Pub Date : 2014-06-27DOI: 10.2174/1874294701408010001
E. Burbridge, S. Rasmussen, F. Bernier, B. K. Kristensen, P. F. McCabe, P. Dix
Peroxidase and hydrogen peroxide both play important roles in the final stages of the lignification pathway. Peroxidase, in the presence of H2O2 catalyses the oxidation of monolignols to give lignin. In order to examine this process we looked at lignification in transgenic tobacco plants expressing a barley peroxidase gene, HvPrx8, either alone or in combination with a wheat germin gene, g.f 2.8, which encodes oxalate oxidase, thereby providing a source of H2O2. Ele- vated activity of the antioxidant ascorbate peroxidase was found in plants expressing oxalate peroxidase and was greatly increased by co-expression with the barley peroxidase, although the latter had no effect when expressed alone. An in- crease was observed in the oxidation of the lignin monomer, syringaldazine in cell lines over-expressing barley peroxi- dase, while a decrease was observed in double transformants. Plants over-expressing barley peroxidase have elevated lev- els of lignin deposition compared to that of wild type tobacco plants. Over-expression of the individual enzymes was also shown to enhance heat-induced programmed cell death (PCD) in cell suspension cultures, an effect which was greatly re- duced in the double-expressing lines.
{"title":"Altered Activity of Peroxidase and Oxalate Oxidase Influences Lignification in Transgenic Tobacco","authors":"E. Burbridge, S. Rasmussen, F. Bernier, B. K. Kristensen, P. F. McCabe, P. Dix","doi":"10.2174/1874294701408010001","DOIUrl":"https://doi.org/10.2174/1874294701408010001","url":null,"abstract":"Peroxidase and hydrogen peroxide both play important roles in the final stages of the lignification pathway. Peroxidase, in the presence of H2O2 catalyses the oxidation of monolignols to give lignin. In order to examine this process we looked at lignification in transgenic tobacco plants expressing a barley peroxidase gene, HvPrx8, either alone or in combination with a wheat germin gene, g.f 2.8, which encodes oxalate oxidase, thereby providing a source of H2O2. Ele- vated activity of the antioxidant ascorbate peroxidase was found in plants expressing oxalate peroxidase and was greatly increased by co-expression with the barley peroxidase, although the latter had no effect when expressed alone. An in- crease was observed in the oxidation of the lignin monomer, syringaldazine in cell lines over-expressing barley peroxi- dase, while a decrease was observed in double transformants. Plants over-expressing barley peroxidase have elevated lev- els of lignin deposition compared to that of wild type tobacco plants. Over-expression of the individual enzymes was also shown to enhance heat-induced programmed cell death (PCD) in cell suspension cultures, an effect which was greatly re- duced in the double-expressing lines.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115634655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-13DOI: 10.2174/1874294701307010039
M. Salvatore, A. Carafa, G. Carratù
Reproductive phenology, reproductive traits and the pre emergent reproductive success (PERS) of Welwitschia mirabilis were studied in plants growing in the Botanical Garden of Portici. The leaves grow throughout the year and growth is positively correlated to temperature and day length; at flowering, the growth rate slows down. The plants have a reproductive cycle lasting 9-10 months; male plants form more branches and strobili than females, female strobili are larger than male ones. Both male and female plants produce cones that differ in the color of the covering bracts. Plants produce a lot of seeds, but most of them are empty; therefore the seed/ovule ratio is low. Filled and empty seeds are morphologically similar; filled seeds have high vitality that is maintained for several years. As probable causes of the low seed/ovule ratio, both pollination and embryo abortion are taken into account; our observations lead us to believe that the embryo abortion hypothesis is more accurate. However, since each plant may produce a discrete number of cones and filled seeds are highly viable, ultimately Welwitschia appears to be a rather efficient plant in terms of pre emergent repro- ductive success.
