Phosphorus (P) is patchily distributed in soil because of its slow diffusion, especially in soil with a high phosphate absorption coefficient (PAC). Root responses to localized supply of phosphate were studied in Sesbania cannabina grown in volcanic andosol, which has a high PAC. Seedlings were grown in soil that was supplied with 0, 10, 100, 500, or 1000 mg P kg. After 30 days, analyses of plant P and root morphological were conducted. Further rhizobox experiments were also conducted. Seedlings were grown with layered P sources or localized P patches. Densely branched lateral roots (DBLRs) developed only in the 10 and 100 mg P kg treatments. Although an increase in shoot dry weight (DW) was observed in the 500 and 1000 mg P kg treatments, DBLRs were not observed. The number of DBLRs was positively correlated with shoot DW, root DW, and number of nodules, and negatively correlated with phosphorus use efficiency of shoots and roots. The rhizobox experiment showed that most DBLRs were observed in the layer with added P and in the position where P fertilizer was present. DBLRs developed so as to monopolize the P fertilizer by completely enveloping the area around it. The results suggest that DBLR formation is one of S. cannabina’s P acquisition strategies.
磷在土壤中扩散缓慢，呈斑状分布，特别是在磷吸收系数高的土壤中。研究了高PAC的火山土中种植的大麻籽(Sesbania cannabina)根系对局部磷供应的响应。幼苗生长在提供0、10、100、500或1000 mg P kg的土壤中。30 d后进行植株磷和根系形态分析。还进行了进一步的根箱试验。采用层状磷源或局部磷斑片育苗。密支侧根(DBLRs)仅在10和100 mg P kg处理下发育。500和1000 mg磷kg处理的茎部干重(DW)增加，但dblr没有增加。dblr数与地上部重、根重、根瘤数呈正相关，与地上部和根磷利用效率呈负相关。根箱试验表明，在施磷层和施磷肥的位置，dblr发生最多。dblr的发展是为了通过完全包围周围的区域来垄断磷肥。结果表明，DBLR的形成是大麻的P获取策略之一。
{"title":"Formation of densely branched lateral roots in Sesbania cannabina triggered by patchily distributed phosphorus in andosolic soils","authors":"Y. Funakoshi, H. Daimon, A. Matsumura","doi":"10.3117/PLANTROOT.9.24","DOIUrl":"https://doi.org/10.3117/PLANTROOT.9.24","url":null,"abstract":"Phosphorus (P) is patchily distributed in soil because of its slow diffusion, especially in soil with a high phosphate absorption coefficient (PAC). Root responses to localized supply of phosphate were studied in Sesbania cannabina grown in volcanic andosol, which has a high PAC. Seedlings were grown in soil that was supplied with 0, 10, 100, 500, or 1000 mg P kg. After 30 days, analyses of plant P and root morphological were conducted. Further rhizobox experiments were also conducted. Seedlings were grown with layered P sources or localized P patches. Densely branched lateral roots (DBLRs) developed only in the 10 and 100 mg P kg treatments. Although an increase in shoot dry weight (DW) was observed in the 500 and 1000 mg P kg treatments, DBLRs were not observed. The number of DBLRs was positively correlated with shoot DW, root DW, and number of nodules, and negatively correlated with phosphorus use efficiency of shoots and roots. The rhizobox experiment showed that most DBLRs were observed in the layer with added P and in the position where P fertilizer was present. DBLRs developed so as to monopolize the P fertilizer by completely enveloping the area around it. The results suggest that DBLR formation is one of S. cannabina’s P acquisition strategies.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"9 1","pages":"24-33"},"PeriodicalIF":0.6,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.9.24","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622293","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}
Within the tip of roots meristems of angiosperms and gymnosperms there is a small group of cells known as the quiescent centre (QC). The concept of the QC was developed 60 years ago by FAL Clowes, working in the Botany School, Oxford University, UK. To celebrate the Jubilee of the QC, a brief outline of the work that led to its demonstration by autoradiography was presented by Dubrovsky and Barlow (2015). The present article traces Clowes's subsequent experimental studies of the QC, especially with regard to how X-irradiation became an important tool for elucidating the properties and significance of the QC for root development. Also reviewed are some of the consequences that subsequently arose from this work with radiation, in particular the concerns over the use of radioisotopes in attempts to describe the kinetics of cell proliferation in the root meristem.
