AOBPreview originally published online on April 18, 2005
Annals of Botany 2005 96(1):81-89; doi:10.1093/aob/mci152
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Respiration and Reproductive Effort in Xanthium canadense
Graduate School of Life Sciences, Tohoku University, Aoba, Sendai 980-8578, Japan
* For correspondence. E-mail kinugasa{at}mail.tains.tohoku.ac.jp
Received: 2 December 2004 Returned for revision: 25 January 2005 Accepted: 1 March 2005 Published electronically: 18 April 2005
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONACKNOWLEDGEMENTSLITERATURE CITED |
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• Background and Aims The proportion of resources devoted to reproduction in the plant is called the reproductive effort (RE), which is most commonly expressed as the proportion of reproductive biomass to total plant biomass production (REW). Reproductive yield is the outcome of photosynthates allocated to reproductive structures minus subsequent respiratory consumption for construction and maintenance of reproductive structures. Thus, REW can differ from RE in terms of photosynthates allocated to reproductive structures (REP).
• Methods Dry mass growth and respiration of vegetative and reproductive organs were measured in Xanthium canadense and the amount of photosynthates and its partitioning to dry mass growth and respiratory consumption were determined. Differences between REW and REP were analysed in terms of growth and maintenance respiration.
• Key Results The fraction of allocated photosynthates that was consumed by respiration was smaller in the reproductive organ than in the vegetative organs. Consequently, REP was smaller than REW. The smaller respiratory consumption in the reproductive organ resulted from its shorter period of existence and a seasonal decline in temperature, as well as a slower rate of maintenance respiration, although the fraction of photosynthates consumed by growth respiration was larger than in the vegetative organs.
• Conclusions Reproductive effort in terms of photosynthates (REP) was smaller than that in terms of biomass (REW). This difference resulted from respiratory consumption for maintenance, which was far smaller in the reproductive organ than in vegetative organs.
Key words: Allocation, construction cost, growth respiration, maintenance respiration, reproductive effort, reproductive yield, Xanthium canadense
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONACKNOWLEDGEMENTSLITERATURE CITED |
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The proportion of resources devoted to reproduction in plants is called the reproductive effort (RE), which is most commonly expressed as the proportion of reproductive biomass to total plant biomass production (REW; Harper, 1977
; Willson, 1983; Bazzaz and Reekie, 1985; Bazzaz and Ackerly, 1992; Obeso, 2002). Reproductive yield is the outcome of photosynthates allocated to reproductive organs minus subsequent respiratory consumption for the construction and maintenance of reproductive structures. Bazzaz and Reekie (1985) suggested that RE in terms of allocation of photosynthates (REP) is a better measure than REW. Although the number of studies that have evaluated these two definitions of RE is limited, substantial differences between the two have been observed. REP was always smaller than REW in Agropyron repens grown under various resource conditions (Reekie and Bazzaz, 1987). Similarly, in two Fragaria species, REP was smaller than REW, and the change in these two RE values with environmental conditions were not in parallel (Jurik, 1983).
If both vegetative and reproductive organs respired the same amount of photosynthates per unit mass during growth, REP would equal REW. Therefore, differences between them imply different respiratory consumption of allocated photosynthates between vegetative and reproductive organs. Respiration has been divided into two components: respiration associated with growth, and that with maintenance (McCree, 1970; Thornley, 1970; Hesketh et al., 1971). Rates of maintenance respiration are smaller in reproductive organs than in vegetative organs (e.g. Hesketh et al., 1971; Winkler, 1971; Kallis and Golovko, 1988), and reproductive organs exist for a shorter period than vegetative organs in the growing season, especially in annuals (e.g. Shitaka and Hirose, 1993). So it may be expected that the fraction of photosynthates consumed by maintenance respiration is smaller in reproductive organs than in vegetative organs. When the vegetative and reproductive organs are different in chemical composition, the growth respiration for synthesizing a unit mass of tissues will differ between the two organs. Penning de Vries (1975) showed that the respiratory energy requirement for construction of leaf and stem was higher than that of rice seeds (with a high carbohydrate content) and lower than that of peanut seeds (with a high lipid content) and bean seeds (with a high N content). Seeds containing a large amount of lipids and proteins require more energy for construction than seeds rich in carbohydrates (Penning de Vries et al., 1983). Thus, whether or not growth respiration in reproductive organs exceeds that in vegetative organs depends on the chemical composition of the seed.
