Flooding reduces soil oxygen necessary for root growth. In some mesophytes low levels of oxygen are mitigated by the formation of aerenchyma or expansion of intercellular spaces. But root immersion in water may have effects on roots in addition to reducing oxygen levels. At temperatures >15°C Pisum sativum primary roots develop cavities in the centers of their vascular cylinders in response to saturated or flooded conditions. In the present study we compared the response of flooded pea roots to their response to hypoxia without flooding by using an innovative system that allows separation of the gas environment of a root system from that of its shoot system. Seedlings were flooded after 4 d growth and compared to seedlings in unflooded medium and to seedlings in the gas-manipulation experiment. At 25°C in slightly moist vermiculite, roots 4 d after planting were exposed to a gas mixture with 10.5% oxygen and shoots to 20.5% oxygen and compared to normoxic controls. Oxygen levels in all containers were monitored, root growth was measured, and frequency and size of vascular cavities were determined for all treatments. Under flooding and low-oxygen gas, root growth was suppressed and vascular cavity frequency was strongly enhanced compared to controls. Significant differences in root growth responses were not seen between these differing hypoxic conditions, but low-oxygen gas caused larger cavities than flooding, which suggests flooding with water may have subtle effects different than simple hypoxia.
{"title":"Comparison of the effects of flooding vs. low-oxygen gas on pea (Pisum sativum L. cv. 'Alaska') primary roots","authors":"T. Niki, Mitsuo Takahashi, D. Gladish","doi":"10.3117/PLANTROOT.5.31","DOIUrl":"https://doi.org/10.3117/PLANTROOT.5.31","url":null,"abstract":"Flooding reduces soil oxygen necessary for root growth. In some mesophytes low levels of oxygen are mitigated by the formation of aerenchyma or expansion of intercellular spaces. But root immersion in water may have effects on roots in addition to reducing oxygen levels. At temperatures >15°C Pisum sativum primary roots develop cavities in the centers of their vascular cylinders in response to saturated or flooded conditions. In the present study we compared the response of flooded pea roots to their response to hypoxia without flooding by using an innovative system that allows separation of the gas environment of a root system from that of its shoot system. Seedlings were flooded after 4 d growth and compared to seedlings in unflooded medium and to seedlings in the gas-manipulation experiment. At 25°C in slightly moist vermiculite, roots 4 d after planting were exposed to a gas mixture with 10.5% oxygen and shoots to 20.5% oxygen and compared to normoxic controls. Oxygen levels in all containers were monitored, root growth was measured, and frequency and size of vascular cavities were determined for all treatments. Under flooding and low-oxygen gas, root growth was suppressed and vascular cavity frequency was strongly enhanced compared to controls. Significant differences in root growth responses were not seen between these differing hypoxic conditions, but low-oxygen gas caused larger cavities than flooding, which suggests flooding with water may have subtle effects different than simple hypoxia.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"5 1","pages":"31-39"},"PeriodicalIF":0.6,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622189","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}
J. Furukawa, Yuta Abe, H. Mizuno, Kaoru Matsuki, Keiko Sagawa, H. Mori, H. Iwai, S. Satoh
To investigate the environmental regulation of root function, xylem sap was annually collected from Populus nigra and the proteins in the sap were analyzed. A 25 kDa xylem sap protein (XSP25) was found to be most abundant in the xylem sap in winter and mass spectrometry analyses showed its high similarity to abscisic acid (ABA)-inducible basic secretory protein reported in tobacco BY-2 cells. By utilizing the information of whole genome sequence of Populus, PmXSP25 was cloned from Populus maximowiczii, naturally growing poplar in Japan. The expression of PmXSP25 was abundant in root at December and February and strongly enhanced by ABA application to the autumn root. We suggest that dormancy- inducing short day length and low temperature promote the synthesis of XSP25 in root, possibly via ABA, as an adaptation to the winter environment.
{"title":"Abscisic acid-inducible 25 kDa xylem sap protein abundant in winter poplar","authors":"J. Furukawa, Yuta Abe, H. Mizuno, Kaoru Matsuki, Keiko Sagawa, H. Mori, H. Iwai, S. Satoh","doi":"10.3117/PLANTROOT.5.63","DOIUrl":"https://doi.org/10.3117/PLANTROOT.5.63","url":null,"abstract":"To investigate the environmental regulation of root function, xylem sap was annually collected from Populus nigra and the proteins in the sap were analyzed. A 25 kDa xylem sap protein (XSP25) was found to be most abundant in the xylem sap in winter and mass spectrometry analyses showed its high similarity to abscisic acid (ABA)-inducible basic secretory protein reported in tobacco BY-2 cells. By utilizing the information of whole genome sequence of Populus, PmXSP25 was cloned from Populus maximowiczii, naturally growing poplar in Japan. The expression of PmXSP25 was abundant in root at December and February and strongly enhanced by ABA application to the autumn root. We suggest that dormancy- inducing short day length and low temperature promote the synthesis of XSP25 in root, possibly via ABA, as an adaptation to the winter environment.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"5 1","pages":"63-68"},"PeriodicalIF":0.6,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.5.63","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622471","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}
J. Furukawa, Yuta Abe, H. Mizuno, Kaoru Matsuki, Keiko Sagawa, M. Kojima, H. Sakakibara, H. Iwai, S. Satoh
Deciduous trees show annual periodicity in shoot growth and development, but such periodicity is not well investigated in roots. To clarify the seasonal fluctuation in root functions, xylem sap from Populus nigra branches was analyzed for 2 years. Various xylem sap components including calcium, potassium, glucose, and proteins showed seasonal fluctuations with peaks from winter to spring. Abscisic acid (ABA) was the most abundant hormone in the xylem sap throughout all seasons and showed two peaks from late autumn to spring. We hypothesize that low temperature in winter promotes metal loading into the xylem sap and the synthesis of proteins and sugars in roots as an adaptation to the winter environment and to prepare for spring bud burst. acetic acid; IA-Ala, indole-3-acetyl- L-alanine; IA-Ile, indole-3-acetyl-L-isoleucine; IA-Leu, indole-3-acetyl- L-leucine; IA-Asp, indole-3-acetyl-L-aspartic acid; IA-Trp, indole-3-acetyl-L-tryptophan; IA-Phe, indole- 3-acetyl-L-phenylalanine; GA, gibberellic acid; ABA, abscisic acid
{"title":"Seasonal fluctuation of organic and inorganic components in xylem sap of Populus nigra","authors":"J. Furukawa, Yuta Abe, H. Mizuno, Kaoru Matsuki, Keiko Sagawa, M. Kojima, H. Sakakibara, H. Iwai, S. Satoh","doi":"10.3117/PLANTROOT.5.56","DOIUrl":"https://doi.org/10.3117/PLANTROOT.5.56","url":null,"abstract":"Deciduous trees show annual periodicity in shoot growth and development, but such periodicity is not well investigated in roots. To clarify the seasonal fluctuation in root functions, xylem sap from Populus nigra branches was analyzed for 2 years. Various xylem sap components including calcium, potassium, glucose, and proteins showed seasonal fluctuations with peaks from winter to spring. Abscisic acid (ABA) was the most abundant hormone in the xylem sap throughout all seasons and showed two peaks from late autumn to spring. We hypothesize that low temperature in winter promotes metal loading into the xylem sap and the synthesis of proteins and sugars in roots as an adaptation to the winter environment and to prepare for spring bud burst. acetic acid; IA-Ala, indole-3-acetyl- L-alanine; IA-Ile, indole-3-acetyl-L-isoleucine; IA-Leu, indole-3-acetyl- L-leucine; IA-Asp, indole-3-acetyl-L-aspartic acid; IA-Trp, indole-3-acetyl-L-tryptophan; IA-Phe, indole- 3-acetyl-L-phenylalanine; GA, gibberellic acid; ABA, abscisic acid","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"40 1","pages":"56-62"},"PeriodicalIF":0.6,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.5.56","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621856","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}
Haniyeh Bidadi, Shinjiro Yamaguchi, M. Asahina, S. Satoh
To elucidate the involvement of gibberellin (GA) in the growth regulation of Arabidopsis roots, effects of shoot-applied GA and GA-biosynthesis inhibitors on the root were examined. Applying GA to the shoot of Arabidopsis slightly enhanced the primary root elongation. Treating shoots with uniconazole, a GA biosynthesis inhibitor, also resulted in enhancement of primary root elongation, while shoots treated with uniconazole were stunted and bolting was delayed. Analysis of the expression of GA3ox and GA20ox confirmed the up-regulation of these genes in roots following the inhibitor application to shoots. The results suggest that the inhibition of GA-biosynthesis enhances the production of bioactive GAs in roots and promotes root elongation.
{"title":"Effects of shoot-applied gibberellin/gibberellin-biosynthesis inhibitors on root growth and expression of gibberellin biosynthesis genes in Arabidopsis thaliana.","authors":"Haniyeh Bidadi, Shinjiro Yamaguchi, M. Asahina, S. Satoh","doi":"10.3117/PLANTROOT.4.4","DOIUrl":"https://doi.org/10.3117/PLANTROOT.4.4","url":null,"abstract":"To elucidate the involvement of gibberellin (GA) in the growth regulation of Arabidopsis roots, effects of shoot-applied GA and GA-biosynthesis inhibitors on the root were examined. Applying GA to the shoot of Arabidopsis slightly enhanced the primary root elongation. Treating shoots with uniconazole, a GA biosynthesis inhibitor, also resulted in enhancement of primary root elongation, while shoots treated with uniconazole were stunted and bolting was delayed. Analysis of the expression of GA3ox and GA20ox confirmed the up-regulation of these genes in roots following the inhibitor application to shoots. The results suggest that the inhibition of GA-biosynthesis enhances the production of bioactive GAs in roots and promotes root elongation.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"4 1","pages":"4-11"},"PeriodicalIF":0.6,"publicationDate":"2010-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.4.4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621762","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 facets reflecting the autopoietic process of Life and Living can be found in plant roots at many levels relevant to their organisation, from cells to ecosystems. At each level, there are sub-processes dedicated to both the auto- reproduction and the self-maintenance of that level, these processes being contained within a boundary appropriate for that level. Auto- reproduction and self-maintenance unite with a third sub-process, cognition, and provide the basis of a coherent multi-levelled programme of root-research.
{"title":"Plant roots: autopoietic and cognitive constructions.","authors":"P. Barlow","doi":"10.3117/PLANTROOT.4.40","DOIUrl":"https://doi.org/10.3117/PLANTROOT.4.40","url":null,"abstract":"Many facets reflecting the autopoietic process of Life and Living can be found in plant roots at many levels relevant to their organisation, from cells to ecosystems. At each level, there are sub-processes dedicated to both the auto- reproduction and the self-maintenance of that level, these processes being contained within a boundary appropriate for that level. Auto- reproduction and self-maintenance unite with a third sub-process, cognition, and provide the basis of a coherent multi-levelled programme of root-research.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"4 1","pages":"40-52"},"PeriodicalIF":0.6,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.4.40","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621824","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}
Before starting to write this letter, I reviewed my message of a year ago and found that I described the global financial crisis and global climate crisis. Up to this time, I have not personally found any sign of recovery from the economic downturn nearby. My students are still having quite a lot of difficulty securing jobs. However, the newspapers mention some signs of recovery from the global financial crisis. Perhaps there is another crisis that should be addressed––one that shows no recovery? Recovery would seem to be almost impossible unless excess carbon dioxide were to vanish somehow from the atmosphere. I often wonder whether any good sign was forthcoming during 2009 for healing of the Earth from its climate crisis. I did hear some interesting news about the Nobel Memorial Prize in Economic Sciences in 2009. One laureate of that prize, Dr. Elinor Ostrom, received it for her study of the management of common natural resources such as forests. Mr. Adam Smith, Editor-in-Chief of Nobelprize.org, says, “Her research reveals that in many, but not all, cases, allowing users to develop their own rules to regulate the use of common property results in the most efficient solution for managing those resources”. This is intriguing to me. In my letter last year, I referred to the “Green New Deal”––an approach based on a standard market mechanism as an environmentally focused investment approach aimed at a sustainable and low-carbon world. On the other hand, the newly introduced management idea for natural resources might indicate a new solution for the climate crisis. That news appeared to be a good sign. However, 2009 eventually yielded only the “great disappointment” of the Copenhagen Climate Summit Meeting (COP15). The real world does not appear to be so easily manageable. As for root studies, is there any movement? Yes. An important meeting for root researchers was convened in 2009: The Symposium on Root Research and Applications (Root RAP) held in Vienna (http://rootrap.boku.ac.at/). As a participant in this meeting, I found that many researchers who deal with tree roots were participating. This is also the case for recent meetings of Japanese Society for Root Research (JSRR). Root studies are becoming more active back in the forest. There we will find some clues to the solutions to our looming climate crisis. Regarding this Journal, we have entered the new term of 2010–2011. I have again been appointed to the position of Editor-in-Chief of the Plant Root for the new term by JSRR, with three new managing editors joining the Editorial Board. I want to express my gratitude to all authors for their contributions, all who have submitted manuscripts to this journal, and to our managing editors, subject editors, and reviewers. I would like to inscribe the Managing and Subject Editors’ names of the 2008–2009 term here on their behalf.