{"title":"Growth and Reproductive Phenology of Welwitschia Mirabilis Hook. F.","authors":"M. Salvatore, A. Carafa, G. Carratù","doi":"10.2174/1874294701307010039","DOIUrl":"https://doi.org/10.2174/1874294701307010039","url":null,"abstract":"Reproductive phenology, reproductive traits and the pre emergent reproductive success (PERS) of Welwitschia mirabilis were studied in plants growing in the Botanical Garden of Portici. The leaves grow throughout the year and growth is positively correlated to temperature and day length; at flowering, the growth rate slows down. The plants have a reproductive cycle lasting 9-10 months; male plants form more branches and strobili than females, female strobili are larger than male ones. Both male and female plants produce cones that differ in the color of the covering bracts. Plants produce a lot of seeds, but most of them are empty; therefore the seed/ovule ratio is low. Filled and empty seeds are morphologically similar; filled seeds have high vitality that is maintained for several years. As probable causes of the low seed/ovule ratio, both pollination and embryo abortion are taken into account; our observations lead us to believe that the embryo abortion hypothesis is more accurate. However, since each plant may produce a discrete number of cones and filled seeds are highly viable, ultimately Welwitschia appears to be a rather efficient plant in terms of pre emergent repro- ductive success.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132387144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-20DOI: 10.2174/1874294701307010031
N. Soltani, R. Nurse, C. Gillard, P. Sikkema
Twelve field trials were conducted over a three-year period (2010, 2011, 2012) at different locations in south- western Ontario, Canada to compare various two-pass weed management strategies in glyphosate-resistant corn for crop injury, weed control, environmental impact, corn yield and profit margin. No visible injury resulted from the herbicide treatments evaluated. One early postemergence (EPOST) application of glyphosate provided good full season control of pigweed species and lady's thumb and fair control of velvetleaf, common ragweed, lamb's-quarters, barnyard grass and green foxtail. One late postemergence (LPOST) application of glyphosate provided excellent control of all weed species evaluated but corn yield was reduced due to early weed interference. The sequential application of glyphosate (EPOST fb LPOST) provided excellent control of all weed species evaluated with no adverse effect on corn yield. The sequential ap- plication of a preemergence residual herbicide followed by an application of glyphosate LPOST provided excellent full season control of all weed species evaluated and corn yield was equal to the weed free control. Among the sequential her- bicide programs the lowest environmental impact was glyphosate EPOST fb LPOST and saflufenacil/dimethenamid-p, isoxaflutole + atrazine or rimsulfuron + s-metolachlor + dicamba applied PRE fb glyphosate LPOST. Based on this study, the most efficacious and profitable weed management programs in glyphosate-resistant corn are a sequential application of glyphosate or a two-pass program of a preemergence residual herbicide followed by glyphosate LPOST. The two-pass programs have glyphosate stewardship benefits.
