The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Guillermo Goldstein - One of the best experts on this subject based on the ideXlab platform.
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determinants of water circulation in a woody bamboo species afternoon use and night time recharge of culm water storage
Tree Physiology, 2015Co-Authors: Shijian Yang, Yongjiang Zhang, Guillermo GoldsteinAbstract:To understand water-use strategies of woody bamboo species, sap flux density (
water storage of bamboo culms was not used for its transpiration in the morning but in the afternoon. Nocturnal sap flow of this woody bamboo was also detected and related to Root Pressure. We conclude that this bamboo has fast sap flow/stomatal responses to irradiance and evaporative demands, and it uses substantial water storage for transpiration in the afternoon, while Root Pressure appears to be a mechanism resulting in culm water storage recharge during the night. -
Investigating xylem embolism formation, refilling and water storage in tree trunks using frequency domain reflectometry
Journal of experimental botany, 2013Co-Authors: Guang-you Hao, James K. Wheeler, N. Michele Holbrook, Guillermo GoldsteinAbstract:Trunks of large trees play an important role in whole-plant water balance but technical difficulties have limited most hydraulic research to small stems, leaves, and Roots. To investigate the dynamics of water-related processes in tree trunks, such as winter embolism refilling, xylem hydraulic vulnerability, and water storage, volumetric water content (VWC) in the main stem was monitored continuously using frequency domain moisture sensors in adult Betula papyrifera trees from early spring through the beginning of winter. An air injection technique was developed to estimate hydraulic vulnerability of the trunk xylem. Trunk VWC increased in early spring and again in autumn, concurrently with Root Pressure during both seasons. Diurnal fluctuations and a gradual decrease in trunk VWC through the growing season were observed, which, in combination with VWC increase after significant rainfall events and depletion during periods of high water demand, indicate the importance of stem water storage in both short- and long-term water balance. Comparisons between the trunk air injection results and conventional branch hydraulic vulnerability curves showed no evidence of ‘vulnerability segmentation’ between the main stem and small branches in B. papyrifera. Measurements of VWC following air injection, together with evidence from air injection and xylem dye perfusion, indicate that embolized vessels can be refilled by active Root Pressure but not in the absence of Root Pressure. The precise, continuous, and non-destructive measurement of wood water content using frequency domain sensors provides an ideal way to probe many hydraulic processes in large tree trunks that are otherwise difficult to investigate.
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recovery of diurnal depression of leaf hydraulic conductance in a subtropical woody bamboo species embolism refilling by nocturnal Root Pressure
Tree Physiology, 2012Co-Authors: Shijian Yang, Yongjiang Zhang, Guillermo GoldsteinAbstract:Despite considerable investigations of diurnal water use characteristics in different plant functional groups, the research on daily water use strategies of woody bamboo grasses remains lacking. We studied the daily water use and gas exchange of Sinarundinaria nitida (Mitford) Nakai, an abundant subtropical bamboo species in Southwest China. We found that the stem relative water content (RWC) and stem hydraulic conductivity (K s ) of this bamboo species did not decrease significantly during the day, whereas the leaf RWC and leaf hydraulic conductance (K leaf ) showed a distinct decrease at midday, compared with the predawn values. Diurnal loss of K leaf was coupled with a midday decline in stomatal conductance (g s ) and CO 2 assimilation. The positive Root Pressures in the different habitats were of sufficient magnitude to refill the embolisms in leaves. We con cluded that (i) the studied bamboo species does not use stem water storage for daily transpiration; (ii) diurnal downregulation in K leaf and gs has the function to slow down potential water loss in stems and protect the stem hydraulic pathway from cavitation; (iii) since K leaf did not recover during late afternoon, refilling of embolism in bamboo leaves probably fully depends on nocturnal Root Pressure. The embolism refilling mechanism by Root Pressure could be helpful for the growth and persistence of this woody monocot species.
Andrew J Mcelrone - One of the best experts on this subject based on the ideXlab platform.
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Differences in hydraulic traits of grapevine Rootstocks are not conferred to a common Vitis vinifera scion.
