Ralstonia pseudosolanacearum F1C1 is a soil-borne phytopathogenic bacterium with a broad host range that infects several economically important crops. This study primarily focuses on the infection of this phytopathogen in two such important crop seedlings: tomato and eggplant. The observations of the study reveal a complex set of symptoms that include drooping and blackening of the seedling stem, as well as blackening, chlorosis, and curling of cotyledon leaves. Notably, the symptom of stem softening and translucency is seen primarily in the water-submerged stem regions of the root-inoculated seedlings. Furthermore, the morphology of stem softening and translucency is more frequent in root-inoculated eggplant seedlings, underscoring a difference between tomato and eggplant seedlings regarding the virulence of the bacterium. By investigating these unique pathological phenotypes in the infected seedlings, this study uncovers unique symptoms previously not reported in seedling inoculation experiments. Such findings deepen our understanding of the complex virulence mechanisms of the pathogen. The work also highlights the distinct escape mechanisms exhibited by seedlings, revealing how some of its host plants might resist wilting despite infection, offering new avenues for future research. These findings contribute to the understanding of R. pseudosolanacearum pathogenesis, shedding light on its virulence and host response mechanisms.
Ralstonia pseudosolanacearum F1C1 是一种土传植物病原菌，寄主范围广泛，可感染多种重要经济作物。本研究主要关注这种植物病原菌对番茄和茄子这两种重要作物幼苗的感染。研究观察发现了一系列复杂的症状，包括幼苗茎干下垂和变黑，以及子叶变黑、萎黄病和卷曲。值得注意的是，茎软化和半透明的症状主要出现在根部接种幼苗的茎部浸水区域。此外，茎软化和半透明的形态在根部接种的茄子幼苗中更为常见，这突出表明了番茄和茄子幼苗在细菌毒力方面的差异。通过研究受感染秧苗的这些独特病理表型，本研究发现了以前在秧苗接种实验中未报道过的独特症状。这些发现加深了我们对病原体复杂毒力机制的理解。这项工作还强调了幼苗表现出的独特逃逸机制，揭示了一些寄主植物如何在感染后仍能抵抗枯萎，为今后的研究提供了新的途径。这些发现有助于人们了解 R. pseudosolanacearum 的致病机理，揭示其毒力和宿主反应机制。
{"title":"Morphology of softening and translucency in the stems of tomato and eggplant seedlings due to infection by Ralstonia pseudosolanacearum F1C1","authors":"Shuvam Bhuyan, Lakhyajit Boruah, Monika Jain, Shuhada Begum, Shubhra Jyoti Giri, Lukapriya Dutta, Manabendra Mandal, Suvendra Kumar Ray","doi":"10.1101/2024.09.10.612199","DOIUrl":"https://doi.org/10.1101/2024.09.10.612199","url":null,"abstract":"<em>Ralstonia pseudosolanacearum</em> F1C1 is a soil-borne phytopathogenic bacterium with a broad host range that infects several economically important crops. This study primarily focuses on the infection of this phytopathogen in two such important crop seedlings: tomato and eggplant. The observations of the study reveal a complex set of symptoms that include drooping and blackening of the seedling stem, as well as blackening, chlorosis, and curling of cotyledon leaves. Notably, the symptom of stem softening and translucency is seen primarily in the water-submerged stem regions of the root-inoculated seedlings. Furthermore, the morphology of stem softening and translucency is more frequent in root-inoculated eggplant seedlings, underscoring a difference between tomato and eggplant seedlings regarding the virulence of the bacterium. By investigating these unique pathological phenotypes in the infected seedlings, this study uncovers unique symptoms previously not reported in seedling inoculation experiments. Such findings deepen our understanding of the complex virulence mechanisms of the pathogen. The work also highlights the distinct escape mechanisms exhibited by seedlings, revealing how some of its host plants might resist wilting despite infection, offering new avenues for future research. These findings contribute to the understanding of <em>R. pseudosolanacearum</em> pathogenesis, shedding light on its virulence and host response mechanisms.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1101/2024.09.11.612519
Maude Dorval, Jonathan Tremblay, Gabrielle Veillet, Marc-Antoine Chiasson, Marie-Claire Goulet, Thiago Gumiere, Steeve Pepin, Charles Goulet, Dominique Michaud
Current climate change scenarios predict an increased incidence of drought episodes likely to affect potato crops worldwide. Potato exhibits a low-density, shallow root system that makes it particularly vulnerable to water shortage and any successful attempt to implement drought tolerance in cultivated potato varieties is potentially relevant from an agronomic standpoint. In this study, we assessed the potential of tomato cystatin SlCYS8 to promote drought tolerance in SlCYS8-expressing potato lines by induction of stress-related pleiotropy. Up to now, protease inhibitors of the cystatin protein superfamily have been mostly considered as biotechnological tools to engineer pest or pathogen resistance in crops, but several recent studies have also revealed a possible link between abiotic stress tolerance and these regulatory proteins in leaf tissue. SlCYS8-expressing plantlets grown on culture medium containing the drought mimic polyethylene glycol (PEG) exhibited an elevated root-to-shoot ratio, an indicator of drought tolerance in potato. A similar conclusion