{"title":"Weed Control, Environmental Impact and Profitability of Two-Pass Weed Management Strategies in Glyphosate-Resistant Corn","authors":"N. Soltani, R. Nurse, C. Gillard, P. Sikkema","doi":"10.2174/1874294701307010031","DOIUrl":"https://doi.org/10.2174/1874294701307010031","url":null,"abstract":"Twelve field trials were conducted over a three-year period (2010, 2011, 2012) at different locations in south- western Ontario, Canada to compare various two-pass weed management strategies in glyphosate-resistant corn for crop injury, weed control, environmental impact, corn yield and profit margin. No visible injury resulted from the herbicide treatments evaluated. One early postemergence (EPOST) application of glyphosate provided good full season control of pigweed species and lady's thumb and fair control of velvetleaf, common ragweed, lamb's-quarters, barnyard grass and green foxtail. One late postemergence (LPOST) application of glyphosate provided excellent control of all weed species evaluated but corn yield was reduced due to early weed interference. The sequential application of glyphosate (EPOST fb LPOST) provided excellent control of all weed species evaluated with no adverse effect on corn yield. The sequential ap- plication of a preemergence residual herbicide followed by an application of glyphosate LPOST provided excellent full season control of all weed species evaluated and corn yield was equal to the weed free control. Among the sequential her- bicide programs the lowest environmental impact was glyphosate EPOST fb LPOST and saflufenacil/dimethenamid-p, isoxaflutole + atrazine or rimsulfuron + s-metolachlor + dicamba applied PRE fb glyphosate LPOST. Based on this study, the most efficacious and profitable weed management programs in glyphosate-resistant corn are a sequential application of glyphosate or a two-pass program of a preemergence residual herbicide followed by glyphosate LPOST. The two-pass programs have glyphosate stewardship benefits.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124893475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-07DOI: 10.2174/1874294701307010024
N. Soltani, R. Nurse, C. Shropshire, P. Sikkema
Field trials were conducted over a three-year period (2009 to 2011) to evaluate the efficacy of pendimethalin preplant-incorporated (PPI), bentazon, fomesafen, bentazon plus fomesafen, or halosulfuron applied postemergence (POST) and the sequential application of pendimethalin applied PPI followed by bentazon, fomesafen, bentazon plus fo- mesafen or halosulfuron applied POST in white bean in Ontario. There was minimal effect on seed moisture content of white bean with the herbicides evaluated. Pendimethalin provided 97% control of A. retroflexus, 9% of A. artemisiifolia, 90% of C. album, 12% of S. arvensis, and 96% of S.viridis. Bentazon, fomesafen, bentazon plus fomesafen, and halosul- furon applied POST provided as much as 93% control of A. retroflexus, 86% control of A. artemisiifolia, 72% control of C. album, 99% control of S. arvensis, and 29% control of S. viridis. The sequential application of pendimethalin applied PPI followed by bentazon, fomesafen, bentazon plus fomesafen, and halosulfuron applied POST provided 100% control of A. retroflexus, 87% control of A. artemisiifolia, 90% control of C. album, 100% control of S. arvensis, and 95% control of S.viridis, respectively. White bean yield generally reflected the level of weed control.
{"title":"Weed Control in White Bean with Pendimethalin Applied Preplant Followed by Postemergence Broadleaved Herbicides","authors":"N. Soltani, R. Nurse, C. Shropshire, P. Sikkema","doi":"10.2174/1874294701307010024","DOIUrl":"https://doi.org/10.2174/1874294701307010024","url":null,"abstract":"Field trials were conducted over a three-year period (2009 to 2011) to evaluate the efficacy of pendimethalin preplant-incorporated (PPI), bentazon, fomesafen, bentazon plus fomesafen, or halosulfuron applied postemergence (POST) and the sequential application of pendimethalin applied PPI followed by bentazon, fomesafen, bentazon plus fo- mesafen or halosulfuron applied POST in white bean in Ontario. There was minimal effect on seed moisture content of white bean with the herbicides evaluated. Pendimethalin provided 97% control of A. retroflexus, 9% of A. artemisiifolia, 90% of C. album, 12% of S. arvensis, and 96% of S.viridis. Bentazon, fomesafen, bentazon plus fomesafen, and halosul- furon applied POST provided as much as 93% control of A. retroflexus, 86% control of A. artemisiifolia, 72% control of C. album, 99% control of S. arvensis, and 29% control of S. viridis. The sequential application of pendimethalin applied PPI followed by bentazon, fomesafen, bentazon plus fomesafen, and halosulfuron applied POST provided 100% control of A. retroflexus, 87% control of A. artemisiifolia, 90% control of C. album, 100% control of S. arvensis, and 95% control of S.viridis, respectively. White bean yield generally reflected the level of weed control.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126718304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-05DOI: 10.2174/1874294701307010017
R. Tzarfati, S. Ben-Dor, I. Sela, E. Goldschmidt