Functional plant biology : FPB, 2019Co-Authors: Felipe H. Barrios-masias, Thorsten Knipfer, M. Andrew Walker, Andrew J McelroneAbstract:Cultivars of grapevine are commonly grafted onto Rootstocks to improve resistance against biotic and abiotic stress, however, it is not clear whether known differences in hydraulic traits are conferred from Rootstocks to a common scion. We recently found that Vitis riparia and Vitis champinii differed in drought-induced embolism susceptibility and repair, which was related to differences in Root Pressure generation after rewatering (Knipfer et al. 2015). In the present study, we tested whether these and other physiological responses to drought are conferred to a common V. vinifera scion (Cabernet Sauvignon) grafted on V. riparia and V. champinii Rootstocks. We measured xylem embolism formation/repair using in vivo microCT imaging, which was accompanied with analysis of leaf gas exchange, osmotic adjustment and Root Pressure. Our data indicate that differences in scion physiological behaviour for both Rootstock combinations were negligible, suggesting that the sensitivity of Cabernet Sauvignon scion to xylem embolism formation/repair, leaf gas exchange and osmotic adjustment is unaffected by either V. riparia or V. champinii Rootstock in response to drought stress.
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in situ visualization of the dynamics in xylem embolism formation and removal in the absence of Root Pressure a study on excised grapevine stems
Plant Physiology, 2016Co-Authors: Thorsten Knipfer, Craig R Brodersen, Italo F Cuneo, Andrew J McelroneAbstract:Gas embolisms formed during drought can disrupt long-distance water transport through plant xylem vessels, but some species have the ability to remove these blockages. Despite evidence suggesting that embolism removal is linked to the presence of vessel-associated parenchyma, the underlying mechanism remains controversial and is thought to involve positive Pressure generated by Roots. Here, we used in situ x-ray microtomography on excised grapevine stems to determine if embolism removal is possible without Root Pressure, and if the embolism formation/removal affects vessel functional status after sample excision. Our data show that embolism removal in excised stems was driven by water droplet growth and was qualitatively identical to refilling in intact plants. When stem segments were rehydrated with H2O after excision, vessel refilling occurred rapidly (<1 h). The refilling process was substantially slower when polyethylene glycol was added to the H2O source, thereby providing new support for an osmotically driven refilling mechanism. In contrast, segments not supplied with H2O showed no refilling and increased embolism formation. Dynamic changes in liquid/wall contact angles indicated that the processes of embolism removal (i.e. vessel refilling) by water influx and embolism formation by water efflux were directly linked to the activity of vessel-associated living tissue. Overall, our results emphasize that Root Pressure is not required as a driving force for vessel refilling, and care should be taken when performing hydraulics measurements on excised plant organs containing living vessel-associated tissue, because the vessel behavior may not be static.
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In Situ Visualization of the Dynamics in Xylem Embolism Formation and Removal in the Absence of Root Pressure: A Study on Excised Grapevine Stems.
Plant physiology, 2016Co-Authors: Thorsten Knipfer, Craig R Brodersen, Italo F Cuneo, Andrew J McelroneAbstract:Gas embolisms formed during drought can disrupt long-distance water transport through plant xylem vessels, but some species have the ability to remove these blockages. Despite evidence suggesting that embolism removal is linked to the presence of vessel-associated parenchyma, the underlying mechanism remains controversial and is thought to involve positive Pressure generated by Roots. Here, we used in situ x-ray microtomography on excised grapevine stems to determine if embolism removal is possible without Root Pressure, and if the embolism formation/removal affects vessel functional status after sample excision. Our data show that embolism removal in excised stems was driven by water droplet growth and was qualitatively identical to refilling in intact plants. When stem segments were rehydrated with H2O after excision, vessel refilling occurred rapidly (
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grapevine species from varied native habitats exhibit differences in embolism formation repair associated with leaf gas exchange and Root Pressure
Plant Cell and Environment, 2015Co-Authors: Thorsten Knipfer, Ashley Eustis, Craig R Brodersen, Andrew Michael Walker, Andrew J McelroneAbstract:Drought induces xylem embolism formation, but grapevines can refill non-functional vessels to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analysed in vivo embolism formation and repair using x-ray computed microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii) and related responses to measurements of leaf gas exchange and Root Pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, Root Pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with Root Pressure and gas exchange responses.
