Physiological N response of field-grown maize hybrids (Zea mays L.) with divergent yield potential and grain protein concentration.
TL;DR: A positive relationship between photosynthetic capacity and yield was revealed by hybrid response to N supply, and the relationship was similar for hybrids with a marked difference in yield potential.
Abstract: Fertilizer N availability impacts photosynthesis and crop performance, although cause–effect relationships are not well established, especially for field-grown plants. Our objective was to determine the relationship between N supply and photosynthetic capacity estimated by leaf area index (LAI) and single leaf photosynthesis using genetically diverse field-grown maize (Zea mays L.) hybrids. We compared a high yield potential commercial hybrid (FR1064 x LH185) and an experimental hybrid (FR1064 x IHP) with low yield potential but exceptionally high grain protein concentration. Plant biomass and physiological traits were measured at tassel emergence (VT) and at the grain milk stage (R3) to assess the effects of N supply on photosynthetic source capacity and N uptake, and grain yield and grain N were measured at maturity. Grain yield of FR1064 x LH185 was much greater than FR1064 x IHP even though plant biomass and LAI were larger for FR1064 x IHP, and single leaf photosynthesis was similar for both hybrids. Although photosynthetic capacity was not related to hybrid differences in productivity, increasing N supply led to proportional increases in grain yield, plant biomass, LAI, photosynthesis, and Rubisco and PEP carboxylase activities for both hybrids. Thus, a positive relationship between photosynthetic capacity and yield was revealed by hybrid response to N supply, and the relationship was similar for hybrids with a marked difference in yield potential. For both hybrids the N response of single leaf CER and initial Rubisco activity was negative when expressed per unit of leaf N. In contrast, PEP carboxylase activity per unit leaf N increased in response to N availability, indicating that PEP carboxylase served as a reservoir for excess N accumulation in field-grown maize leaves. The correlation between CER and initial Rubisco activity was highly significant when expressed on a leaf area or a total leaf basis. The results suggest that regardless of genotypic yield potential, maize CER, and potentially grain yield, could be improved by increasing the partitioning of N into Rubisco.
Citations
More filters
TL;DR: In this paper, the impact of integrated soil fertility management (ISFM) on the agronomic efficiency (AE) of applied nutrient inputs in maize-based systems in sub-Saharan Africa was evaluated through meta-analysis.
Abstract: Traditionally, crop production in sub-Saharan Africa (SSA) depends primarily on mining soil nutrients. Integrated Soil Fertility Management (ISFM) is an approach for intensifying agriculture in SSA that aims at maximizing the agronomic efficiency (AE) of applied nutrient inputs. ISFM contains the following essential components: proper fertilizer management, use of improved varieties, the combined application of organic inputs and fertilizer, and adaptation of input application rates to within-farm soil fertility gradients where these are important. This paper evaluates, through meta-analysis, the impact of these components on the AE of fertilizer N (N-AE), defined as extra grain yield per kg fertilizer N applied, in maize-based systems in SSA. Since N-AE is low for excessive fertilizer N application rates or when fertilizer is applied on fertile, unresponsive soil, as was confirmed by scatter plots against control yields and fertilizer N application rates, such values were removed from the database in order to focus on and elucidate the more variable and complex responses under less than ideal conditions typical for SSA. Compared with local varieties, the use of hybrid maize varieties significantly increased N-AE values (17 and 26 kg (kg N)−1, respectively) with no differences observed between local and improved, open-pollinated varieties. Mixing fertilizer with manure or compost resulted in the highest N-AE values [36 kg (kg N)−1] while organic inputs of medium quality also showed significantly higher N-AE values compared with the sole fertilizer treatment but only at low organic input application rates (40 and 23 kg (kg N)−1, respectively). High quality organic inputs (Class I) and those with a high C-to-N ratio (Class III) or high lignin content (Class IV) did not affect N-AE values in comparison with the sole fertilizer treatment. Application of N fertilizer on infields resulted in significantly higher N-AE values [31 kg (kg N)−1] compared with the outfields [17 kg (kg N)−1]. The obtained information indicates that N-AE is amenable to improved management practices and that the various components embedded in the ISFM definition result in improvements in N-AE.
372 citations
Cites background from "Physiological N response of field-g..."
...…maize in a 15-year study in the USA while rain-fed maize had N-AE values of 18 and 11 kg (kg N)−1 for fertilizer application rates of 56 and 112 kg N ha−1, respectively (Uribelarrea et al. 2009). xIn India, N-AE of 19.5 kg (kg N)−1 was observed for sole N applied in Prasat India (Roberts 2008)....