{"title":"Back in the forest","authors":"I. Karahara","doi":"10.3117/PLANTROOT.4.1","DOIUrl":"https://doi.org/10.3117/PLANTROOT.4.1","url":null,"abstract":"Before starting to write this letter, I reviewed my message of a year ago and found that I described the global financial crisis and global climate crisis. Up to this time, I have not personally found any sign of recovery from the economic downturn nearby. My students are still having quite a lot of difficulty securing jobs. However, the newspapers mention some signs of recovery from the global financial crisis. Perhaps there is another crisis that should be addressed––one that shows no recovery? Recovery would seem to be almost impossible unless excess carbon dioxide were to vanish somehow from the atmosphere. I often wonder whether any good sign was forthcoming during 2009 for healing of the Earth from its climate crisis. I did hear some interesting news about the Nobel Memorial Prize in Economic Sciences in 2009. One laureate of that prize, Dr. Elinor Ostrom, received it for her study of the management of common natural resources such as forests. Mr. Adam Smith, Editor-in-Chief of Nobelprize.org, says, “Her research reveals that in many, but not all, cases, allowing users to develop their own rules to regulate the use of common property results in the most efficient solution for managing those resources”. This is intriguing to me. In my letter last year, I referred to the “Green New Deal”––an approach based on a standard market mechanism as an environmentally focused investment approach aimed at a sustainable and low-carbon world. On the other hand, the newly introduced management idea for natural resources might indicate a new solution for the climate crisis. That news appeared to be a good sign. However, 2009 eventually yielded only the “great disappointment” of the Copenhagen Climate Summit Meeting (COP15). The real world does not appear to be so easily manageable. As for root studies, is there any movement? Yes. An important meeting for root researchers was convened in 2009: The Symposium on Root Research and Applications (Root RAP) held in Vienna (http://rootrap.boku.ac.at/). As a participant in this meeting, I found that many researchers who deal with tree roots were participating. This is also the case for recent meetings of Japanese Society for Root Research (JSRR). Root studies are becoming more active back in the forest. There we will find some clues to the solutions to our looming climate crisis. Regarding this Journal, we have entered the new term of 2010–2011. I have again been appointed to the position of Editor-in-Chief of the Plant Root for the new term by JSRR, with three new managing editors joining the Editorial Board. I want to express my gratitude to all authors for their contributions, all who have submitted manuscripts to this journal, and to our managing editors, subject editors, and reviewers. I would like to inscribe the Managing and Subject Editors’ names of the 2008–2009 term here on their behalf.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"4 1","pages":"1-3"},"PeriodicalIF":0.6,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.4.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621892","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}
Row crops commonly grown under irrigation in the Vertisols of north-western New South Wales, Australia, include summer crops such as corn (Zea mays L.) and cotton (Gossy- pium hirsutum L.). Soil organic carbon (SOC) and residue (SOR) dynamics in these farming systems have been analysed primarily in terms of inputs of above-ground material and root mass towards the end of a growing season. Addition of root material to SOC and SOR stocks either in the form of roots dying and decaying during and after the crop's growing season may, however, be significant. Carbon inputs by roots of irrigated corn to an irrigated Vertisol were evaluated in an experiment near Narrabri, Australia, where corn grown as a monoculture was compared with corn sown in rotation with cotton. Root growth in the surface 0.10 m was measured with the core-break method, and that in the 0.10 to 1.0 m depth with a minirhizotron and I-CAP image capture system. These measurements were used to derive root length per unit area (LA), root C added to soil through intra-seasonal root death (Clost), C in roots remaining at end of season (Croot) and root C potentially available for addition to soil (Ctotal). Ctotal averaged 5.0 Mg ha -1 with cotton-corn and 9.3 Mg ha -1 with corn monocul- ture, with average Clost accounting for 11%. Intra-seasonal root death from corn made only a small contribution to soil carbon stocks. LA of corn was higher with corn monoculture than with cotton-corn.
在澳大利亚新南威尔士州西北部的Vertisols，通常在灌溉下种植的行作物包括夏季作物，如玉米(Zea mays L.)和棉花(Gossy- pium hirsutum L.)。在这些耕作系统中，土壤有机碳(SOC)和残留物(SOR)的动态主要是根据生长季节结束时地上物质和根系质量的投入来分析的。然而，在作物生长季节期间和之后，以根系死亡和腐烂的形式向有机碳和SOR砧木中添加根系物质可能是显著的。在澳大利亚Narrabri附近进行的一项试验中，对灌溉玉米根部向灌溉的Vertisol的碳输入进行了评估，该试验将玉米单作种植与玉米轮作种植进行了比较。采用岩心破碎法测量地表0.10 m的根系生长，采用minirhizotron和I-CAP图像捕获系统测量地表0.10 ~ 1.0 m的根系生长。这些测量结果用于计算单位面积根长度(LA)、通过季节内根死亡(Clost)添加到土壤中的根C、季末剩余根中的根C (Croot)和潜在可添加到土壤中的根C (Ctotal)。棉花玉米的Ctotal平均为5.0 Mg ha -1，玉米单作的Ctotal平均为9.3 Mg ha -1，平均Clost占11%。玉米的季节性根系死亡对土壤碳储量的贡献很小。玉米单作玉米的LA高于棉-玉米单作玉米。
{"title":"Carbon inputs by irrigated corn roots to a Vertisol","authors":"N. Hulugalle, T. Weaver, L. Finlay","doi":"10.3117/PLANTROOT.4.18","DOIUrl":"https://doi.org/10.3117/PLANTROOT.4.18","url":null,"abstract":"Row crops commonly grown under irrigation in the Vertisols of north-western New South Wales, Australia, include summer crops such as corn (Zea mays L.) and cotton (Gossy- pium hirsutum L.). Soil organic carbon (SOC) and residue (SOR) dynamics in these farming systems have been analysed primarily in terms of inputs of above-ground material and root mass towards the end of a growing season. Addition of root material to SOC and SOR stocks either in the form of roots dying and decaying during and after the crop's growing season may, however, be significant. Carbon inputs by roots of irrigated corn to an irrigated Vertisol were evaluated in an experiment near Narrabri, Australia, where corn grown as a monoculture was compared with corn sown in rotation with cotton. Root growth in the surface 0.10 m was measured with the core-break method, and that in the 0.10 to 1.0 m depth with a minirhizotron and I-CAP image capture system. These measurements were used to derive root length per unit area (LA), root C added to soil through intra-seasonal root death (Clost), C in roots remaining at end of season (Croot) and root C potentially available for addition to soil (Ctotal). Ctotal averaged 5.0 Mg ha -1 with cotton-corn and 9.3 Mg ha -1 with corn monocul- ture, with average Clost accounting for 11%. Intra-seasonal root death from corn made only a small contribution to soil carbon stocks. LA of corn was higher with corn monoculture than with cotton-corn.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"4 1","pages":"18-21"},"PeriodicalIF":0.6,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.4.18","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622047","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 distribution of roots in soil determines their acquisition of spatially varying resources. It may be altered by changing the response of roots to gravity. The aim of the study was to assess gravitropic set-point angles (GSAs) of maize (Zea mays L.) roots, their response to temperature and the feasibility to measure them in growth pouches. The GSAs of the primary, seminal and crown roots of a set of nine temperate inbred lines were measured. The lines were grown under controlled conditions in growth columns either at 15/13°C or 24/20°C (day/night) until the two-leaf stage (V2). The GSA was measured as the deviation of the initial 3 cm of root axis from the vertical zero. Low temperature resulted in a decrease in the GSAs of the crown roots by 10°, i.e. the roots oriented more vertically. The effect of the GSAs on the distribution of the roots was verified in wider columns using two extreme inbred lines. The proportion of roots in the upper 5 cm of the columns was 78% for the line S335 with the strongest tendency to horizontal root growth and only 39% for CM105 with almost vertical orientation of the roots. The differences in GSAs between these two genotypes were even more pronounced in growth pouches, thus proving the feasibility of this system for rapid screening. The results indicate that there is a huge genetic variability available to alter the growth direction of the seedling roots of maize. However, there was little effect of the temperature.
{"title":"Genetic variation in the gravitropic response of maize roots to low temperatures","authors":"A. Hund","doi":"10.3117/PLANTROOT.4.22","DOIUrl":"https://doi.org/10.3117/PLANTROOT.4.22","url":null,"abstract":"The distribution of roots in soil determines their acquisition of spatially varying resources. It may be altered by changing the response of roots to gravity. The aim of the study was to assess gravitropic set-point angles (GSAs) of maize (Zea mays L.) roots, their response to temperature and the feasibility to measure them in growth pouches. The GSAs of the primary, seminal and crown roots of a set of nine temperate inbred lines were measured. The lines were grown under controlled conditions in growth columns either at 15/13°C or 24/20°C (day/night) until the two-leaf stage (V2). The GSA was measured as the deviation of the initial 3 cm of root axis from the vertical zero. Low temperature resulted in a decrease in the GSAs of the crown roots by 10°, i.e. the roots oriented more vertically. The effect of the GSAs on the distribution of the roots was verified in wider columns using two extreme inbred lines. The proportion of roots in the upper 5 cm of the columns was 78% for the line S335 with the strongest tendency to horizontal root growth and only 39% for CM105 with almost vertical orientation of the roots. The differences in GSAs between these two genotypes were even more pronounced in growth pouches, thus proving the feasibility of this system for rapid screening. The results indicate that there is a huge genetic variability available to alter the growth direction of the seedling roots of maize. However, there was little effect of the temperature.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"4 1","pages":"22-30"},"PeriodicalIF":0.6,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.4.22","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69622108","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}
Aerenchyma promotes gas exchange between shoots and roots that supports plant to survive under waterlogged conditions. To understand the process of aerenchyma formation under waterlogged conditions, we developed a method for creating hypoxic pot-culture conditions using different water depths, and used this system to examine the effects of hypoxia on seedling growth and the anatomy of the seminal roots of spring wheat (Triticum aestivum cv. Bobwhite line SH 98 26). After 72 h of waterlogging, the redox potentials of a well-drained control and treatments with a water depth 15 cm below (T-15) and 3 cm above (T+3) the soil surface were +426, +357, and +292 mV, respectively. The root growth of the seedlings was reduced in T+3 plants while the shoot growth did not change significantly during 72 h waterlogging. Root anatomy study showed that wheat formed no aerenchyma under our control condition, but formed aerenchyma in the root cortex in response to hypoxia in T-15 and T+3 conditions. The aerenchyma was initially formed at 2 to 5 cm behind the root tip after 72 h in T-15 and 48 h in T+3. The aerenchyma in T+3 plants then extended by an additional 5 cm towards root base during the next 24 h. Evans blue staining indicated that wheat aerenchyma was lysigenous which resulted from degradation of cortical cells. Thus, the combination of the plant material and the pot-culture method can be used for a basic tool with which to analyse the molecular and physiological mechanisms of lysigenous aerenchyma formation in wheat.
{"title":"Formation and extension of lysigenous aerenchyma in seminal root cortex of spring wheat (Triticum aestivum cv. Bobwhite line SH 98 26) seedlings under different strengths of waterlogging","authors":"M. Haque, Fumitaka Abe, K. Kawaguchi","doi":"10.3117/PLANTROOT.4.31","DOIUrl":"https://doi.org/10.3117/PLANTROOT.4.31","url":null,"abstract":"Aerenchyma promotes gas exchange between shoots and roots that supports plant to survive under waterlogged conditions. To understand the process of aerenchyma formation under waterlogged conditions, we developed a method for creating hypoxic pot-culture conditions using different water depths, and used this system to examine the effects of hypoxia on seedling growth and the anatomy of the seminal roots of spring wheat (Triticum aestivum cv. Bobwhite line SH 98 26). After 72 h of waterlogging, the redox potentials of a well-drained control and treatments with a water depth 15 cm below (T-15) and 3 cm above (T+3) the soil surface were +426, +357, and +292 mV, respectively. The root growth of the seedlings was reduced in T+3 plants while the shoot growth did not change significantly during 72 h waterlogging. Root anatomy study showed that wheat formed no aerenchyma under our control condition, but formed aerenchyma in the root cortex in response to hypoxia in T-15 and T+3 conditions. The aerenchyma was initially formed at 2 to 5 cm behind the root tip after 72 h in T-15 and 48 h in T+3. The aerenchyma in T+3 plants then extended by an additional 5 cm towards root base during the next 24 h. Evans blue staining indicated that wheat aerenchyma was lysigenous which resulted from degradation of cortical cells. Thus, the combination of the plant material and the pot-culture method can be used for a basic tool with which to analyse the molecular and physiological mechanisms of lysigenous aerenchyma formation in wheat.","PeriodicalId":20205,"journal":{"name":"Plant Root","volume":"19 1","pages":"31-39"},"PeriodicalIF":0.6,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3117/PLANTROOT.4.31","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69621703","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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