Differences in the incidence and the amount of anthracnose fruit rot (AFR) among strawberry genot... more Differences in the incidence and the amount of anthracnose fruit rot (AFR) among strawberry genotypes in the field indicate that there may be genetic differences in susceptibility to AFR. Fruit of seven strawberry genotypes (Gen) were inoculated with five concentrations of Colletotrichum acutatum conidia (Inoc). The experimental design was a split plot with Inoc (0, 1x10 3 , 1x10 4 , 1x10 5 , and 1x10 6 conidia.ml -1 ) as the whole plot. The Gen were the subplot and were arranged in a RCBD with three replicates. The experiment was conducted three times within a growth chamber. Green to fully ripe fruit were inoculated. Data on lesion length and width, incubation period (IP), and fruit age were collected. For most genotypes, the biggest increase and largest range in percent lesions was observed at 1x10 conidia.ml -1 . Fruit age at inoculation affected the probability of lesion formation among the seven Gen: probability of lesion formation generally is low at young fruit age, increases at median age, and then rapidly decreases at older ages. This response curve was different among Gen. IP was not different among Gen or the Gen x Inoc interaction. Rate of AFR lesion diameter increase was different among Inoc, Gen, and the Inoc x Gen interaction. The susceptible 'Camarosa' and 'Chandler' had the largest rates of lesion diameter increase, 'Sweet Charlie' and NCR 95-08 had much lower rates, and 'Pelican' had the lowest rate. These results indicate that strawberry fruit of some genotypes are resistant to AFR and that fruit age and rate-limiting resistance are two components of resistance.
... transgenic plants Rahul Gupta, Vishal Arora, and Earl Petzold for help in designing primers S... more ... transgenic plants Rahul Gupta, Vishal Arora, and Earl Petzold for help in designing primers Suzanne Piovano for teaching me the art of plant tissue culture and for her friendship throughout my studies at Virginia Tech My fellow ...
Virginia Cooperative Extension programs and employment are open to all, regardless of race, color... more Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. An equal opportunity/affirmative action employer. Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Mark A. McCann, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; Alma C. Hobbs, Administrator, 1890 Extension Program, Virginia State, Petersburg. ACTIGARD MAY REDUCE DISEASE IN STRAWBERRY Joel L. Shuman, Research Assistant Professor, Department of Horticulture, VPI & SU, Blacksburg, VA
Metabolomics is the methodology that identifies and measures global pools of small molecules (of ... more Metabolomics is the methodology that identifies and measures global pools of small molecules (of less than about 1,000 Da) of a biological sample, which are collectively called the metabolome. Metabolomics can therefore reveal the metabolic outcome of a genetic or environmental perturbation of a metabolic regulatory network, and thus provide insights into the structure and regulation of that network. Because of the chemical complexity of the metabolome and limitations associated with individual analytical platforms for determining the metabolome, it is currently difficult to capture the complete metabolome of an organism or tissue, which is in contrast to genomics and transcriptomics. This paper describes the analysis of Arabidopsis metabolomics data sets acquired by a consortium that includes five analytical laboratories, bioinformaticists, and biostatisticians, which aims to develop and validate metabolomics as a hypothesis-generating functional genomics tool. The consortium is de...
In North Carolina, anthracnose fruit rot of strawberry (Fragaria × ananassa Duch.) is caused by t... more In North Carolina, anthracnose fruit rot of strawberry (Fragaria × ananassa Duch.) is caused by the fungus Colletotrichum acutatum Simmonds. Little is known about the mechanisms of field resistance of fruits to anthracnose. It appears that resistance of various plant parts including runners, crowns, and foliage is not always correlated with resistance of fruit. Resistance of fruit may be simply overwhelmed by excessive fungal conidia. Is there a threshold level of inoculum and does this threshold vary for fruit of different cultivars? The objective of this study was to determine the effect of inoculum level on the response of seven strawberry cultivars/breeding lines to a single C. acutatum (CA-1) isolate. The experimental design was a split-plot with five levels of inoculum (0, 1 × 103, 1 × 104, 1 × 105, and 1×106 conidia/ml) as the whole plot and seven cultivars/breeding lines (`Apollo', `Chandler', `Camerosa', `Pelican', `Sweet Charley', NCH 95-173, and NCR 94...
