The Experts below are selected from a list of 12258 Experts worldwide ranked by ideXlab platform
Sebastiano Salleo - One of the best experts on this subject based on the ideXlab platform.
-
Trees (2003) 17:529–534 DOI 10.1007/s00468-003-0265-z
2016Co-Authors: Andrea Nardini, Sebastiano Salleo, Fabio RaimondoAbstract:Abstract The impact of xylem cavitation and Embolism on leaf (Kleaf) and stem (Kstem) hydraulic conductance was measured in current-year shoots of Cercis siliquastrum L. (Judas tree) using the vacuum chamber technique. Kstem decreased at leaf water potentials (YL) lower than 1.0 MPa, while Kleaf started to decrease only at YL <1.5 MPa. Leaf infiltration under vacuum with Phloxine B revealed that minor Veins underwent extensive embo-lism and became non-functional at YL <1.5 MPa, thus indicating that leaf Vein Embolism was closely related to Kleaf changes. Field measurements of leaf conductance to water vapour (gL) and YL showed that stomata closed when YL decreased below the YL threshold inducing loss of hydraulic conductance in the leaf. The partitioning of hydraulic resistances within shoots and leaves was measured using the high-pressure flow meter method. The ratio of leaf to shoot hydraulic resistance was about 0.8, suggesting that stem cavitation had a limited impact on whole shoot hydraulic conductance. We suggest that stomatal aperture may be regulated by the cavitation-induced reduction of hydraulic conductance of the soil-to-leaf water pathway which, in turn, strongly depends on the hydraulic architecture of the plant and, in particular, on leaf hydraulics
-
impairment of leaf hydraulics in young plants of citrus aurantium sour orange infected by phoma tracheiphila
Functional Plant Biology, 2007Co-Authors: Fabio Raimondo, Sebastiano Salleo, F Raudino, S O Cacciola, Maria Lo A GulloAbstract:Phoma trachephila (Petri) Kantschaveli et Gikachvili causes dieback of several Citrus species. The impact of this fungus on leaf hydraulics was studied in Citrus aurantium L. (sour orange) with the aim of identifying the primary mechanism of damage to leaves. Leaves inoculated with a conidial suspension were measured for conductance to water vapor (gL) and specific hydraulic conductance (Kleaf) every 3 days after inoculation. The earliest symptom of infection consisted of Vein chlorosis. Functional Vein density (FVD) was monitored and microscopic observations were made of major Vein conduits. Impairment of Vein hydraulics started 25 days after inoculation with a losses of Kleaf of 40% and gL of ~60%. Most minor Veins within chlorotic areas were no longer functioning and some conduits of the major Veins showed digested interconduit pits leading to Vein cavitation. The close Kleaf-FVD relationship revealed that Vein impairment caused drop of Kleaf and, consequently, of gL at chlorotic areas. Leaf infection was focused to Veins that were first forced to embolise and then invaded by fungal hyphae. The Vein Embolism due to the Phoma amplifies the native dominant hydraulic resistance of leaf Veins, and leads ultimately to early shedding of infected leaves.
-
kinetics of recovery of leaf hydraulic conductance and Vein functionality from cavitation induced Embolism in sunflower
Journal of Experimental Botany, 2003Co-Authors: Patrizia Trifilo, Andrea Nardini, Fabio Raimondo, Antonio Gasco, Sebastiano SalleoAbstract:The kinetics of leaf Vein recovery from cavitation-induced Embolism was studied in plants of sunflower cv. Margot, together with the impact of Vein Embolism on the overall leaf hydraulic conductance (K l e a f ). During the air-dehydration of leaves to leaf water potentials (Ψ L ) of -1.25 MPa, K l e a f was found to decrease by about 46% with respect to values recorded in well-hydrated leaves. When leaves, previously dehydrated to Ψ L = -1.1 MPa (corresponding to the turgor loss point), were put in contact with water, K l e a f recovered completely in 10 min and so did leaf water potential. Functional Vein density was estimated In both dehydrating and rehydrating leaves in terms of total length of red-stained Veins infiltrated with a Phloxine B solution per unit leaf surface area. Veins were found to embolize (unstained) with kinetics showing a linear relationship with K l e a f so that about a 70% loss of functional Veins corresponded with a K l e a f loss of 46%. Cavitated Veins recovered from Embolism within 10 min from the beginning of leaf rehydration. These data indicate that: (a) leaves of sunflower underwent substiantial Vein Embolism during dehydration; (b) Vein Embolism and leaf hydraulic efficiency apparently recovered from dehydration completely and rapidly upon rehydration; (c) Vein refilling occurred while conduits were still at more negative xylem pressures than those required for spontaneous bubble dissolution on the basis of Henry's law. The possible consistent contribution of vital mechanisms for Vein refilling is discussed.
