Variation in Carbon Isotope Discrimination and Its Relationship to Specific Leaf Area and Ribulose-1,5-Bisphosphate Carboxylase Content in Groundnut Genotypes

Variation in cahn isotope discrimination (Δ) and ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) content per unit leaf area was examined in leaves from upper and lower positions in the canopy of six groundnut (Arachis hypogaea L.) genotypes, grown under irrigated and mild water-deficit conditions in the field. The leaf mass per unit leaf area (ρL) and soluble proteins in leaves were determined at 80, 96, 111 and 127 days after sowing (DAS), while Δ and Rubisco were determined at 80 DAS only. The mean Δ ranged from 18.2 to 20.20 among genotypes, representing a significant (P < 0.01) variation. Rubisco content per unit leaf area also varied significantly (P < 0.01) with genotype and leaf position. There was a trend to an increase in Rubisco content under water deficit, but the effects were not significant. Leaves at the top of the canopy had a higher Rubisco content and lower Δ, than leaves at the bottom of the canopy. Genotype × leaf position interaction was significant for Δ and Rubisco, indicating the importance of leaf position in selecting for water-use efficiency (W), using leaf traits in groundnut. Rubisco content and Δ were negatively related (r2 = 0.65, P < 0.01). There was a significantly positive correlation between Rubisco content and ρL in the upper leaves (r2 = 0.60, P < 0.01 ), but not in the lower leaves in the canopy. However, the overall relationship between Rubisco and ρL (r2 = 0.40) was not as strong as it was between Rubisco and Δ. The results suggest that, in groundnut, the basis of genotypic variation in was mostly (> 60%) attributable to Rubisco content per unit leaf area. In view of the leaf positional effects on Δ and Rubisco, the upper leaves in the canopy should be used for selecting genotypes for W based on leaf traits like ρL or Δ.

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Photosynthetic Responses of Pisum sativum to an Increase in Irradiance During Growth. I. Photosynthetic Activities

Functional Plant Biology ◽

10.1071/pp9870001 ◽

1987 ◽

Vol 14 (1) ◽

pp. 1 ◽

Cited By ~ 32

Author(s):

WS Chow ◽

JM Anderson

Keyword(s):

Electron Transport ◽

Leaf Area ◽

Time Course ◽

High Light ◽

Lag Phase ◽

Total Chlorophyll ◽

Bisphosphate Carboxylase ◽

Unit Leaf Area ◽

Unit Leaf ◽

Photosynthetic Activities

The extent and time course of changes in photosynthetic activities of leaves and isolated chloroplasts was followed in pea plants which were adapted to low light (60 �mol photons m-2 s-1, 400-700 nm, 16 h light/ 8 h dark cycles), and subsequently transferred to higher light (390 �mol photons m-2 s-1). The photosynthetic rates of leaves in CO2-saturating conditions, measured at light saturation or subsaturation, increased with no noticeable lag, doubling within 1 week after transfer to high light. In contrast, the increase of in vitro ribulose-1,5-bisphosphate carboxylase activity (~ 130%) and photosystem II electron transport capacity (~ 60%) occurred with an apparent lag of - 1 day after transfer to high light. The capacity for uncoupled whole-chain electron transport also increased slowly (~ 70%). Whilst the total chlorophyll (Chl) per unit leaf area remained steady, the Chl a/Chl b ratio increased with no apparent lag phase from 2.7 in low irradiance to 3.2 in high irradiance within 1 week. The results demonstrate that, following an increase of growth irradiance, pea leaves readily increase the capacity for utilising high light effectively, even when the total chlorophyll per unit leaf area remained constant. However, a better understanding of the time course of response requires measurements of other chloroplast parameters.

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Correlations Between Carbon Isotope Discrimination and Climate of Native Habitats for Diverse Eucalypt Taxa Growing in a Common Garden

Functional Plant Biology ◽

10.1071/pp9960311 ◽

1996 ◽

Vol 23 (3) ◽

pp. 311 ◽

Cited By ~ 50

Author(s):

JE Anderson ◽

J Williams ◽

PE Kriedemann ◽

MP Austin ◽

GD Farquhar

Keyword(s):