Grafting is an important, widely used plant propagation technique but its physiological effects are as yet insufficiently understood. Recent studies indicate that movement of proteins and small RNAs through the graft union might be involved. MicroRNAs are known to play a significant role in regulation of higher plants' developmental and metabolic traits. Extending this logic, we hypothesize that changes in activity of specific microRNAs are one of the mechanisms involved in physiological effects of grafting. The objective of the present study was to test this hypothesis. We determined the expression of a broad range of microRNAs in Citrus leaf petioles, as affected by grafting. Four stock/scion combinations ('Merav' mandarin and 'Star Ruby' grapefruit scions X 'Troyer' citrange and 'Volkamer' lemon rootstocks), rootstock auto-grafts and plants of the variety used as rootstock (= non-grafted) were examined. Grafting caused a dramatic reduction in the expression of the major microRNAs, miR156 (and miR157), which appear to be associated with reduction of juvenility in perennial woody plants. This effect was strongest in hetero-grafts but evident also in auto-grafts. Expression of miR894 also declined upon grafting. Differences in the expression of miR397 were found among grafted scion cultivars, while in non-grafted rootstocks expression of miR397 was barely detectable. Bioinformatic analysis confirmed the presence of miR397 in the citrus genome, validated its sequence and demonstrated its ability to form a stem loop. The differences in miR397 expression might be related to specific copper and other micronutrient requirements of citrus stock-scion combinations.Thus, our results support the hypothesis, indicating the involvement of specific microRNAs in engendering physiological effects of grafting in Citrus. The precise, underlying mechanism needs to be elucidated.
{"title":"Graft-induced Changes in MicroRNA Expression Patterns in Citrus Leaf Petioles","authors":"R. Tzarfati, S. Ben-Dor, I. Sela, E. Goldschmidt","doi":"10.2174/1874294701307010017","DOIUrl":"https://doi.org/10.2174/1874294701307010017","url":null,"abstract":"Grafting is an important, widely used plant propagation technique but its physiological effects are as yet insufficiently understood. Recent studies indicate that movement of proteins and small RNAs through the graft union might be involved. MicroRNAs are known to play a significant role in regulation of higher plants' developmental and metabolic traits. Extending this logic, we hypothesize that changes in activity of specific microRNAs are one of the mechanisms involved in physiological effects of grafting. The objective of the present study was to test this hypothesis. We determined the expression of a broad range of microRNAs in Citrus leaf petioles, as affected by grafting. Four stock/scion combinations ('Merav' mandarin and 'Star Ruby' grapefruit scions X 'Troyer' citrange and 'Volkamer' lemon rootstocks), rootstock auto-grafts and plants of the variety used as rootstock (= non-grafted) were examined. Grafting caused a dramatic reduction in the expression of the major microRNAs, miR156 (and miR157), which appear to be associated with reduction of juvenility in perennial woody plants. This effect was strongest in hetero-grafts but evident also in auto-grafts. Expression of miR894 also declined upon grafting. Differences in the expression of miR397 were found among grafted scion cultivars, while in non-grafted rootstocks expression of miR397 was barely detectable. Bioinformatic analysis confirmed the presence of miR397 in the citrus genome, validated its sequence and demonstrated its ability to form a stem loop. The differences in miR397 expression might be related to specific copper and other micronutrient requirements of citrus stock-scion combinations.Thus, our results support the hypothesis, indicating the involvement of specific microRNAs in engendering physiological effects of grafting in Citrus. The precise, underlying mechanism needs to be elucidated.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123856773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-03-19DOI: 10.2174/1874294701206010001
V. Baligar, J. Bunce, M. Elson, N. Fageria
Crotalarias are tropical legumes grown as cover crops or as green manure to improve soil fertility. As an understory plant in plantation systems, these cover crops receive low levels of irradiance and are subjected to elevated levels of CO2 and temperatures. A greenhouse experiment was conducted to evaluate the independent short-term effects of photosynthetic photon flux density (PPFD), external carbon dioxide concentration (Ca) and temperature (T) on net photosynthesis (PN), internal CO2 (Ci), stomatal conductance (gs) and transpiration (E) in four Crotalaria species (C. breviflora, C. mucronata, C. ochroleuca, C. spectabilis). These crotalarias responded differently to changing PPFD, Ca and T. In all the Crotalaria species, increasing PPFD from 50 to 1500 � mol m -2 s -1 increased PN by 21 fold, increased gs by 2.3 fold (136%), decreased Ci by 3.9 times, and increased E by 2.1 times. Increasing the external Ca from 100 to 1000 cm 3 m -3 increased PN by 4.7 fold, decreased gs by 1.3 times, increased Ci by 28 fold, and decreased E by 1.2 times. Increasing the T from 25 to 35 °C increased PN of Crotalaria species by 11%, decreased gs by 33%, decreased Ci by 64%, and increased E by 56%. Shade management is critical to maintaining the productivity of these tropical legumes.
