of CO 2 fixation via the Calvin‐Benson‐Bassham (CBB) cycle. Here we explored the possibility to harness chloroplast metabolism for the light‐driven production of HA in the model organism tobacco ( Nicotiana tabacum ). An operon of five streptococcal genes were introduced into the plastid genome of tobacco to drive HA‐synthesis by expression elements that confer low, medium or high expression levels. Photoautotrophic growth over the entire life cycle was only achieved in transplastomic lines with low transgene expression levels. Surprisingly, accumulation of HA polymers was observed only under heterotrophic growth conditions. Proteomic analysis revealed low accumulation levels of the first pathway enzyme in the transplastomic lines, and low contents of the final pathway enzyme (HA synthase) upon autotrophic growth. Altered abundances of proteins involved in photosynthesis and central metabolism were observed under autotrophic growth conditions, and metabolite profiling confirmed that photoautotrophic HA biosynthesis depleted CBB cycle derivatives and triggered plastid‐associated stress responses. Our work demonstrated the feasibility of tapping the CBB cycle for HA synthesis and identified bottlenecks for plant‐based production of carbohydrate polymers.
{"title":"Plastid Engineering for Photosynthesis‐Driven Synthesis of Hyaluronic Acid in Tobacco","authors":"Amanda Lopes, Omar Sandoval‐Ibáñez, Stéphanie Arrivault, David Rolo, F. Vanessa Loiacono, Alexander Erban, Daniel Karcher, Stephan Obst, Stephanie Ruf, Joachim Kopka, Ralph Bock","doi":"10.1111/pbi.70504","DOIUrl":"https://doi.org/10.1111/pbi.70504","url":null,"abstract":"Hyaluronic acid (HA) is a glycosaminoglycan composed of alternating units of N‐acetylglucosamine and glucuronic acid. High moisture retention, viscoelasticity and biocompatibility are unique features that make HA polymers attractive compounds for medical applications and aesthetic purposes. Current synthesis of HA polymers relies on microorganisms and requires supply of glucose in bioreactors to produce glucose‐6‐phosphate and fructose‐6‐phosphate as precursors for HA biosynthesis. By contrast, photosynthetic organisms generate glucose‐6‐phosphate and fructose‐6‐phosphate as autotrophic products of CO <jats:sub>2</jats:sub> fixation via the Calvin‐Benson‐Bassham (CBB) cycle. Here we explored the possibility to harness chloroplast metabolism for the light‐driven production of HA in the model organism tobacco ( <jats:styled-content style=\"fixed-case\"> <jats:italic>Nicotiana tabacum</jats:italic> </jats:styled-content> ). An operon of five streptococcal genes were introduced into the plastid genome of tobacco to drive HA‐synthesis by expression elements that confer low, medium or high expression levels. Photoautotrophic growth over the entire life cycle was only achieved in transplastomic lines with low transgene expression levels. Surprisingly, accumulation of HA polymers was observed only under heterotrophic growth conditions. Proteomic analysis revealed low accumulation levels of the first pathway enzyme in the transplastomic lines, and low contents of the final pathway enzyme (HA synthase) upon autotrophic growth. Altered abundances of proteins involved in photosynthesis and central metabolism were observed under autotrophic growth conditions, and metabolite profiling confirmed that photoautotrophic HA biosynthesis depleted CBB cycle derivatives and triggered plastid‐associated stress responses. Our work demonstrated the feasibility of tapping the CBB cycle for HA synthesis and identified bottlenecks for plant‐based production of carbohydrate polymers.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"16 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785896","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}
Saroj Kumar Sah, Zhiyang Zhai, Hai Shi, Jin Chai, Elen Deng, Jorg Schwender, Xiao‐Hong Yu, John Shanklin
Improving seed oil yield is essential for developing Camelina sativa as a sustainable biofuel crop. Fatty acid synthesis depends on the production of acetyl‐CoA from photosynthetically derived sugars. Trehalose 6‐phosphate (T6P), a proxy for sucrose availability, can link sugar status to plant growth and development. Synthesised by trehalose 6‐phosphate synthase (TPS) from UDP‐glucose and glucose‐6‐phosphate, T6P plays a regulatory role in metabolism. Our previous studies on Arabidopsis transgenic lines constitutively expressing the E. coli otsA (encoding TPS) showed increased T6P levels and seed triacylglycerol, along with stunted growth. In the present study we express otsA in camelina under the control of a seed‐specific Phaseolin promoter. Seeds of the resulting transgenic lines accumulated high levels of T6P, and a 15%–20% increase in total fatty acids and triacylglycerol compared to wild‐type. Molecular analysis showed the transgenic seeds had reduced SnRK1 activity, elevated WRI1 protein levels, and increased the levels of WRI1 and its target genes, along with enhanced rates of fatty acid synthesis that increased seed weights relative to wild type. Notably, the increase in oil did not affect seed protein levels but did reduce the soluble metabolite fraction. Crucially, seed‐specific expression of otsA mitigated the growth defects associated with constitutive otsA expression, and the transgenic lines showed normal seed development and germination. These findings demonstrate that targeted T6P modulation via seed‐specific otsA expression is an effective metabolic engineering strategy to boost oil production in camelina and potentially in other oilseed crops and bioenergy crops such as energycane, sorghum and miscanthus.
