Photosynthesis in C3 plants is significantly limited by mesophyll
conductance (gm), which can var... more Photosynthesis in C3 plants is significantly limited by mesophyll conductance (gm), which can vary with leaf anatomical traits and nitrogen (N) supplements. Several studies have investigated the response of gm to N supplements; however, none examined the implications of N supplements on the response of gm to rapid environmental changes. Here we investigated the effect of N supplement on gm and the response of gm to change of CO2, temperature and irradiance in rice. High N supplement (HN) increased mesophyll cell wall surface area and chloroplast surface area exposed to intercellular airspace per leaf area, and reduced cell wall thickness. These changes resulted in increased gm. The gm of leaves with HN was more sensitive to changes in CO2 concentration, temperature and irradiance.The difference in leaf structural features between low N supplement and HN indicates that a rapid change in gm is related to the regulation of diffusion through biological membranes rather than leaf structural features. These results will contribute to an understanding of the determinants of gm response to rapid changes in environmental factors
Increasing leaf photosynthesis rate (A) is considered an important strategy to increase C3 crop y... more Increasing leaf photosynthesis rate (A) is considered an important strategy to increase C3 crop yields. Leaf A is usually represented by point measurements, but A varies within each leaf, especially within large leaves. However, little is known about the effect of heterogeneity of A within leaves on rice performance. Here we investigated the changes in gas-exchange parameters and leaf structural and chemical features along leaf blades in two rice cultivars. Stomatal and mesophyll conductance as well as leaf nitrogen (N), Rubisco and chlorophyll contents increased from base to apex; consequently, A increased along leaves in both cultivars. The variation in A, leaf N content and Rubisco content within leaves was similar to the variations among cultivars, and the extent of A heterogeneity within leaves varied between cultivars, leading to different efficiencies of biomass accumulation. Furthermore, variation of A within leaves was closely associated with leaf structural and chemical features. Our findings emphasise that functional changes along leaf blades are associated with structural and chemical trait variation and that variation of A within leaves should be considered to achieve progress in future breeding programs.
Chlorophyll meters are widely used to guide nitrogen (N) management by monitoring leaf N status
i... more Chlorophyll meters are widely used to guide nitrogen (N) management by monitoring leaf N status in agricultural systems, but the effects of environmental factors and leaf characteristics on leaf N estimations are still unclear. In the present study, we estimated the relationships among SPAD readings, chlorophyll content and leaf N content per leaf area for seven species grown in multiple environments. There were similar relationships between SPAD readings and chlorophyll content per leaf area for the species groups, but the relationship between chlorophyll content and leaf N content per leaf area, and the relationship between SPAD readings and leaf N content per leaf area varied widely among the species groups. A significant impact of light-dependent chloroplast movement on SPAD readings was observed under low leaf N supplementation in both rice and soybean but not under high N supplementation. Furthermore, the allocation of leaf N to chlorophyll was strongly influenced by short-term changes in growth light. We demonstrate that the relationship between SPAD readings and leaf N content per leaf area is profoundly affected by environmental factors and leaf features of crop species, which should be accounted for when using a chlorophyll meter to guide N management in agricultural systems.
Leaf hydraulic conductance (Kleaf) is a major determinant of photosynthetic rate in plants. Previ... more Leaf hydraulic conductance (Kleaf) is a major determinant of photosynthetic rate in plants. Previous work has assessed the relationships between leaf morpho-anatomical traits and Kleaf with woody species, but there has been very little focus on cereal crops. The genus Oryza, which includes rice (Oryza sativa) and wild species (such as O. rufipogon cv. Griff), is ideal material for identifying leaf features associated with Kleaf and gas exchange. Leaf morpho-anatomical traits, Kleaf, leaf N content per leaf area, and CO2 diffusion efficiency were investigated in 11 Oryza cultivars. Kleaf was positively correlated with leaf thickness and related traits, and therefore positively correlated with leaf mass per area and leaf N content per leaf area, and negatively with inter-veinal distance. Kleaf was also positively correlated with leaf area and its related traits, and therefore negatively correlated with the proportion of minor vein length per area. In addition, coordination between Kleaf and CO2 diffusion conductance in leaves was observed. We conclude that leaf morpho-anatomical traits and N content per leaf area strongly influence Kleaf. Our results suggest that more detailed anatomical and structural studies are needed to elucidate the impacts of leaf feature traits on Kleaf and gas exchange in grasses.