Production of pickling cucumber (Cucumis sativus L.) requires a significant expenditure of labor ... more Production of pickling cucumber (Cucumis sativus L.) requires a significant expenditure of labor and money. Those resources could be better managed if both yield and harvest date could be predicted for a given planting date and production area. The objective of this experiment was to develop a model to simulate growth and yield of pickling cucumbers under field conditions in North Carolina. Detailed measurements of leaf area, branching habit, flowering, fruiting, and dry weight distribution were obtained for the cultigens `Calypso', M 21, `Wis. SMR 18', and WI 2757 for 10 planting dates. Light interception, air temperature, and rainfall were also recorded. There were differences among cultigens and planting dates for time needed to reach certain growth stages. Number of days to reach a given stage generally decreased with later planting dates. Addition of nodes over time to the main stem was linear and the interaction of planting date by cultigen was significant. Number of s...
Anthracnose fruit rot (AFR) and crown rot can cause severe economic losses on susceptible `Chandl... more Anthracnose fruit rot (AFR) and crown rot can cause severe economic losses on susceptible `Chandler' and `Camarosa' strawberry in Virginia: `Sweet Charlie' and `Bish' are moderately resistant to resistant. Actigard (acibenzolar-S-methyl), an inducer of systemic acquired resistance, has been effective at reducing black spot and speck on tomato, blue mold on tobacco, and fire blight on apple. The objective of this study was to determine if Actigard, when spray-applied to field-grown strawberry, can reduce AFR better than or equal to several registered fungicides. Four varieties (VAR) (Chandler, Camarosa, Sweet Charlie, and Bish) were treated with four fungicides (FUNG) (water control, azoxystrobin, chlorothalonil, and actigard). Experimental design was a split plot with FUNG as the main plot and VAR as the split plot with four replicates. Standard annual hill system practices were used throughout. Plots were inoculated three times throughout the harvest season with a c...
Drought and heat stress have been extensively studied in plants, but little is known about how th... more Drought and heat stress have been extensively studied in plants, but little is known about how the combination of drought and heat impact their physiology and metabolism. The metabolite profile of Arabidopsis subjected to heat, drought, and the combination of heat and drought were analyzed by gas-chromatography-mass spectrometry (GC-MS). Fatty acid retention time standards and the internal standard (IS) ribitol (adonitol) were added to each leaf sample and the polar phase was extracted, methoximated, and derivatized (trimethylsilylated) prior to analysis by GC-MS (Trace DSQ with Combi-PAL autosampler). Compounds were identified based upon retention time (relative to fatty acid standards) and comparison with reference spectra in our custom mass spectral library. Semi-quantitation of compound peak area was done relative to the internal standard. Plants subjected to both heat and drought stress accumulated sucrose and other sugars/sugar alchohols such as maltose, gulose, mannitol. The ...
International journal for parasitology. Drugs and drug resistance, Apr 1, 2017
The incidence and global distribution of chloroquine resistant (CR) Plasmodium vivax infection ha... more The incidence and global distribution of chloroquine resistant (CR) Plasmodium vivax infection has increased since emerging in 1989. The mechanism of resistance in CR P. vivax has not been defined. The resistance likely relates to the formation and disposition of hemozoin as chloroquine's primary mechanism of action involves disruption of hemozoin formation. CR P. berghei strains, like CR P. vivax strains, are confined to reticulocyte host cells and reportedly they do not accumulate appreciable intraerythrocytic hemozoin. Reports comparing hemozoin production between P. vivax strains and CR to chloroquine sensitive (CS) P. berghei are absent. Here we compare in vivo patterns of hemozoin formation and distribution in blood, spleen and liver tissue of male Swiss mice infected with CS or CR P. berghei not treated with chloroquine and CR P. berghei also treated with chloroquine. Light microscopy, laser desorption mass spectrometry and a colorimetric hemozoin assay detect trace hemoz...