{"title":"Expression of a Bacterial Trehalose 6‐Phosphate Synthase Gene otsA in Camelina sativa Seeds Promotes the Channelling of Carbon Towards Oil Accumulation","authors":"Saroj Kumar Sah, Zhiyang Zhai, Hai Shi, Jin Chai, Elen Deng, Jorg Schwender, Xiao‐Hong Yu, John Shanklin","doi":"10.1111/pbi.70506","DOIUrl":"https://doi.org/10.1111/pbi.70506","url":null,"abstract":"Improving seed oil yield is essential for developing <jats:styled-content style=\"fixed-case\"> <jats:italic>Camelina sativa</jats:italic> </jats:styled-content> as a sustainable biofuel crop. Fatty acid synthesis depends on the production of acetyl‐CoA from photosynthetically derived sugars. Trehalose 6‐phosphate (T6P), a proxy for sucrose availability, can link sugar status to plant growth and development. Synthesised by trehalose 6‐phosphate synthase (TPS) from UDP‐glucose and glucose‐6‐phosphate, T6P plays a regulatory role in metabolism. Our previous studies on Arabidopsis transgenic lines constitutively expressing the <jats:italic> <jats:styled-content style=\"fixed-case\">E. coli</jats:styled-content> otsA </jats:italic> (encoding TPS) showed increased T6P levels and seed triacylglycerol, along with stunted growth. In the present study we express <jats:italic>otsA</jats:italic> in camelina under the control of a seed‐specific Phaseolin promoter. Seeds of the resulting transgenic lines accumulated high levels of T6P, and a 15%–20% increase in total fatty acids and triacylglycerol compared to wild‐type. Molecular analysis showed the transgenic seeds had reduced SnRK1 activity, elevated WRI1 protein levels, and increased the levels of WRI1 and its target genes, along with enhanced rates of fatty acid synthesis that increased seed weights relative to wild type. Notably, the increase in oil did not affect seed protein levels but did reduce the soluble metabolite fraction. Crucially, seed‐specific expression of <jats:italic>otsA</jats:italic> mitigated the growth defects associated with constitutive <jats:italic>otsA</jats:italic> expression, and the transgenic lines showed normal seed development and germination. These findings demonstrate that targeted T6P modulation via seed‐specific <jats:italic>otsA</jats:italic> expression is an effective metabolic engineering strategy to boost oil production in camelina and potentially in other oilseed crops and bioenergy crops such as energycane, sorghum and miscanthus.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"179 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785898","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}
Macronutrients nitrogen and phosphorus are essential for plant growth and development, thus being crucial for the productivity of crops. However, the molecular mechanism regulating the utilisation of nitrogen and phosphorus remains elusive. Here, we show that the wheat (Triticum aestivum L.) transcription factor PHOSPHATE STARVATION RESPONSE-LIKE7 (TaPHL7) regulates nitrogen and phosphorus utilisation. TaPHL7 binds to the promoter of TaGS1;3, encoding a key enzyme of nitrogen assimilation, to repress its expression. Nitrate relieves the transcriptional repression on a subset of nitrogen utilisation genes imposed by TaPHL7. Conversely, TaPHL7 activates the expression of a subset of Pi transporter genes, thus promoting both nitrogen utilisation and Pi acquisition. In developing seeds, TaPHL7 expression is progressively attenuated, leading to the increased expression of TaGS1;3, thus enhancing nitrogen reassimilation. Notably, mutations in TaPHL7 cause increased nitrogen remobilisation efficiency, early maturation and accelerated grain filling, eventually boosting grain yield. Moreover, TaPHL7-1A has been subjected to artificial selection during wheat breeding. We propose that TaPHL7 regulates the utilisation of nitrogen and phosphorus, thus representing a promising target for genetic improvement of wheat.