{"title":"The concept of the quiescent centre and how it found support from work with X-rays. I. Historical perspectives","authors":"P. Barlow","doi":"10.3117/PLANTROOT.9.43","DOIUrl":"https://doi.org/10.3117/PLANTROOT.9.43","url":null,"abstract":"Within the tip of roots meristems of angiosperms and gymnosperms there is a small group of cells known as the quiescent centre (QC). The concept of the QC was developed 60 years ago by FAL Clowes, working in the Botany School, Oxford University, UK. To celebrate the Jubilee of the QC, a brief outline of the work that led to its demonstration by autoradiography was presented by Dubrovsky and Barlow (2015). The present article traces Clowes's subsequent experimental studies of the QC, especially with regard to how X-irradiation became an important tool for elucidating the properties and significance of the QC for root development. Also reviewed are some of the consequences that subsequently arose from this work with radiation, in particular the concerns over the use of radioisotopes in attempts to describe the kinetics of cell proliferation in the root meristem.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"240 1","pages":"43-55"},"PeriodicalIF":0.6,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.9.43","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622808","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}
With the advent of the molecular era of plant biology, the location and activity of the quiescent centre (QC) within the root meristem were reappraised with respect to the transport and distribution of hormones, especially auxin. Later, when methods for probing gene activity became established, the genes and their regulators that were identifiably specific to the QC were also actively studied, at first in relation to the establishment of the root and its QC in the proembryo and later in relation to the interaction of the QC with neighbouring meristem cells. Auxin distribution in and around the QC was found to be associated with co-located oxidative enzymes which established a redox system within the root apex. This system is pivotal in both maintenance of quiescence and the activation of cell proliferation in the QC via the generation of reactive oxygen species (ROS) and their interaction with mitochondria. These and other features of QC biology are summarised.
{"title":"The concept of the quiescent centre and how it found support from work with X-rays. II. The molecular aftermath","authors":"P. Barlow","doi":"10.3117/PLANTROOT.9.56","DOIUrl":"https://doi.org/10.3117/PLANTROOT.9.56","url":null,"abstract":"With the advent of the molecular era of plant biology, the location and activity of the quiescent centre (QC) within the root meristem were reappraised with respect to the transport and distribution of hormones, especially auxin. Later, when methods for probing gene activity became established, the genes and their regulators that were identifiably specific to the QC were also actively studied, at first in relation to the establishment of the root and its QC in the proembryo and later in relation to the interaction of the QC with neighbouring meristem cells. Auxin distribution in and around the QC was found to be associated with co-located oxidative enzymes which established a redox system within the root apex. This system is pivotal in both maintenance of quiescence and the activation of cell proliferation in the QC via the generation of reactive oxygen species (ROS) and their interaction with mitochondria. These and other features of QC biology are summarised.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"9 1","pages":"56-67"},"PeriodicalIF":0.6,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.9.56","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622826","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}
Fine roots of Cryptomeria japonica were separated into two functional groups: primary roots that serve as the principal agent for water and nutrient absorption and secondary roots that have transport capacity and protect the plant from environmental stress. Individual roots can also be categorized by three characteristics: diameter, branching order, and number of protoxylem groups. We investigated the relationships of these two functional groups with the three categories and evaluated which category was a better index for distinguishing primary from secondary roots by using the Pianka overlap index. Primary and secondary roots showed no exact correspondence to any of the three categories and had overlap in each category. Therefore neither was a useful indicator to distinguish primary from secondary roots. However, in the case of Cryptomeria japonica, we can roughly distinguish primary from secondary roots on the basis of whether root diameter is less than or greater than 0.6 mm.