Cell migration, angiogenesis, inflammation, and extracellular matrix remodeling are key events in... more Cell migration, angiogenesis, inflammation, and extracellular matrix remodeling are key events in wound healing. Natural products, including fatty acids (FAs), can accelerate wound healing by modulating the aforementioned events. This study aims to evaluate the effect of lucuma (Pouteria lucuma O Kezte) nut oil (LNO) on fibroblasts migration, angiogenesis, inflammation, bacterial and fungal growth, and wound healing. Methods GC-MS analysis of FAs methyl esters (FAMES) was used for chemical characterization of LNO. In vitro studies were carried out with LNO investigating the induction of cell migration, cytoskeleton remodeling of human fibroblasts, inhibition of LPS-induced nitric oxide production in macrophages, and antibacterial and antifungal effects. Two in vivo studies were carried out to study LNO's effect on angiogenesis and wound healing: (i) tail fin regeneration in transgenic zebrafish larvae expressing enhanced green fluorescent protein (EGFP) in vascular endothelial cells was used to study vessel sprouting and wound healing and (ii) the closure of wounds was evaluated in CD-1 mice after topical applications of LNO-containing formulations. Lucuma nut oil is a mixture of FAs, 99.7% of which were characterized. Major components of LNO (w/w) are linoleic acid (38.9%), oleic acid (27.9%), palmitic acid (18.6%), stearic acid (8.9%), and γ linolenic acid (2.9%). In vitro studies showed that LNO significantly promoted migration and vinculin expression in human fibroblasts. LNO decreased LPS-induced nitric oxide production and did not display significant antibacterial or antifungal effects. LNO induced tail fin regeneration in transgenic zebrafish larvae 48 h after tail fin amputation and significantly accelerated cutaneous wound closure in CD-1 mice. Natural FAs from P. lucuma nut promote skin regeneration and, thus, may have applications in medicine and skin care.
Some popular garden perennials yield low numbers of viable cuttings per stock plant and/or produc... more Some popular garden perennials yield low numbers of viable cuttings per stock plant and/or produce cuttings that are slow to develop significant root mass, preventing propagators from meeting demand for rooted liners. Our objective was to determine the impacts of stock plant nutrition on number of potential cuttings, rooting percentage, and the subsequent root development of cuttings of some popular but difficult to propagate perennials. Gaura lindheimeri ‘Siskiyou Pink’, Dianthus ‘Pixie Star’, Perovskia atriplicifolia ‘Filigran’, and Salvia x sylvestris ‘May Night’, were evaluated using five treatments of 0, 50, 100,150, 200, and 250 mg·L‾¹ N. Greenhouse-grown stock plants were fertilized with a custom-formulated complete liquid feed for ten weeks at which time potential cuttings were counted, and the sample cuttings were taken for rooting. Petiole sap nitrate was measured with a specific ion meter (Cardy) to correlate real-time nitrogen status to cutting yield and subsequent root ...
... A metabolomics study of Plasmodium falciparum infection of red blood cells in the absence and... more ... A metabolomics study of Plasmodium falciparum infection of red blood cells in the absence and presence of antimalarials. Nigel Deighton 1 , Joel Shuman 1 , Jianghong Qian 1 , Vladimir Shulaev 1 , Dominique Rasoloson 2 , Tosin ... Ridley, RG Nature 415, 686-693 (2002). ...
Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic... more Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic challenges in their environment. These are activated at the initial site of exposure to stress, as well as in systemic tissues that have not been subjected to stress (termed systemic acquired acclimation [SAA]). Although SAA is thought to play a key role in plant survival during stress, little is known about the signaling mechanisms underlying it. Here, we report that SAA in plants requires at least two different signals: an autopropagating wave of reactive oxygen species (ROS) that rapidly spreads from the initial site of exposure to the entire plant and a stress-specific signal that conveys abiotic stress specificity. We further demonstrate that SAA is stress specific and that a temporal–spatial interaction between ROS and abscisic acid regulates rapid SAA to heat stress in plants. In addition, we demonstrate that the rapid ROS signal is associated with the propagation of electric sig...
Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic... more Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic challenges in their environment. These are activated at the initial site of exposure to stress, as well as in systemic tissues that have not been subjected to stress (termed systemic acquired acclimation [SAA]). Although SAA is thought to play a key role in plant survival during stress, little is known about the signaling mechanisms underlying it. Here, we report that SAA in plants requires at least two different signals: an autopropagating wave of reactive oxygen species (ROS) that rapidly spreads from the initial site of exposure to the entire plant and a stress-specific signal that conveys abiotic stress specificity. We further demonstrate that SAA is stress specific and that a temporal–spatial interaction between ROS and abscisic acid regulates rapid SAA to heat stress in plants. In addition, we demonstrate that the rapid ROS signal is associated with the propagation of electric sig...