{"title":"TaPHL7 Transcription Factor Regulates Utilisation of Nitrogen and Phosphorus in Wheat.","authors":"Huali Wang,Zhiyong Zhang,Yafei Guo,Qing Wang,Xiaochun Wang,Xiaohui Ma,Jinqiang Nian,Shuping Xiong,Xinbo Lin,Yingyin Yao,Zhongfu Ni,Fei Lu,Jianru Zuo,Xinming Ma","doi":"10.1111/pbi.70493","DOIUrl":"https://doi.org/10.1111/pbi.70493","url":null,"abstract":"Macronutrients nitrogen and phosphorus are essential for plant growth and development, thus being crucial for the productivity of crops. However, the molecular mechanism regulating the utilisation of nitrogen and phosphorus remains elusive. Here, we show that the wheat (Triticum aestivum L.) transcription factor PHOSPHATE STARVATION RESPONSE-LIKE7 (TaPHL7) regulates nitrogen and phosphorus utilisation. TaPHL7 binds to the promoter of TaGS1;3, encoding a key enzyme of nitrogen assimilation, to repress its expression. Nitrate relieves the transcriptional repression on a subset of nitrogen utilisation genes imposed by TaPHL7. Conversely, TaPHL7 activates the expression of a subset of Pi transporter genes, thus promoting both nitrogen utilisation and Pi acquisition. In developing seeds, TaPHL7 expression is progressively attenuated, leading to the increased expression of TaGS1;3, thus enhancing nitrogen reassimilation. Notably, mutations in TaPHL7 cause increased nitrogen remobilisation efficiency, early maturation and accelerated grain filling, eventually boosting grain yield. Moreover, TaPHL7-1A has been subjected to artificial selection during wheat breeding. We propose that TaPHL7 regulates the utilisation of nitrogen and phosphorus, thus representing a promising target for genetic improvement of wheat.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"10 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145777261","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}
Chloroplasts are essential organelles responsible for photosynthesis, providing energy and metabolic intermediates required for plant growth and productivity. Chloroplast development is highly sensitive to environmental stresses such as drought, and this sensitivity is closely associated with growth inhibition and yield reduction under stress conditions. However, the molecular mechanisms governing this process remain largely elusive. In this study, we demonstrate that chloroplastic ROS metabolism plays a pivotal role in modulating chloroplast development in response to abiotic stress, and we identify OsFeSOD3 , which encodes a chloroplast‐localised iron superoxide dismutase, as a key regulator of this process. Time‐lapse visualisation of cellular ROS dynamics and characterisation of OsFeSOD3 ‐overexpressing rice showed that OsFeSOD3‐ mediated chloroplastic ROS metabolism is tightly associated with cytoplasmic ROS accumulation under stress conditions, and that overexpression of OsFeSOD3 is sufficient to enhance rice stress tolerance by reducing cellular ROS accumulation. Furthermore, agronomic trait analyses over 2 years of cultivation revealed that OsFeSOD3 ‐overexpressing rice exhibits a 33%–42% increase in grain yield under drought conditions compared with wild‐type plants, highlighting OsFeSOD3 as a promising genetic target for developing stress‐tolerant, high‐yielding crops. Moreover, phenotypic and molecular characterisation of OsFeSOD3 knock‐out mutants indicates that OsFeSOD3 functions as a PEP‐complex component regulating chloroplast biogenesis in rice, a role further supported by its direct interaction with other PEP‐complex proteins. Taken together, our findings suggest that OsFeSOD3 serves as a bifunctional regulator that coordinates chloroplastic ROS metabolism and chloroplast biogenesis in rice.