Soil Moisture ◽

Leaf Area ◽

Carbon Isotope ◽

Carbon Isotope Discrimination ◽

Common Garden ◽

Potential Evaporation ◽

Unit Leaf Area ◽

Isotope Discrimination ◽

Unit Leaf ◽

Native Habitats

Distributions of common species of Eucalyptus in south-eastem Australia are related to gradients in temperature and rainfall. To determine whether intrinsic water-use efficiency (as indexed by carbon isotope discrimination, Δ) or other leaf attributes were related to climate of native habitats, we sampled 17 populations representing 14 species of Eucalyptus growing in a common garden in south- central New South Wales. Phreatophytes were clearly distinguished from populations that are totally dependent upon soil moisture derived from rainfall by having higher Δ at a particular level of rainfall. Among 12 non-phreatophytic populations (11 species), Δ was positively correlated with mean annual precipitation (r = 0.75, P = 0.005), December-March precipitation (r = 0.79, P = 0.002), an index of annual soil moisture (r = 0.81, P = 0.001) and seasonality of precipitation (r = 0.85, P < 0.001). There were similarly strong but negative correlations between Δ and potential evaporation during the summer months, but Δ was not correlated with annual potential evaporation of the source sites. Leaf mass per unit area (ρe) was negatively correlated with indices of water availability, positively correlated with nitrogen per unit leaf area (r = 0.90, P < 0.001), and negatively correlated with Δ (r = -0.73, P = 0.007). A was negatively correlated with area-based leaf nitrogen (r = -0.79, P = 0.002). These complementary correlations among Δ, ρe, and nitrogen per unit leaf area indicate that variation in Δ may stem largely from variation in photosynthetic capacity. The results provide strong evidence that variation in Δ and ρe reflect genetic adaptations to native habitats.

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Growth and Fruiting of Short-internode Main Dwarf, Normal-internode Parent, and Hybrid

HortScience ◽

10.21273/hortsci.25.10.1277 ◽

1990 ◽

Vol 25 (10) ◽

pp. 1277-1279 ◽

Cited By ~ 1

Author(s):

Dean E. Knavel ◽

Robert L. Houtz

Keyword(s):

Leaf Area ◽

Dry Weight ◽

Rubisco Activity ◽

Bisphosphate Carboxylase ◽

Unit Leaf Area ◽

Short Internode ◽

Unit Leaf ◽

Leaf Chlorophyll ◽

Ribulose 1 ◽

Total Dry Weight

Plants of Main Dwarf, a short-internode mutant of the normal-internode `Mainstream' muskmelon (Cucumis melo L.), have shorter internodes, fewer nodes, less total vine length, less total dry weight, smaller leaves, increased chlorophyll concentrations, increased specific leaf dry weight, and increased ribulose-1, 5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39, rubisco) activity per unit leaf area than `Mainstream' plants. Main Dwarf plants produce an equal number of fruit as `Mainstream' plants but are only half their size. Many of the plant and fruit characteristics for F1(Main Dwarf × `Mainstream') are similar to those of `Mainstream', except for greater leaf chlorophyll and rubisco activity per unit leaf area. The F1 (`Mainstream' × Main Dwarf) produced fewer and lower weight fruit than its reciprocal, F1 (Main Dwarf × `Mainstream').

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Rates of Photosynthesis Relative to Activity of Photosynthetic Enzymes, Chlorophyll and Soluble Protein Content Among Ten C4 Species

Functional Plant Biology ◽

10.1071/pp9840509 ◽

1984 ◽

Vol 11 (6) ◽

pp. 509 ◽

Cited By ~ 24

Author(s):

H Usuda ◽

MSB Ku ◽

GE Edwards

Keyword(s):

