Fabien Sénéchal, Sarah Robinson, Evert Van Schaik, Martine Trévisan, Prashant Saxena, Didier Reinhardt, Christian Fankhauser
Plants growing with neighbors compete for light and consequently increase the growth of their vegetative organs to enhance access to sunlight. This response, called shade avoidance syndrome (SAS), involves photoreceptors such as phytochromes as well as phytochrome interacting factors (PIFs), which regulate the expression of growth‐mediating genes. Numerous cell wall‐related genes belong to the putative targets of PIFs, and the importance of cell wall modifications for enabling growth was extensively shown in developmental models such as dark‐grown hypocotyl. However, the contribution of the cell wall in the growth of de‐etiolated seedlings regulated by shade cues remains poorly established. Through analyses of mechanical and biochemical properties of the cell wall coupled with transcriptomic analysis of cell wall‐related genes from previously published data, we provide evidence suggesting that cell wall modifications are important for neighbor proximity‐induced elongation. Further analysis using loss‐of‐function mutants impaired in the synthesis and remodeling of the main cell wall polymers corroborated this. We focused on the cgr2cgr3 double mutant that is defective in methylesterification of homogalacturonan (HG)‐type pectins. By following hypocotyl growth kinetically and spatially and analyzing the mechanical and biochemical properties of cell walls, we found that methylesterification of HG‐type pectins was required to enable global cell wall modifications underlying neighbor proximity‐induced hypocotyl growth. Collectively, our work suggests that plant competition for light induces changes in the expression of numerous cell wall genes to enable modifications in biochemical and mechanical properties of cell walls that contribute to neighbor proximity‐induced growth.
{"title":"Pectin methylesterification state and cell wall mechanical properties contribute to neighbor proximity‐induced hypocotyl growth in Arabidopsis","authors":"Fabien Sénéchal, Sarah Robinson, Evert Van Schaik, Martine Trévisan, Prashant Saxena, Didier Reinhardt, Christian Fankhauser","doi":"10.1002/pld3.584","DOIUrl":"https://doi.org/10.1002/pld3.584","url":null,"abstract":"Plants growing with neighbors compete for light and consequently increase the growth of their vegetative organs to enhance access to sunlight. This response, called shade avoidance syndrome (SAS), involves photoreceptors such as phytochromes as well as phytochrome interacting factors (PIFs), which regulate the expression of growth‐mediating genes. Numerous cell wall‐related genes belong to the putative targets of PIFs, and the importance of cell wall modifications for enabling growth was extensively shown in developmental models such as dark‐grown hypocotyl. However, the contribution of the cell wall in the growth of de‐etiolated seedlings regulated by shade cues remains poorly established. Through analyses of mechanical and biochemical properties of the cell wall coupled with transcriptomic analysis of cell wall‐related genes from previously published data, we provide evidence suggesting that cell wall modifications are important for neighbor proximity‐induced elongation. Further analysis using loss‐of‐function mutants impaired in the synthesis and remodeling of the main cell wall polymers corroborated this. We focused on the <jats:italic>cgr2cgr3</jats:italic> double mutant that is defective in methylesterification of homogalacturonan (HG)‐type pectins. By following hypocotyl growth kinetically and spatially and analyzing the mechanical and biochemical properties of cell walls, we found that methylesterification of HG‐type pectins was required to enable global cell wall modifications underlying neighbor proximity‐induced hypocotyl growth. Collectively, our work suggests that plant competition for light induces changes in the expression of numerous cell wall genes to enable modifications in biochemical and mechanical properties of cell walls that contribute to neighbor proximity‐induced growth.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"38 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140634427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juan Alejandro Perdomo, Joanna C. Scales, Wing-Sham Lee, Kostya Kanyuka, Elizabete Carmo-Silva
Rubisco activase (Rca) is an essential photosynthetic enzyme that removes inhibitors from the catalytic sites of the carboxylating enzyme Rubisco. In wheat, Rca is composed of one longer 46 kDa α-isoform and two shorter 42 kDa β-isoforms encoded by the genes TaRca1 and TaRca2. TaRca1 produces a single transcript from which a short 1β-isoform is expressed, whereas two alternative transcripts are generated from TaRca2 directing expression of either a long 2α-isoform or a short 2β-isoform. The 2β isoform is similar but not identical to 1β. Here, virus-induced gene silencing (VIGS) was used to silence the different TaRca transcripts. Abundance of the transcripts and the respective protein isoforms was then evaluated in the VIGS-treated and control plants. Remarkably, treatment with the construct specifically targeting TaRca1 efficiently decreased expression not only of TaRca1 but also of the two alternative TaRca2 transcripts. Similarly, specific targeting of the TaRca2 transcript encoding a long isoform TaRca2α resulted in silencing of both TaRca2 alternative transcripts. The corresponding protein isoforms decreased in abundance. These findings indicate concomitant down-regulation of TaRca1 and TaRca2 at both transcript and protein levels and may impact the feasibility of altering the relative abundance of Rca isoforms in wheat.