[...]
...Johnson and Raun (2003) observed N-AE of 27 kg (kg N) (fertilizer application rate of 90 kg N ha) with irrigated maize in a 15-year study in the USA while rain-fed maize had N-AE values of 18 and 11 kg (kg N) for fertilizer application rates of 56 and 112 kg N ha, respectively (Uribelarrea et al. 2009)....
[...]
TL;DR: Both plant density and N rate affected growth parameters and grain yield in this study, but hybrid effects were negligible and plant density-driven increases in N uptake by shoot and/or ear components were not enough, by themselves, to increase NUE.
286 citations
Cites background from "Physiological N response of field-g..."
...Substantial genetic ariability for adaptation to low and high soil N supply was also Research 121 (2011) 2–18 3 observed in other research (Paponov and Engels, 2003; Paponov et al., 2005; Uribelarrea et al., 2007, 2009)....
[...]
...Genetic selection has resulted in wide-ranging genotypic variaion for NUE (Balko and Russell, 1980; Paponov and Engels, 2003; aponov et al., 2005; Uribelarrea et al., 2007, 2009)....
[...]
TL;DR: A generalized nitrogen budget for a C3 leaf cell is provided and the potential for improving photosynthesis from a nitrogen perspective is discussed.
Abstract: Global food security depends on three main cereal crops (wheat, rice and maize) achieving and maintaining high yields, as well as increasing their future yields. Fundamental to the production of this biomass is photosynthesis. The process of photosynthesis involves a large number of proteins that together account for the majority of the nitrogen in leaves. As large amounts of nitrogen are removed in the harvested grain, this needs to be replaced either from synthetic fertilizer or biological nitrogen fixation. Knowledge about photosynthetic properties of leaves in natural ecosystems is also important, particularly when we consider the potential impacts of climate change. While the relationship between nitrogen and photosynthetic capacity of a leaf differs between species, leaf nitrogen content provides a useful way to incorporate photosynthesis into models of ecosystems and the terrestrial biosphere. This review provides a generalized nitrogen budget for a C3 leaf cell and discusses the potential for improving photosynthesis from a nitrogen perspective.
182 citations
TL;DR: It was concluded that maize root growth, especially initiation and development of the shoot-borne roots, as well as the amount of N taken up were coordinated with shoot growth and demand for nutrients.
154 citations
Cites background from "Physiological N response of field-g..."
...006 activities involved inNmetabolismwithin leaves, stover and cob at different periods of plant development (Seebauer et al., 2004; Hirel et al., 2005a, 2005b; Uribelarrea et al., 2009)....
[...]
TL;DR: The physiological response of photosynthesis to N deficiency in leaf structure and N allocation within the leaf is summarized and a generalized N allocation in response to N stress is provided and gives a new prospect for breeding N-efficient genotypes.
132 citations
References
More filters
01 Jan 1966
1,821 citations
"Physiological N response of field-g..." refers background or methods in this paper
...The fertilizer was hand applied in a diffuse band down the center of the row as ammonium sulfate and incorporated when the crop was between the V2 and V3 growth stages (Ritchie et al. 1997)....
[...]
...By R6, maize plants are considered to have attained their maximum biomass (Ritchie et al. 1997)....
[...]
TL;DR: Changes in specific leaf area (SLA, projected leaf area per unit leaf dry mass) and nitrogen partitioning between proteins within leaves occur during the acclimation of plants to their growth irradiance, and the relative importance of both of these changes in maximizing carbon gain is quantified.
Abstract: Changes in specific leaf area (SLA, projected leaf area per unit leaf dry mass) and nitrogen partitioning between proteins within leaves occur during the acclimation of plants to their growth irradiance. In this paper, the relative importance of both of these changes in maximizing carbon gain is quantified. Photosynthesis, SLA and nitrogen partitioning within leaves was determined from 10 dicotyledonous C 3 species grown in photon irradiances of 200 and 1000 μ mol m - 2 s - 1 . Photosynthetic rate per unit leaf area measured under the growth irradiance was, on average, three times higher for high-light-grown plants than for those grown under low light, and two times higher when measured near light saturation. However, light-saturated photosynthetic rate per unit leaf dry mass was unaltered by growth irradiance because low-light plants had double the SLA. Nitrogen concentrations per unit leaf mass were constant between the two light treatments, but plants grown in low light partitioned a larger fraction of leaf nitrogen into light harvesting. Leaf absorptance was curvilinearly related to chlorophyll content and independent of SLA. Daily photosynthesis per unit leaf dry mass under low-light conditions was much more responsive to changes in SLA than to nitrogen partitioning. Under high light, sensitivity to nitrogen partitioning increased, but changes in SLA were still more important.