could be drawn with greenhouse-grown acclimated plants, confirming a relative root growth-promoting effect for the recombinant inhibitor upon water deficit. SlCYS8-potato lines also showed a high tuber yield compared to the control line under both limiting and non-limiting water regimes, suggesting an improved efficiency of the primary metabolism and the avoidance of a growth/stress response tradeoff in the modified lines. Accordingly, SlCYS8 expression was associated with a stress response-oriented proteome in leaves likely explained by pleiotropic effects of the recombinant cystatin driving the constitutive expression of stress-related proteins and the upregulation of primary metabolism-associated proteins. Overall, these data suggest the potential of cystatins as molecular triggers of tuber biomass production and drought resilience in potato. Complementary studies will be warranted to assess tuber yield of the SlCYS8-lines under different water regimes in field conditions.
{"title":"Tomato cystatin SlCYS8 as a trigger of drought tolerance and tuber yield in potato","authors":"Maude Dorval, Jonathan Tremblay, Gabrielle Veillet, Marc-Antoine Chiasson, Marie-Claire Goulet, Thiago Gumiere, Steeve Pepin, Charles Goulet, Dominique Michaud","doi":"10.1101/2024.09.11.612519","DOIUrl":"https://doi.org/10.1101/2024.09.11.612519","url":null,"abstract":"Current climate change scenarios predict an increased incidence of drought episodes likely to affect potato crops worldwide. Potato exhibits a low-density, shallow root system that makes it particularly vulnerable to water shortage and any successful attempt to implement drought tolerance in cultivated potato varieties is potentially relevant from an agronomic standpoint. In this study, we assessed the potential of tomato cystatin SlCYS8 to promote drought tolerance in SlCYS8-expressing potato lines by induction of stress-related pleiotropy. Up to now, protease inhibitors of the cystatin protein superfamily have been mostly considered as biotechnological tools to engineer pest or pathogen resistance in crops, but several recent studies have also revealed a possible link between abiotic stress tolerance and these regulatory proteins in leaf tissue. SlCYS8-expressing plantlets grown on culture medium containing the drought mimic polyethylene glycol (PEG) exhibited an elevated root-to-shoot ratio, an indicator of drought tolerance in potato. A similar conclusion could be drawn with greenhouse-grown acclimated plants, confirming a relative root growth-promoting effect for the recombinant inhibitor upon water deficit. SlCYS8-potato lines also showed a high tuber yield compared to the control line under both limiting and non-limiting water regimes, suggesting an improved efficiency of the primary metabolism and the avoidance of a growth/stress response tradeoff in the modified lines. Accordingly, SlCYS8 expression was associated with a stress response-oriented proteome in leaves likely explained by pleiotropic effects of the recombinant cystatin driving the constitutive expression of stress-related proteins and the upregulation of primary metabolism-associated proteins. Overall, these data suggest the potential of cystatins as molecular triggers of tuber biomass production and drought resilience in potato. Complementary studies will be warranted to assess tuber yield of the SlCYS8-lines under different water regimes in field conditions.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1101/2024.09.09.612062
Roberto Espinoza-Corral, Tomáš Zavřel, Markus Sutter, Chase H Leslie, Kunwei Yang, Warren F Beck, Jan Červený, Cheryl A Kerfeld
Phycobilisomes are versatile cyanobacterial antenna complexes that harvest light energy to drive photosynthesis. These complexes can also adapt to various light conditions, dismantling under high light to prevent photo-oxidation and arranging in rows under low light to increase light harvesting efficiency. Light quality also influences phycobilisome structure and function, as observed under far-red light exposure. Here we describe a new, phycobilisome linker protein, ApcI (previously hypothetical protein sll1911), expressed specifically under red light. We characterized ApcI in Synechocystis sp. PCC 6803 using mutant strain analyses, phycobilisome binding experiments, and protein interaction studies. Mutation of apcI conferred high light tolerance to Synechocystis sp. PCC 6803 compared to wild type with reduced energy transfer from phycobilisomes to the photosystems. Binding experiments revealed that ApcI replaces the linker protein ApcG at the membrane-facing side of the phycobilisome core using a paralogous C-terminal domain. Additionally, the N-terminal extension of ApcI was found to interact with photosystem II. Our findings highlight the importance of phycobilisome remodeling for adaptation under different light conditions. The characterization of ApcI provides new insights into the mechanisms by which cyanobacteria optimize light-harvesting in response to varying light environments.