In this paper, we determine life-time respiratory energy consumption in the vegetative and reproductive organs to evaluate reproductive efforts in terms of biomass and photosynthates in Xanthium canadense. Respiration was analysed in terms of its two functional components, growth and maintenance respiration. Specifically, we address the following questions. (1) How much photosynthate is consumed by respiration in vegetative and reproductive organs through the growing period? (2) What is the partitioning of respiratory energy for growth and maintenance and is it different between vegetative and reproductive organs? If so, what causes the difference? (3) To what extent is the reproductive effort influenced by growth and maintenance respiration?
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MATERIALS AND METHODS |
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Study species
Xanthium canadense Mill., a short-day summer annual, requires a minimum length of continuous darkness for flowering (Ray and Alexander, 1966
; McMillan, 1974). After fertilization, fruit grows rapidly and produces a capsule with two dimorphic seeds in it. As the two seeds are different in their germination potential (Esashi and Leopold, 1968; Harper, 1977), only the lower seeds that have a higher potential of germination were used for the experiment.
Experimental design
Seeds were sown on 27 June 2001 on plastic dishes at 30 °C in an incubator (M-230, Taiyo, Japan). Germination occurred within 5 d after sowing, and germinated seeds were transplanted individually into pots (1·5 L volume) filled with washed river sand. On 4 July, when seedlings emerged from soil, they were moved into two open-top chambers placed outdoors in the experimental garden of Tohoku University, Sendai, Japan (38°15'N, 140°50'E). The chambers were ventilated with ambient air, and growth conditions in the chambers were close to those outside, except on clear sunny days when the daytime temperature in the chambers was temporally increased by around 5 °C over the ambient temperature. A standard nutrient solution was used, following Epstein (1972): N 16 (
), P 2, K 6, Ca 4, S 1, and Mg 1 mmol L–1. From 1 d after the first harvest on 4 July, 50 mL of x1·5 strength of the solution was added per pot every week. Plants received tap water as needed during the experimental period. Pots were rotated periodically within the chambers to minimize differences in growth conditions between plants. Air and soil temperatures were monitored every 30 min with a copper–constantan thermocouple and logged with a data logger (Thermodac-EF, Eto-Denki, Japan). The probe for soil temperature was inserted in the centre of a pot. Daily means of air and soil temperatures are presented in Fig. 1.
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The date of flowering was recorded when the first flower was observed and the date of death when all leaves and stem had completely turned brown. Average dates of flowering and of death were 25 August and 9 December, respectively. The first harvest was done when seedlings emerged from the soil (4 July). Thereafter, plants were harvested at about 1-month intervals until flowering, and at 2-week intervals during the reproductive period. At least six plants, including three plants for the measurement of respiration, were sampled at every harvest. Harvested plants were separated into leaves, stems, roots, dead leaves, and reproductive organs (seeds and capsules). The amount of mass allocated to male flowers was not included in plant mass, because it represented only a small fraction of the total (<1 %; Shitaka and Hirose, 1993
, 1998). Leaf area was determined with a leaf area meter (Li-3100, Li-Cor, USA). Dry mass was determined after oven-drying at 70 °C for more than 4 d. After grinding samples with a Wiley mill, N content was determined with a NC analyzer (NC-80, Shimazu, Japan) and heat of combustion with a calorimeter (CA-4PJ, Shimazu, Japan). Ash content was measured after burning with a NC analyzer for 1 h. For the measurement of heat of combustion and ash content, vegetative organs on 27 July (in the vegetative growth period) and reproductive organs at the end of the growing period were used.
Respiration
On every harvest occasion, the rate of dark respiration was determined from three individuals after sunset until midnight. Plant parts were enclosed in a 1·7 L acrylic chamber and specific respiration rates (SRR, respiration rate per unit mass) were determined at 25 °C using an infrared gas analyzer (URA-107, Shimadzu, Japan). Before measurements, individuals were subjected to complete darkness for more than 1 h. The CO2 concentration in the chamber was maintained at 360 ± 15 µmol mol–1 and temperature at 25 ± 0·5 °C. Moistened paper was placed in the chamber to avoid drying. Individuals were dissected into leaves, stems, roots and reproductive organs immediately before measurement, and the whole structure included in each organ was used for respiratory measurement. Increase in SRR with cutting was disregarded, because a preliminary experiment showed that the increase was small (less than 3·5 % of SRR). Temperature dependence of SRR was determined in each organ on every harvest occasion from the measurement of SRR at three temperatures covering the range of growth temperatures experienced around the sampling date. When these measurements could not be finished by midnight, the remainder were done in the next evening.