Differences in the incidence and the amount of anthracnose fruit rot (AFR) among strawberry genot... more Differences in the incidence and the amount of anthracnose fruit rot (AFR) among strawberry genotypes in the field indicate that there may be genetic differences in susceptibility to AFR. Fruit of seven strawberry genotypes (Gen) were inoculated with five concentrations of Colletotrichum acutatum conidia (Inoc). The experimental design was a split plot with Inoc (0, 1x10 3 , 1x10 4 , 1x10 5 , and 1x10 6 conidia.ml -1 ) as the whole plot. The Gen were the subplot and were arranged in a RCBD with three replicates. The experiment was conducted three times within a growth chamber. Green to fully ripe fruit were inoculated. Data on lesion length and width, incubation period (IP), and fruit age were collected. For most genotypes, the biggest increase and largest range in percent lesions was observed at 1x10 conidia.ml -1 . Fruit age at inoculation affected the probability of lesion formation among the seven Gen: probability of lesion formation generally is low at young fruit age, increases at median age, and then rapidly decreases at older ages. This response curve was different among Gen. IP was not different among Gen or the Gen x Inoc interaction. Rate of AFR lesion diameter increase was different among Inoc, Gen, and the Inoc x Gen interaction. The susceptible 'Camarosa' and 'Chandler' had the largest rates of lesion diameter increase, 'Sweet Charlie' and NCR 95-08 had much lower rates, and 'Pelican' had the lowest rate. These results indicate that strawberry fruit of some genotypes are resistant to AFR and that fruit age and rate-limiting resistance are two components of resistance.
... transgenic plants Rahul Gupta, Vishal Arora, and Earl Petzold for help in designing primers S... more ... transgenic plants Rahul Gupta, Vishal Arora, and Earl Petzold for help in designing primers Suzanne Piovano for teaching me the art of plant tissue culture and for her friendship throughout my studies at Virginia Tech My fellow ...
Virginia Cooperative Extension programs and employment are open to all, regardless of race, color... more Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. An equal opportunity/affirmative action employer. Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Mark A. McCann, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; Alma C. Hobbs, Administrator, 1890 Extension Program, Virginia State, Petersburg. ACTIGARD MAY REDUCE DISEASE IN STRAWBERRY Joel L. Shuman, Research Assistant Professor, Department of Horticulture, VPI & SU, Blacksburg, VA
Metabolomics is the methodology that identifies and measures global pools of small molecules (of ... more Metabolomics is the methodology that identifies and measures global pools of small molecules (of less than about 1,000 Da) of a biological sample, which are collectively called the metabolome. Metabolomics can therefore reveal the metabolic outcome of a genetic or environmental perturbation of a metabolic regulatory network, and thus provide insights into the structure and regulation of that network. Because of the chemical complexity of the metabolome and limitations associated with individual analytical platforms for determining the metabolome, it is currently difficult to capture the complete metabolome of an organism or tissue, which is in contrast to genomics and transcriptomics. This paper describes the analysis of Arabidopsis metabolomics data sets acquired by a consortium that includes five analytical laboratories, bioinformaticists, and biostatisticians, which aims to develop and validate metabolomics as a hypothesis-generating functional genomics tool. The consortium is de...
In North Carolina, anthracnose fruit rot of strawberry (Fragaria × ananassa Duch.) is caused by t... more In North Carolina, anthracnose fruit rot of strawberry (Fragaria × ananassa Duch.) is caused by the fungus Colletotrichum acutatum Simmonds. Little is known about the mechanisms of field resistance of fruits to anthracnose. It appears that resistance of various plant parts including runners, crowns, and foliage is not always correlated with resistance of fruit. Resistance of fruit may be simply overwhelmed by excessive fungal conidia. Is there a threshold level of inoculum and does this threshold vary for fruit of different cultivars? The objective of this study was to determine the effect of inoculum level on the response of seven strawberry cultivars/breeding lines to a single C. acutatum (CA-1) isolate. The experimental design was a split-plot with five levels of inoculum (0, 1 × 103, 1 × 104, 1 × 105, and 1×106 conidia/ml) as the whole plot and seven cultivars/breeding lines (`Apollo', `Chandler', `Camerosa', `Pelican', `Sweet Charley', NCH 95-173, and NCR 94...