{"title":"Down-regulation of wheat Rubisco activase isoforms expression by virus-induced gene silencing","authors":"Juan Alejandro Perdomo, Joanna C. Scales, Wing-Sham Lee, Kostya Kanyuka, Elizabete Carmo-Silva","doi":"10.1002/pld3.583","DOIUrl":"https://doi.org/10.1002/pld3.583","url":null,"abstract":"Rubisco activase (Rca) is an essential photosynthetic enzyme that removes inhibitors from the catalytic sites of the carboxylating enzyme Rubisco. In wheat, Rca is composed of one longer 46 kDa α-isoform and two shorter 42 kDa β-isoforms encoded by the genes <i>TaRca1</i> and <i>TaRca2</i>. <i>TaRca1</i> produces a single transcript from which a short 1β-isoform is expressed, whereas two alternative transcripts are generated from <i>TaRca2</i> directing expression of either a long 2α-isoform or a short 2β-isoform. The 2β isoform is similar but not identical to 1β. Here, virus-induced gene silencing (VIGS) was used to silence the different <i>TaRca</i> transcripts. Abundance of the transcripts and the respective protein isoforms was then evaluated in the VIGS-treated and control plants. Remarkably, treatment with the construct specifically targeting <i>TaRca1</i> efficiently decreased expression not only of <i>TaRca1</i> but also of the two alternative <i>TaRca2</i> transcripts. Similarly, specific targeting of the <i>TaRca2</i> transcript encoding a long isoform <i>TaRca2α</i> resulted in silencing of both <i>TaRca2</i> alternative transcripts. The corresponding protein isoforms decreased in abundance. These findings indicate concomitant down-regulation of <i>TaRca1</i> and <i>TaRca2</i> at both transcript and protein levels and may impact the feasibility of altering the relative abundance of Rca isoforms in wheat.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"51 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140564929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jakob Lang, Sergio E. Ramos, Marharyta Smohunova, Laurent Bigler, Meredith C. Schuman
Mass spectrometry‐based plant metabolomics is frequently used to identify novel natural products or study the effect of specific treatments on a plant's metabolism. Reliable sample handling is required to avoid artifacts, which is why most protocols mandate shock freezing of plant tissue in liquid nitrogen and an uninterrupted cooling chain. However, the logistical challenges of this approach make it infeasible for many ecological studies. Especially for research in the tropics, permanent cooling poses a challenge, which is why many of those studies use dried leaf tissue instead. We screened a total of 10 extraction and storage approaches for plant metabolites extracted from maize leaf tissue across two cropping seasons to develop a methodology for agroecological studies in logistically challenging tropical locations. All methods were evaluated based on changes in the metabolite profile across a 2‐month storage period at different temperatures with the goal of reproducing the metabolite profile of the living plant as closely as possible. We show that our newly developed on‐site liquid–liquid extraction protocol provides a good compromise between sample replicability, extraction efficiency, material logistics, and metabolite profile stability. We further discuss alternative methods which showed promising results and feasibility of on‐site sample handling for field studies.