Respiration expressed as CO2 release was converted into dry mass with a conversion factor of 0·614, which is the molecular weight of one carbohydrate unit (C6H10O5, 162) divided by the molecular weight of six CO2 molecules (264).
Amount of photosynthates and reproductive effort
The amount of photosynthates assimilated in the period [0, t], from germination to time t, P(t), was obtained by summing the photosynthates allocated to organ k in the period [0, t], Pk(t):
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 | (2) |
 | (3) |
):
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Q10 characterizes the temperature dependence of SRR and is given as the ratio of increase in SRR with a 10 °C increase:
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Rk(t) was calculated every 30 min with Sk(25; t) and bk(t) averaged over the harvest interval, and T measured every 30 min. Wk(t) was determined from observed dry mass growth.
Reproductive effort in terms of biomass (REW) was calculated as the proportion of reproductive dry mass to total plant mass including dead leaves at the end of the growing period. Reproductive effort in term of photosynthates (REP) was calculated as the fraction of photosynthates allocated to the reproductive organ in the growing period.
Growth and maintenance respiration
Respiration includes two functional components, maintenance and growth respiration (Thornley, 1970; Hesketh et al., 1971). Specific respiration rate (SRR) is expressed as a linear function of relative growth rate (RGR) with coefficients for growth respiration (respiration required for the synthesis of a unit tissue mass, 
) and for maintenance respiration (respiration rate for the maintenance of a unit tissue mass, µ):
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and µ were determined as the slope and the y-intercept, respectively, in the regression of SRR at 25 °C on RGR for each organ. For this estimation, we used SRR at 25 °C averaged between successive harvests and the corresponding RGR was calculated by assuming exponential dry mass growth. Three plants for the measurement of respiration were arranged according to the order of their total plant mass, and average SRR and RGR were calculated pairwise for the plants in the same order.
Assuming that is independent of temperature (Szaniawski and Kielkiewicz, 1982; Johnson and Thornley, 1985; Marcelis and Hofman-Eijer, 1995), photosynthates used for growth respiration were estimated as the product of and dry mass. The maintenance respiration was obtained by subtracting growth respiration from total respiratory consumption.
Construction cost
Construction cost (C, g glucose g–1 dry mass) was estimated from the heat of combustion and nitrogen content following Williams et al. (1987):
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HC is the ash-free heat of combustion (kJ g–1), A is ash content (g g–1), k is the oxidation state of the nitrogen substrate (+5 for 
, –3 for 
), and N is nitrogen content (g g–1). We applied k = 4 assuming the source of nitrogen to be the same as that in the nutrient solution (). |
RESULTS |
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Plant dry mass increased nearly exponentially until flowering, and thereafter the rate of increase declined and became zero at around 100 d (lower line in Fig. 2E). The reproductive organ grew rapidly after flowering. Plant dry mass at seed maturation was 16·1 g, and the fractions of dry mass in leaves (including dead leaves), stem, root and the reproductive organ were 18, 25, 15 and 42 % (REW), respectively (Table 1).
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Figure 3 shows SRR determined at 25 °C. SRR was high at emergence and decreased thereafter. Leaves maintained a relatively high SRR and showed an abrupt increase in SRR before death. This increase was probably caused by climacteric respiration that met energetic requirements for remobilization of structural materials to other, still-growing organs (Amthor, 1989
). SRR of the reproductive organ decreased to nearly zero at seed maturation. Relatively high root respiration late in the growing period might have been caused by activities of soil microbes inhabiting the root surface (Amthor, 1989). The temperature dependence of SRR was characterized by Q10, which is given as the ratio of increase in SRR with a 10 °C increase (eqn 6). The values of Q10 changed through the growing period (Table 2) but within the range reported in earlier studies (cf. Amthor, 1989).