-
axial to radial water permeability of leaf major Veins a possible determinant of the impact of Vein Embolism on leaf hydraulics
Plant Cell and Environment, 2003Co-Authors: Sebastiano Salleo, Fabio Raimondo, Patrizia Trifilo, Andrea NardiniAbstract:The leaf hydraulic conductance (KL) was measured in Prunus laurocerasus L. and Juglans regia L. in which previous measurements had revealed different impacts of dehydration on KL. Leaves of P. laurocerasus lost 8% of their KL at water potentials (ΨL) of −2.0 MPa. Leaflets of J. regia showed KL losses of 40% at ΨL = −1.0 MPa. When major Veins were blocked using cyanoacrylate to simulate their Embolism, the KL of P. laurocerasus was reduced by 57% but that of J. regia leaflets was reduced by 80%. Such differences were hypothesized to be due to different axial-to-radial permeabilites of major Veins. Infiltration of leaves with Phoxine B revealed that P. laurocerasus major Veins were largely leaky in the radial direction whereas those of J. regia leaflets showed prevailing axial water transport. Differences between species in terms of axial-to-radial water permeability were confirmed by measurements of changes of hydraulic resistance along the midrib. The two hydraulic models are discussed in terms of leaf vulnerability to Embolism and plant adaptation to dry habitats.
-
changes in leaf hydraulic conductance correlate with leaf Vein Embolism in cercis siliquastrum l
Trees-structure and Function, 2003Co-Authors: Andrea Nardini, Sebastiano Salleo, Fabio RaimondoAbstract:The impact of xylem cavitation and Embolism on leaf (K leaf) and stem (K stem) hydraulic conductance was measured in current-year shoots of Cercis siliquastrum L. (Judas tree) using the vacuum chamber technique. K stem decreased at leaf water potentials (ΨL) lower than −1.0 MPa, while K leaf started to decrease only at ΨL <−1.5 MPa. Leaf infiltration under vacuum with Phloxine B revealed that minor Veins underwent extensive Embolism and became non-functional at ΨL <−1.5 MPa, thus indicating that leaf Vein Embolism was closely related to K leaf changes. Field measurements of leaf conductance to water vapour (g L) and ΨL showed that stomata closed when ΨL decreased below the ΨL threshold inducing loss of hydraulic conductance in the leaf. The partitioning of hydraulic resistances within shoots and leaves was measured using the high-pressure flow meter method. The ratio of leaf to shoot hydraulic resistance was about 0.8, suggesting that stem cavitation had a limited impact on whole shoot hydraulic conductance. We suggest that stomatal aperture may be regulated by the cavitation-induced reduction of hydraulic conductance of the soil-to-leaf water pathway which, in turn, strongly depends on the hydraulic architecture of the plant and, in particular, on leaf hydraulics.
Andrea Nardini - One of the best experts on this subject based on the ideXlab platform.