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Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and Root Pressure.
Plant cell & environment, 2015Co-Authors: Thorsten Knipfer, Ashley Eustis, Craig R Brodersen, Andrew Michael Walker, Andrew J McelroneAbstract:Drought induces xylem embolism formation, but grapevines can refill non-functional vessels to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analysed in vivo embolism formation and repair using x-ray computed microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii) and related responses to measurements of leaf gas exchange and Root Pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, Root Pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with Root Pressure and gas exchange responses.
Thorsten Knipfer - One of the best experts on this subject based on the ideXlab platform.
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Differences in hydraulic traits of grapevine Rootstocks are not conferred to a common Vitis vinifera scion.
Functional plant biology : FPB, 2019Co-Authors: Felipe H. Barrios-masias, Thorsten Knipfer, M. Andrew Walker, Andrew J McelroneAbstract:Cultivars of grapevine are commonly grafted onto Rootstocks to improve resistance against biotic and abiotic stress, however, it is not clear whether known differences in hydraulic traits are conferred from Rootstocks to a common scion. We recently found that Vitis riparia and Vitis champinii differed in drought-induced embolism susceptibility and repair, which was related to differences in Root Pressure generation after rewatering (Knipfer et al. 2015). In the present study, we tested whether these and other physiological responses to drought are conferred to a common V. vinifera scion (Cabernet Sauvignon) grafted on V. riparia and V. champinii Rootstocks. We measured xylem embolism formation/repair using in vivo microCT imaging, which was accompanied with analysis of leaf gas exchange, osmotic adjustment and Root Pressure. Our data indicate that differences in scion physiological behaviour for both Rootstock combinations were negligible, suggesting that the sensitivity of Cabernet Sauvignon scion to xylem embolism formation/repair, leaf gas exchange and osmotic adjustment is unaffected by either V. riparia or V. champinii Rootstock in response to drought stress.
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in situ visualization of the dynamics in xylem embolism formation and removal in the absence of Root Pressure a study on excised grapevine stems
Plant Physiology, 2016Co-Authors: Thorsten Knipfer, Craig R Brodersen, Italo F Cuneo, Andrew J McelroneAbstract:Gas embolisms formed during drought can disrupt long-distance water transport through plant xylem vessels, but some species have the ability to remove these blockages. Despite evidence suggesting that embolism removal is linked to the presence of vessel-associated parenchyma, the underlying mechanism remains controversial and is thought to involve positive Pressure generated by Roots. Here, we used in situ x-ray microtomography on excised grapevine stems to determine if embolism removal is possible without Root Pressure, and if the embolism formation/removal affects vessel functional status after sample excision. Our data show that embolism removal in excised stems was driven by water droplet growth and was qualitatively identical to refilling in intact plants. When stem segments were rehydrated with H2O after excision, vessel refilling occurred rapidly (<1 h). The refilling process was substantially slower when polyethylene glycol was added to the H2O source, thereby providing new support for an osmotically driven refilling mechanism. In contrast, segments not supplied with H2O showed no refilling and increased embolism formation. Dynamic changes in liquid/wall contact angles indicated that the processes of embolism removal (i.e. vessel refilling) by water influx and embolism formation by water efflux were directly linked to the activity of vessel-associated living tissue. Overall, our results emphasize that Root Pressure is not required as a driving force for vessel refilling, and care should be taken when performing hydraulics measurements on excised plant organs containing living vessel-associated tissue, because the vessel behavior may not be static.
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In Situ Visualization of the Dynamics in Xylem Embolism Formation and Removal in the Absence of Root Pressure: A Study on Excised Grapevine Stems.