{"title":"OsFeSOD3 Functions as an Enzymatic Component of the PEP Complex, Bifunctionally Regulating Chloroplastic ROS Metabolism and Chloroplast Biogenesis in Rice","authors":"Deok Hyun Seo, Jiwoong Jung, Geupil Jang","doi":"10.1111/pbi.70508","DOIUrl":"https://doi.org/10.1111/pbi.70508","url":null,"abstract":"Chloroplasts are essential organelles responsible for photosynthesis, providing energy and metabolic intermediates required for plant growth and productivity. Chloroplast development is highly sensitive to environmental stresses such as drought, and this sensitivity is closely associated with growth inhibition and yield reduction under stress conditions. However, the molecular mechanisms governing this process remain largely elusive. In this study, we demonstrate that chloroplastic ROS metabolism plays a pivotal role in modulating chloroplast development in response to abiotic stress, and we identify <jats:italic>OsFeSOD3</jats:italic> , which encodes a chloroplast‐localised iron superoxide dismutase, as a key regulator of this process. Time‐lapse visualisation of cellular ROS dynamics and characterisation of <jats:italic>OsFeSOD3</jats:italic> ‐overexpressing rice showed that <jats:italic>OsFeSOD3‐</jats:italic> mediated chloroplastic ROS metabolism is tightly associated with cytoplasmic ROS accumulation under stress conditions, and that overexpression of <jats:italic>OsFeSOD3</jats:italic> is sufficient to enhance rice stress tolerance by reducing cellular ROS accumulation. Furthermore, agronomic trait analyses over 2 years of cultivation revealed that <jats:italic>OsFeSOD3</jats:italic> ‐overexpressing rice exhibits a 33%–42% increase in grain yield under drought conditions compared with wild‐type plants, highlighting <jats:italic>OsFeSOD3</jats:italic> as a promising genetic target for developing stress‐tolerant, high‐yielding crops. Moreover, phenotypic and molecular characterisation of <jats:italic>OsFeSOD3</jats:italic> knock‐out mutants indicates that OsFeSOD3 functions as a PEP‐complex component regulating chloroplast biogenesis in rice, a role further supported by its direct interaction with other PEP‐complex proteins. Taken together, our findings suggest that <jats:italic>OsFeSOD3</jats:italic> serves as a bifunctional regulator that coordinates chloroplastic ROS metabolism and chloroplast biogenesis in rice.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"9 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145765428","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}
Abraham Ontiveros‐Cisneros, Jule Salfeld, Sofia Paulsson, Bao‐Jian Ding, Hong‐Lei Wang, Magne Friberg, Christer Löfstedt, Olivier Van Aken
Bark beetle species of the genera Ips and Dendroctonus represent a threat to forests in both North America and Europe. Under normal circumstances, these beetles recycle dying trees into nutrients, but under certain conditions, growing populations can overcome healthy tree defenses and cause severe economic loss in forestry. The most economically relevant bark beetle species communicate with aggregation pheromones such as ipsdienol, cis ‐verbenol and trans‐ verbenol. These pheromones are currently used in synthetic baits as part of control strategies for bark beetles, although their chemical synthesis makes them expensive to use. Here, we explore the possibility of producing bark beetle pheromones in plant factories, since these compounds can be derived from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) from the mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathways in plants. By the combined expression of enzymes from plants and bark beetles, we show that Arabidopsis thaliana can produce the intermediates β‐myrcene (ipsdienol biosynthesis pathway) and α‐pinene (verbenol biosynthesis pathway). Furthermore, we were able to produce the final products cis‐ verbenol and trans‐ verbenol in stably transformed Arabidopsis, without the addition of external substrates. Finally, we achieved the production of verbenone, an anti‐aggregation pheromone derived from verbenol, which deters bark beetles from a host. These results are an important step towards using plants as biofactories for a cheaper and greener production of pheromones and repellent components for artificial baits.
{"title":"A Plant‐Based Platform for the Production of Bark Beetle Pheromones","authors":"Abraham Ontiveros‐Cisneros, Jule Salfeld, Sofia Paulsson, Bao‐Jian Ding, Hong‐Lei Wang, Magne Friberg, Christer Löfstedt, Olivier Van Aken","doi":"10.1111/pbi.70481","DOIUrl":"https://doi.org/10.1111/pbi.70481","url":null,"abstract":"Bark beetle species of the genera <jats:italic>Ips</jats:italic> and <jats:italic>Dendroctonus</jats:italic> represent a threat to forests in both North America and Europe. Under normal circumstances, these beetles recycle dying trees into nutrients, but under certain conditions, growing populations can overcome healthy tree defenses and cause severe economic loss in forestry. The most economically relevant bark beetle species communicate with aggregation pheromones such as ipsdienol, <jats:italic>cis</jats:italic> ‐verbenol and <jats:italic>trans‐</jats:italic> verbenol. These pheromones are currently used in synthetic baits as part of control strategies for bark beetles, although their chemical synthesis makes them expensive to use. Here, we explore the possibility of producing bark beetle pheromones in plant factories, since these compounds can be derived from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) from the mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathways in plants. By the combined expression of enzymes from plants and bark beetles, we show that <jats:styled-content style=\"fixed-case\"> <jats:italic>Arabidopsis thaliana</jats:italic> </jats:styled-content> can produce the intermediates β‐myrcene (ipsdienol biosynthesis pathway) and α‐pinene (verbenol biosynthesis pathway). Furthermore, we were able to produce the final products <jats:italic>cis‐</jats:italic> verbenol and <jats:italic>trans‐</jats:italic> verbenol in stably transformed Arabidopsis, without the addition of external substrates. Finally, we achieved the production of verbenone, an anti‐aggregation pheromone derived from verbenol, which deters bark beetles from a host. These results are an important step towards using plants as biofactories for a cheaper and greener production of pheromones and repellent components for artificial baits.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"1 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145765465","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}