Leaf Area ◽

Soluble Protein ◽

High Light ◽

Soluble Protein Content ◽

Bisphosphate Carboxylase ◽

Unit Leaf ◽

C4 Species ◽

Photosynthetic Enzymes ◽

Rate Of Photosynthesis ◽

High Degree

Among 10 C4 species having a wide range in photosynthetic activity, the rates of photosynthesis/leaf area under high light were examined and compared with the chlorophyll and soluble protein content and the activities of several photosynthetic enzymes. The species examined were Digitaria sanguinalis, Echinochloa crus-galli, Microstegium vimineum, Panicum capillare, Panicum miliaceum, Paspalum dilatatum, Paspalum notatum, Pennisetum purpureum, Setaria lutescens, and Zea mays. The photosynthetic rates per unit leaf area ranged from 10 to 38 �mol CO2 fixed m-2 s-1. Among the 10 species there was a high degree of correlation of rate of photosynthesis/leaf area with soluble protein (r = 0.88), ribulose 1,5-bisphosphate carboxylase (r = 0.88) and pyruvate,PI dikinase (r = 0.94), but a lower correlation of photosynthetic rate/leaf area with phosphoenolpyruvate carboxylase (r = 0.74) and no significant correlation of photosynthetic rate/leaf area with chlorophyll content (r = 0.56). Among eight species of the NADP-malic enzyme C4 subgroup, there was a good correlation of photosynthetic ratelleaf area with NADP-malate dehydrogenase (r = 0.88) and NADP- malic enzyme (r = 0.92). Extractable activities of both the ribulose 1,5-bisphosphate carboxylase and the dikinase were generally close to the rate of photosynthesis. When comparing the activity per unit leaf area of one enzyme with another, generally a high degree of correlation was found among the species. The results suggest that a given C4 species tends to maintain a balance in the activities of several photosynthetic enzymes and that there is potential to estimate capacity for C4 photosynthesis under high light through determining activity of certain photosynthetic enzymes.

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Stomatal Development During Leaf Expansion in Tobacco and Sunflower

Australian Journal of Botany ◽

10.1071/bt9750253 ◽

1975 ◽

Vol 23 (2) ◽

pp. 253 ◽

Cited By ~ 19

Author(s):

HM Rawson ◽

CL Craven

Keyword(s):

Leaf Area ◽

Stomatal Density ◽

Stomatal Development ◽

Developmental Patterns ◽

Full Size ◽

Unit Leaf Area ◽

Unit Leaf ◽

Wide Range ◽

Young Leaves ◽

Different Levels

Changes in stomatal density and size were followed in tobacco and sunflower leaves expanding from 10% of final area (10% Amax) to Amax under different levels of radiation. Lower radiation increased final leaf area, reduced stomatal densities, and increased area per stoma but had little effect on stomatal area per unit leaf area at Amax. In very young leaves (20% Amax) there was a wide range in the sizes of individual stomata, some stomata being close to full size, but by Amax differences were small. The possible relationship between the developmental patterns described and photosynthesis is briefly discussed.

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Effect of Interspecific Interference, Light Intensity, and Soil Moisture on Soybean (Glycine max), Common Cocklebur (Xanthium strumarium), and Sicklepod (Cassia obtusifolia) Water Uptake

Weed Science ◽

10.1017/s004317450007627x ◽

1993 ◽

Vol 41 (4) ◽

pp. 534-540 ◽

Cited By ~ 10

Author(s):

Ronald E. Jones ◽

Robert H. Walker

Keyword(s):

Soil Moisture ◽

Light Intensity ◽

Leaf Area ◽

Water Uptake ◽

Root Weight ◽

Pressure Potential ◽

Unit Leaf Area ◽

Unit Leaf ◽

Shoot Weight ◽

The Relationship

Greenhouse and growth chamber experiments with potted plants were conducted to determine the effects of interspecific root and canopy interference, light intensity, and soil moisture on water uptake and biomass of soybean, common cocklebur, and sicklepod. Canopy interference and canopy plus root interference of soybean with common cocklebur increased soybean water uptake per plant and per unit leaf area. Root interference with soybean decreased common cocklebur water uptake per plant. Canopy interference of soybean with sicklepod increased soybean water uptake per unit leaf area, while root interference decreased uptake per plant. Combined root and canopy interference with soybean decreased water uptake per plant for sicklepod. Soybean leaf area and shoot weight were reduced by root interference with both weeds. Common cocklebur and sicklepod leaf area and shoot weight were reduced by root and canopy interference with soybeans. Only common cocklebur root weight decreased when canopies interfered and roots did not. The relationship between light intensity and water uptake per unit leaf area was linear in both years with water uptake proportional to light intensity. In 1991 water uptake response to tight was greater for common cocklebur than for sicklepod. The relationship between soil moisture level and water uptake was logarithmic. Common cocklebur water uptake was two times that of soybean or sicklepod at −2 kPa of pressure potential. In 1991 common cocklebur water uptake decreased at a greater rate than soybean or sicklepod in response to pressure potential changes from −2 to −100 kPa.