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Photosynthates allocated to vegetative organs (leaves, stem and root) increased rapidly after germination, although the increase became smaller after around 80 d (upper lines in Fig. 2A–C). By the end of the growing period, 9·2, 9·9 and 8·5 g of photosynthates were allocated to leaves, stem and root, respectively. Photosynthates allocated to the reproductive organ increased rapidly after flowering, reaching 11·1 g by the end of the growing period (Fig. 2D). The fraction of photosynthates respired by the end of the growing period was 69, 60, 71 and 39 % in leaves, stem, root and the reproductive organ, respectively. The whole plant respired 59 % of photosynthates in the growing period (Fig. 2E).
Photosynthates in the growing period were allocated to the four organs nearly evenly (Table 1). The fraction of photosynthates allocated to vegetative organs was larger than that of biomass, whereas the fraction of photosynthates allocated to the reproductive organ (REP) was smaller than that of biomass (REW).
In all organs, SRR was positively correlated with RGR (Fig. 4). The slope and the y-intercept of the regression line give the coefficients for growth () and maintenance respiration (µ, eqn 7), respectively. was highest in the reproductive organ and lowest in leaves and stem, whereas µ was highest in leaves and lowest in the stem and the reproductive organ (Table 3).
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The fraction of photosynthates consumed by growth respiration by the end of the growing period was larger in the reproductive organ (34 %) than in leaves, stem and root (8, 15 and 15 %, respectively, Fig. 5). On the other hand, consumption for maintenance respiration was far lower in the reproductive organ (5 %) than in leaves, stem and root (61, 46 and 56 %, respectively). Growth respiration accounted for 86 % of respiratory consumption in the reproductive organ, whereas it was at most 25 % (stem) in vegetative organs.
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Construction cost determined from heat of combustion was highest in seeds. Therefore, the reproductive organ had a higher construction cost than vegetative organs, although the cost for capsules was not higher than that for vegetative organs (Table 4). There were no significant differences in construction cost between the three vegetative organs.
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DISCUSSION |
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Respiratory consumption in the growth of Xanthium canadense
The reproductive organ consumed 39 % of photosynthates through respiration (Fig. 2). This value was much lower than that in vegetative organs (69, 60 and 71 % in leaves, stem and root, respectively). This difference was caused by the fraction of photosynthates consumed by maintenance respiration, which was smaller in the reproductive than in the vegetative organs, although the fraction for growth respiration was larger in the reproductive organ (Fig. 5). Hence REP was smaller than REW (29 vs. 42 %, Table 1), which is in accord with other studies (Jurik, 1983
; Reekie and Bazzaz, 1987). We assumed that reproductive growth was supported solely by photosynthates allocated from vegetative organs. In some species, however, part of reproductive growth is supported by reproductive photosynthesis (Bazzaz and Carlson, 1979). Although capsules of X. canadense are green during the early reproductive stage, their N concentration (less than 1 %) was lower than that of dead leaves, which indicates that the contribution of reproductive photosynthesis was small. If there was significant reproductive photosynthesis, REP would be even smaller than our calculation (see Reekie and Bazzaz, 1987).
We estimated respiratory consumption, assuming that the dark respiration rate is constant throughout a day (eqn 3). However, leaf respiration is sometimes lower in light than in darkness (Krömer, 1995; Villar et al., 1995; Atkin et al., 1997). In Xanthium strumarium, which is closely related to our species, the rate of dark respiration in leaves was reduced by 29–35 % in the light (Wang et al., 2001). When those values were applied to the estimation of respiratory consumption with an average day length in our experiment (12 h), respiratory consumption in leaves was reduced by 14·5–17·5 %. This reduction would decrease the amount of photosynthates allocated to leaves, with an increase in REP by 1 %. Thus the reduced leaf respiration in the light has little effect on the calculation of REP. Although we did not consider root death in the evaluation of the amount of photosynthates allocated to roots, substantial amounts of root decay have been reported by several authors (Van Noordwijk et al., 1994; Swinnen et al., 1995; Steingrobe et al., 2001). If root decay occurred substantially in X. canadense, REP would be smaller than our estimation, and consequently the difference between REP and REW would be increased.
Respiratory consumption for maintenance and for growth are characterized by two coefficients, µ and . Our X. canadense had µ and in the range reported in earlier studies (Amthor, 1989). µ was lower in the reproductive organ than in vegetative organs except for the stem (Table 3), which contributed to the smaller respiratory consumption in the reproductive than in the vegetative organs (Fig. 5). It has been shown that µ is low in storage organs such as tubers and seeds (e.g. Hesketh et al., 1971; Winkler, 1971; Kallis and Golovko, 1988). This has been attributed to a slow turnover rate of storage proteins and a low activity for maintaining intracellular ion-gradients in storage organs (Amthor, 1989, 2000).