Crotalarias是一种热带豆科植物，用作覆盖作物或绿肥，以提高土壤肥力。作为人工林系统中的林下植物，这些覆盖作物接受低水平的辐照，并受到二氧化碳水平升高和温度升高的影响。通过温室试验，研究了光合光子通量密度(PPFD)、外部二氧化碳浓度(Ca)和温度(T)对短花豆属(C. breviflora, C. mucronata, C. ochroleuca, C. spectabilis) 4种花豆属植物净光合作用(PN)、内部二氧化碳(Ci)、气孔导度(gs)和蒸腾(E)的独立短期影响。不同种类的Crotalaria对PPFD、Ca和t的响应不同，PPFD从50 μ mol m -2 s -1增加到1500 μ mol m -2 s -1, PN增加21倍，gs增加2.3倍(136%)，Ci降低3.9倍，E增加2.1倍。将外源Ca从100 cm 3 m -3增加到1000 cm 3 m -3, PN提高4.7倍，gs降低1.3倍，Ci提高28倍，E降低1.2倍。温度从25°C增加到35°C，绿豆属植物的PN增加11%，gs减少33%，Ci减少64%，E增加56%。遮荫管理对维持这些热带豆科植物的生产力至关重要。
{"title":"Photosynthetic Photon Flux Density, Carbon Dioxide Concentration andTemperature Influence Photosynthesis in Crotalaria Species","authors":"V. Baligar, J. Bunce, M. Elson, N. Fageria","doi":"10.2174/1874294701206010001","DOIUrl":"https://doi.org/10.2174/1874294701206010001","url":null,"abstract":"Crotalarias are tropical legumes grown as cover crops or as green manure to improve soil fertility. As an understory plant in plantation systems, these cover crops receive low levels of irradiance and are subjected to elevated levels of CO2 and temperatures. A greenhouse experiment was conducted to evaluate the independent short-term effects of photosynthetic photon flux density (PPFD), external carbon dioxide concentration (Ca) and temperature (T) on net photosynthesis (PN), internal CO2 (Ci), stomatal conductance (gs) and transpiration (E) in four Crotalaria species (C. breviflora, C. mucronata, C. ochroleuca, C. spectabilis). These crotalarias responded differently to changing PPFD, Ca and T. In all the Crotalaria species, increasing PPFD from 50 to 1500 � mol m -2 s -1 increased PN by 21 fold, increased gs by 2.3 fold (136%), decreased Ci by 3.9 times, and increased E by 2.1 times. Increasing the external Ca from 100 to 1000 cm 3 m -3 increased PN by 4.7 fold, decreased gs by 1.3 times, increased Ci by 28 fold, and decreased E by 1.2 times. Increasing the T from 25 to 35 °C increased PN of Crotalaria species by 11%, decreased gs by 33%, decreased Ci by 64%, and increased E by 56%. Shade management is critical to maintaining the productivity of these tropical legumes.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126951462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-08-17DOI: 10.2174/1874294701105010029
N. Kovalskaya, Yan Zhao, R. Hammond
To enhance plant protection against phytopathogens, we constructed a fusion gene (SAP) for the simultaneous production of snakin-1 (SN1) and defensin-1 (PTH1) cysteine-rich antimicrobial proteins originally identified in potato. Prior to in vivo evaluation of antimicrobial activity, SAP produced in Escherichia coli was tested in in vitro against four phytopathogenic microorganisms. SAP exhibited the highest antimicrobial activity against the bacterium Clavibacter michiganensis subsp. sepedonicus, which is the cause of potato ring rot disease, and the anthracnose-causing fungus Colletotrichum coccoides, by complete inhibition of cell growth or spore germination, respectively, at a concentration of 6 � M. Notably, SAP showed higher inhibitory activities against Pseudomonas syringae pv. syringae, P. syringae pv. tabaci and Colletotrichum coccoides, than individual SN1 and PTH1, whereas its effect on C. michiganensis subsp. Sepedonicus in in vitro was comparable to that of PTH1 alone. Antimicrobial activity of SAP against C. coccoides and C. michiganensis subsp. sepedonicus was assessed in plants on Nicotiana benthamiana and Solanum tuberosum, respectively, using SAP expressed from the Potato virus X-based vectors pP2C2S and/or pGR107. Both SAP-producing plants were significantly more resistant to infection than control plants. Our results demonstrated that in vivo co- production of recombinant SN1 and PTH1 as a hybrid protein is a promising strategy for antimicrobial plant defense applications.