Tengwei Yu, Zhikai Chang, Bingtang Chen, Lingtong Liu, Zhuyun Deng, Zizhang Wang, Tai Wang
Head rice yield (HRY) is a crucial quality trait that determines the final commodity yield and commercial value of rice. Conversely, chalkiness represents an undesirable appearance characteristic, significantly impairing rice marketability. Thus, developing rice germplasms with superior HRY and appearance traits is highly desirable for rice production and marketing. However, the master modules and regulatory networks underlying HRY and chalkiness remain largely unknown. Here, we demonstrate that the rice transcription factor OsMYB99 acts as a master regulator conferring high HRY and low chalkiness. Functional loss of OsMYB99 impairs cuticular wax biosynthesis and deposition in caryopses and causes accumulation of reactive oxygen species (ROS) in endosperms, consequently decreasing HRY and increasing chalkiness. Mechanistically, OsMYB99 functions as a transcription activator; it binds promoters and positively regulates the expression of wax biosynthesis gene OsGL1‐4 and ROS scavenger OsMT2b . OsGL1‐4 promotes cuticular wax biosynthesis and deposition in caryopses, while OsMT2b eliminates excess ROS in endosperms. Together, these actions lead to HRY enhancement and chalkiness reduction. Our study uncovers the master regulator OsMYB99 and its molecular network modulating HRY and chalkiness in rice, offering a strategy to improve these traits through modifying cuticular wax deposition and ROS production.
{"title":"OsMYB99 Modulates Grain Wax Biosynthesis and Redox Homeostasis to Control Head Rice Yield and Chalkiness","authors":"Tengwei Yu, Zhikai Chang, Bingtang Chen, Lingtong Liu, Zhuyun Deng, Zizhang Wang, Tai Wang","doi":"10.1111/pbi.70505","DOIUrl":"https://doi.org/10.1111/pbi.70505","url":null,"abstract":"Head rice yield (HRY) is a crucial quality trait that determines the final commodity yield and commercial value of rice. Conversely, chalkiness represents an undesirable appearance characteristic, significantly impairing rice marketability. Thus, developing rice germplasms with superior HRY and appearance traits is highly desirable for rice production and marketing. However, the master modules and regulatory networks underlying HRY and chalkiness remain largely unknown. Here, we demonstrate that the rice transcription factor OsMYB99 acts as a master regulator conferring high HRY and low chalkiness. Functional loss of <jats:italic>OsMYB99</jats:italic> impairs cuticular wax biosynthesis and deposition in caryopses and causes accumulation of reactive oxygen species (ROS) in endosperms, consequently decreasing HRY and increasing chalkiness. Mechanistically, OsMYB99 functions as a transcription activator; it binds promoters and positively regulates the expression of wax biosynthesis gene <jats:italic>OsGL1‐4</jats:italic> and ROS scavenger <jats:italic>OsMT2b</jats:italic> . OsGL1‐4 promotes cuticular wax biosynthesis and deposition in caryopses, while OsMT2b eliminates excess ROS in endosperms. Together, these actions lead to HRY enhancement and chalkiness reduction. Our study uncovers the master regulator OsMYB99 and its molecular network modulating HRY and chalkiness in rice, offering a strategy to improve these traits through modifying cuticular wax deposition and ROS production.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"34 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145765466","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}
Autophagy and the ubiquitin/26S proteasome system (UPS) play critical roles in the immune defence of the host against pathogen invasion. As a countermeasure, pathogens deploy effector proteins to subvert or hijack autophagy and UPS processes. However, it is unclear whether and how a single pathogen effector coordinately modulates both proteolytic systems. Here, we identified a RING finger E3 ligase of Citrus sinensis , CsRHY1A, that directly interacts with SDE4405, an effector protein from Candidatus Liberibacter asiaticus ( C Las), the causal agent of citrus Huanglongbing (HLB). CsRHY1A ubiquitinated SDE4405 at Lys87 and Lys92, causing SDE4405 degradation via the 26S proteasome. Furthermore, SDE4405 targeted the ubiquitin‐associated (UBA) domain of the autophagic receptor NEIGHBOR OF BRCA1 (CsNBR1) and competitively disrupted CsRHY1A‐mediated degradation by decreasing the ubiquitination of SDE4405. Lys87 and Lys92 of SDE4405 were required for its interactions with CsRHY1A and CsNBR1 and were essential for CsNBR1‐dependent stabilisation of SDE4405. SDE4405 also inhibited the binding of CsNBR1 to CsATG8s, suppressing CsNBR1‐mediated selective autophagic degradation of C Las effector protein SDE1. These findings reveal the sophisticated strategy of bacteria to counteract both autophagy and proteasome‐dependent degradation, providing opportunities for developing HLB‐resistant citrus varieties.