{"title":"Which is the best indicator for distinguishing between fine roots with primary and secondary development in Cryptomeria japonica D. Don: Diameter, branching order, or protoxylem groups?","authors":"Yusuke Tawa, H. Takeda","doi":"10.3117/PLANTROOT.9.79","DOIUrl":"https://doi.org/10.3117/PLANTROOT.9.79","url":null,"abstract":"Fine roots of Cryptomeria japonica were separated into two functional groups: primary roots that serve as the principal agent for water and nutrient absorption and secondary roots that have transport capacity and protect the plant from environmental stress. Individual roots can also be categorized by three characteristics: diameter, branching order, and number of protoxylem groups. We investigated the relationships of these two functional groups with the three categories and evaluated which category was a better index for distinguishing primary from secondary roots by using the Pianka overlap index. Primary and secondary roots showed no exact correspondence to any of the three categories and had overlap in each category. Therefore neither was a useful indicator to distinguish primary from secondary roots. However, in the case of Cryptomeria japonica, we can roughly distinguish primary from secondary roots on the basis of whether root diameter is less than or greater than 0.6 mm.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"9 1","pages":"79-84"},"PeriodicalIF":0.6,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622965","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}
Understanding morphology of lateral roots in rice is important in modeling different agricultural management system. The objective of the study was to explore the morphology of lateral roots of lowland transplanted-aman rice cultivars to mechanistically model length, surface area and volume of an individual root. Seedlings of twelve selected rice cultivars at 30 days of age were transplanted and a series of measurements was carried out on 14, 20, 33 and 60 days after transplantation (DAT). Lateral roots and root hairs were studied under a light microscope. Individual main axes produced up to second-order laterals. Mean main axis diameter and length of twelve cultivars measured 0.94 mm and 20.4 cm respectively at 60 days after transplantation. Diameter reduced at the first-order and second-order laterals up to 4.56 and 21.4 times respectively compared to main axis on 60 DAT. Root hair diameter measured 4.0 µm. An individual root on 60 DAT estimated 911 m in the length, 1714 cm 2 in the surface area and in the 467 mm 3 volume. Root hairs had the highest contribution towards total length and surface area of an individual root whereas main axis and first order laterals mostly contributed root volume.
了解水稻侧根形态对建立不同的农业管理制度具有重要意义。摘要本研究的目的是探讨低地移栽水稻品种侧根的形态，以机械方式模拟单根的长度、表面积和体积。选择12个30日龄的水稻品种进行移栽，并在移栽后14、20、33和60 d (DAT)进行了一系列测量。光镜下观察侧根和根毛。单个主轴产生二级横向。移植后60 d, 12个品种的平均主轴直径和长度分别为0.94 mm和20.4 cm。与主轴相比，一阶和二阶侧径分别减小了4.56倍和21.4倍。根毛直径测量4.0µm。60 DAT上的单根估计长度为911 m，表面积为1714 cm 2，体积为467 mm 3。根毛对单根总长度和表面积的贡献最大，而主轴和一级侧根对根体积的贡献最大。
{"title":"Morphology of lateral roots of twelve rice cultivars of Bangladesh: dimension increase and diameter reduction in progressive root branching at the vegetative stage","authors":"Arif Hasan Khan Robin, P. Saha","doi":"10.3117/PLANTROOT.9.34","DOIUrl":"https://doi.org/10.3117/PLANTROOT.9.34","url":null,"abstract":"Understanding morphology of lateral roots in rice is important in modeling different agricultural management system. The objective of the study was to explore the morphology of lateral roots of lowland transplanted-aman rice cultivars to mechanistically model length, surface area and volume of an individual root. Seedlings of twelve selected rice cultivars at 30 days of age were transplanted and a series of measurements was carried out on 14, 20, 33 and 60 days after transplantation (DAT). Lateral roots and root hairs were studied under a light microscope. Individual main axes produced up to second-order laterals. Mean main axis diameter and length of twelve cultivars measured 0.94 mm and 20.4 cm respectively at 60 days after transplantation. Diameter reduced at the first-order and second-order laterals up to 4.56 and 21.4 times respectively compared to main axis on 60 DAT. Root hair diameter measured 4.0 µm. An individual root on 60 DAT estimated 911 m in the length, 1714 cm 2 in the surface area and in the 467 mm 3 volume. Root hairs had the highest contribution towards total length and surface area of an individual root whereas main axis and first order laterals mostly contributed root volume.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"9 1","pages":"34-42"},"PeriodicalIF":0.6,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.9.34","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622756","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}