叶绿体是一种多功能蓝藻天线复合体，可收集光能以驱动光合作用。这些复合体还能适应各种光照条件，在强光下分解以防止光氧化，在弱光下排列成行以提高光收集效率。光质也会影响藻体的结构和功能，如在远红光照射下观察到的那样。在这里，我们描述了一种新的藻体连接蛋白ApcI（以前的假说蛋白sll1911），它在红光下特异表达。我们利用突变菌株分析、藻胶体结合实验和蛋白质相互作用研究对 Synechocystis sp.与野生型相比，apcI 的突变赋予了 Synechocystis sp.结合实验表明，ApcI利用一个同源的C-末端结构域取代了连接蛋白ApcG位于藻体核心面向膜的一侧。此外，还发现 ApcI 的 N 端延伸部分与光系统 II 相互作用。我们的发现凸显了藻体重塑对适应不同光照条件的重要性。ApcI的表征为蓝藻优化光收集以应对不同光环境的机制提供了新的见解。
{"title":"The new phycobilisome linker protein ApcI regulates high light adaptation in Synechocystis sp. PCC 6803","authors":"Roberto Espinoza-Corral, Tomáš Zavřel, Markus Sutter, Chase H Leslie, Kunwei Yang, Warren F Beck, Jan Červený, Cheryl A Kerfeld","doi":"10.1101/2024.09.09.612062","DOIUrl":"https://doi.org/10.1101/2024.09.09.612062","url":null,"abstract":"Phycobilisomes are versatile cyanobacterial antenna complexes that harvest light energy to drive photosynthesis. These complexes can also adapt to various light conditions, dismantling under high light to prevent photo-oxidation and arranging in rows under low light to increase light harvesting efficiency. Light quality also influences phycobilisome structure and function, as observed under far-red light exposure. Here we describe a new, phycobilisome linker protein, ApcI (previously hypothetical protein sll1911), expressed specifically under red light. We characterized ApcI in Synechocystis sp. PCC 6803 using mutant strain analyses, phycobilisome binding experiments, and protein interaction studies. Mutation of apcI conferred high light tolerance to Synechocystis sp. PCC 6803 compared to wild type with reduced energy transfer from phycobilisomes to the photosystems. Binding experiments revealed that ApcI replaces the linker protein ApcG at the membrane-facing side of the phycobilisome core using a paralogous C-terminal domain. Additionally, the N-terminal extension of ApcI was found to interact with photosystem II. Our findings highlight the importance of phycobilisome remodeling for adaptation under different light conditions. The characterization of ApcI provides new insights into the mechanisms by which cyanobacteria optimize light-harvesting in response to varying light environments.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The surface-localized receptor kinase FLS2 detects the flg22 epitope from bacterial flagella. FLS2 is conserved across land plants, but bacterial pathogens exhibit polymorphic flg22 epitopes. Most FLS2 homologs possess narrow perception ranges, but four with expanded perception ranges have been identified. Using diversity analyses, AlphaFold modeling, and amino acid properties, key residues enabling expanded recognition were mapped to FLS2's concave surface, interacting with the co-receptor and polymorphic flg22 residues. Synthetic biology enabled engineering of expanded recognition from QvFLS2 (Quercus variabilis) and FLS2XL (Vitis riparia) into homologs with canonical perception. Evolutionary analyses across three plant orders showed residues under positive selection aligning with those binding the co-receptor and flg22's C-terminus, suggesting more alleles with expanded perception exist. Our experimental data enabled the identification of specific receptor amino acid properties and AlphaFold3 metrics that facilitate predicting FLS2-flg22 recognition. This study provides a framework for rational receptor engineering to enhance pathogen restriction.