自噬和泛素/26S蛋白酶体系统（UPS）在宿主抵御病原体入侵的免疫防御中起着至关重要的作用。作为对策，病原体部署效应蛋白来破坏或劫持自噬和UPS过程。然而，目前尚不清楚单一病原体效应是否以及如何协调调节这两个蛋白水解系统。本研究中，我们鉴定了柑橘的RING finger E3连接酶CsRHY1A，该连接酶可直接与柑橘黄龙冰（HLB）病原菌亚洲解放候选菌（Candidatus Liberibacter asiaticus, C Las）的效应蛋白SDE4405相互作用。CsRHY1A在Lys87和Lys92位点泛素化SDE4405，导致SDE4405通过26S蛋白酶体降解。此外，SDE4405靶向BRCA1自噬受体邻居（CsNBR1）的泛素相关（UBA）结构域，并通过降低SDE4405的泛素化，竞争性地破坏了CsRHY1A介导的降解。SDE4405的Lys87和Lys92是其与CsRHY1A和CsNBR1相互作用所必需的，并且是SDE4405的CsNBR1依赖性稳定所必需的。SDE4405还抑制CsNBR1与CsATG8s的结合，抑制CsNBR1介导的C Las效应蛋白SDE1的选择性自噬降解。这些发现揭示了细菌对抗自噬和蛋白酶体依赖性降解的复杂策略，为开发抗HLB柑橘品种提供了机会。
{"title":"A Bacterial Effector Hijacks NBR1 to Modulate Both Autophagy and Ubiquitination‐Mediated Degradation That Promotes Bacterial Infection","authors":"Yaqian Shi, Fang Fang, Xuejin Cui, Hongwei Shi, Zaiyu Yang, Xueyi Li, Changyong Zhou, Xuefeng Wang","doi":"10.1111/pbi.70509","DOIUrl":"https://doi.org/10.1111/pbi.70509","url":null,"abstract":"Autophagy and the ubiquitin/26S proteasome system (UPS) play critical roles in the immune defence of the host against pathogen invasion. As a countermeasure, pathogens deploy effector proteins to subvert or hijack autophagy and UPS processes. However, it is unclear whether and how a single pathogen effector coordinately modulates both proteolytic systems. Here, we identified a RING finger E3 ligase of <jats:styled-content style=\"fixed-case\"> <jats:italic>Citrus sinensis</jats:italic> </jats:styled-content> , CsRHY1A, that directly interacts with SDE4405, an effector protein from <jats:italic>Candidatus</jats:italic> Liberibacter asiaticus ( <jats:italic>C</jats:italic> Las), the causal agent of citrus Huanglongbing (HLB). CsRHY1A ubiquitinated SDE4405 at Lys87 and Lys92, causing SDE4405 degradation via the 26S proteasome. Furthermore, SDE4405 targeted the ubiquitin‐associated (UBA) domain of the autophagic receptor NEIGHBOR OF BRCA1 (CsNBR1) and competitively disrupted CsRHY1A‐mediated degradation by decreasing the ubiquitination of SDE4405. Lys87 and Lys92 of SDE4405 were required for its interactions with CsRHY1A and CsNBR1 and were essential for CsNBR1‐dependent stabilisation of SDE4405. SDE4405 also inhibited the binding of CsNBR1 to CsATG8s, suppressing CsNBR1‐mediated selective autophagic degradation of <jats:italic>C</jats:italic> Las effector protein SDE1. These findings reveal the sophisticated strategy of bacteria to counteract both autophagy and proteasome‐dependent degradation, providing opportunities for developing HLB‐resistant citrus varieties.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"4 1","pages":""},"PeriodicalIF":13.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145765467","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}
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