{"title":"Screening of leaf extraction and storage conditions for eco‐metabolomics studies","authors":"Jakob Lang, Sergio E. Ramos, Marharyta Smohunova, Laurent Bigler, Meredith C. Schuman","doi":"10.1002/pld3.578","DOIUrl":"https://doi.org/10.1002/pld3.578","url":null,"abstract":"Mass spectrometry‐based plant metabolomics is frequently used to identify novel natural products or study the effect of specific treatments on a plant's metabolism. Reliable sample handling is required to avoid artifacts, which is why most protocols mandate shock freezing of plant tissue in liquid nitrogen and an uninterrupted cooling chain. However, the logistical challenges of this approach make it infeasible for many ecological studies. Especially for research in the tropics, permanent cooling poses a challenge, which is why many of those studies use dried leaf tissue instead. We screened a total of 10 extraction and storage approaches for plant metabolites extracted from maize leaf tissue across two cropping seasons to develop a methodology for agroecological studies in logistically challenging tropical locations. All methods were evaluated based on changes in the metabolite profile across a 2‐month storage period at different temperatures with the goal of reproducing the metabolite profile of the living plant as closely as possible. We show that our newly developed on‐site liquid–liquid extraction protocol provides a good compromise between sample replicability, extraction efficiency, material logistics, and metabolite profile stability. We further discuss alternative methods which showed promising results and feasibility of on‐site sample handling for field studies.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"196 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140565494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juan C. Baca Cabrera, Jan Vanderborght, Valentin Couvreur, Dominik Behrend, Thomas Gaiser, Thuy Huu Nguyen, Guillaume Lobet
Root hydraulic properties are key physiological traits that determine the capacity of root systems to take up water, at a specific evaporative demand. They can strongly vary among species, cultivars or even within the same genotype, but a systematic analysis of their variation across plant functional types (PFTs) is still missing. Here, we reviewed published empirical studies on root hydraulic properties at the segment‐, individual root‐, or root system scale and determined its variability and the main factors contributing to it. This corresponded to a total of 241 published studies, comprising 213 species, including woody and herbaceous vegetation.We observed an extremely large range of variation (of orders of magnitude) in root hydraulic properties, but this was not caused by systematic differences among PFTs. Rather, the (combined) effect of factors such as root system age, driving force used for measurement, or stress treatments shaped the results. We found a significant decrease in root hydraulic properties under stress conditions (drought and aquaporin inhibition, p < .001) and a significant effect of the driving force used for measurement (hydrostatic or osmotic gradients, p < .001). Furthermore, whole root system conductance increased significantly with root system age across several crop species (p < .01), causing very large variation in the data (>2 orders of magnitude). Interestingly, this relationship showed an asymptotic shape, with a steep increase during the first days of growth and a flattening out at later stages of development. We confirmed this dynamic through simulations using a state‐of‐the‐art computational model of water flow in the root system for a variety of crop species, suggesting common patterns across studies and species.These findings provide better understanding of the main causes of root hydraulic properties variations observed across empirical studies. They also open the door to better representation of hydraulic processes across multiple plant functional types and at large scales. All data collected in our analysis has been aggregated into an open access database (https://roothydraulic-properties.shinyapps.io/database/), fostering scientific exchange.
{"title":"Root hydraulic properties: An exploration of their variability across scales","authors":"Juan C. Baca Cabrera, Jan Vanderborght, Valentin Couvreur, Dominik Behrend, Thomas Gaiser, Thuy Huu Nguyen, Guillaume Lobet","doi":"10.1002/pld3.582","DOIUrl":"https://doi.org/10.1002/pld3.582","url":null,"abstract":"Root hydraulic properties are key physiological traits that determine the capacity of root systems to take up water, at a specific evaporative demand. They can strongly vary among species, cultivars or even within the same genotype, but a systematic analysis of their variation across plant functional types (PFTs) is still missing. Here, we reviewed published empirical studies on root hydraulic properties at the segment‐, individual root‐, or root system scale and determined its variability and the main factors contributing to it. This corresponded to a total of 241 published studies, comprising 213 species, including woody and herbaceous vegetation.We observed an extremely large range of variation (of orders of magnitude) in root hydraulic properties, but this was not caused by systematic differences among PFTs. Rather, the (combined) effect of factors such as root system age, driving force used for measurement, or stress treatments shaped the results. We found a significant decrease in root hydraulic properties under stress conditions (drought and aquaporin inhibition, <jats:italic>p</jats:italic> < .001) and a significant effect of the driving force used for measurement (hydrostatic or osmotic gradients, <jats:italic>p</jats:italic> < .001). Furthermore, whole root system conductance increased significantly with root system age across several crop species (<jats:italic>p</jats:italic> < .01), causing very large variation in the data (>2 orders of magnitude). Interestingly, this relationship showed an asymptotic shape, with a steep increase during the first days of growth and a flattening out at later stages of development. We confirmed this dynamic through simulations using a state‐of‐the‐art computational model of water flow in the root system for a variety of crop species, suggesting common patterns across studies and species.These findings provide better understanding of the main causes of root hydraulic properties variations observed across empirical studies. They also open the door to better representation of hydraulic processes across multiple plant functional types and at large scales. All data collected in our analysis has been aggregated into an open access database (<jats:ext-link xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"https://roothydraulic-properties.shinyapps.io/database/\">https://roothydraulic-properties.shinyapps.io/database/</jats:ext-link>), fostering scientific exchange.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"107 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140564774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vivian H. Tran, Kristen M. Nolting, Lisa A. Donovan, Andries A. Temme