In contrast to µ, was larger in the reproductive organ than in the vegetative organs (Table 3). Organs containing a large amount of costly compounds such as proteins, lipids and lignin show a higher respiratory requirement for construction (Penning de Vries et al., 1974, 1983; Penning de Vries, 1975). Seeds of X. canadense have a high N concentration (8 %, Kinugasa et al., 2003) implying proteins to be a main storage substance. High growth respiration in the reproductive organ is consistent with its high construction cost, as determined by the heat of combustion (Table 4).
Although construction cost was similar between vegetative organs (Table 4), was larger in roots than in the leaves and stem (Table 3). High -values in roots have been reported in several studies (see Amthor, 1989). This may partly be attributed to the two-component regression model (eqn 7) we used to estimate for the root, where respiration for ion uptake was ignored (Veen, 1980, 1981; Johnson, 1983; Lambers and Van der Werf, 1988). Veen (1980, 1981) divided root respiration into three components (growth, maintenance and ion uptake). The coefficients for these three components were determined by a multiple regression in which root mass, root growth and ion uptake were independent variables. Because about 90 % of the total anion uptake was attributed to (Veen, 1980, 1981) and costs for uptake of other ions were much lower (Cannell and Thornley, 2000), we may consider the cost for nitrogen assimilation as representing the total cost for ion uptake. Nitrate uptake was estimated from the increase in plant N using the ratio of to in the nutrient solution (7 : 1). Assuming that the respiratory cost for uptake is half of that for , (Cannell and Thornley, 2000), in roots as estimated by the three-component regression model (472 mg CO2 g–1) was 32 % smaller than that by the two-component regression model (691 mg CO2 g–1, Table 3), but was still higher than in other vegetative organs. of roots estimated by the three-component regression model was sometimes higher than the theoretical values (Bouma et al., 1996). This may be ascribed to a greater engagement of alternative pathway in roots than in other organs (Lambers and Smakman, 1978; Lambers et al., 1979, 1983), although problems have been pointed out in the method used to evaluate the activity of alternative pathways (Wagner and Krab, 1995; Noguchi et al., 2001).
We assumed that the respiratory coefficients were constant throughout the growing period. Several studies have reported reduction in µ and/or with plant growth (McCree, 1983; Kallis and Golovko, 1988; McCullough and Hunt, 1993). If this is the case with X. canadense, our µ-values would be somewhat underestimated and -values overestimated, although there is no evidence that the respiratory coefficients change with growth in Xanthium species.
Contribution of µ and to respiratory consumption in the reproductive organ
Here we employ a simple sensitivity analysis to evaluate the contribution of the lower µ in the reproductive than in the vegetative organs to the smaller respiratory consumption of photosynthates in the former (Fig. 5). To calculate the reproductive growth, we applied the ‘model A’ in Thornley and Cannell (2000; see fig. 1 therein) where maintenance had priority. In that model, maintenance respiration is subtracted from photosynthates and then the residue is used for growth with growth respiration. In the present analysis, the values of µ and of the reproductive organ were changed, with the observed time-course of photosynthate allocation to the reproductive organ (Fig. 2), air temperatures (Fig. 1) and Q10 of SRR in the reproductive organ (Table 2) kept unchanged. When the value of µ for the reproductive organ (0·69 mg CO2 g–1 h–1) was replaced with that for leaves (1·84 mg CO2 g–1 h–1), respiratory consumption of photosynthates in the reproductive organ was calculated to be 58 %. This value was higher than the observed respiratory consumption in the reproductive organ (39 %, Fig. 5) but was still lower than that in leaves (69 %). Thus, the low µ in the reproductive organ explained the smaller respiratory consumption there than in leaves by 63 %. Similarly, lower µ in the reproductive organ than in roots did not fully explain the smaller respiratory consumption in the reproductive organ. Hence, there are clearly other factors contributing to the smaller respiratory consumption in the reproductive than in the vegetative organs.