To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.... more To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.) cultivars and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates (NSC) inHTtolerance is related to E, a pot experiment supplied with twoNlevels (low N, 0.077 g urea kg–1 soil; sufficient N, 0.538 g urea kg–1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could be partly offset by a sufficientNsupply. The most HT-tolerant cultivar, N22, had the highest E and stem NSCconcentrations under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations. A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments were related to E, and possibly to NSC concentration.
To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.... more To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.) cultivars and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates (NSC) in HT tolerance is related to E, a pot experiment supplied with two N levels (low N, 0.077 g urea kg -1 soil; sufficient N, 0.538 g urea kg -1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could be partly offset by a sufficient N supply. The most HT-tolerant cultivar, N22, had the highest E and stem NSC concentrations under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations. A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments were related to E, and possibly to NSC concentration.
Photosynthesis in C3 plants is significantly limited by mesophyll
conductance (gm), which can var... more Photosynthesis in C3 plants is significantly limited by mesophyll conductance (gm), which can vary with leaf anatomical traits and nitrogen (N) supplements. Several studies have investigated the response of gm to N supplements; however, none examined the implications of N supplements on the response of gm to rapid environmental changes. Here we investigated the effect of N supplement on gm and the response of gm to change of CO2, temperature and irradiance in rice. High N supplement (HN) increased mesophyll cell wall surface area and chloroplast surface area exposed to intercellular airspace per leaf area, and reduced cell wall thickness. These changes resulted in increased gm. The gm of leaves with HN was more sensitive to changes in CO2 concentration, temperature and irradiance.The difference in leaf structural features between low N supplement and HN indicates that a rapid change in gm is related to the regulation of diffusion through biological membranes rather than leaf structural features. These results will contribute to an understanding of the determinants of gm response to rapid changes in environmental factors
Increasing leaf photosynthesis rate (A) is considered an important strategy to increase C3 crop y... more Increasing leaf photosynthesis rate (A) is considered an important strategy to increase C3 crop yields. Leaf A is usually represented by point measurements, but A varies within each leaf, especially within large leaves. However, little is known about the effect of heterogeneity of A within leaves on rice performance. Here we investigated the changes in gas-exchange parameters and leaf structural and chemical features along leaf blades in two rice cultivars. Stomatal and mesophyll conductance as well as leaf nitrogen (N), Rubisco and chlorophyll contents increased from base to apex; consequently, A increased along leaves in both cultivars. The variation in A, leaf N content and Rubisco content within leaves was similar to the variations among cultivars, and the extent of A heterogeneity within leaves varied between cultivars, leading to different efficiencies of biomass accumulation. Furthermore, variation of A within leaves was closely associated with leaf structural and chemical features. Our findings emphasise that functional changes along leaf blades are associated with structural and chemical trait variation and that variation of A within leaves should be considered to achieve progress in future breeding programs.
Chlorophyll meters are widely used to guide nitrogen (N) management by monitoring leaf N status
i... more Chlorophyll meters are widely used to guide nitrogen (N) management by monitoring leaf N status in agricultural systems, but the effects of environmental factors and leaf characteristics on leaf N estimations are still unclear. In the present study, we estimated the relationships among SPAD readings, chlorophyll content and leaf N content per leaf area for seven species grown in multiple environments. There were similar relationships between SPAD readings and chlorophyll content per leaf area for the species groups, but the relationship between chlorophyll content and leaf N content per leaf area, and the relationship between SPAD readings and leaf N content per leaf area varied widely among the species groups. A significant impact of light-dependent chloroplast movement on SPAD readings was observed under low leaf N supplementation in both rice and soybean but not under high N supplementation. Furthermore, the allocation of leaf N to chlorophyll was strongly influenced by short-term changes in growth light. We demonstrate that the relationship between SPAD readings and leaf N content per leaf area is profoundly affected by environmental factors and leaf features of crop species, which should be accounted for when using a chlorophyll meter to guide N management in agricultural systems.