{"title":"Antibacterial and antifungal activity of a snakin-defensin hybrid protein expressed in tobacco and potato plants.","authors":"N. Kovalskaya, Yan Zhao, R. Hammond","doi":"10.2174/1874294701105010029","DOIUrl":"https://doi.org/10.2174/1874294701105010029","url":null,"abstract":"To enhance plant protection against phytopathogens, we constructed a fusion gene (SAP) for the simultaneous production of snakin-1 (SN1) and defensin-1 (PTH1) cysteine-rich antimicrobial proteins originally identified in potato. Prior to in vivo evaluation of antimicrobial activity, SAP produced in Escherichia coli was tested in in vitro against four phytopathogenic microorganisms. SAP exhibited the highest antimicrobial activity against the bacterium Clavibacter michiganensis subsp. sepedonicus, which is the cause of potato ring rot disease, and the anthracnose-causing fungus Colletotrichum coccoides, by complete inhibition of cell growth or spore germination, respectively, at a concentration of 6 � M. Notably, SAP showed higher inhibitory activities against Pseudomonas syringae pv. syringae, P. syringae pv. tabaci and Colletotrichum coccoides, than individual SN1 and PTH1, whereas its effect on C. michiganensis subsp. Sepedonicus in in vitro was comparable to that of PTH1 alone. Antimicrobial activity of SAP against C. coccoides and C. michiganensis subsp. sepedonicus was assessed in plants on Nicotiana benthamiana and Solanum tuberosum, respectively, using SAP expressed from the Potato virus X-based vectors pP2C2S and/or pGR107. Both SAP-producing plants were significantly more resistant to infection than control plants. Our results demonstrated that in vivo co- production of recombinant SN1 and PTH1 as a hybrid protein is a promising strategy for antimicrobial plant defense applications.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121310287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-09DOI: 10.2174/1874294701105010014
V. K. Hgaza, L. Diby, T. Tié, A. Tschannen, S. Aké, A. Assa, E. Frossard
Water yam (Dioscorea alata) is a staple crop for many of the poorest in the tropics. Yam tuber response to fertiliser application has been reported to be erratic. We hypothesised that this variable response could be due to the development of a suboptimal root system that would not allow the plant to capture the nutrients added with the fertiliser. To verify this hypothesis we studied during two seasons (2006 and 2007) in Central Cote d'Ivoire, the growth of yam root system in relation to plant growth as affected by fertiliser input, using sequential root coring. In addition, we assessed the horizontal and vertical distribution of yam roots using the wall profile method in the same site. Three root types (seminal, adventitious and tubercular roots) were identified. Roots grew within the mound until 100 days after planting (DAP) and afterwards, extended radially in the soil outside of the mound remaining in the first soil horizon (15 cm depth). Maximum root extension was observed at 160 DAP. Root length density and root mass density were higher at higher soil temperature whereas the average root diameter decreased at higher soil temperature. Specific root length did not change with soil temperature. Root growth parameters were not affected by fertiliser application. Roots were mostly distributed in clumps. As tuber yield formation was independent from root growth we conclude that the root system of this cultivar did not limit tuber productivity. Other factors have to be considered to explain the variable response of yam to mineral fertiliser additions.
{"title":"Growth and Distribution of Roots of Dioscorea Alata L. Do Not Respond to Mineral Fertiliser Application","authors":"V. K. Hgaza, L. Diby, T. Tié, A. Tschannen, S. Aké, A. Assa, E. Frossard","doi":"10.2174/1874294701105010014","DOIUrl":"https://doi.org/10.2174/1874294701105010014","url":null,"abstract":"Water yam (Dioscorea alata) is a staple crop for many of the poorest in the tropics. Yam tuber response to fertiliser application has been reported to be erratic. We hypothesised that this variable response could be due to the development of a suboptimal root system that would not allow the plant to capture the nutrients added with the fertiliser. To verify this hypothesis we studied during two seasons (2006 and 2007) in Central Cote d'Ivoire, the growth of yam root system in relation to plant growth as affected by fertiliser input, using sequential root coring. In addition, we assessed the horizontal and vertical distribution of yam roots using the wall profile method in the same site. Three root types (seminal, adventitious and tubercular roots) were identified. Roots grew within the mound until 100 days after planting (DAP) and afterwards, extended radially in the soil outside of the mound remaining in the first soil horizon (15 cm depth). Maximum root extension was observed at 160 DAP. Root length density and root mass density were higher at higher soil temperature whereas the average root diameter decreased at higher soil temperature. Specific root length did not change with soil temperature. Root growth parameters were not affected by fertiliser application. Roots were mostly distributed in clumps. As tuber yield formation was independent from root growth we conclude that the root system of this cultivar did not limit tuber productivity. Other factors have to be considered to explain the variable response of yam to mineral fertiliser additions.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115239434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-09DOI: 10.2174/1874294701105010023
M. Saxena, S. Roy, S. Singla-Pareek, S. Sopory, N. Bhalla-Sarin
Engineering of salinity tolerance in agronomically important crop plants is required to increase their productivity by enabling them to grow in saline soils, which are otherwise left uncultivated. Since an increase in the enzymes of glyoxalase system has been shown to impart salinity tolerance in the model plant tobacco, we used the glyoxalase II gene for engineering salinity tolerance in an important oil yielding crop, Brassica juncea. The transgenic plants of B. juncea overexpressing the glyoxalase II gene showed higher salinity tolerance as compared to the untransformed control plants as observed by delayed senescence in leaf discs at 400 mM and 800 mM NaCl in T1 generation. The percentage of germination of the T2 transgenic seeds was higher at 150 mM and 200 mM NaCl as compared to the seeds of untransformed plants. This for the first time demonstrates the applicability of utilizing the glyoxalase II gene for enhanced salinity tolerance in an oilseed crop plant B. juncea.
在农艺学上重要的作物植物中，需要进行耐盐工程，以提高它们的生产力，使它们能够在盐碱地中生长，否则这些土壤就会被闲置。由于乙二醛酶系统中酶的增加已被证明能提高模式植物烟草的耐盐性，我们使用乙二醛酶II基因来改造一种重要的油料作物芥菜的耐盐性。过表达乙二醛酶II基因的芥菜转基因植株T1代叶片在400 mM和800 mM NaCl条件下的衰老延迟，表现出比未转化对照植株更高的耐盐性。T2转基因种子在150 mM和200 mM NaCl处理下的发芽率高于未转化植株的种子。这首次证明了利用乙二醛酶II基因增强油料作物芥菜耐盐性的适用性。
{"title":"Overexpression of the Glyoxalase II Gene Leads to Enhanced Salinity Tolerance in Brassica Juncea","authors":"M. Saxena, S. Roy, S. Singla-Pareek, S. Sopory, N. Bhalla-Sarin","doi":"10.2174/1874294701105010023","DOIUrl":"https://doi.org/10.2174/1874294701105010023","url":null,"abstract":"Engineering of salinity tolerance in agronomically important crop plants is required to increase their productivity by enabling them to grow in saline soils, which are otherwise left uncultivated. Since an increase in the enzymes of glyoxalase system has been shown to impart salinity tolerance in the model plant tobacco, we used the glyoxalase II gene for engineering salinity tolerance in an important oil yielding crop, Brassica juncea. The transgenic plants of B. juncea overexpressing the glyoxalase II gene showed higher salinity tolerance as compared to the untransformed control plants as observed by delayed senescence in leaf discs at 400 mM and 800 mM NaCl in T1 generation. The percentage of germination of the T2 transgenic seeds was higher at 150 mM and 200 mM NaCl as compared to the seeds of untransformed plants. This for the first time demonstrates the applicability of utilizing the glyoxalase II gene for enhanced salinity tolerance in an oilseed crop plant B. juncea.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128269307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-09DOI: 10.2174/1874294701105010009
M. Tripepi, Mechthild Pohlschroder, M. B. Bitonti
Dehydrins (DHNs) belong to a large family of proteins whose expression is associated with dehydration during seed maturation, pollen grain development and bud dormancy during winter, as well as plant adaptive response to various stressors. However, the exact roles played by different members of this protein family have not been fully defined. To gain a better understanding of DHN functions in olive plants, we used Western blot analyses to investigate their expression in the leaves of olive plants subjected to wounding, water-deprivation and salt-treatment. Two prominent bands having molecular masses of approximately 40 kD and 42 kD were constitutively expressed, however, their levels increased when the leaves were exposed to stress. Dehydration and salt stress also resulted in the accumulation of two additional proteins, which had molecular masses of approximately 16 kDa and 18 kD. These additional proteins were not detected following wounding. Our results suggest a physiological function for DHNs in olive plants during normal growth conditions and specialized functions during responses to certain types of stress.
{"title":"Diversity of Dehydrins in Oleae europaea Plants Exposed to Stress","authors":"M. Tripepi, Mechthild Pohlschroder, M. B. Bitonti","doi":"10.2174/1874294701105010009","DOIUrl":"https://doi.org/10.2174/1874294701105010009","url":null,"abstract":"Dehydrins (DHNs) belong to a large family of proteins whose expression is associated with dehydration during seed maturation, pollen grain development and bud dormancy during winter, as well as plant adaptive response to various stressors. However, the exact roles played by different members of this protein family have not been fully defined. To gain a better understanding of DHN functions in olive plants, we used Western blot analyses to investigate their expression in the leaves of olive plants subjected to wounding, water-deprivation and salt-treatment. Two prominent bands having molecular masses of approximately 40 kD and 42 kD were constitutively expressed, however, their levels increased when the leaves were exposed to stress. Dehydration and salt stress also resulted in the accumulation of two additional proteins, which had molecular masses of approximately 16 kDa and 18 kD. These additional proteins were not detected following wounding. Our results suggest a physiological function for DHNs in olive plants during normal growth conditions and specialized functions during responses to certain types of stress.","PeriodicalId":355995,"journal":{"name":"The Open Plant Science Journal","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125504862","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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