A shorter period for reproductive growth than for vegetative growth (106 vs. 158 d) contributed to the smaller respiratory consumption of photosynthates in the reproductive organ. Because maintenance respiration is incurred only when an organ is in existence, a shorter period leads to a smaller respiratory consumption of photosynthates (Jurik, 1983). Lower temperature in the reproductive period (Fig. 1) also contributed to the smaller respiratory consumption of photosynthates in the reproductive organ: SRR depends on temperature (Table 2) and the reproductive organ was absent in the vegetative period of relatively high temperature. Temperature dependence of SRR comes from maintenance respiration, because growth respiration does not depend on temperature (Szaniawski and Kielkiewicz, 1982; Johnson and Thornley, 1985; Mariko and Koizumi, 1993). The average temperature in the vegetative period (23·3 °C) was higher than that in the reproductive period (13·5 °C). If growth temperature in the reproductive period had not decreased from that in the vegetative period, the amount of respiration in the reproductive organ would have been roughly two times larger than the observed value when the averaged Q10 (= 2·2) of SRR in the reproductive organ was assumed.
Penning de Vries et al. (1983) showed that for reproductive organs varied widely from 297 mg CO2 g–1 in rice (Oryza sativa) to 956 mg CO2 g–1 in groundnut (Arachis hypogaea). These differences in among reproductive organs may influence the degree and direction of the difference between REW and REP. When the -values for rice and groundnut were applied with the observed value for µ of the reproductive organ, respiratory consumption of photosynthates in the reproductive organ was 30 and 41 %, and consequently REW was calculated as 46 and 42 %, respectively. Thus, REP (29 %) was always smaller than REW, irrespective of -values of reproductive organs, and the difference between the two RE values was little affected by different of reproductive organs.
In total, X. canadense consumed more than half of its assimilated photosynthates by respiration in the growing period. However, respiratory consumption in the reproductive organ was smaller than that in the vegetative organs. This difference was caused by the lower maintenance respiration rate, with a shorter period of existence of the reproductive organ than those of the vegetative organs, and a seasonal decline in temperature, although the growth respiration was highest in the reproductive organ. Consequently, reproductive effort was smaller in terms of photosynthates (REP) than in terms of biomass (REW). Sensitivity analysis showed that different construction costs of reproductive organs had little effect on the difference between the two RE values. A smaller REP than REW resulted from respiratory consumption for maintenance that was far smaller in the reproductive organ than in the vegetative organs.
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ACKNOWLEDGEMENTS |
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We thank K. Sato, M. Kato, S. Oikawa, Y. Onoda and R. Oguchi for advice and assistance with the experiment. This study was partly supported by the Sasakawa Scientific Research Grant from The Japan Science Society and Grants-in-aid from the Japan Ministry of Education, Science and Culture.
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LITERATURE CITED |
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-
Amthor JS. 1989. Respiration and crop productivity. New York: Springer-Verlag.
Amthor JS. 2000. The McCree–de Wit-Penning de Vries–Thornley respiration paradigms: 30 years later. Annals of Botany 86: 1–20.
Atkin OK, Westbeek MHM, Cambridge ML, Lambers H, Pons TL. 1997. Leaf respiration in light and darkness—a comparison of slow- and fast-growing Poa species. Plant Physiology 113: 961–965.[Abstract]
Bazzaz FA, Ackerly DD. 1992. Reproductive allocation and reproductive effort in plants. In: Fenner M, ed. Seeds. the ecology of regeneration in plant communities. Oxford: C.A.B. International, 1–26.
Bazzaz FA, Carlson RW. 1979. Contribution to reproductive effort by photosynthesis of flower and fruits. Nature 279: 554–555.[CrossRef]
Bazzaz FA, Reekie EG. 1985. The meaning and measurement of reproductive effort in plants. In: White J, ed. Studies on plant demography: a festschrift for John L. Harper. London: Academic Press Inc, 373–387.
Bouma TJ, Broekhuysen AGM, Veen BW. 1996. Analysis of root respiration Solanum tuberosum as related to growth, ion uptake and maintenance of biomass. Plant Physiology and Biochemistry 34: 795–806.
Cannell MGR, Thornley JHM. 2000. Modelling the components of plant respiration: some guiding principles. Annals of Botany 85: 45–54.
Epstein E. 1972. Mineral nutrition of plants: principles and perspectives. New York: Wiley.
Esashi Y, Leopold AC. 1968. Physical forces in dormancy and germination of Xanthium seeds. Plant Physiology 43: 871–876.
Harper JL. 1977. Population biology of plants. London: Academic Press.