Leaf hydraulic conductance (Kleaf) is a major determinant of photosynthetic rate in plants. Previ... more Leaf hydraulic conductance (Kleaf) is a major determinant of photosynthetic rate in plants. Previous work has assessed the relationships between leaf morpho-anatomical traits and Kleaf with woody species, but there has been very little focus on cereal crops. The genus Oryza, which includes rice (Oryza sativa) and wild species (such as O. rufipogon cv. Griff), is ideal material for identifying leaf features associated with Kleaf and gas exchange. Leaf morpho-anatomical traits, Kleaf, leaf N content per leaf area, and CO2 diffusion efficiency were investigated in 11 Oryza cultivars. Kleaf was positively correlated with leaf thickness and related traits, and therefore positively correlated with leaf mass per area and leaf N content per leaf area, and negatively with inter-veinal distance. Kleaf was also positively correlated with leaf area and its related traits, and therefore negatively correlated with the proportion of minor vein length per area. In addition, coordination between Kleaf and CO2 diffusion conductance in leaves was observed. We conclude that leaf morpho-anatomical traits and N content per leaf area strongly influence Kleaf. Our results suggest that more detailed anatomical and structural studies are needed to elucidate the impacts of leaf feature traits on Kleaf and gas exchange in grasses.
To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.... more To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.) cultivars and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates (NSC) inHTtolerance is related to E, a pot experiment supplied with twoNlevels (low N, 0.077 g urea kg–1 soil; sufficient N, 0.538 g urea kg–1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could be partly offset by a sufficientNsupply. The most HT-tolerant cultivar, N22, had the highest E and stem NSCconcentrations under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations. A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments were related to E, and possibly to NSC concentration.
To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.... more To determine whether variations in high-temperature (HT) tolerance in three rice (Oryza sativa L.) cultivars and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates (NSC) in HT tolerance is related to E, a pot experiment supplied with two N levels (low N, 0.077 g urea kg -1 soil; sufficient N, 0.538 g urea kg -1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could be partly offset by a sufficient N supply. The most HT-tolerant cultivar, N22, had the highest E and stem NSC concentrations under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations. A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments were related to E, and possibly to NSC concentration.
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Papers by 栋梁 熊
conductance (gm), which can vary with leaf anatomical
traits and nitrogen (N) supplements. Several studies have
investigated the response of gm to N supplements; however,
none examined the implications of N supplements on the
response of gm to rapid environmental changes. Here we
investigated the effect of N supplement on gm and the
response of gm to change of CO2, temperature and irradiance
in rice. High N supplement (HN) increased mesophyll cell
wall surface area and chloroplast surface area exposed to
intercellular airspace per leaf area, and reduced cell wall
thickness. These changes resulted in increased gm. The gm of
leaves with HN was more sensitive to changes in CO2 concentration,
temperature and irradiance.The difference in leaf
structural features between low N supplement and HN indicates
that a rapid change in gm is related to the regulation of
diffusion through biological membranes rather than leaf
structural features. These results will contribute to an understanding of the determinants of gm response to rapid changes in environmental factors
is usually represented by point measurements, but A varies within each leaf, especially within large leaves. However, little
is known about the effect of heterogeneity of A within leaves on rice performance. Here we investigated the changes in
gas-exchange parameters and leaf structural and chemical features along leaf blades in two rice cultivars. Stomatal and
mesophyll conductance as well as leaf nitrogen (N), Rubisco and chlorophyll contents increased from base to apex;
consequently, A increased along leaves in both cultivars. The variation in A, leaf N content and Rubisco content within
leaves was similar to the variations among cultivars, and the extent of A heterogeneity within leaves varied between
cultivars, leading to different efficiencies of biomass accumulation. Furthermore, variation of A within leaves was closely
associated with leaf structural and chemical features. Our findings emphasise that functional changes along leaf blades are associated with structural and chemical trait variation and that variation of A within leaves should be considered to
achieve progress in future breeding programs.