Production of pickling cucumber (Cucumis sativus L.) requires a significant expenditure of labor ... more Production of pickling cucumber (Cucumis sativus L.) requires a significant expenditure of labor and money. Those resources could be better managed if both yield and harvest date could be predicted for a given planting date and production area. The objective of this experiment was to develop a model to simulate growth and yield of pickling cucumbers under field conditions in North Carolina. Detailed measurements of leaf area, branching habit, flowering, fruiting, and dry weight distribution were obtained for the cultigens `Calypso', M 21, `Wis. SMR 18', and WI 2757 for 10 planting dates. Light interception, air temperature, and rainfall were also recorded. There were differences among cultigens and planting dates for time needed to reach certain growth stages. Number of days to reach a given stage generally decreased with later planting dates. Addition of nodes over time to the main stem was linear and the interaction of planting date by cultigen was significant. Number of s...
Anthracnose fruit rot (AFR) and crown rot can cause severe economic losses on susceptible `Chandl... more Anthracnose fruit rot (AFR) and crown rot can cause severe economic losses on susceptible `Chandler' and `Camarosa' strawberry in Virginia: `Sweet Charlie' and `Bish' are moderately resistant to resistant. Actigard (acibenzolar-S-methyl), an inducer of systemic acquired resistance, has been effective at reducing black spot and speck on tomato, blue mold on tobacco, and fire blight on apple. The objective of this study was to determine if Actigard, when spray-applied to field-grown strawberry, can reduce AFR better than or equal to several registered fungicides. Four varieties (VAR) (Chandler, Camarosa, Sweet Charlie, and Bish) were treated with four fungicides (FUNG) (water control, azoxystrobin, chlorothalonil, and actigard). Experimental design was a split plot with FUNG as the main plot and VAR as the split plot with four replicates. Standard annual hill system practices were used throughout. Plots were inoculated three times throughout the harvest season with a c...
Drought and heat stress have been extensively studied in plants, but little is known about how th... more Drought and heat stress have been extensively studied in plants, but little is known about how the combination of drought and heat impact their physiology and metabolism. The metabolite profile of Arabidopsis subjected to heat, drought, and the combination of heat and drought were analyzed by gas-chromatography-mass spectrometry (GC-MS). Fatty acid retention time standards and the internal standard (IS) ribitol (adonitol) were added to each leaf sample and the polar phase was extracted, methoximated, and derivatized (trimethylsilylated) prior to analysis by GC-MS (Trace DSQ with Combi-PAL autosampler). Compounds were identified based upon retention time (relative to fatty acid standards) and comparison with reference spectra in our custom mass spectral library. Semi-quantitation of compound peak area was done relative to the internal standard. Plants subjected to both heat and drought stress accumulated sucrose and other sugars/sugar alchohols such as maltose, gulose, mannitol. The ...
International journal for parasitology. Drugs and drug resistance, Apr 1, 2017
The incidence and global distribution of chloroquine resistant (CR) Plasmodium vivax infection ha... more The incidence and global distribution of chloroquine resistant (CR) Plasmodium vivax infection has increased since emerging in 1989. The mechanism of resistance in CR P. vivax has not been defined. The resistance likely relates to the formation and disposition of hemozoin as chloroquine's primary mechanism of action involves disruption of hemozoin formation. CR P. berghei strains, like CR P. vivax strains, are confined to reticulocyte host cells and reportedly they do not accumulate appreciable intraerythrocytic hemozoin. Reports comparing hemozoin production between P. vivax strains and CR to chloroquine sensitive (CS) P. berghei are absent. Here we compare in vivo patterns of hemozoin formation and distribution in blood, spleen and liver tissue of male Swiss mice infected with CS or CR P. berghei not treated with chloroquine and CR P. berghei also treated with chloroquine. Light microscopy, laser desorption mass spectrometry and a colorimetric hemozoin assay detect trace hemoz...
Cell migration, angiogenesis, inflammation, and extracellular matrix remodeling are key events in... more Cell migration, angiogenesis, inflammation, and extracellular matrix remodeling are key events in wound healing. Natural products, including fatty acids (FAs), can accelerate wound healing by modulating the aforementioned events. This study aims to evaluate the effect of lucuma (Pouteria lucuma O Kezte) nut oil (LNO) on fibroblasts migration, angiogenesis, inflammation, bacterial and fungal growth, and wound healing. Methods GC-MS analysis of FAs methyl esters (FAMES) was used for chemical characterization of LNO. In vitro studies were carried out with LNO investigating the induction of cell migration, cytoskeleton remodeling of human fibroblasts, inhibition of LPS-induced nitric oxide production in macrophages, and antibacterial and antifungal effects. Two in vivo studies were carried out to study LNO's effect on angiogenesis and wound healing: (i) tail fin regeneration in transgenic zebrafish larvae expressing enhanced green fluorescent protein (EGFP) in vascular endothelial cells was used to study vessel sprouting and wound healing and (ii) the closure of wounds was evaluated in CD-1 mice after topical applications of LNO-containing formulations. Lucuma nut oil is a mixture of FAs, 99.7% of which were characterized. Major components of LNO (w/w) are linoleic acid (38.9%), oleic acid (27.9%), palmitic acid (18.6%), stearic acid (8.9%), and γ linolenic acid (2.9%). In vitro studies showed that LNO significantly promoted migration and vinculin expression in human fibroblasts. LNO decreased LPS-induced nitric oxide production and did not display significant antibacterial or antifungal effects. LNO induced tail fin regeneration in transgenic zebrafish larvae 48 h after tail fin amputation and significantly accelerated cutaneous wound closure in CD-1 mice. Natural FAs from P. lucuma nut promote skin regeneration and, thus, may have applications in medicine and skin care.
Some popular garden perennials yield low numbers of viable cuttings per stock plant and/or produc... more Some popular garden perennials yield low numbers of viable cuttings per stock plant and/or produce cuttings that are slow to develop significant root mass, preventing propagators from meeting demand for rooted liners. Our objective was to determine the impacts of stock plant nutrition on number of potential cuttings, rooting percentage, and the subsequent root development of cuttings of some popular but difficult to propagate perennials. Gaura lindheimeri ‘Siskiyou Pink’, Dianthus ‘Pixie Star’, Perovskia atriplicifolia ‘Filigran’, and Salvia x sylvestris ‘May Night’, were evaluated using five treatments of 0, 50, 100,150, 200, and 250 mg·L‾¹ N. Greenhouse-grown stock plants were fertilized with a custom-formulated complete liquid feed for ten weeks at which time potential cuttings were counted, and the sample cuttings were taken for rooting. Petiole sap nitrate was measured with a specific ion meter (Cardy) to correlate real-time nitrogen status to cutting yield and subsequent root ...
... A metabolomics study of Plasmodium falciparum infection of red blood cells in the absence and... more ... A metabolomics study of Plasmodium falciparum infection of red blood cells in the absence and presence of antimalarials. Nigel Deighton 1 , Joel Shuman 1 , Jianghong Qian 1 , Vladimir Shulaev 1 , Dominique Rasoloson 2 , Tosin ... Ridley, RG Nature 415, 686-693 (2002). ...
Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic... more Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic challenges in their environment. These are activated at the initial site of exposure to stress, as well as in systemic tissues that have not been subjected to stress (termed systemic acquired acclimation [SAA]). Although SAA is thought to play a key role in plant survival during stress, little is known about the signaling mechanisms underlying it. Here, we report that SAA in plants requires at least two different signals: an autopropagating wave of reactive oxygen species (ROS) that rapidly spreads from the initial site of exposure to the entire plant and a stress-specific signal that conveys abiotic stress specificity. We further demonstrate that SAA is stress specific and that a temporal–spatial interaction between ROS and abscisic acid regulates rapid SAA to heat stress in plants. In addition, we demonstrate that the rapid ROS signal is associated with the propagation of electric sig...
Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic... more Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic challenges in their environment. These are activated at the initial site of exposure to stress, as well as in systemic tissues that have not been subjected to stress (termed systemic acquired acclimation [SAA]). Although SAA is thought to play a key role in plant survival during stress, little is known about the signaling mechanisms underlying it. Here, we report that SAA in plants requires at least two different signals: an autopropagating wave of reactive oxygen species (ROS) that rapidly spreads from the initial site of exposure to the entire plant and a stress-specific signal that conveys abiotic stress specificity. We further demonstrate that SAA is stress specific and that a temporal–spatial interaction between ROS and abscisic acid regulates rapid SAA to heat stress in plants. In addition, we demonstrate that the rapid ROS signal is associated with the propagation of electric sig...
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Papers by Joel Shuman