1,055 citations
"Physiological N response of field-g..." refers background in this paper
...Photosynthetic N use efficiency is determined in large part by specific leaf weight (SLW) and by the allocation of leaf N to photosynthetic enzymes (Poorter and Evans 1998; Evans and Poorter 2001)....
[...]
...Photosynthetic N use efficiency is determined in large part by specific leaf weight (SLW) and by the allocation of leaf N to photosynthetic enzymes (Poorter and Evans 1998; Evans and Poorter 2001)....
[...]
TL;DR: The results indicate that, as temperature increases, the rate of Rubisco deactivation exceeds the capacity of activase to promote activation, and that this response was inconsistent with the response predicted from the properties of fully activated Rubisco.
Abstract: Net photosynthesis (Pn) is inhibited by moderate heat stress. To elucidate the mechanism of inhibition, we examined the effects of temperature on gas exchange and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activation in cotton and tobacco leaves and compared the responses to those of the isolated enzymes. Depending on the CO2 concentration, Pn decreased when temperatures exceeded 35–40°C. This response was inconsistent with the response predicted from the properties of fully activated Rubisco. Rubisco deactivated in leaves when temperature was increased and also in response to high CO2 or low O2. The decrease in Rubisco activation occurred when leaf temperatures exceeded 35°C, whereas the activities of isolated activase and Rubisco were highest at 42°C and >50°C, respectively. In the absence of activase, isolated Rubisco deactivated under catalytic conditions and the rate of deactivation increased with temperature but not with CO2. The ability of activase to maintain or promote Rubisco activation in vitro also decreased with temperature but was not affected by CO2. Increasing the activase/Rubisco ratio reduced Rubisco deactivation at higher temperatures. The results indicate that, as temperature increases, the rate of Rubisco deactivation exceeds the capacity of activase to promote activation. The decrease in Rubisco activation that occurred in leaves at high CO2 was not caused by a faster rate of deactivation, but by reduced activase activity possibly in response to unfavorable ATP/ADP ratios. When adjustments were made for changes in activation state, the kinetic properties of Rubisco predicted the response of Pn at high temperature and CO2.
652 citations
"Physiological N response of field-g..." refers methods in this paper
...Leaf tissue was also assayed for initial Rubisco activity as described in detail by Crafts-Brandner and Salvucci (2000)....
[...]
TL;DR: It is concluded that inactivation of Rubisco was the primary constraint on the rate of Pn of maize leaves as leaf temperature increased above 30°C, and acclimation was associated with the expression of a new activase polypeptide.
Abstract: Our objective was to determine the sensitivity of components of the photosynthetic apparatus of maize (Zea mays), a C4 plant, to high temperature stress. Net photosynthesis (Pn) was inhibited at leaf temperatures above 38°C, and the inhibition was much more severe when the temperature was increased rapidly rather than gradually. Transpiration rate increased progressively with leaf temperature, indicating that inhibition was not associated with stomatal closure. Nonphotochemical fluorescence quenching (qN) increased at leaf temperatures above 30°C, indicating increased thylakoid energization even at temperatures that did not inhibit Pn. Compared with CO2 assimilation, the maximum quantum yield of photosystem II (Fv/Fm) was relatively insensitive to leaf temperatures up to 45°C. The activation state of phosphoenolpyruvate carboxylase decreased marginally at leaf temperatures above 40°C, and the activity of pyruvate phosphate dikinase was insensitive to temperature up to 45°C. The activation state of Rubisco decreased at temperatures exceeding 32.5°C, with nearly complete inactivation at 45°C. Levels of 3-phosphoglyceric acid and ribulose-1,5-bisphosphate decreased and increased, respectively, as leaf temperature increased, consistent with the decrease in Rubisco activation. When leaf temperature was increased gradually, Rubisco activation acclimated in a similar manner as Pn, and acclimation was associated with the expression of a new activase polypeptide. Rates of Pn calculated solely from the kinetics of Rubisco were remarkably similar to measured rates if the calculation included adjustment for temperature effects on Rubisco activation. We conclude that inactivation of Rubisco was the primary constraint on the rate of Pn of maize leaves as leaf temperature increased above 30°C.
566 citations
"Physiological N response of field-g..." refers methods in this paper
...PEP carboxylase was assayed spectrophotometrically at 30°C as described by Crafts-Brandner and Salvucci (2002)....
[...]