in agricultural systems, but the effects of environmental factors and leaf characteristics on leaf N
estimations are still unclear. In the present study, we estimated the relationships among SPAD
readings, chlorophyll content and leaf N content per leaf area for seven species grown in multiple
environments. There were similar relationships between SPAD readings and chlorophyll content per
leaf area for the species groups, but the relationship between chlorophyll content and leaf N content
per leaf area, and the relationship between SPAD readings and leaf N content per leaf area varied
widely among the species groups. A significant impact of light-dependent chloroplast movement on
SPAD readings was observed under low leaf N supplementation in both rice and soybean but not
under high N supplementation. Furthermore, the allocation of leaf N to chlorophyll was strongly
influenced by short-term changes in growth light. We demonstrate that the relationship between
SPAD readings and leaf N content per leaf area is profoundly affected by environmental factors and
leaf features of crop species, which should be accounted for when using a chlorophyll meter to guide
N management in agricultural systems.
the relationships between leaf morpho-anatomical traits and Kleaf with woody species, but there has been very little
focus on cereal crops. The genus Oryza, which includes rice (Oryza sativa) and wild species (such as O. rufipogon cv.
Griff), is ideal material for identifying leaf features associated with Kleaf and gas exchange. Leaf morpho-anatomical
traits, Kleaf, leaf N content per leaf area, and CO2 diffusion efficiency were investigated in 11 Oryza cultivars. Kleaf was
positively correlated with leaf thickness and related traits, and therefore positively correlated with leaf mass per area
and leaf N content per leaf area, and negatively with inter-veinal distance. Kleaf was also positively correlated with
leaf area and its related traits, and therefore negatively correlated with the proportion of minor vein length per area.
In addition, coordination between Kleaf and CO2 diffusion conductance in leaves was observed. We conclude that leaf
morpho-anatomical traits and N content per leaf area strongly influence Kleaf. Our results suggest that more detailed
anatomical and structural studies are needed to elucidate the impacts of leaf feature traits on Kleaf and gas exchange
in grasses.
and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates
(NSC) inHTtolerance is related to E, a pot experiment supplied with twoNlevels (low N, 0.077 g urea kg–1 soil; sufficient N,
0.538 g urea kg–1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B
and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could
be partly offset by a sufficientNsupply. The most HT-tolerant cultivar, N22, had the highest E and stem NSCconcentrations
under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations.
A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting
percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC
concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments
were related to E, and possibly to NSC concentration.
conductance (gm), which can vary with leaf anatomical
traits and nitrogen (N) supplements. Several studies have
investigated the response of gm to N supplements; however,
none examined the implications of N supplements on the
response of gm to rapid environmental changes. Here we
investigated the effect of N supplement on gm and the
response of gm to change of CO2, temperature and irradiance
in rice. High N supplement (HN) increased mesophyll cell
wall surface area and chloroplast surface area exposed to
intercellular airspace per leaf area, and reduced cell wall
thickness. These changes resulted in increased gm. The gm of
leaves with HN was more sensitive to changes in CO2 concentration,
temperature and irradiance.The difference in leaf
structural features between low N supplement and HN indicates
that a rapid change in gm is related to the regulation of
diffusion through biological membranes rather than leaf
structural features. These results will contribute to an understanding of the determinants of gm response to rapid changes in environmental factors
is usually represented by point measurements, but A varies within each leaf, especially within large leaves. However, little
is known about the effect of heterogeneity of A within leaves on rice performance. Here we investigated the changes in
gas-exchange parameters and leaf structural and chemical features along leaf blades in two rice cultivars. Stomatal and
mesophyll conductance as well as leaf nitrogen (N), Rubisco and chlorophyll contents increased from base to apex;
consequently, A increased along leaves in both cultivars. The variation in A, leaf N content and Rubisco content within
leaves was similar to the variations among cultivars, and the extent of A heterogeneity within leaves varied between
cultivars, leading to different efficiencies of biomass accumulation. Furthermore, variation of A within leaves was closely
associated with leaf structural and chemical features. Our findings emphasise that functional changes along leaf blades are associated with structural and chemical trait variation and that variation of A within leaves should be considered to
achieve progress in future breeding programs.