-
Trees (2003) 17:529–534 DOI 10.1007/s00468-003-0265-z
2016Co-Authors: Andrea Nardini, Sebastiano Salleo, Fabio RaimondoAbstract:Abstract The impact of xylem cavitation and Embolism on leaf (Kleaf) and stem (Kstem) hydraulic conductance was measured in current-year shoots of Cercis siliquastrum L. (Judas tree) using the vacuum chamber technique. Kstem decreased at leaf water potentials (YL) lower than 1.0 MPa, while Kleaf started to decrease only at YL <1.5 MPa. Leaf infiltration under vacuum with Phloxine B revealed that minor Veins underwent extensive embo-lism and became non-functional at YL <1.5 MPa, thus indicating that leaf Vein Embolism was closely related to Kleaf changes. Field measurements of leaf conductance to water vapour (gL) and YL showed that stomata closed when YL decreased below the YL threshold inducing loss of hydraulic conductance in the leaf. The partitioning of hydraulic resistances within shoots and leaves was measured using the high-pressure flow meter method. The ratio of leaf to shoot hydraulic resistance was about 0.8, suggesting that stem cavitation had a limited impact on whole shoot hydraulic conductance. We suggest that stomatal aperture may be regulated by the cavitation-induced reduction of hydraulic conductance of the soil-to-leaf water pathway which, in turn, strongly depends on the hydraulic architecture of the plant and, in particular, on leaf hydraulics
-
kinetics of recovery of leaf hydraulic conductance and Vein functionality from cavitation induced Embolism in sunflower
Journal of Experimental Botany, 2003Co-Authors: Patrizia Trifilo, Andrea Nardini, Fabio Raimondo, Antonio Gasco, Sebastiano SalleoAbstract:The kinetics of leaf Vein recovery from cavitation-induced Embolism was studied in plants of sunflower cv. Margot, together with the impact of Vein Embolism on the overall leaf hydraulic conductance (K l e a f ). During the air-dehydration of leaves to leaf water potentials (Ψ L ) of -1.25 MPa, K l e a f was found to decrease by about 46% with respect to values recorded in well-hydrated leaves. When leaves, previously dehydrated to Ψ L = -1.1 MPa (corresponding to the turgor loss point), were put in contact with water, K l e a f recovered completely in 10 min and so did leaf water potential. Functional Vein density was estimated In both dehydrating and rehydrating leaves in terms of total length of red-stained Veins infiltrated with a Phloxine B solution per unit leaf surface area. Veins were found to embolize (unstained) with kinetics showing a linear relationship with K l e a f so that about a 70% loss of functional Veins corresponded with a K l e a f loss of 46%. Cavitated Veins recovered from Embolism within 10 min from the beginning of leaf rehydration. These data indicate that: (a) leaves of sunflower underwent substiantial Vein Embolism during dehydration; (b) Vein Embolism and leaf hydraulic efficiency apparently recovered from dehydration completely and rapidly upon rehydration; (c) Vein refilling occurred while conduits were still at more negative xylem pressures than those required for spontaneous bubble dissolution on the basis of Henry's law. The possible consistent contribution of vital mechanisms for Vein refilling is discussed.
-
axial to radial water permeability of leaf major Veins a possible determinant of the impact of Vein Embolism on leaf hydraulics
Plant Cell and Environment, 2003Co-Authors: Sebastiano Salleo, Fabio Raimondo, Patrizia Trifilo, Andrea NardiniAbstract:The leaf hydraulic conductance (KL) was measured in Prunus laurocerasus L. and Juglans regia L. in which previous measurements had revealed different impacts of dehydration on KL. Leaves of P. laurocerasus lost 8% of their KL at water potentials (ΨL) of −2.0 MPa. Leaflets of J. regia showed KL losses of 40% at ΨL = −1.0 MPa. When major Veins were blocked using cyanoacrylate to simulate their Embolism, the KL of P. laurocerasus was reduced by 57% but that of J. regia leaflets was reduced by 80%. Such differences were hypothesized to be due to different axial-to-radial permeabilites of major Veins. Infiltration of leaves with Phoxine B revealed that P. laurocerasus major Veins were largely leaky in the radial direction whereas those of J. regia leaflets showed prevailing axial water transport. Differences between species in terms of axial-to-radial water permeability were confirmed by measurements of changes of hydraulic resistance along the midrib. The two hydraulic models are discussed in terms of leaf vulnerability to Embolism and plant adaptation to dry habitats.
-
changes in leaf hydraulic conductance correlate with leaf Vein Embolism in cercis siliquastrum l
Trees-structure and Function, 2003Co-Authors: Andrea Nardini, Sebastiano Salleo, Fabio RaimondoAbstract:The impact of xylem cavitation and Embolism on leaf (K leaf) and stem (K stem) hydraulic conductance was measured in current-year shoots of Cercis siliquastrum L. (Judas tree) using the vacuum chamber technique. K stem decreased at leaf water potentials (ΨL) lower than −1.0 MPa, while K leaf started to decrease only at ΨL <−1.5 MPa. Leaf infiltration under vacuum with Phloxine B revealed that minor Veins underwent extensive Embolism and became non-functional at ΨL <−1.5 MPa, thus indicating that leaf Vein Embolism was closely related to K leaf changes. Field measurements of leaf conductance to water vapour (g L) and ΨL showed that stomata closed when ΨL decreased below the ΨL threshold inducing loss of hydraulic conductance in the leaf. The partitioning of hydraulic resistances within shoots and leaves was measured using the high-pressure flow meter method. The ratio of leaf to shoot hydraulic resistance was about 0.8, suggesting that stem cavitation had a limited impact on whole shoot hydraulic conductance. We suggest that stomatal aperture may be regulated by the cavitation-induced reduction of hydraulic conductance of the soil-to-leaf water pathway which, in turn, strongly depends on the hydraulic architecture of the plant and, in particular, on leaf hydraulics.
-
changes in leaf hydraulics and stomatal conductance following drought stress and irrigation in ceratonia siliqua carob tree
Physiologia Plantarum, 2003Co-Authors: Maria Lo A Gullo, Andrea Nardini, Patrizia Trifilo, Sebastiano SalleoAbstract:Changes in leaf hydraulic conductance (K) were measured using the vacuum chamber technique during dehydration and rehydration of potted plants of Ceratonia siliqua. K of whole, compound leaves as well as that of rachides and leaflets decreased by 20-30% at leaf water potentials (Ψ L ) of -1.5 and -2.0 MPa, i.e. at Ψ L values commonly recorded in field-growing plants of the species. Higher K losses (up to 50%) were measured for leaves at Ψ L of -2.5 and -3.0 MPa, i.e. near or beyond the leaf turgor loss point. Leaves of plants rehydrated while in the dark for 30 min, 90 min and 12 h recovered from K loss with characteristic times and to extents inversely proportional to the initial water stress applied. Leaf conductance to water vapour of plants dehydrated to decreasing Ψ L and rehydrated at low transpiration was inversely related to loss of K, thus suggesting that leaf Vein Embolism and refilling (and related changes in leaf hydraulics) may play a significant role in the stomatal response.
Fabio Raimondo - One of the best experts on this subject based on the ideXlab platform.
-
Trees (2003) 17:529–534 DOI 10.1007/s00468-003-0265-z
2016Co-Authors: Andrea Nardini, Sebastiano Salleo, Fabio RaimondoAbstract:Abstract The impact of xylem cavitation and Embolism on leaf (Kleaf) and stem (Kstem) hydraulic conductance was measured in current-year shoots of Cercis siliquastrum L. (Judas tree) using the vacuum chamber technique. Kstem decreased at leaf water potentials (YL) lower than 1.0 MPa, while Kleaf started to decrease only at YL <1.5 MPa. Leaf infiltration under vacuum with Phloxine B revealed that minor Veins underwent extensive embo-lism and became non-functional at YL <1.5 MPa, thus indicating that leaf Vein Embolism was closely related to Kleaf changes. Field measurements of leaf conductance to water vapour (gL) and YL showed that stomata closed when YL decreased below the YL threshold inducing loss of hydraulic conductance in the leaf. The partitioning of hydraulic resistances within shoots and leaves was measured using the high-pressure flow meter method. The ratio of leaf to shoot hydraulic resistance was about 0.8, suggesting that stem cavitation had a limited impact on whole shoot hydraulic conductance. We suggest that stomatal aperture may be regulated by the cavitation-induced reduction of hydraulic conductance of the soil-to-leaf water pathway which, in turn, strongly depends on the hydraulic architecture of the plant and, in particular, on leaf hydraulics
-
impairment of leaf hydraulics in young plants of citrus aurantium sour orange infected by phoma tracheiphila
Functional Plant Biology, 2007Co-Authors: Fabio Raimondo, Sebastiano Salleo, F Raudino, S O Cacciola, Maria Lo A GulloAbstract:Phoma trachephila (Petri) Kantschaveli et Gikachvili causes dieback of several Citrus species. The impact of this fungus on leaf hydraulics was studied in Citrus aurantium L. (sour orange) with the aim of identifying the primary mechanism of damage to leaves. Leaves inoculated with a conidial suspension were measured for conductance to water vapor (gL) and specific hydraulic conductance (Kleaf) every 3 days after inoculation. The earliest symptom of infection consisted of Vein chlorosis. Functional Vein density (FVD) was monitored and microscopic observations were made of major Vein conduits. Impairment of Vein hydraulics started 25 days after inoculation with a losses of Kleaf of 40% and gL of ~60%. Most minor Veins within chlorotic areas were no longer functioning and some conduits of the major Veins showed digested interconduit pits leading to Vein cavitation. The close Kleaf-FVD relationship revealed that Vein impairment caused drop of Kleaf and, consequently, of gL at chlorotic areas. Leaf infection was focused to Veins that were first forced to embolise and then invaded by fungal hyphae. The Vein Embolism due to the Phoma amplifies the native dominant hydraulic resistance of leaf Veins, and leads ultimately to early shedding of infected leaves.
-
kinetics of recovery of leaf hydraulic conductance and Vein functionality from cavitation induced Embolism in sunflower
Journal of Experimental Botany, 2003Co-Authors: Patrizia Trifilo, Andrea Nardini, Fabio Raimondo, Antonio Gasco, Sebastiano SalleoAbstract:The kinetics of leaf Vein recovery from cavitation-induced Embolism was studied in plants of sunflower cv. Margot, together with the impact of Vein Embolism on the overall leaf hydraulic conductance (K l e a f ). During the air-dehydration of leaves to leaf water potentials (Ψ L ) of -1.25 MPa, K l e a f was found to decrease by about 46% with respect to values recorded in well-hydrated leaves. When leaves, previously dehydrated to Ψ L = -1.1 MPa (corresponding to the turgor loss point), were put in contact with water, K l e a f recovered completely in 10 min and so did leaf water potential. Functional Vein density was estimated In both dehydrating and rehydrating leaves in terms of total length of red-stained Veins infiltrated with a Phloxine B solution per unit leaf surface area. Veins were found to embolize (unstained) with kinetics showing a linear relationship with K l e a f so that about a 70% loss of functional Veins corresponded with a K l e a f loss of 46%. Cavitated Veins recovered from Embolism within 10 min from the beginning of leaf rehydration. These data indicate that: (a) leaves of sunflower underwent substiantial Vein Embolism during dehydration; (b) Vein Embolism and leaf hydraulic efficiency apparently recovered from dehydration completely and rapidly upon rehydration; (c) Vein refilling occurred while conduits were still at more negative xylem pressures than those required for spontaneous bubble dissolution on the basis of Henry's law. The possible consistent contribution of vital mechanisms for Vein refilling is discussed.
-
axial to radial water permeability of leaf major Veins a possible determinant of the impact of Vein Embolism on leaf hydraulics
Plant Cell and Environment, 2003Co-Authors: Sebastiano Salleo, Fabio Raimondo, Patrizia Trifilo, Andrea NardiniAbstract:The leaf hydraulic conductance (KL) was measured in Prunus laurocerasus L. and Juglans regia L. in which previous measurements had revealed different impacts of dehydration on KL. Leaves of P. laurocerasus lost 8% of their KL at water potentials (ΨL) of −2.0 MPa. Leaflets of J. regia showed KL losses of 40% at ΨL = −1.0 MPa. When major Veins were blocked using cyanoacrylate to simulate their Embolism, the KL of P. laurocerasus was reduced by 57% but that of J. regia leaflets was reduced by 80%. Such differences were hypothesized to be due to different axial-to-radial permeabilites of major Veins. Infiltration of leaves with Phoxine B revealed that P. laurocerasus major Veins were largely leaky in the radial direction whereas those of J. regia leaflets showed prevailing axial water transport. Differences between species in terms of axial-to-radial water permeability were confirmed by measurements of changes of hydraulic resistance along the midrib. The two hydraulic models are discussed in terms of leaf vulnerability to Embolism and plant adaptation to dry habitats.
-
changes in leaf hydraulic conductance correlate with leaf Vein Embolism in cercis siliquastrum l
Trees-structure and Function, 2003Co-Authors: Andrea Nardini, Sebastiano Salleo, Fabio RaimondoAbstract:The impact of xylem cavitation and Embolism on leaf (K leaf) and stem (K stem) hydraulic conductance was measured in current-year shoots of Cercis siliquastrum L. (Judas tree) using the vacuum chamber technique. K stem decreased at leaf water potentials (ΨL) lower than −1.0 MPa, while K leaf started to decrease only at ΨL <−1.5 MPa. Leaf infiltration under vacuum with Phloxine B revealed that minor Veins underwent extensive Embolism and became non-functional at ΨL <−1.5 MPa, thus indicating that leaf Vein Embolism was closely related to K leaf changes. Field measurements of leaf conductance to water vapour (g L) and ΨL showed that stomata closed when ΨL decreased below the ΨL threshold inducing loss of hydraulic conductance in the leaf. The partitioning of hydraulic resistances within shoots and leaves was measured using the high-pressure flow meter method. The ratio of leaf to shoot hydraulic resistance was about 0.8, suggesting that stem cavitation had a limited impact on whole shoot hydraulic conductance. We suggest that stomatal aperture may be regulated by the cavitation-induced reduction of hydraulic conductance of the soil-to-leaf water pathway which, in turn, strongly depends on the hydraulic architecture of the plant and, in particular, on leaf hydraulics.
Patrizia Trifilo - One of the best experts on this subject based on the ideXlab platform.
-
axial to radial water permeability of leaf major Veins a possible determinant of the impact of Vein Embolism on leaf hydraulics
Plant Cell and Environment, 2003Co-Authors: Sebastiano Salleo, Fabio Raimondo, Patrizia Trifilo, Andrea NardiniAbstract:The leaf hydraulic conductance (KL) was measured in Prunus laurocerasus L. and Juglans regia L. in which previous measurements had revealed different impacts of dehydration on KL. Leaves of P. laurocerasus lost 8% of their KL at water potentials (ΨL) of −2.0 MPa. Leaflets of J. regia showed KL losses of 40% at ΨL = −1.0 MPa. When major Veins were blocked using cyanoacrylate to simulate their Embolism, the KL of P. laurocerasus was reduced by 57% but that of J. regia leaflets was reduced by 80%. Such differences were hypothesized to be due to different axial-to-radial permeabilites of major Veins. Infiltration of leaves with Phoxine B revealed that P. laurocerasus major Veins were largely leaky in the radial direction whereas those of J. regia leaflets showed prevailing axial water transport. Differences between species in terms of axial-to-radial water permeability were confirmed by measurements of changes of hydraulic resistance along the midrib. The two hydraulic models are discussed in terms of leaf vulnerability to Embolism and plant adaptation to dry habitats.
-
kinetics of recovery of leaf hydraulic conductance and Vein functionality from cavitation induced Embolism in sunflower
Journal of Experimental Botany, 2003Co-Authors: Patrizia Trifilo, Andrea Nardini, Fabio Raimondo, Antonio Gasco, Sebastiano SalleoAbstract:The kinetics of leaf Vein recovery from cavitation-induced Embolism was studied in plants of sunflower cv. Margot, together with the impact of Vein Embolism on the overall leaf hydraulic conductance (K l e a f ). During the air-dehydration of leaves to leaf water potentials (Ψ L ) of -1.25 MPa, K l e a f was found to decrease by about 46% with respect to values recorded in well-hydrated leaves. When leaves, previously dehydrated to Ψ L = -1.1 MPa (corresponding to the turgor loss point), were put in contact with water, K l e a f recovered completely in 10 min and so did leaf water potential. Functional Vein density was estimated In both dehydrating and rehydrating leaves in terms of total length of red-stained Veins infiltrated with a Phloxine B solution per unit leaf surface area. Veins were found to embolize (unstained) with kinetics showing a linear relationship with K l e a f so that about a 70% loss of functional Veins corresponded with a K l e a f loss of 46%. Cavitated Veins recovered from Embolism within 10 min from the beginning of leaf rehydration. These data indicate that: (a) leaves of sunflower underwent substiantial Vein Embolism during dehydration; (b) Vein Embolism and leaf hydraulic efficiency apparently recovered from dehydration completely and rapidly upon rehydration; (c) Vein refilling occurred while conduits were still at more negative xylem pressures than those required for spontaneous bubble dissolution on the basis of Henry's law. The possible consistent contribution of vital mechanisms for Vein refilling is discussed.
-
changes in leaf hydraulics and stomatal conductance following drought stress and irrigation in ceratonia siliqua carob tree
Physiologia Plantarum, 2003Co-Authors: Maria Lo A Gullo, Andrea Nardini, Patrizia Trifilo, Sebastiano SalleoAbstract:Changes in leaf hydraulic conductance (K) were measured using the vacuum chamber technique during dehydration and rehydration of potted plants of Ceratonia siliqua. K of whole, compound leaves as well as that of rachides and leaflets decreased by 20-30% at leaf water potentials (Ψ L ) of -1.5 and -2.0 MPa, i.e. at Ψ L values commonly recorded in field-growing plants of the species. Higher K losses (up to 50%) were measured for leaves at Ψ L of -2.5 and -3.0 MPa, i.e. near or beyond the leaf turgor loss point. Leaves of plants rehydrated while in the dark for 30 min, 90 min and 12 h recovered from K loss with characteristic times and to extents inversely proportional to the initial water stress applied. Leaf conductance to water vapour of plants dehydrated to decreasing Ψ L and rehydrated at low transpiration was inversely related to loss of K, thus suggesting that leaf Vein Embolism and refilling (and related changes in leaf hydraulics) may play a significant role in the stomatal response.
Maria Lo A Gullo - One of the best experts on this subject based on the ideXlab platform.
-
impairment of leaf hydraulics in young plants of citrus aurantium sour orange infected by phoma tracheiphila
Functional Plant Biology, 2007Co-Authors: Fabio Raimondo, Sebastiano Salleo, F Raudino, S O Cacciola, Maria Lo A GulloAbstract:Phoma trachephila (Petri) Kantschaveli et Gikachvili causes dieback of several Citrus species. The impact of this fungus on leaf hydraulics was studied in Citrus aurantium L. (sour orange) with the aim of identifying the primary mechanism of damage to leaves. Leaves inoculated with a conidial suspension were measured for conductance to water vapor (gL) and specific hydraulic conductance (Kleaf) every 3 days after inoculation. The earliest symptom of infection consisted of Vein chlorosis. Functional Vein density (FVD) was monitored and microscopic observations were made of major Vein conduits. Impairment of Vein hydraulics started 25 days after inoculation with a losses of Kleaf of 40% and gL of ~60%. Most minor Veins within chlorotic areas were no longer functioning and some conduits of the major Veins showed digested interconduit pits leading to Vein cavitation. The close Kleaf-FVD relationship revealed that Vein impairment caused drop of Kleaf and, consequently, of gL at chlorotic areas. Leaf infection was focused to Veins that were first forced to embolise and then invaded by fungal hyphae. The Vein Embolism due to the Phoma amplifies the native dominant hydraulic resistance of leaf Veins, and leads ultimately to early shedding of infected leaves.
-
changes in leaf hydraulics and stomatal conductance following drought stress and irrigation in ceratonia siliqua carob tree
Physiologia Plantarum, 2003Co-Authors: Maria Lo A Gullo, Andrea Nardini, Patrizia Trifilo, Sebastiano SalleoAbstract:Changes in leaf hydraulic conductance (K) were measured using the vacuum chamber technique during dehydration and rehydration of potted plants of Ceratonia siliqua. K of whole, compound leaves as well as that of rachides and leaflets decreased by 20-30% at leaf water potentials (Ψ L ) of -1.5 and -2.0 MPa, i.e. at Ψ L values commonly recorded in field-growing plants of the species. Higher K losses (up to 50%) were measured for leaves at Ψ L of -2.5 and -3.0 MPa, i.e. near or beyond the leaf turgor loss point. Leaves of plants rehydrated while in the dark for 30 min, 90 min and 12 h recovered from K loss with characteristic times and to extents inversely proportional to the initial water stress applied. Leaf conductance to water vapour of plants dehydrated to decreasing Ψ L and rehydrated at low transpiration was inversely related to loss of K, thus suggesting that leaf Vein Embolism and refilling (and related changes in leaf hydraulics) may play a significant role in the stomatal response.