{"title":"Unlocking expanded flagellin perception through rational receptor engineering","authors":"Tianrun Li, Esteban Jarquin Bolanos, Danielle Stevens, Hanxu Sha, Daniil M Prigozhin, Gitta Coaker","doi":"10.1101/2024.09.09.612155","DOIUrl":"https://doi.org/10.1101/2024.09.09.612155","url":null,"abstract":"The surface-localized receptor kinase FLS2 detects the flg22 epitope from bacterial flagella. FLS2 is conserved across land plants, but bacterial pathogens exhibit polymorphic flg22 epitopes. Most FLS2 homologs possess narrow perception ranges, but four with expanded perception ranges have been identified. Using diversity analyses, AlphaFold modeling, and amino acid properties, key residues enabling expanded recognition were mapped to FLS2's concave surface, interacting with the co-receptor and polymorphic flg22 residues. Synthetic biology enabled engineering of expanded recognition from QvFLS2 (Quercus variabilis) and FLS2XL (Vitis riparia) into homologs with canonical perception. Evolutionary analyses across three plant orders showed residues under positive selection aligning with those binding the co-receptor and flg22's C-terminus, suggesting more alleles with expanded perception exist. Our experimental data enabled the identification of specific receptor amino acid properties and AlphaFold3 metrics that facilitate predicting FLS2-flg22 recognition. This study provides a framework for rational receptor engineering to enhance pathogen restriction.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1101/2024.09.10.612258
Deep Shikha, Sanskar Mishra, Santosh B Satbhai
Iron (Fe) is an essential element for most of the living organisms including plants and humans, where plants serve as the primary source of our dietary iron intake. The availability of Fe determines plant fitness and yield. Thus, understanding of iron uptake, its acquisition and utilization is of critical importance to reap nutritional benefits from plant breeding. Despite significant progress in uncovering how iron homeostasis is regulated by transcription factors and phytohormones, molecular pathways that mediate Fe deficiency through the action of signalling peptides remain elusive. In this work, we reported the role of PROPEP2 (Plant Elicitor Peptide 2) and PEPR (Perception of Arabidopsis danger signal peptide receptor) in regulating plant growth and development under Fe-deprived conditions. We revealed that a Damage Associated Molecular Pattern (DAMP) such as PROPEP2 is significantly induced under Fe deficiency. We also show that PEP2 modulates the expression of Iron Regulated Transporter 1 (IRT1) and Ferric-Reduction Oxidase (FRO2) under Fe deficiency. Furthermore, we showed that PEPR2 perceives PEP2 to positively regulate reactive oxygen species (ROS) content and negatively regulate the primary root growth, iron content and rhizosphere acidification. Our findings reveal the complex interplay between Fe and DAMP signalling pathways in plants.
{"title":"An endogenous peptide PEP2 modulates Iron-deficiency signalling and root growth in Arabidopsis.","authors":"Deep Shikha, Sanskar Mishra, Santosh B Satbhai","doi":"10.1101/2024.09.10.612258","DOIUrl":"https://doi.org/10.1101/2024.09.10.612258","url":null,"abstract":"Iron (Fe) is an essential element for most of the living organisms including plants and humans, where plants serve as the primary source of our dietary iron intake. The availability of Fe determines plant fitness and yield. Thus, understanding of iron uptake, its acquisition and utilization is of critical importance to reap nutritional benefits from plant breeding. Despite significant progress in uncovering how iron homeostasis is regulated by transcription factors and phytohormones, molecular pathways that mediate Fe deficiency through the action of signalling peptides remain elusive. In this work, we reported the role of PROPEP2 (Plant Elicitor Peptide 2) and PEPR (Perception of Arabidopsis danger signal peptide receptor) in regulating plant growth and development under Fe-deprived conditions. We revealed that a Damage Associated Molecular Pattern (DAMP) such as PROPEP2 is significantly induced under Fe deficiency. We also show that PEP2 modulates the expression of Iron Regulated Transporter 1 (IRT1) and Ferric-Reduction Oxidase (FRO2) under Fe deficiency. Furthermore, we showed that PEPR2 perceives PEP2 to positively regulate reactive oxygen species (ROS) content and negatively regulate the primary root growth, iron content and rhizosphere acidification. Our findings reveal the complex interplay between Fe and DAMP signalling pathways in plants.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Enset (Ensete ventricosum, Musaceae) is an important economic crop from Ethiopia which accounts for 20% of the staple diet in Ethiopia today. However, its evolutionary history and spread is poorly understood. Archaeology could provide evidence of past use and contribute to our understanding of its early history, but so far, this has not transpired. Cultivated enset is clonally reproduced and seed production rarely occurs, therefore, looking for seed remains is futile and instead archaeobotanical research should focus on microfossils such as phytoliths. Phytoliths have been shown to be diagnostic for the presence of banana (Musa) and are expected to be similarly useful for identifying enset, but we need a better understanding of phytolith production and variability, and the extent to which this may be used to track domestication. The current study provides a fundamental baseline for the identification of Ensete phytoliths through the examination of phytoliths from leaves and other plant parts based on their size and shape. We consider the differentiation of phytoliths across a single plant, based on location in the leaf, the age of the leaf, and different organs of the plant. We also compare phytoliths in the Musaceae Family, and between the enset cultivar and wild samples.