in agricultural systems, but the effects of environmental factors and leaf characteristics on leaf N
estimations are still unclear. In the present study, we estimated the relationships among SPAD
readings, chlorophyll content and leaf N content per leaf area for seven species grown in multiple
environments. There were similar relationships between SPAD readings and chlorophyll content per
leaf area for the species groups, but the relationship between chlorophyll content and leaf N content
per leaf area, and the relationship between SPAD readings and leaf N content per leaf area varied
widely among the species groups. A significant impact of light-dependent chloroplast movement on
SPAD readings was observed under low leaf N supplementation in both rice and soybean but not
under high N supplementation. Furthermore, the allocation of leaf N to chlorophyll was strongly
influenced by short-term changes in growth light. We demonstrate that the relationship between
SPAD readings and leaf N content per leaf area is profoundly affected by environmental factors and
leaf features of crop species, which should be accounted for when using a chlorophyll meter to guide
N management in agricultural systems.
the relationships between leaf morpho-anatomical traits and Kleaf with woody species, but there has been very little
focus on cereal crops. The genus Oryza, which includes rice (Oryza sativa) and wild species (such as O. rufipogon cv.
Griff), is ideal material for identifying leaf features associated with Kleaf and gas exchange. Leaf morpho-anatomical
traits, Kleaf, leaf N content per leaf area, and CO2 diffusion efficiency were investigated in 11 Oryza cultivars. Kleaf was
positively correlated with leaf thickness and related traits, and therefore positively correlated with leaf mass per area
and leaf N content per leaf area, and negatively with inter-veinal distance. Kleaf was also positively correlated with
leaf area and its related traits, and therefore negatively correlated with the proportion of minor vein length per area.
In addition, coordination between Kleaf and CO2 diffusion conductance in leaves was observed. We conclude that leaf
morpho-anatomical traits and N content per leaf area strongly influence Kleaf. Our results suggest that more detailed
anatomical and structural studies are needed to elucidate the impacts of leaf feature traits on Kleaf and gas exchange
in grasses.
and two N treatments are related to leaf transpiration rate (E), and whether the involvement of nonstructural carbohydrates
(NSC) inHTtolerance is related to E, a pot experiment supplied with twoNlevels (low N, 0.077 g urea kg–1 soil; sufficient N,
0.538 g urea kg–1 soil) was conducted under ambient temperature (AT) and HT with three cultivars, N22, Zhenshan 97B
and Koshihikari. HT significantly decreased grain yield and seed setting percentage in Koshihikari and ZS97, which could
be partly offset by a sufficientNsupply. The most HT-tolerant cultivar, N22, had the highest E and stem NSCconcentrations
under both N treatments, whereas the most sensitive cultivar, Koshihikari, had the lowest E and stem NSC concentrations.
A sufficient N supply significantly increased E in the three cultivars under the HT treatment. Grain yield and seed-setting
percentage were positively related to E and plant NSC concentration under HT, and E was positively related to NSC
concentration under both AT and HT. Therefore, variations in HT tolerance among rice cultivars and nitrogen treatments
were related to E, and possibly to NSC concentration.