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Carbon Isotope Discrimination and Gas Exchange in Coffea arabica During Adjustment to Different Soil Moisture Regimes

Functional Plant Biology ◽

10.1071/pp9920171 ◽

1992 ◽

Vol 19 (2) ◽

pp. 171 ◽

Cited By ~ 32

Author(s):

FC Meinzer ◽

NZ Saliendra ◽

C Crisosto

Keyword(s):

Soil Moisture ◽

Gas Exchange ◽

Leaf Area ◽

Coffea Arabica ◽

Carbon Isotope Discrimination ◽

Total Leaf Area ◽

Unit Leaf Area ◽

Unit Leaf ◽

Moisture Regimes ◽

Area Basis

Although carbon isotope discrimination (Δ) has been reported to decline in plants growing under reduced soil moisture, there is little information available concerning the dynamics of adjustments in Δ and gas exchange following a change in soil water availability. In this study Δ, photosynthetic gas exchange, and growth were monitored in container-grown coffee (Coffea arabica L.) plants for 120 days under three soil moisture regimes. At the end of 120 d, total leaf area of plants irrigated twice weekly was one half that of plants irrigated twice daily, although their assimilation rates on a unit leaf area basis were nearly equal throughout the experiment. This suggested that maintenance of nearly constant photosynthetic characteristics on a unit leaf area basis through maintenance of a smaller total leaf area may constitute a major mode of adjustment to reduced soil moisture availability in coffee. Intrinsic water-use efficiency (WUE) predicted from foliar Δ values was highest in plants irrigated weekly, intermediate in plants irrigated twice weekly and lowest in plants irrigated twice daily. When instantaneous WUE was estimated from independent measurements of total transpiration per plant and assimilation on a unit leaf area basis, the reverse ranking was obtained. The lack of correspondence between intrinsic and instantaneous WUE was attributed to adjustments in canopy morphology and leaf size in the plants grown under reduced water supply which enhanced transpiration relative to assimilation. Values of Δ predicted from the ratio of intercellular to ambient CO2 partial pressure determined during gas exchange measurements were not always consistent with measured foliar Δ. This may have resulted from a patchy distribution of stomatal apertures in plants irrigated weekly and from a lag period between adjustment in gas exchange and subsequent alteration in Δ of expanding leaves. The importance of considering temporal and spatial scales, and previous growth and environmental histories in comparing current single leaf gas exchange behaviour with foliar Δ values is discussed.

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Photosynthetic Acclimation of Alocasia macrorrhiza (L.) G. Don

Functional Plant Biology ◽

10.1071/pp9880107 ◽

1988 ◽

Vol 15 (2) ◽

pp. 107 ◽

Cited By ~ 40

Author(s):

WS Chow ◽

L Qian ◽

DJ Goodchild ◽

JM Anderson

Keyword(s):

Charge Density ◽

Leaf Area ◽

Cell Walls ◽

Surface Charge Density ◽

Leaf Tissue ◽

O2 Evolution ◽

Palisade Cell ◽

Unit Leaf Area ◽

Unit Leaf ◽

Growth Irradiance

The photosynthetic acclimation of Alocasia macrorrhiza (L.) G. Don, a species naturally occurring in deep shade in rainforests, has been studied in relation to a wide range of controlled irradiances during growth (~3-780 �mol photons m-2 s-1 of fluorescent or incandescent light, 10 h light/ 14 h dark). At the maximum growth irradiances, the light- and CO2-saturated rates of O2 evolution per unit leaf area were ~4 times as high as at low irradiance, and approached those of glasshouse-grown spinach. Growth at maximum irradiances reduced the quantum yield of O2 evolution only slightly. Changes in the anatomy of leaf tissue, the ultrastructure of chloroplasts and the composition of chloroplast components accompanied the changes in photosynthetic functional characteristics. At low growth irradiance, palisade cell chloroplasts were preferentially located adjacent to the distal periclinal cell walls and had large granal stacks, and the destacked thylakoids had a very low surface charge density. In contrast, at higher growth irradiance, palisade cell chloroplasts were preferentially located adjacent to the anticlinal cell walls; they had small granal stacks, large stromal space, and a high surface charge density on the destacked thylakoids. The number of chloroplasts per unit section length increased with growth irradiance. Ribulosebisphosphate carboxylase activity per unit leaf area increased markedly with irradiance. Photosystem II, cytochrome f and latent ATPase activity per unit chlorophyll increased to a lesser extent. While the chlorophyll a/chlorophyll b ratio increased substantially with growth irradiance, the chlorophyll content per unit leaf area declined slightly. Our results show that coordinated changes in the structure of leaf tissue, and the organisation and composition of chloroplast components are responsible for Alocasia being capable of acclimation to high as well as low irradiance.

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