Hesketh JD, Baker DN, Duncan WG. 1971. Stimulation of growth and yield in cotton: respiration and the carbon balance. Crop Science 11: 394–398.
Johnson IR. 1983. Nitrate uptake and respiration in roots and shoots—a model. Physiologia Plantarum 58: 145–147.[CrossRef]
Johnson IR, Thornley HM. 1985. Temperature dependence of plant and crop processes. Annals of Botany 55: 1–24.
Jurik TW. 1983. Reproductive effort and CO2 dynamics of wild strawberry populations. Ecology 64: 1329–1342.[CrossRef][Web of Science]
Kallis A, Golovko T. 1988. Potato plant respiration pattern during growth period. Acta Physiologiae Plantarum 10: 123–132.
Kinugasa T, Hikosaka K, Hirose T. 2003. Reproductive allocation of an annual, Xanthium canadense, at an elevated carbon dioxide concentration. Oecologia 137: 1–9.[CrossRef][Web of Science][Medline]
Krömer S. 1995. Respiration during photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology 46: 45–70.[CrossRef][Web of Science]
Lambers H, Smakman G. 1978. Respiration of roots of flood-tolerant and flood-intolerant Senecio species—affinity for oxygen and resistance to cyanide. Physiologia Plantarum 42: 163–166.[CrossRef]
Lambers H, Van der Werf A. 1988. Variation in the rate of root respiration of two Carex species—a comparison of four related methods to determine the energy-requirements for growth, maintenance and ion uptake. Plant and Soil 111: 207–211.[CrossRef]
Lambers H, Noord R, Posthumus F. 1979. Respiration of Senecio shoots—inhibition during photosynthesis, resistance to cyanide and relation to growth and maintenance. Physiologia Plantarum 45: 351–356.[CrossRef]
Lambers H, Day DA, Azcon-Bieto J. 1983. Cyanide-resistant respiration in roots and leaves—measurements with intact tissues and isolated-mitochondria. Physiologia Plantarum 58: 148–154.[CrossRef]
Marcelis LFM, Hofman-Eijer LRB. 1995. Growth and maintenance respiratory costs of cucumber fruits as affected by temperature, and ontogeny and size of the fruits. Physiologia Plantarum 93: 484–492.[CrossRef]
Mariko S, Koizumi H. 1993. Respiration for maintenance and growth in Reynoutria Japonica ecotypes from different altitudes on Mt Fuji. Ecological Research 8: 241–246.
McCree KJ. 1970. An equation for the rate of respiration of white clover plants grown under controlled conditions. In: Setlik I, ed. Prediction and measurement of photosynthetic productivity. Wageningen: Centre for Agricultural Publishing and Documentation, 221–229.
McCree KJ. 1983. Carbon balance as a function of plant size in sorghum plants. Crop Science 23: 1173–1177.
McCullough DE, Hunt LA. 1993. Mature tissue and crop canopy respiratory characteristics of rye, triticale and wheat. Annals of Botany 72: 269–282.
McMillan C. 1974. Photoperiodic adaptation of Xanthium strumarium in Europe, Asia Minor, and northern Africa. Canadian Journal of Botany 52: 1779–1791.
Noguchi K, Go C-S, Terashima I, Ueda S, Yoshinari T. 2001. Activities of the cyanide-resistant respiratory pathway in leaves of sun and shade species. Australian Journal of Plant Physiology 28: 27–35.
Obeso JR. 2002. The costs of reproduction in plants. New Phytologist 155: 321–348.[CrossRef][Web of Science]
Penning de Vries FWT. 1975. Use of assimilates in higher plants. In: Cooper JP, ed. Photosynthesis and productivity in different environments. New York: Cambridge University Press, 459–480.
Penning de Vries FWT, Brunsting AHM, van Laar HH. 1974. Products, requirements and efficiency of biosynthesis: a quantitative approach. Journal of Theoretical Biology 45: 339–377.[CrossRef][Web of Science][Medline]
Penning de Vries FWT, van Laar HH, Chardon MCM. 1983. Bioenergetics of growth of seeds, fruits, and storage organs. In: Potential productivity of field crops under different environments. Manila: International Rice Research Institute, 37–59.
Ray P, Alexander W. 1966. Photoperiodic adaptation to latitude in Xanthium strumarium. American Journal of Botany 53: 806–816.[CrossRef][Web of Science]
Reekie EG, Bazzaz FA. 1987. