A buttress is a prominent lateral-vertical structures of surface roots of a canopy or emergent trees frequently observed in tropical forests. Buttresses are probably formed to enhance mechanical stability of tree trunks and/or promote nutrient acquisition. However, the morphological diversity and control of buttress development remain unclear. Therefore, we aimed to clarify variations in buttress development related to prevailing wind and declination of tree trunks in warm temperate forests of Japan. We chose two pairs of forest sites with similar precipitation and geographical locations, but with contrasting wind regimes. Buttresses of two Castanopsis species, C. sieboldii and C. cuspidata, were assessed, and the size and direction of the most developed buttress (MDB) were measured for each individual. The average MDB height at the stem of trees at the strong wind site, Sumoto, was less than half of that at the control site, Himeji. However, the result was the opposite at the other strong wind site, Muroto, and control site, Kochi. The average MDB length did not differ between the strong wind and control sites. MDBs were formed corresponding to the direction of the most frequent wind at strong wind sites but not at control sites. The direction of growth of MDBs was almost the same as that at slopes at all the sites. Our results suggest that wind loading likely influences the development of buttresses; however, its effect could also be site-dependent. These results suggest the potential roles of buttress formation on mechanical stability of trees, which have not been appreciated in temperate forests.
{"title":"Influence of wind and slope on buttress development in temperate tree species","authors":"Nanaho Kuwabe, Kiyosada Kawai, I. Endo, M. Ohashi","doi":"10.3117/plantroot.15.50","DOIUrl":"https://doi.org/10.3117/plantroot.15.50","url":null,"abstract":"A buttress is a prominent lateral-vertical structures of surface roots of a canopy or emergent trees frequently observed in tropical forests. Buttresses are probably formed to enhance mechanical stability of tree trunks and/or promote nutrient acquisition. However, the morphological diversity and control of buttress development remain unclear. Therefore, we aimed to clarify variations in buttress development related to prevailing wind and declination of tree trunks in warm temperate forests of Japan. We chose two pairs of forest sites with similar precipitation and geographical locations, but with contrasting wind regimes. Buttresses of two Castanopsis species, C. sieboldii and C. cuspidata, were assessed, and the size and direction of the most developed buttress (MDB) were measured for each individual. The average MDB height at the stem of trees at the strong wind site, Sumoto, was less than half of that at the control site, Himeji. However, the result was the opposite at the other strong wind site, Muroto, and control site, Kochi. The average MDB length did not differ between the strong wind and control sites. MDBs were formed corresponding to the direction of the most frequent wind at strong wind sites but not at control sites. The direction of growth of MDBs was almost the same as that at slopes at all the sites. Our results suggest that wind loading likely influences the development of buttresses; however, its effect could also be site-dependent. These results suggest the potential roles of buttress formation on mechanical stability of trees, which have not been appreciated in temperate forests.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621470","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}
M. Zhiponova, Jefri Heyman, L. De Veylder, A. Iantcheva
Root growth is under constant dynamic regulation for optimal response to developmental and environmental stimuli. At the posttranslational level, protein abundance is controlled by proteasomal degradation of targeted proteins. The substrate-specificity of this process is exerted by F-box proteins taking part in the SCFs (SKP1-CULLIN-F-box protein ligase) E3 ubiquitin protein ligases. In this work an Arabidopsis thaliana AtF-box, which regulates leucine homeostasis, was analyzed in the context of root development. Publicly available data sets and reporter lines revealed AtF-box expression in the primary and lateral roots. Aberrant stem cell divisions were detected in the distal stem cells (DSC) of the AtF-box knockdown lines (AtF-boxamiRNA), suggesting that AtF-box is required for the optimal cell division. Microscopic observations revealed the premature exit from cell proliferation and slower cell division activity. Conversely, in AtF-box overexpression (AtFboxOE) lines the cell division phase was prolonged. The root growth rate was respectively reduced and enhanced in the AtF-boxamiRNA and AtF-boxOE lines compared to the control. From the results of these studies, we concluded that the AtF-box gene is important for the fine-tuning of root growth.
{"title":"AtF-box gene expression fine-tunes Arabidopsis thaliana root development","authors":"M. Zhiponova, Jefri Heyman, L. De Veylder, A. Iantcheva","doi":"10.3117/plantroot.15.69","DOIUrl":"https://doi.org/10.3117/plantroot.15.69","url":null,"abstract":"Root growth is under constant dynamic regulation for optimal response to developmental and environmental stimuli. At the posttranslational level, protein abundance is controlled by proteasomal degradation of targeted proteins. The substrate-specificity of this process is exerted by F-box proteins taking part in the SCFs (SKP1-CULLIN-F-box protein ligase) E3 ubiquitin protein ligases. In this work an Arabidopsis thaliana AtF-box, which regulates leucine homeostasis, was analyzed in the context of root development. Publicly available data sets and reporter lines revealed AtF-box expression in the primary and lateral roots. Aberrant stem cell divisions were detected in the distal stem cells (DSC) of the AtF-box knockdown lines (AtF-boxamiRNA), suggesting that AtF-box is required for the optimal cell division. Microscopic observations revealed the premature exit from cell proliferation and slower cell division activity. Conversely, in AtF-box overexpression (AtFboxOE) lines the cell division phase was prolonged. The root growth rate was respectively reduced and enhanced in the AtF-boxamiRNA and AtF-boxOE lines compared to the control. From the results of these studies, we concluded that the AtF-box gene is important for the fine-tuning of root growth.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621496","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}
: As aged kiwifruit trees often reduce the fruit productivity and quality, those aged kiwifruits are replaced with juvenile vigorous plants. Howev-er, the productivity and quality of the replaced kiwifruits remain relatively low. In the present research, autotoxicity and allelopathy of kiwifruit roots were evaluated. Aqueous methanol extracts of kiwifruit roots inhibited the growth of cress, lettuce, alfalfa, Lolium multiflorum , Phleum pretense and Echino chloa crus-galli . The extracts of kiwifruit roots also showed an inhibitory effect on the growth of kiwi fruits themselves. These results suggest that kiwifruit roots may contain allelopathic and autotoxic substances. The accumulation of autotoxic substances in orchard soil may occur by continuous exudation of autotoxic substances from kiwifruit roots over the long-term cultivations, and by liberation of the substances from the root residues. Accumulated autotoxic substances may suppress the fruit productivity and quality of the replaced kiwifruits. Therefore, autotoxicity may be involved in the replant problem of kiwifruits.
{"title":"Involvement of kiwifruit root autotoxicity in its replant problem","authors":"S. Okada, H. Kato‐Noguchi","doi":"10.3117/plantroot.15.79","DOIUrl":"https://doi.org/10.3117/plantroot.15.79","url":null,"abstract":": As aged kiwifruit trees often reduce the fruit productivity and quality, those aged kiwifruits are replaced with juvenile vigorous plants. Howev-er, the productivity and quality of the replaced kiwifruits remain relatively low. In the present research, autotoxicity and allelopathy of kiwifruit roots were evaluated. Aqueous methanol extracts of kiwifruit roots inhibited the growth of cress, lettuce, alfalfa, Lolium multiflorum , Phleum pretense and Echino chloa crus-galli . The extracts of kiwifruit roots also showed an inhibitory effect on the growth of kiwi fruits themselves. These results suggest that kiwifruit roots may contain allelopathic and autotoxic substances. The accumulation of autotoxic substances in orchard soil may occur by continuous exudation of autotoxic substances from kiwifruit roots over the long-term cultivations, and by liberation of the substances from the root residues. Accumulated autotoxic substances may suppress the fruit productivity and quality of the replaced kiwifruits. Therefore, autotoxicity may be involved in the replant problem of kiwifruits.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621557","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}
S. Nishiuchi, Kohtaro Watanabe, Saori Sato, H. Takahashi, M. Nakazono
: The radial oxygen loss (ROL) barrier formed on the outer cell layers of roots of rice ( Oryza sativa ) contributes to efficient oxygen trans fer through the aerenchyma from the aerial parts to the root apex. It is hypothesized that suberin accumulation in the exodermis contributes to an apoplastic barrier and plays a vital role in ROL barrier formation. A previous study reported that some genes encoding cytochrome P450 family 86 ( CYP86 ) and glycerol-3-phosphate acyltransferase ( GPAT ) might be involved in suberin biosynthesis during ROL barrier development of rice roots. However, how these genes are expressed and their contribution to the sequential development of suberin accumulation in rice roots remains unclear. In this study, four CYP86 and five GPAT genes of rice were identified as candidate genes involved in suberin biosynthesis in roots using sequence homology alignment with Arabidopsis suberin and cutin biosynthesis genes. Gene expression analyses revealed that expression of the candidate genes was induced at the region where suberin biosynthesis occurred under stagnant deoxygenated conditions. These genes showed two types of spatiotemporal expression patterns, at the regions of 5–25 mm and 25–35 mm from the root apex. Tissue-specific expression analyses using laser microdissection and histochemical GUS staining revealed that candidate gene expression was similar in the cell layer of the root exodermis. These results suggest that the selected CYP86 and GPAT genes are involved in suberin biosynthesis in the exodermis, and that suberin biosynthesis in the root may be controlled by the spatiotemporal expression of two groups of genes.
{"title":"Expression analysis of genes for cytochrome P450 CYP86 and glycerol-3-phosphate acyltransferase related to suberin biosynthesis in rice roots under stagnant deoxygenated conditions","authors":"S. Nishiuchi, Kohtaro Watanabe, Saori Sato, H. Takahashi, M. Nakazono","doi":"10.3117/PLANTROOT.15.19","DOIUrl":"https://doi.org/10.3117/PLANTROOT.15.19","url":null,"abstract":": The radial oxygen loss (ROL) barrier formed on the outer cell layers of roots of rice ( Oryza sativa ) contributes to efficient oxygen trans fer through the aerenchyma from the aerial parts to the root apex. It is hypothesized that suberin accumulation in the exodermis contributes to an apoplastic barrier and plays a vital role in ROL barrier formation. A previous study reported that some genes encoding cytochrome P450 family 86 ( CYP86 ) and glycerol-3-phosphate acyltransferase ( GPAT ) might be involved in suberin biosynthesis during ROL barrier development of rice roots. However, how these genes are expressed and their contribution to the sequential development of suberin accumulation in rice roots remains unclear. In this study, four CYP86 and five GPAT genes of rice were identified as candidate genes involved in suberin biosynthesis in roots using sequence homology alignment with Arabidopsis suberin and cutin biosynthesis genes. Gene expression analyses revealed that expression of the candidate genes was induced at the region where suberin biosynthesis occurred under stagnant deoxygenated conditions. These genes showed two types of spatiotemporal expression patterns, at the regions of 5–25 mm and 25–35 mm from the root apex. Tissue-specific expression analyses using laser microdissection and histochemical GUS staining revealed that candidate gene expression was similar in the cell layer of the root exodermis. These results suggest that the selected CYP86 and GPAT genes are involved in suberin biosynthesis in the exodermis, and that suberin biosynthesis in the root may be controlled by the spatiotemporal expression of two groups of genes.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621400","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}
Root form and function is key to the productivity of natural and agricultural ecosystems. The growth and development of roots is highly adaptable to the environment. Studies show that species differ in their root system adaptation and function in response to high CO2, which may lead to changes in global species composition in the future. However, knowledge of genetic variation and molecular responses in roots to elevated CO2 is still lacking. This review examines the effects of elevated CO2 on root system and offers perspectives for future research.
{"title":"Effects of elevated CO 2 on plant root form and function: a review","authors":"Zhong Ma","doi":"10.3117/PLANTROOT.15.36","DOIUrl":"https://doi.org/10.3117/PLANTROOT.15.36","url":null,"abstract":"Root form and function is key to the productivity of natural and agricultural ecosystems. The growth and development of roots is highly adaptable to the environment. Studies show that species differ in their root system adaptation and function in response to high CO2, which may lead to changes in global species composition in the future. However, knowledge of genetic variation and molecular responses in roots to elevated CO2 is still lacking. This review examines the effects of elevated CO2 on root system and offers perspectives for future research.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"15 1","pages":"36-49"},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621416","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}
Natsumi Ueda, Shiro Mitsuya, A. Yamauchi, Maria Corazon J. Cabral, Mana Kano‐Nakata
: Water stress such as drought and waterlogging is considered to be a major limiting factor in crop production. Roots play important roles in crop adaptation to water stress. This study aimed to characterize the vertical root distribution patterns and analyze the root-shoot relationships of different cereal species with different water requirements in response to different soil moisture conditions. Sorghum, maize, and rice were grown under 5% w/w soil moisture content (SMC5), 20% w/w soil moisture content (SMC20) and in waterlogged soil (WL) for 35 days using root box pin-board method. For sorghum and maize, the optimal soil water condition was SMC20 which produced the greatest shoot and root growth, while rice had greatest shoot and root growth under WL. Sorghum significantly increased root to shoot ratio in both water stress conditions, suggesting that sorghum prioritizes carbon partitioning of assimilates towards the roots. Although whole root dry weight and total root length were reduced by water stress, vertical distribution of root traits varied with soil water conditions and promoted root response was observed in specific soil layer. A highly posi tive relationship between root and shoot traits was observed in rice, suggesting that root and shoot trait responses are coupled with changing soil water conditions. Further studies are needed to confirm root architectural changes focusing on differ ent root component traits as well as other root traits related to root architectural structure.
{"title":"Root system characteristics under different water regimes in three cereal species","authors":"Natsumi Ueda, Shiro Mitsuya, A. Yamauchi, Maria Corazon J. Cabral, Mana Kano‐Nakata","doi":"10.3117/PLANTROOT.15.10","DOIUrl":"https://doi.org/10.3117/PLANTROOT.15.10","url":null,"abstract":": Water stress such as drought and waterlogging is considered to be a major limiting factor in crop production. Roots play important roles in crop adaptation to water stress. This study aimed to characterize the vertical root distribution patterns and analyze the root-shoot relationships of different cereal species with different water requirements in response to different soil moisture conditions. Sorghum, maize, and rice were grown under 5% w/w soil moisture content (SMC5), 20% w/w soil moisture content (SMC20) and in waterlogged soil (WL) for 35 days using root box pin-board method. For sorghum and maize, the optimal soil water condition was SMC20 which produced the greatest shoot and root growth, while rice had greatest shoot and root growth under WL. Sorghum significantly increased root to shoot ratio in both water stress conditions, suggesting that sorghum prioritizes carbon partitioning of assimilates towards the roots. Although whole root dry weight and total root length were reduced by water stress, vertical distribution of root traits varied with soil water conditions and promoted root response was observed in specific soil layer. A highly posi tive relationship between root and shoot traits was observed in rice, suggesting that root and shoot trait responses are coupled with changing soil water conditions. Further studies are needed to confirm root architectural changes focusing on differ ent root component traits as well as other root traits related to root architectural structure.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69620988","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}
Keina Motegi, Yoshihiro Kobae, Emi Kameoka, Mikoto Kaneko, T. Hatanaka, S. Hobara
Surface humic soils, where fine roots are mainly distributed, can be accidentally buried due to coverage by deposits such as volcanic ash. This buried humic soil may influence the vertical distribution of fine roots because soil organic matter strongly affects soil functions. However, fine root distributions in buried humic soils are little understood. In order to elucidate the effects of buried humic soils on fine root distribution, we investigated fine root biomass and soil characteristics in a soil profile down to 3.3 m with two buried humic soils formed by tephra in Tomakomai, Hokkaido, Japan. In this profile, fine root biomass decreased with soil depth, but increased in buried humic soils that had higher soil total carbon (C) content and higher fine soil ratio than buried nonhumic soils. These results lead us to surmise a preferential development of active fine roots in buried humic soils rich in organic C rather than nonhumic soils.
{"title":"Vertical distribution of tree fine roots in the tephra profile with two buried humic soil layers","authors":"Keina Motegi, Yoshihiro Kobae, Emi Kameoka, Mikoto Kaneko, T. Hatanaka, S. Hobara","doi":"10.3117/plantroot.15.60","DOIUrl":"https://doi.org/10.3117/plantroot.15.60","url":null,"abstract":"Surface humic soils, where fine roots are mainly distributed, can be accidentally buried due to coverage by deposits such as volcanic ash. This buried humic soil may influence the vertical distribution of fine roots because soil organic matter strongly affects soil functions. However, fine root distributions in buried humic soils are little understood. In order to elucidate the effects of buried humic soils on fine root distribution, we investigated fine root biomass and soil characteristics in a soil profile down to 3.3 m with two buried humic soils formed by tephra in Tomakomai, Hokkaido, Japan. In this profile, fine root biomass decreased with soil depth, but increased in buried humic soils that had higher soil total carbon (C) content and higher fine soil ratio than buried nonhumic soils. These results lead us to surmise a preferential development of active fine roots in buried humic soils rich in organic C rather than nonhumic soils.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621480","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 fine root systems of ericaceous plants possess both absorptive fibrous roots and skeletal pioneer roots. This functional differentiation (heterorhizy) can be coupled with a specific mycorrhization pattern, in which fibrous roots form more ericoid mycorrhizas than pioneer roots. However, the behaviors of root-associated fungi on the different individual roots remain largely unknown. We investigated the colonization patterns and root modifications of Leohumicola verrucosa, Oidiodendron maius, and Leptobacillium leptobactrum strains on Vaccinium oldhamii hypocotyl cuttings in vitro. Three putative and true mycorrhizal fungal strains (one L. verrucosa and two O. maius) exhibited typical heterorhizic colonization patterns and tended to increase pioneer root branching. However, a root endophytic fungus (L. leptobactrum) uniformly exhibited a lower colonization across the different roots and did not increase the number of pioneer root branches. The colonization patterns and root modification ability of mycorrhizal fungi may be linked, thereby ensuring sufficient colonization sites.
{"title":"In vitro inoculation effects and colonization pattern of Leohumicola verrucosa, Oidiodendron maius, and Leptobacillium leptobactrum on fibrous and pioneer roots of Vaccinium oldhamii hypocotyl cuttings","authors":"T. Baba, D. Hirose, T. Ban","doi":"10.3117/PLANTROOT.15.1","DOIUrl":"https://doi.org/10.3117/PLANTROOT.15.1","url":null,"abstract":"The fine root systems of ericaceous plants possess both absorptive fibrous roots and skeletal pioneer roots. This functional differentiation (heterorhizy) can be coupled with a specific mycorrhization pattern, in which fibrous roots form more ericoid mycorrhizas than pioneer roots. However, the behaviors of root-associated fungi on the different individual roots remain largely unknown. We investigated the colonization patterns and root modifications of Leohumicola verrucosa, Oidiodendron maius, and Leptobacillium leptobactrum strains on Vaccinium oldhamii hypocotyl cuttings in vitro. Three putative and true mycorrhizal fungal strains (one L. verrucosa and two O. maius) exhibited typical heterorhizic colonization patterns and tended to increase pioneer root branching. However, a root endophytic fungus (L. leptobactrum) uniformly exhibited a lower colonization across the different roots and did not increase the number of pioneer root branches. The colonization patterns and root modification ability of mycorrhizal fungi may be linked, thereby ensuring sufficient colonization sites.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"21 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69620945","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}
: Lifecycle and temporal functionality of ericaceous fine roots can be affected by coloniza tion dynamics of diverse root colonizing fungi. However, states of colonization are unknown for most of the root endophytes, which also obscures their lifestyles. To recognize characteristics of colo nization of Leohumicola fungi, we investigated (1) the vitality of rhizodermal cells by using FUN-1 stain (vital staining) and (2) morphology of coloniz ing hyphae by N -acetylglucosamine-specific stain ing (DAB staining). All the twelve strains, identified as L. verrucosa , L. minima , and Leohumicola spp., colonized vital and non-vital rhizodermal cells of Vaccinium seedlings. We observed at least four different states of host cells encompassing coils. DAB staining visualized intracellular hyphae that resembled coils of typical ericoid mycorrhizal fungi. Heterogeneous staining states of coils were also observed in DAB staining. The variable states of Leohumicola coils can be comparable with ericoid mycorrhizal fungi, and indicate various develop mental
{"title":"Morphological characteristics of rhizodermal colonization by Leohumicola species in an ericaceous host","authors":"T. Baba, D. Hirose","doi":"10.3117/plantroot.14.1","DOIUrl":"https://doi.org/10.3117/plantroot.14.1","url":null,"abstract":": Lifecycle and temporal functionality of ericaceous fine roots can be affected by coloniza tion dynamics of diverse root colonizing fungi. However, states of colonization are unknown for most of the root endophytes, which also obscures their lifestyles. To recognize characteristics of colo nization of Leohumicola fungi, we investigated (1) the vitality of rhizodermal cells by using FUN-1 stain (vital staining) and (2) morphology of coloniz ing hyphae by N -acetylglucosamine-specific stain ing (DAB staining). All the twelve strains, identified as L. verrucosa , L. minima , and Leohumicola spp., colonized vital and non-vital rhizodermal cells of Vaccinium seedlings. We observed at least four different states of host cells encompassing coils. DAB staining visualized intracellular hyphae that resembled coils of typical ericoid mycorrhizal fungi. Heterogeneous staining states of coils were also observed in DAB staining. The variable states of Leohumicola coils can be comparable with ericoid mycorrhizal fungi, and indicate various develop mental","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69620828","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}
Siti Noorrohmah, Siti Noorrohmah, H. Takahashi, M. Nakazono, M. Nakazono
A barrier to restrict radial oxygen loss (ROL) promotes the adaptation of plants to waterlogged soil conditions. A ROL barrier is formed in the basal parts of roots and contributes to the enhancement of the longitudinal diffusion of oxygen (O2) via aerenchyma toward the root tips. The adventitious roots of rice (Oryza sativa) can form a ROL barrier in waterlogged soil; however, whether a ROL barrier can be formed in the lateral roots (LRs) of rice remains unclear. Rice possesses two types of LRs: Land S-type. L-type LRs are generally long, thick, and capable of branching, whereas S-type LRs are short, thin, and incapable of branching. In this study, we examined whether the Land S-type LRs of rice possess the ability to form ROL barriers. In L-type LRs, a ROL barrier was formed; the aerenchyma, which is constitutively formed under aerated conditions, was further developed under stagnant deoxygenated conditions, suggesting that these traits promote the supply of O2 to the root tips of LRs. However, neither a ROL barrier, nor aerenchyma was formed in Stype LRs, and thus ROL was observed mostly in the basal parts. Patterns of deposition of suberin, which is thought to be one of the components of the ROL barrier, were consistent with the patterns of ROL-barrier formation in L-type and S-type LRs. These results suggest that Land S-type LRs play distinct roles in the growth of rice plants in waterlogged soils and in oxygenating the rhizosphere.
限制径向氧损失(ROL)的屏障促进了植物对涝渍土壤条件的适应。在根系基部形成ROL屏障，促进氧(O2)通过通气组织向根尖的纵向扩散。水稻(Oryza sativa)不定根可以在渍水土壤中形成ROL屏障;然而，水稻侧根是否能形成ROL屏障尚不清楚。水稻有两种LRs: Land s型。l型LRs通常又长又厚，能够分支，而s型LRs则又短又薄，不能分支。在本研究中，我们考察了水稻的Land s型LRs是否具有形成ROL屏障的能力。l型LRs形成ROL屏障;通气条件下本构形成的通气组织在缺氧停滞条件下进一步发育，说明这些性状促进了LRs根尖的氧供应。然而，在型LRs中，既没有形成ROL屏障，也没有形成通气组织，因此ROL主要发生在基部。被认为是ROL屏障成分之一的亚木素的沉积模式与l型和s型lr中ROL屏障的形成模式一致。这些结果表明，陆地s型LRs对水稻在涝渍土壤中的生长和根际氧合具有明显的作用。
{"title":"Formation of a barrier to radial oxygen loss in L-type lateral roots of rice","authors":"Siti Noorrohmah, Siti Noorrohmah, H. Takahashi, M. Nakazono, M. Nakazono","doi":"10.3117/PLANTROOT.14.33","DOIUrl":"https://doi.org/10.3117/PLANTROOT.14.33","url":null,"abstract":"A barrier to restrict radial oxygen loss (ROL) promotes the adaptation of plants to waterlogged soil conditions. A ROL barrier is formed in the basal parts of roots and contributes to the enhancement of the longitudinal diffusion of oxygen (O2) via aerenchyma toward the root tips. The adventitious roots of rice (Oryza sativa) can form a ROL barrier in waterlogged soil; however, whether a ROL barrier can be formed in the lateral roots (LRs) of rice remains unclear. Rice possesses two types of LRs: Land S-type. L-type LRs are generally long, thick, and capable of branching, whereas S-type LRs are short, thin, and incapable of branching. In this study, we examined whether the Land S-type LRs of rice possess the ability to form ROL barriers. In L-type LRs, a ROL barrier was formed; the aerenchyma, which is constitutively formed under aerated conditions, was further developed under stagnant deoxygenated conditions, suggesting that these traits promote the supply of O2 to the root tips of LRs. However, neither a ROL barrier, nor aerenchyma was formed in Stype LRs, and thus ROL was observed mostly in the basal parts. Patterns of deposition of suberin, which is thought to be one of the components of the ROL barrier, were consistent with the patterns of ROL-barrier formation in L-type and S-type LRs. These results suggest that Land S-type LRs play distinct roles in the growth of rice plants in waterlogged soils and in oxygenating the rhizosphere.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69620935","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：