Cultivated crops are generally expected to have less abiotic stress tolerance than their wild relatives. However, this assumption is not well supported by empirical literature and may depend on the type of stress and how it is imposed, as well as the measure of tolerance being used. Here, we investigated whether wild and cultivated accessions of Helianthus annuus differed in stress tolerance assessed as proportional decline in biomass due to drought and whether wild and cultivated accessions differed in trait responses to drought and trait associations with tolerance. In a greenhouse study, H. annuus accessions in the two domestication classes (eight cultivated and eight wild accessions) received two treatments: a well‐watered control and a moderate drought implemented as a dry down followed by maintenance at a predetermined soil moisture level with automated irrigation. Treatments were imposed at the seedling stage, and plants were harvested after 2 weeks of treatment. The proportional biomass decline in response to drought was 24% for cultivated H. annuus accessions but was not significant for the wild accessions. Thus, using the metric of proportional biomass decline, the cultivated accessions had less drought tolerance. Among accessions, there was no tradeoff between drought tolerance and vigor assessed as biomass in the control treatment. In a multivariate analysis, wild and cultivated accessions did not differ from each other or in response to drought for a subset of morphological, physiological, and allocational traits. Analyzed individually, traits varied in response to drought in wild and/or cultivated accessions, including declines in specific leaf area, leaf theoretical maximum stomatal conductance (gsmax), and stomatal pore length, but there was no treatment response for stomatal density, succulence, or the ability to osmotically adjust. Focusing on traits associations with tolerance, plasticity in gsmax was the most interesting because its association with tolerance differed by domestication class (although the effects were relatively weak) and thus might contribute to lower tolerance of cultivated sunflower. Our H. annuus results support the expectation that stress tolerance is lower in crops than wild relatives under some conditions. However, determining the key traits that underpin differences in moderate drought tolerance between wild and cultivated H. annuus remains elusive.
{"title":"Cultivated sunflower (Helianthus annuus L.) has lower tolerance of moderate drought stress than its con‐specific wild relative, but the underlying traits remain elusive","authors":"Vivian H. Tran, Kristen M. Nolting, Lisa A. Donovan, Andries A. Temme","doi":"10.1002/pld3.581","DOIUrl":"https://doi.org/10.1002/pld3.581","url":null,"abstract":"Cultivated crops are generally expected to have less abiotic stress tolerance than their wild relatives. However, this assumption is not well supported by empirical literature and may depend on the type of stress and how it is imposed, as well as the measure of tolerance being used. Here, we investigated whether wild and cultivated accessions of <jats:styled-content style=\"fixed-case\"><jats:italic>Helianthus annuus</jats:italic></jats:styled-content> differed in stress tolerance assessed as proportional decline in biomass due to drought and whether wild and cultivated accessions differed in trait responses to drought and trait associations with tolerance. In a greenhouse study, <jats:styled-content style=\"fixed-case\"><jats:italic>H. annuus</jats:italic></jats:styled-content> accessions in the two domestication classes (eight cultivated and eight wild accessions) received two treatments: a well‐watered control and a moderate drought implemented as a dry down followed by maintenance at a predetermined soil moisture level with automated irrigation. Treatments were imposed at the seedling stage, and plants were harvested after 2 weeks of treatment. The proportional biomass decline in response to drought was 24% for cultivated <jats:styled-content style=\"fixed-case\"><jats:italic>H. annuus</jats:italic></jats:styled-content> accessions but was not significant for the wild accessions. Thus, using the metric of proportional biomass decline, the cultivated accessions had less drought tolerance. Among accessions, there was no tradeoff between drought tolerance and vigor assessed as biomass in the control treatment. In a multivariate analysis, wild and cultivated accessions did not differ from each other or in response to drought for a subset of morphological, physiological, and allocational traits. Analyzed individually, traits varied in response to drought in wild and/or cultivated accessions, including declines in specific leaf area, leaf theoretical maximum stomatal conductance (g<jats:sub>smax</jats:sub>), and stomatal pore length, but there was no treatment response for stomatal density, succulence, or the ability to osmotically adjust. Focusing on traits associations with tolerance, plasticity in g<jats:sub>smax</jats:sub> was the most interesting because its association with tolerance differed by domestication class (although the effects were relatively weak) and thus might contribute to lower tolerance of cultivated sunflower. Our <jats:styled-content style=\"fixed-case\"><jats:italic>H. annuus</jats:italic></jats:styled-content> results support the expectation that stress tolerance is lower in crops than wild relatives under some conditions. However, determining the key traits that underpin differences in moderate drought tolerance between wild and cultivated <jats:styled-content style=\"fixed-case\"><jats:italic>H. annuus</jats:italic></jats:styled-content> remains elusive.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"1 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140565316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Because of their photosynthetic capacity, leaves function as solar panels providing the basis for the growth of the entire plant. Although the molecular mechanisms of leaf development have been well studied in model dicot and monocot species, a lot of information is still needed about the interplay of the genes that regulate cell division and differentiation and thereby affect the photosynthetic performance of the leaf. We were specifically interested in understanding the differentiation of mesophyll and bundle sheath cells in Arabidopsis thaliana and aimed to identify genes that are involved in determining bundle sheath anatomy. To this end, we established a forward genetic screen by using ethyl methanesulfonate (EMS) for mutagenizing a reporter line expressing a chloroplast‐targeted green fluorescent protein (sGFP) under the control of a bundle sheath‐specific promoter. Based on the GFP fluorescence phenotype, numerous mutants were produced, and by pursuing a mapping‐by‐sequencing approach, the genomic segments containing mutated candidate genes were identified. One of the lines with an enhanced GFP fluorescence phenotype (named ELEVATED BUNDLE SHEATH CELLS SIGNAL 1 [ebss1]) was selected for further study, and the responsible gene was verified by CRISPR/Cas9‐based mutagenesis of candidate genes located in the mapped genomic segment. The verified gene, At2g25970, encodes a K homology (KH) domain‐containing protein.
由于叶片具有光合作用能力，因此叶片就像太阳能电池板一样，为整个植物的生长提供了基础。虽然在双子叶和单子叶植物中对叶片发育的分子机制进行了深入研究，但对于调控细胞分裂和分化并进而影响叶片光合作用性能的基因之间的相互作用，仍有许多信息需要了解。我们特别想了解拟南芥叶肉细胞和束鞘细胞的分化过程，目的是找出参与决定束鞘解剖结构的基因。为此，我们利用甲基磺酸乙酯（EMS）诱变表达叶绿体靶向绿色荧光蛋白（sGFP）的报告基因系，并在束鞘特异性启动子的控制下建立了正向遗传筛选。根据 GFP 荧光表型，产生了许多突变体，并通过测序映射方法确定了含有突变候选基因的基因组片段。其中一个具有增强 GFP 荧光表型的品系（命名为 ELEVATED BUNDLE SHEATH CELLS SIGNAL 1 [ebss1]）被选中作进一步研究，并通过基于 CRISPR/Cas9 诱变位于映射基因组片段的候选基因来验证责任基因。经过验证的基因 At2g25970 编码一个含 K 同源（KH）结构域的蛋白质。
{"title":"A K homology (KH) domain protein identified by a forward genetic screen affects bundle sheath anatomy in Arabidopsis thaliana","authors":"Zahida Bano, Peter Westhoff","doi":"10.1002/pld3.577","DOIUrl":"https://doi.org/10.1002/pld3.577","url":null,"abstract":"Because of their photosynthetic capacity, leaves function as solar panels providing the basis for the growth of the entire plant. Although the molecular mechanisms of leaf development have been well studied in model dicot and monocot species, a lot of information is still needed about the interplay of the genes that regulate cell division and differentiation and thereby affect the photosynthetic performance of the leaf. We were specifically interested in understanding the differentiation of mesophyll and bundle sheath cells in <jats:styled-content style=\"fixed-case\"><jats:italic>Arabidopsis thaliana</jats:italic></jats:styled-content> and aimed to identify genes that are involved in determining bundle sheath anatomy. To this end, we established a forward genetic screen by using ethyl methanesulfonate (EMS) for mutagenizing a reporter line expressing a chloroplast‐targeted green fluorescent protein (sGFP) under the control of a bundle sheath‐specific promoter. Based on the GFP fluorescence phenotype, numerous mutants were produced, and by pursuing a mapping‐by‐sequencing approach, the genomic segments containing mutated candidate genes were identified. One of the lines with an enhanced GFP fluorescence phenotype (named <jats:italic>ELEVATED BUNDLE SHEATH CELLS SIGNAL 1 [ebss1]</jats:italic>) was selected for further study, and the responsible gene was verified by CRISPR/Cas9‐based mutagenesis of candidate genes located in the mapped genomic segment. The verified gene, At2g25970, encodes a K homology (KH) domain‐containing protein.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"83 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140564754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oyeyemi Ajayi, Ellen Zelinsky, Charles T. Anderson
Cell walls surround all plant cells, and their composition and structure are tightly regulated to maintain cellular and organismal homeostasis. In response to wall damage, the cell wall integrity (CWI) system is engaged to ameliorate effects on plant growth. Despite the central role CWI plays in plant development, our current understanding of how this system functions at the molecular level is limited. Here, we investigated the transcriptomes of etiolated seedlings of mutants of Arabidopsis thaliana with defects in three major wall polysaccharides, pectin (quasimodo2), cellulose (cellulose synthase3je5), and xyloglucan (xyloglucan xylosyltransferase1 and 2), to probe whether changes in the expression of cell wall‐related genes occur and are similar or different when specific wall components are reduced or missing. Many changes occurred in the transcriptomes of pectin‐ and cellulose‐deficient plants, but fewer changes occurred in the transcriptomes of xyloglucan‐deficient plants. We hypothesize that this might be because pectins interact with other wall components and/or integrity sensors, whereas cellulose forms a major load‐bearing component of the wall; defects in either appear to trigger the expression of structural proteins to maintain wall cohesion in the absence of a major polysaccharide. This core set of genes functioning in CWI in plants represents an attractive target for future genetic engineering of robust and resilient cell walls.
{"title":"A core of cell wall proteins functions in wall integrity responses in Arabidopsis thaliana","authors":"Oyeyemi Ajayi, Ellen Zelinsky, Charles T. Anderson","doi":"10.1002/pld3.579","DOIUrl":"https://doi.org/10.1002/pld3.579","url":null,"abstract":"Cell walls surround all plant cells, and their composition and structure are tightly regulated to maintain cellular and organismal homeostasis. In response to wall damage, the cell wall integrity (CWI) system is engaged to ameliorate effects on plant growth. Despite the central role CWI plays in plant development, our current understanding of how this system functions at the molecular level is limited. Here, we investigated the transcriptomes of etiolated seedlings of mutants of <jats:styled-content style=\"fixed-case\"><jats:italic>Arabidopsis thaliana</jats:italic></jats:styled-content> with defects in three major wall polysaccharides, pectin (<jats:italic>quasimodo2</jats:italic>), cellulose (<jats:italic>cellulose synthase3</jats:italic><jats:sup><jats:italic>je5</jats:italic></jats:sup>), and xyloglucan (<jats:italic>xyloglucan xylosyltransferase1</jats:italic> and <jats:italic>2</jats:italic>), to probe whether changes in the expression of cell wall‐related genes occur and are similar or different when specific wall components are reduced or missing. Many changes occurred in the transcriptomes of pectin‐ and cellulose‐deficient plants, but fewer changes occurred in the transcriptomes of xyloglucan‐deficient plants. We hypothesize that this might be because pectins interact with other wall components and/or integrity sensors, whereas cellulose forms a major load‐bearing component of the wall; defects in either appear to trigger the expression of structural proteins to maintain wall cohesion in the absence of a major polysaccharide. This core set of genes functioning in CWI in plants represents an attractive target for future genetic engineering of robust and resilient cell walls.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"6 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140564770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plant genomes contain numerous genes encoding chitinase‐like (CTL) proteins, which have a similar protein structure to chitinase belonging to the glycoside hydrolase (GH) family but lack the chitinolytic activity to cleave the β‐1,4‐glycosidic bond in chitins, polymers of N‐acetylglucosamine. CTL1 mutations found in rice and Arabidopsis have caused pleiotropic developmental defects, including altered cell wall composition and decreased abiotic stress tolerance, likely due to reduced cellulose content. In this study, we identified suppressor of hot2 1 (suh1) as a genetic suppressor of the ctl1hot2‐1 mutation in Arabidopsis. The mutation in SUH1 restored almost all examined ctl1hot2‐1 defects to nearly wild‐type levels or at least partially. SUH1 encodes a Golgi‐located type II membrane protein with glycosyltransferase (GT) activity, and its mutations lead to a reduction in cellulose content and hypersensitivity to cellulose biosynthesis inhibitors, although to a lesser extent than ctl1hot2‐1 mutation. The SUH1 promoter fused with the GUS reporter gene exhibited GUS activity in interfascicular fibers and xylem in stems; meanwhile, the ctl1hot2‐1 mutation significantly increased this activity. Our findings provide genetic and molecular evidence that the antagonistic activities of CTL1 and SUH1 play an essential role in assembling the cell wall in Arabidopsis.