A. Noguchi, Yoshifumi Houman, F. Shinmachi, R. Chen, X. Zhao, R. Shen, I. Hasegawa
Two Melaleuca species, M. cajuputi and M. bracteata, were compared to identify the factors determining their distinct aluminum (Al) resistance levels. The presence of Al in a liquid culture medium (maximum tested concentration, 2 mM) did not affect the growth of M. cajuputi, but severely inhibited the growth of M. bracteata. The Al content in the roots was 50% higher in Al-sensitive M. bracteata than in Al-resistant M. cajuputi. Al penetration and tissue damage were obvious in the roots of M. bracteata, but only mild in the roots of M. cajuputi. Relatively high levels of fumarate were released by the roots of M. cajuputi, but not by those of M. bracteata. Supplementation of Al-containing liquid media with fumarate resulted in a reduction of Al toxicity on M. bracteata. These results suggest that Al-resistant M. cajuputi releases fumarate from its roots, thereby detoxifying Al.
{"title":"Exudation of fumarate from roots contributes to high aluminum resistance in Melaleuca cajuputi","authors":"A. Noguchi, Yoshifumi Houman, F. Shinmachi, R. Chen, X. Zhao, R. Shen, I. Hasegawa","doi":"10.3117/PLANTROOT.9.15","DOIUrl":"https://doi.org/10.3117/PLANTROOT.9.15","url":null,"abstract":"Two Melaleuca species, M. cajuputi and M. bracteata, were compared to identify the factors determining their distinct aluminum (Al) resistance levels. The presence of Al in a liquid culture medium (maximum tested concentration, 2 mM) did not affect the growth of M. cajuputi, but severely inhibited the growth of M. bracteata. The Al content in the roots was 50% higher in Al-sensitive M. bracteata than in Al-resistant M. cajuputi. Al penetration and tissue damage were obvious in the roots of M. bracteata, but only mild in the roots of M. cajuputi. Relatively high levels of fumarate were released by the roots of M. cajuputi, but not by those of M. bracteata. Supplementation of Al-containing liquid media with fumarate resulted in a reduction of Al toxicity on M. bracteata. These results suggest that Al-resistant M. cajuputi releases fumarate from its roots, thereby detoxifying Al.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"9 1","pages":"15-23"},"PeriodicalIF":0.6,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622248","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}
{"title":"Got rice? Several topics related to rice root research","authors":"I. Karahara","doi":"10.3117/PLANTROOT.8.1","DOIUrl":"https://doi.org/10.3117/PLANTROOT.8.1","url":null,"abstract":"","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"8 1","pages":"1-4"},"PeriodicalIF":0.6,"publicationDate":"2014-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622380","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}
Tsubasa Yano, A. Yamamoto, H. Kunitake, Y. Saeki, R. Akashi
For systematic functional analysis of genes, we attempted the application of the FOX-hunting system to super growing-roots (SR) of legume species Lotus corniculatus which was previously reported by Himuro et al. (2011). In this study, we investigated the functional analysis of FSL#35, which was expressed by the rolB gene derived from the Agrobacterium rhizogenes Ri plasmid. In monoculture roots grown in liquid media, the FSL#35 showed specific phenotypes that increased root length, lateral root number and root surface area compared with SR. These enhanced phenotypes of FSL#35 were caused by cell profile alteration, while increased total root length and increased lateral root number were caused by the expansion of cortex cells and increased pericycle cells, respectively. In addition, the FSL#35 root showed high and specific respiration activity compared with SR. These results suggest that distinct cell profiles of FSL#35 were induced by the alteration of respiration activity in root tissue. The enhanced root growth in the FSL#35 root might be induced by alteration of ROS metabolisms. Investigating the details of the rolB gene function, for example by phytohormone analysis, will elucidate the novel benefits of the rolB gene for agriculture.
为了对基因进行系统的功能分析，我们尝试将FOX-hunting系统应用于Himuro et al.(2011)先前报道的豆科植物莲花(Lotus corniculatus)的超生长根(SR)。本研究对根状农杆菌Ri质粒中rolB基因表达的FSL#35进行了功能分析。在液体培养基中培养的单根中，FSL#35表现出比sr更高的根长、侧根数和根表面积的特殊表型，这些表型的增加是由细胞形态改变引起的，而总根长和侧根数的增加分别是由皮质细胞和中柱鞘细胞的扩增引起的。此外，与sr相比，FSL#35的根系呼吸活性表现出较高的特异性。这些结果表明，FSL#35不同的细胞形态是由根系呼吸活性的改变引起的。FSL#35根系生长增强可能与活性氧代谢改变有关。研究rolB基因功能的细节，例如通过植物激素分析，将阐明rolB基因对农业的新益处。
{"title":"The phenomenon of root elongation and high respiration activity in the rolB-gene-enhanced FSL#35 variant of Lotus corniculatus FOX-SR line","authors":"Tsubasa Yano, A. Yamamoto, H. Kunitake, Y. Saeki, R. Akashi","doi":"10.3117/PLANTROOT.8.82","DOIUrl":"https://doi.org/10.3117/PLANTROOT.8.82","url":null,"abstract":"For systematic functional analysis of genes, we attempted the application of the FOX-hunting system to super growing-roots (SR) of legume species Lotus corniculatus which was previously reported by Himuro et al. (2011). In this study, we investigated the functional analysis of FSL#35, which was expressed by the rolB gene derived from the Agrobacterium rhizogenes Ri plasmid. In monoculture roots grown in liquid media, the FSL#35 showed specific phenotypes that increased root length, lateral root number and root surface area compared with SR. These enhanced phenotypes of FSL#35 were caused by cell profile alteration, while increased total root length and increased lateral root number were caused by the expansion of cortex cells and increased pericycle cells, respectively. In addition, the FSL#35 root showed high and specific respiration activity compared with SR. These results suggest that distinct cell profiles of FSL#35 were induced by the alteration of respiration activity in root tissue. The enhanced root growth in the FSL#35 root might be induced by alteration of ROS metabolisms. Investigating the details of the rolB gene function, for example by phytohormone analysis, will elucidate the novel benefits of the rolB gene for agriculture.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"8 1","pages":"82-91"},"PeriodicalIF":0.6,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622667","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}
Many crops are sensitive to waterlogging. A small, fast-growing grass, Brachypodium distachyon (Bd21), whose genome has been sequenced, is a new model for studying cereal crops such as wheat and barley, and for developing novel biomass grasses. However, its waterlogging tolerance and oxygen transport properties are not known. Here, we show that in stagnant deoxygenated nutrient solution, which mimics waterlogged soil, B. distachyon grows poorly and does not increase the number of newly formed roots. In both aerated and stagnant conditions, aerenchyma was hardly observed in roots, and root porosities were low. Suberin and lignin, which are thought to be constituents of the barrier to radial oxygen loss, did not develop in the outer part of roots in either aerated or stagnant conditions. Our results suggest that the abilities of oxygen transport in B. distachyon are insufficient to grow and survive in stagnant deoxygenated conditions.
{"title":"Waterlogging tolerance and capacity for oxygen transport in Brachypodium distachyon (Bd21)","authors":"K. Shiono, Sumiyo Yamada","doi":"10.3117/PLANTROOT.8.5","DOIUrl":"https://doi.org/10.3117/PLANTROOT.8.5","url":null,"abstract":"Many crops are sensitive to waterlogging. A small, fast-growing grass, Brachypodium distachyon (Bd21), whose genome has been sequenced, is a new model for studying cereal crops such as wheat and barley, and for developing novel biomass grasses. However, its waterlogging tolerance and oxygen transport properties are not known. Here, we show that in stagnant deoxygenated nutrient solution, which mimics waterlogged soil, B. distachyon grows poorly and does not increase the number of newly formed roots. In both aerated and stagnant conditions, aerenchyma was hardly observed in roots, and root porosities were low. Suberin and lignin, which are thought to be constituents of the barrier to radial oxygen loss, did not develop in the outer part of roots in either aerated or stagnant conditions. Our results suggest that the abilities of oxygen transport in B. distachyon are insufficient to grow and survive in stagnant deoxygenated conditions.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"8 1","pages":"5-12"},"PeriodicalIF":0.6,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622510","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}
F. Pitre, J. Cooke, S. Caron, W. Kayal, M. Ouellet, Kim Lam, W. Nissim, J. MacKay
We investigated the short-term response of poplar roots to low and high nitrogen availability in order to elucidate the mechanisms involved in nutrient acquisition. After 28 days of fertilization with low versus high ammonium nitrate, an increase in aboveground biomass was observed accompanied by a decrease in root biomass, reducing the root: shoot ratio after 28 days. These changes in biomass allocation were accompanied by changes in root architecture and altered gene expression. The gene expression response was evaluated after 7 days using a custom cDNA micrarray following transfer to low and high nitrogen supply. We found that 56 sequences were differentially expressed in poplar roots. Many of these 56 genes could be associated with putative roles in development or response to biotic and abiotic stress. A time course analysis of selected cell wall-related genes by RT-qPCR confirmed the expression patterns obtained by microarray and also showed the timing of this differential response. Our results show that patterns of transcript accumulation in roots of poplars are influenced by nitrogen supply, providing evidence of unique nitrogen-adaptative mechanisms.
{"title":"Identification of nitrogen responsive genes in poplar roots grown under two contrasting nitrogen levels","authors":"F. Pitre, J. Cooke, S. Caron, W. Kayal, M. Ouellet, Kim Lam, W. Nissim, J. MacKay","doi":"10.3117/PLANTROOT.8.42","DOIUrl":"https://doi.org/10.3117/PLANTROOT.8.42","url":null,"abstract":"We investigated the short-term response of poplar roots to low and high nitrogen availability in order to elucidate the mechanisms involved in nutrient acquisition. After 28 days of fertilization with low versus high ammonium nitrate, an increase in aboveground biomass was observed accompanied by a decrease in root biomass, reducing the root: shoot ratio after 28 days. These changes in biomass allocation were accompanied by changes in root architecture and altered gene expression. The gene expression response was evaluated after 7 days using a custom cDNA micrarray following transfer to low and high nitrogen supply. We found that 56 sequences were differentially expressed in poplar roots. Many of these 56 genes could be associated with putative roles in development or response to biotic and abiotic stress. A time course analysis of selected cell wall-related genes by RT-qPCR confirmed the expression patterns obtained by microarray and also showed the timing of this differential response. Our results show that patterns of transcript accumulation in roots of poplars are influenced by nitrogen supply, providing evidence of unique nitrogen-adaptative mechanisms.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"8 1","pages":"42-54"},"PeriodicalIF":0.6,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.8.42","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622498","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：