Plant physiology, 2016Co-Authors: Thorsten Knipfer, Craig R Brodersen, Italo F Cuneo, Andrew J McelroneAbstract:Gas embolisms formed during drought can disrupt long-distance water transport through plant xylem vessels, but some species have the ability to remove these blockages. Despite evidence suggesting that embolism removal is linked to the presence of vessel-associated parenchyma, the underlying mechanism remains controversial and is thought to involve positive Pressure generated by Roots. Here, we used in situ x-ray microtomography on excised grapevine stems to determine if embolism removal is possible without Root Pressure, and if the embolism formation/removal affects vessel functional status after sample excision. Our data show that embolism removal in excised stems was driven by water droplet growth and was qualitatively identical to refilling in intact plants. When stem segments were rehydrated with H2O after excision, vessel refilling occurred rapidly (
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grapevine species from varied native habitats exhibit differences in embolism formation repair associated with leaf gas exchange and Root Pressure
Plant Cell and Environment, 2015Co-Authors: Thorsten Knipfer, Ashley Eustis, Craig R Brodersen, Andrew Michael Walker, Andrew J McelroneAbstract:Drought induces xylem embolism formation, but grapevines can refill non-functional vessels to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analysed in vivo embolism formation and repair using x-ray computed microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii) and related responses to measurements of leaf gas exchange and Root Pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, Root Pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with Root Pressure and gas exchange responses.
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Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and Root Pressure.
Plant cell & environment, 2015Co-Authors: Thorsten Knipfer, Ashley Eustis, Craig R Brodersen, Andrew Michael Walker, Andrew J McelroneAbstract:Drought induces xylem embolism formation, but grapevines can refill non-functional vessels to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analysed in vivo embolism formation and repair using x-ray computed microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii) and related responses to measurements of leaf gas exchange and Root Pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, Root Pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with Root Pressure and gas exchange responses.
Shijian Yang - One of the best experts on this subject based on the ideXlab platform.
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determinants of water circulation in a woody bamboo species afternoon use and night time recharge of culm water storage
Tree Physiology, 2015Co-Authors: Shijian Yang, Yongjiang Zhang, Guillermo GoldsteinAbstract:To understand water-use strategies of woody bamboo species, sap flux density (
water storage of bamboo culms was not used for its transpiration in the morning but in the afternoon. Nocturnal sap flow of this woody bamboo was also detected and related to Root Pressure. We conclude that this bamboo has fast sap flow/stomatal responses to irradiance and evaporative demands, and it uses substantial water storage for transpiration in the afternoon, while Root Pressure appears to be a mechanism resulting in culm water storage recharge during the night. -
The maximum height of grasses is determined by Roots
Ecology letters, 2012Co-Authors: Kunfang Cao, Shijian Yang, Yongjiang Zhang, Timothy J. BrodribbAbstract:Grasses such as bamboos can produce upright stems more than 30 m tall, yet the processes that constrain plant height in this important group have never been investigated. Air embolisms form commonly in the water transport system of grasses and we hypothesised that Root Pressure-dependent refilling these embolisms should limit the maximum height of grass species to the magnitude of their Root Pressure. Confirming this hypothesis, we show that in 59 species of bamboo grown in two common gardens, the maximum heights of culms of 67 clones are closely predicted by the maximum measured Root Pressure overnight. Furthermore, we demonstrate that water transport in these bamboo species is dependent on Root Pressure to repair hydraulic dysfunction sustained during normal diurnal gas exchange. Our results established the critical importance of Root Pressure in the tallest grass species and provide a new basis for understanding the limits for plant growth.
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recovery of diurnal depression of leaf hydraulic conductance in a subtropical woody bamboo species embolism refilling by nocturnal Root Pressure
Tree Physiology, 2012Co-Authors: Shijian Yang, Yongjiang Zhang, Guillermo GoldsteinAbstract:Despite considerable investigations of diurnal water use characteristics in different plant functional groups, the research on daily water use strategies of woody bamboo grasses remains lacking. We studied the daily water use and gas exchange of Sinarundinaria nitida (Mitford) Nakai, an abundant subtropical bamboo species in Southwest China. We found that the stem relative water content (RWC) and stem hydraulic conductivity (K s ) of this bamboo species did not decrease significantly during the day, whereas the leaf RWC and leaf hydraulic conductance (K leaf ) showed a distinct decrease at midday, compared with the predawn values. Diurnal loss of K leaf was coupled with a midday decline in stomatal conductance (g s ) and CO 2 assimilation. The positive Root Pressures in the different habitats were of sufficient magnitude to refill the embolisms in leaves. We con cluded that (i) the studied bamboo species does not use stem water storage for daily transpiration; (ii) diurnal downregulation in K leaf and gs has the function to slow down potential water loss in stems and protect the stem hydraulic pathway from cavitation; (iii) since K leaf did not recover during late afternoon, refilling of embolism in bamboo leaves probably fully depends on nocturnal Root Pressure. The embolism refilling mechanism by Root Pressure could be helpful for the growth and persistence of this woody monocot species.
Yongjiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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determinants of water circulation in a woody bamboo species afternoon use and night time recharge of culm water storage
Tree Physiology, 2015Co-Authors: Shijian Yang, Yongjiang Zhang, Guillermo GoldsteinAbstract:To understand water-use strategies of woody bamboo species, sap flux density (
water storage of bamboo culms was not used for its transpiration in the morning but in the afternoon. Nocturnal sap flow of this woody bamboo was also detected and related to Root Pressure. We conclude that this bamboo has fast sap flow/stomatal responses to irradiance and evaporative demands, and it uses substantial water storage for transpiration in the afternoon, while Root Pressure appears to be a mechanism resulting in culm water storage recharge during the night. -
The maximum height of grasses is determined by Roots
Ecology letters, 2012Co-Authors: Kunfang Cao, Shijian Yang, Yongjiang Zhang, Timothy J. BrodribbAbstract:Grasses such as bamboos can produce upright stems more than 30 m tall, yet the processes that constrain plant height in this important group have never been investigated. Air embolisms form commonly in the water transport system of grasses and we hypothesised that Root Pressure-dependent refilling these embolisms should limit the maximum height of grass species to the magnitude of their Root Pressure. Confirming this hypothesis, we show that in 59 species of bamboo grown in two common gardens, the maximum heights of culms of 67 clones are closely predicted by the maximum measured Root Pressure overnight. Furthermore, we demonstrate that water transport in these bamboo species is dependent on Root Pressure to repair hydraulic dysfunction sustained during normal diurnal gas exchange. Our results established the critical importance of Root Pressure in the tallest grass species and provide a new basis for understanding the limits for plant growth.
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recovery of diurnal depression of leaf hydraulic conductance in a subtropical woody bamboo species embolism refilling by nocturnal Root Pressure
Tree Physiology, 2012Co-Authors: Shijian Yang, Yongjiang Zhang, Guillermo GoldsteinAbstract:Despite considerable investigations of diurnal water use characteristics in different plant functional groups, the research on daily water use strategies of woody bamboo grasses remains lacking. We studied the daily water use and gas exchange of Sinarundinaria nitida (Mitford) Nakai, an abundant subtropical bamboo species in Southwest China. We found that the stem relative water content (RWC) and stem hydraulic conductivity (K s ) of this bamboo species did not decrease significantly during the day, whereas the leaf RWC and leaf hydraulic conductance (K leaf ) showed a distinct decrease at midday, compared with the predawn values. Diurnal loss of K leaf was coupled with a midday decline in stomatal conductance (g s ) and CO 2 assimilation. The positive Root Pressures in the different habitats were of sufficient magnitude to refill the embolisms in leaves. We con cluded that (i) the studied bamboo species does not use stem water storage for daily transpiration; (ii) diurnal downregulation in K leaf and gs has the function to slow down potential water loss in stems and protect the stem hydraulic pathway from cavitation; (iii) since K leaf did not recover during late afternoon, refilling of embolism in bamboo leaves probably fully depends on nocturnal Root Pressure. The embolism refilling mechanism by Root Pressure could be helpful for the growth and persistence of this woody monocot species.