{"title":"Antagonistic functions of CTL1 and SUH1 mediate cell wall assembly in Arabidopsis","authors":"Nguyen Thi Thuy, Hyun‐Jung Kim, Suk‐Whan Hong","doi":"10.1002/pld3.580","DOIUrl":"https://doi.org/10.1002/pld3.580","url":null,"abstract":"Plant genomes contain numerous genes encoding chitinase‐like (CTL) proteins, which have a similar protein structure to chitinase belonging to the glycoside hydrolase (GH) family but lack the chitinolytic activity to cleave the <jats:italic>β</jats:italic>‐1,4‐glycosidic bond in chitins, polymers of <jats:italic>N</jats:italic>‐acetylglucosamine. <jats:italic>CTL1</jats:italic> mutations found in rice and <jats:italic>Arabidopsis</jats:italic> have caused pleiotropic developmental defects, including altered cell wall composition and decreased abiotic stress tolerance, likely due to reduced cellulose content. In this study, we identified <jats:italic>suppressor of hot2 1</jats:italic> (<jats:italic>suh1</jats:italic>) as a genetic suppressor of the <jats:italic>ctl1</jats:italic><jats:sup><jats:italic>hot2‐1</jats:italic></jats:sup> mutation in <jats:italic>Arabidopsis</jats:italic>. The mutation in <jats:italic>SUH1</jats:italic> restored almost all examined <jats:italic>ctl1</jats:italic><jats:sup><jats:italic>hot2‐1</jats:italic></jats:sup> defects to nearly wild‐type levels or at least partially. <jats:italic>SUH1</jats:italic> encodes a Golgi‐located type II membrane protein with glycosyltransferase (GT) activity, and its mutations lead to a reduction in cellulose content and hypersensitivity to cellulose biosynthesis inhibitors, although to a lesser extent than <jats:italic>ctl1</jats:italic><jats:sup><jats:italic>hot2‐1</jats:italic></jats:sup> mutation. The <jats:italic>SUH1</jats:italic> promoter fused with the GUS reporter gene exhibited GUS activity in interfascicular fibers and xylem in stems; meanwhile, the <jats:italic>ctl1</jats:italic><jats:sup><jats:italic>hot2‐1</jats:italic></jats:sup> mutation significantly increased this activity. Our findings provide genetic and molecular evidence that the antagonistic activities of CTL1 and SUH1 play an essential role in assembling the cell wall in <jats:italic>Arabidopsis</jats:italic>.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"304 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-21eCollection Date: 2024-03-01DOI: 10.1002/pld3.576
Fidel González-Torralva, Jason K Norsworthy
Johnsongrass [Sorghum halepense (L.) Pers.] is a troublesome weed species in different agricultural and non-agricultural areas. Because of its biology, reproductive system, and seed production, effective management is challenging. An accession with low susceptibility to the acetyl-CoA carboxylase (ACCase)-inhibiting herbicides fluazifop-p-butyl (fluazifop) and pinoxaden was collected in eastern Arkansas. In this research, the molecular mechanisms responsible for ACCase resistance were investigated. Dose-response experiments showed a resistance factor of 181 and 133 for fluazifop and pinoxaden, respectively. Molecular analysis of both ACCase1 and ACCase2 genes was researched. Nucleotide comparison of ACCase1 between resistant and susceptible accessions showed no single nucleotide polymorphisms. Nonetheless, analysis of ACCase2 in fluazifop-resistant johnsongrass plants revealed the Ile1781Leu target-site mutation was dominant (nearly 75%), whereas the majority of pinoxaden-resistant johnsongrass plants had the Ile2041Asn (60%). Not all sequenced johnsongrass plants displayed a target-site mutation, suggesting the presence of additional resistance mechanisms. Amplification of ACCase1 and ACCase2 was not responsible for resistance because of the similar values obtained in both resistant and susceptible accessions. Experiments with malathion and NBD-Cl suggest the presence of herbicide metabolism. Outcomes of this research demonstrated that fluazifop- and pinoxaden-resistant johnsongrass plants displayed a target-site mutation in ACCase2, but also that non-target-site resistance mechanisms would be involved and require a detailed study.
{"title":"Target-site mutations Ile1781Leu and Ile2041Asn in the <i>ACCase2</i> gene confer resistance to fluazifop-p-butyl and pinoxaden herbicides in a johnsongrass accession from Arkansas, USA.","authors":"Fidel González-Torralva, Jason K Norsworthy","doi":"10.1002/pld3.576","DOIUrl":"10.1002/pld3.576","url":null,"abstract":"<p><p>Johnsongrass [<i>Sorghum halepense</i> (L.) Pers.] is a troublesome weed species in different agricultural and non-agricultural areas. Because of its biology, reproductive system, and seed production, effective management is challenging. An accession with low susceptibility to the acetyl-CoA carboxylase (ACCase)-inhibiting herbicides fluazifop-p-butyl (fluazifop) and pinoxaden was collected in eastern Arkansas. In this research, the molecular mechanisms responsible for ACCase resistance were investigated. Dose-response experiments showed a resistance factor of 181 and 133 for fluazifop and pinoxaden, respectively. Molecular analysis of both <i>ACCase1</i> and <i>ACCase2</i> genes was researched. Nucleotide comparison of <i>ACCase1</i> between resistant and susceptible accessions showed no single nucleotide polymorphisms. Nonetheless, analysis of <i>ACCase2</i> in fluazifop-resistant johnsongrass plants revealed the Ile1781Leu target-site mutation was dominant (nearly 75%), whereas the majority of pinoxaden-resistant johnsongrass plants had the Ile2041Asn (60%). Not all sequenced johnsongrass plants displayed a target-site mutation, suggesting the presence of additional resistance mechanisms. Amplification of <i>ACCase1</i> and <i>ACCase2</i> was not responsible for resistance because of the similar values obtained in both resistant and susceptible accessions. Experiments with malathion and NBD-Cl suggest the presence of herbicide metabolism. Outcomes of this research demonstrated that fluazifop- and pinoxaden-resistant johnsongrass plants displayed a target-site mutation in <i>ACCase2</i>, but also that non-target-site resistance mechanisms would be involved and require a detailed study.</p>","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"8 3","pages":"e576"},"PeriodicalIF":2.3,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10955616/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140185349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extracellular matrix (ECM) plays central roles in cell architecture, innate defense and cell wall integrity (CWI) signaling. During transition to multicellularity, modular domain structures of ECM proteins and proteoforms have evolved due to continuous adaptation across taxonomic clades under different ecological niche. Although this incredible diversity has to some extent been investigated at protein level, extracellular phosphorylation events and molecular evolution of ECM proteoform families remains unexplored. We developed matrisome proteoform atlas in a grain legume, chickpea and performed meta-analyses of 74 plant matrisomes. MS/MS analysis identified 1,424 proteins and 315 phosphoproteins involved in diverse functions. Cross-species ECM protein network identified proteoforms associated with CWI maintenance system. Phylogenetic characterization of eighteen matrix protein families highlighted the role of taxon-specific paralogs and orthologs. Novel information was acquired on gene expansion and loss, co-divergence, sub functionalization and neofunctionalization during evolution. Modular networks of matrix protein families and hub proteins showed higher diversity across taxonomic clades than among organs. Furthermore, protein families differ in nonsynonymous to synonymous substitution rates. Our study pointed towards the matrix proteoform functionality, sequence divergence variation, interactions between wall remodelers and molecular evolution using a phylogenetic framework. This is the first report on comprehensive matrisome proteoform network illustrating presence of CWI signaling proteins in land plants.
{"title":"Combining extracellular matrix proteome and phosphoproteome of chickpea and meta-analysis reveal novel proteoforms and evolutionary significance of clade-specific wall-associated events in plant","authors":"Kanika Narula, Arunima Sinha, Pooja Choudhary, Sudip Ghosh, Eman Elagamey, Archana Sharma, Atreyee Sengupta, Niranjan Chakraborty, Subhra Chakraborty","doi":"10.1002/pld3.572","DOIUrl":"https://doi.org/10.1002/pld3.572","url":null,"abstract":"Extracellular matrix (ECM) plays central roles in cell architecture, innate defense and cell wall integrity (CWI) signaling. During transition to multicellularity, modular domain structures of ECM proteins and proteoforms have evolved due to continuous adaptation across taxonomic clades under different ecological niche. Although this incredible diversity has to some extent been investigated at protein level, extracellular phosphorylation events and molecular evolution of ECM proteoform families remains unexplored. We developed matrisome proteoform atlas in a grain legume, chickpea and performed meta-analyses of 74 plant matrisomes. MS/MS analysis identified 1,424 proteins and 315 phosphoproteins involved in diverse functions. Cross-species ECM protein network identified proteoforms associated with CWI maintenance system. Phylogenetic characterization of eighteen matrix protein families highlighted the role of taxon-specific paralogs and orthologs. Novel information was acquired on gene expansion and loss, co-divergence, sub functionalization and neofunctionalization during evolution. Modular networks of matrix protein families and hub proteins showed higher diversity across taxonomic clades than among organs. Furthermore, protein families differ in nonsynonymous to synonymous substitution rates. Our study pointed towards the matrix proteoform functionality, sequence divergence variation, interactions between wall remodelers and molecular evolution using a phylogenetic framework. This is the first report on comprehensive matrisome proteoform network illustrating presence of CWI signaling proteins in land plants.","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"148 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140152965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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