{"title":"Differentiating wild and domesticated enset (Musaceae) using phytolith analysis","authors":"Cristina Castillo Cobo, Alemseged Beldados, Philippa Ryan, Sandra Bond, Luc Vrydaghs, Ermias Lulekal Molla, James Borrell, Harriet Hunt, Dorian Q Fuller","doi":"10.1101/2024.09.09.611979","DOIUrl":"https://doi.org/10.1101/2024.09.09.611979","url":null,"abstract":"Enset (Ensete ventricosum, Musaceae) is an important economic crop from Ethiopia which accounts for 20% of the staple diet in Ethiopia today. However, its evolutionary history and spread is poorly understood. Archaeology could provide evidence of past use and contribute to our understanding of its early history, but so far, this has not transpired. Cultivated enset is clonally reproduced and seed production rarely occurs, therefore, looking for seed remains is futile and instead archaeobotanical research should focus on microfossils such as phytoliths. Phytoliths have been shown to be diagnostic for the presence of banana (Musa) and are expected to be similarly useful for identifying enset, but we need a better understanding of phytolith production and variability, and the extent to which this may be used to track domestication. The current study provides a fundamental baseline for the identification of Ensete phytoliths through the examination of phytoliths from leaves and other plant parts based on their size and shape. We consider the differentiation of phytoliths across a single plant, based on location in the leaf, the age of the leaf, and different organs of the plant. We also compare phytoliths in the Musaceae Family, and between the enset cultivar and wild samples.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1101/2024.09.06.611734
Yesica Daniela Chazarreta, Santiago Alvarez Prado, Maria Elena Otegui
Maize (Zea mays L.) production in Argentina changed markedly during the last decade due to the widespread adoption of late sowings, expanding its productive area, and diversifying crop end-uses. This study evaluated environment (two years × two sowing dates) and management practices (two nitrogen levels) effects on kernel weight, its physiological determinants, source/sink ratios, and water-soluble carbohydrates in stem (WSCS) of eight temperate maize hybrids bred for different uses (3 graniferous, 2 dual-purpose, 2 silage). Crop growth simulations allowed the estimation of percent variation in WSCS remobilization (null, partial, or total) for different production systems (18 scenarios) and climate conditions (41 growing seasons). Nitrogen fertilization increased kernel weight in early sowings, with minimal effects in late sowings. WSCS remobilization during kernel filling was higher in late than in early sowings, with no differences among hybrid types. Regarding hybrid types, dual-purpose and silage hybrids showed the highest and the lowest kernel weight respectively, and graniferous hybrids had the highest source/sink ratio during the effective kernel-filling period. Simulations underscored the importance of sowing date and nitrogen supply on WSCS for irrigated and dryland maize farming systems in a temperate environment, with important implications for grain and silage production at the farm level.
{"title":"Kernel weight and source/sink ratio determination of temperate maize hybrids with different end uses under contrasting environments","authors":"Yesica Daniela Chazarreta, Santiago Alvarez Prado, Maria Elena Otegui","doi":"10.1101/2024.09.06.611734","DOIUrl":"https://doi.org/10.1101/2024.09.06.611734","url":null,"abstract":"Maize (Zea mays L.) production in Argentina changed markedly during the last decade due to the widespread adoption of late sowings, expanding its productive area, and diversifying crop end-uses. This study evaluated environment (two years × two sowing dates) and management practices (two nitrogen levels) effects on kernel weight, its physiological determinants, source/sink ratios, and water-soluble carbohydrates in stem (WSCS) of eight temperate maize hybrids bred for different uses (3 graniferous, 2 dual-purpose, 2 silage). Crop growth simulations allowed the estimation of percent variation in WSCS remobilization (null, partial, or total) for different production systems (18 scenarios) and climate conditions (41 growing seasons). Nitrogen fertilization increased kernel weight in early sowings, with minimal effects in late sowings. WSCS remobilization during kernel filling was higher in late than in early sowings, with no differences among hybrid types. Regarding hybrid types, dual-purpose and silage hybrids showed the highest and the lowest kernel weight respectively, and graniferous hybrids had the highest source/sink ratio during the effective kernel-filling period. Simulations underscored the importance of sowing date and nitrogen supply on WSCS for irrigated and dryland maize farming systems in a temperate environment, with important implications for grain and silage production at the farm level.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142182974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arabidopsis thaliana is known to position nuclei on the bottom wall of leaf cells, distancing genetic material from external stresses, and, in response to intense blue light, it relocates them to the side walls to escape UV-induced DNA damage. However, how this protective system evolved in land plants remains unclear. Here, we show that Chara corallina, the charophyte alga, has no light-dependent nuclear relocation and that Marchantia polymorpha, a modern relative of the earliest land plants, has a nuclear positioning system distinct from that of Arabidopsis: it positions nuclei on the upper walls of the epidermal cells of the young thalli in the dark and even in prolonged intense light. We also show that, in response to intense blue light, M. polymorpha has the ability to immediately move nuclei from the upper to the side walls in an actin filament-dependent manner similarly to Arabidopsis. However, the relocation is transient and the nuclei return to the upper walls depending on two cytoskeletal components (actin filaments and microtubules). Together, these findings suggest that light-dependent nuclear relocation was initially established in bryophytes and then diverged as land plants evolved.
众所周知，拟南芥将细胞核置于叶肉细胞的底壁，使遗传物质与外界压力保持距离，而在强烈的蓝光照射下，拟南芥会将细胞核移至侧壁，以躲避紫外线引起的 DNA 损伤。然而，这种保护系统在陆生植物中是如何进化的仍不清楚。在这里，我们展示了珊瑚藻类（Chara corallina）没有依赖光的核迁移，而最早的陆生植物的近缘种--马钱科植物（Marchantia polymorpha）则具有与拟南芥不同的核定位系统：在黑暗中，甚至在长时间的强光下，它都会将核定位在幼苗表皮细胞的上壁上。我们还发现，在强烈的蓝光照射下，M. polymorpha 能以类似拟南芥的肌动蛋白丝依赖方式立即将细胞核从上壁移到侧壁。不过，这种移动是短暂的，细胞核能否返回上壁取决于两种细胞骨架成分（肌动蛋白丝和微管）。这些发现共同表明，依赖光的核搬迁最初是在红叶植物中建立起来的，然后随着陆地植物的进化而分化。
{"title":"Evolutionary acquisition of a primitive light-dependent nuclear relocation in Marchantia polymorpha","authors":"Kosei Iwabuchi, Hiroki Yagi, Kenta C. Moriya, Aino Komatsu, Noriyuki Suetsugu, Yuuki Sakai, Tomoo Shimada, Ryuichi Nishihama, Takayuki Kohchi, Akiko Harada, Yo-hei Watanabe, Haruko Ueda, Ikuko Hara-Nishimura","doi":"10.1101/2024.09.11.611950","DOIUrl":"https://doi.org/10.1101/2024.09.11.611950","url":null,"abstract":"<em>Arabidopsis thaliana</em> is known to position nuclei on the bottom wall of leaf cells, distancing genetic material from external stresses, and, in response to intense blue light, it relocates them to the side walls to escape UV-induced DNA damage. However, how this protective system evolved in land plants remains unclear. Here, we show that <em>Chara corallina</em>, the charophyte alga, has no light-dependent nuclear relocation and that <em>Marchantia polymorpha</em>, a modern relative of the earliest land plants, has a nuclear positioning system distinct from that of Arabidopsis: it positions nuclei on the upper walls of the epidermal cells of the young thalli in the dark and even in prolonged intense light. We also show that, in response to intense blue light, <em>M. polymorpha</em> has the ability to immediately move nuclei from the upper to the side walls in an actin filament-dependent manner similarly to Arabidopsis. However, the relocation is transient and the nuclei return to the upper walls depending on two cytoskeletal components (actin filaments and microtubules). Together, these findings suggest that light-dependent nuclear relocation was initially established in bryophytes and then diverged as land plants evolved.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142182955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ethylene plays a crucial role in regulating polyphenol metabolism, however the underlying mechanism remains largely unknown. This work demonstrated that ethylene release occurred earlier than melatonin during seed ripening. Ethylene treatment increased the VvASMT expression and melatonin content. VvERF5 was elucidated to bind to the ERE element in the VvASMT promoter. VvERF5 overexpression increased ASMT expression and melatonin content while its suppression generated the opposite results in grape seeds, calli and/or Arabidopsis seeds. Using the promoter of VvMYB14, which was strongly induced by melatonin, a melatonin responsive element (MTRE) was identified. VvERF104 was revealed not only to be strongly induced by melatonin but to bind to the MTRE of the VvMYB14. VvERF104 overexpression and suppression largely increased and decreased the MYB14 expression, respectively, in grape seeds, calli and/or Arabidopsis seeds. VvMYB14 overexpression widely modified the expression of genes in phenylpropanoid pathway and phenolic compound content in grape seeds. DAP-seq revealed that the MEME-1 motif was the most likely binding sites of VvMYB14. VvPAL, VvC4H and VvCHS were verified to be the target genes of VvMYB14. Additionally, the roles of VvERF5, VvASMT and VvERF104 in mediating ethylene-induced changes in phenylpropanoid pathway were elucidated using their suppressing seeds. Collectively, ethylene increased the VvMYB14 expression via the pathway of ERF5-melatonin-ERF104 and thereby modified phenylpropanoid pathway.
{"title":"Ethylene Modulates the Phenylpropanoid Pathway by Enhancing VvMYB14 Expression via the ERF5-Melatonin-ERF104 Pathway in Grape Seeds","authors":"Shiwei Gao, Fei Wang, Shengnan Wang, Shuxia Lan, Yujiao Xu, Xinning Lyu, Hui Kang, Yuxin Yao","doi":"10.1101/2024.09.10.612321","DOIUrl":"https://doi.org/10.1101/2024.09.10.612321","url":null,"abstract":"Ethylene plays a crucial role in regulating polyphenol metabolism, however the underlying mechanism remains largely unknown. This work demonstrated that ethylene release occurred earlier than melatonin during seed ripening. Ethylene treatment increased the VvASMT expression and melatonin content. VvERF5 was elucidated to bind to the ERE element in the VvASMT promoter. VvERF5 overexpression increased ASMT expression and melatonin content while its suppression generated the opposite results in grape seeds, calli and/or Arabidopsis seeds. Using the promoter of VvMYB14, which was strongly induced by melatonin, a melatonin responsive element (MTRE) was identified. VvERF104 was revealed not only to be strongly induced by melatonin but to bind to the MTRE of the VvMYB14. VvERF104 overexpression and suppression largely increased and decreased the MYB14 expression, respectively, in grape seeds, calli and/or Arabidopsis seeds. VvMYB14 overexpression widely modified the expression of genes in phenylpropanoid pathway and phenolic compound content in grape seeds. DAP-seq revealed that the MEME-1 motif was the most likely binding sites of VvMYB14. VvPAL, VvC4H and VvCHS were verified to be the target genes of VvMYB14. Additionally, the roles of VvERF5, VvASMT and VvERF104 in mediating ethylene-induced changes in phenylpropanoid pathway were elucidated using their suppressing seeds. Collectively, ethylene increased the VvMYB14 expression via the pathway of ERF5-melatonin-ERF104 and thereby modified phenylpropanoid pathway.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-13DOI: 10.1101/2024.09.10.612026
Guilherme T Braz, Lucas B Riboldi, Maísa S Pinto, Eliana R Forni-Martins, Juliana E C T Yassitepe, Ricardo A Dante, Isabel R Gerhardt
Chromosome number is the most fundamental trait of a karyotype. Accurate chromosome counting is essential for further analyses including cytogenomics, taxonomic, evolutionary, and genomic studies. Despite its importance, miscounting is common, especially in early publications on species with small and morphologically similar chromosomes. Vellozia Vand. is a genus mainly distributed throughout South America belonging to the angiosperm family Velloziaceae, a dominant taxon in the Brazilian ″campos rupestres″. Cytogenetic studies within the group have been rare and have shown conflicting chromosome counts, even within the same species. These discrepancies are associated with the presence of a few small chromosome-like structures, which were previously classified as possible satellites. Here, to accurately determine the chromosome number of species belonging to the genus, we used different cytogenomics approaches, including the immunostaining of the KNL1 kinetochore protein combined with chromosome spread preparation using tissue culture-derived samples. Our results revealed 2n = 18 chromosomes for all six species studied. This finding suggests that the basic chromosome number for Vellozia is x = 9 and not x = 8, as previously proposed. The immunolocalization of functional centromeres was fundamental for undoubtedly identifying the smaller chromosome pair as real chromosomes and accurately determining the correct chromosome number of these species. This will provide substantial support for further studies, including investigations into karyotype evolution and the generation of reference genomes for the species of the family.
染色体数目是核型最基本的特征。准确的染色体计数对于细胞遗传组学、分类学、进化和基因组研究等进一步分析至关重要。尽管其重要性不言而喻，但染色体数目计算错误却很常见，尤其是在早期发表的关于染色体较小且形态相似的物种的文章中。Vellozia Vand.属主要分布在南美洲各地，属于被子植物 Velloziaceae 科，是巴西″campos rupestres″中的主要分类群。该类植物的细胞遗传学研究很少见，即使在同一物种中，染色体数目也相互矛盾。这些差异与一些类似染色体的小结构的存在有关，这些结构以前被归类为可能的卫星。在此，为了准确确定该属物种的染色体数目，我们采用了不同的细胞基因组学方法，包括免疫染色 KNL1 动点蛋白和利用组织培养样本进行染色体扩增制备。我们的研究结果表明，所有六个物种的染色体都是 2n = 18。这一发现表明，Vellozia 的基本染色体数是 x = 9，而不是之前提出的 x = 8。功能性中心粒的免疫定位对于确定较小的染色体对为真正的染色体和准确确定这些物种的正确染色体数目无疑是至关重要的。这将为进一步的研究提供大量支持，包括研究核型进化和为该科物种生成参考基因组。
{"title":"Revisiting the cytogenetics of Vellozia Vand.: immunolocalization of KLN1 elucidates the chromosome number for the genus","authors":"Guilherme T Braz, Lucas B Riboldi, Maísa S Pinto, Eliana R Forni-Martins, Juliana E C T Yassitepe, Ricardo A Dante, Isabel R Gerhardt","doi":"10.1101/2024.09.10.612026","DOIUrl":"https://doi.org/10.1101/2024.09.10.612026","url":null,"abstract":"Chromosome number is the most fundamental trait of a karyotype. Accurate chromosome counting is essential for further analyses including cytogenomics, taxonomic, evolutionary, and genomic studies. Despite its importance, miscounting is common, especially in early publications on species with small and morphologically similar chromosomes. <em>Vellozia</em> Vand. is a genus mainly distributed throughout South America belonging to the angiosperm family Velloziaceae, a dominant taxon in the Brazilian ″campos rupestres″. Cytogenetic studies within the group have been rare and have shown conflicting chromosome counts, even within the same species. These discrepancies are associated with the presence of a few small chromosome-like structures, which were previously classified as possible satellites. Here, to accurately determine the chromosome number of species belonging to the genus, we used different cytogenomics approaches, including the immunostaining of the KNL1 kinetochore protein combined with chromosome spread preparation using tissue culture-derived samples. Our results revealed 2n = 18 chromosomes for all six species studied. This finding suggests that the basic chromosome number for <em>Vellozia</em> is x = 9 and not x = 8, as previously proposed. The immunolocalization of functional centromeres was fundamental for undoubtedly identifying the smaller chromosome pair as real chromosomes and accurately determining the correct chromosome number of these species. This will provide substantial support for further studies, including investigations into karyotype evolution and the generation of reference genomes for the species of the family.","PeriodicalId":501341,"journal":{"name":"bioRxiv - Plant Biology","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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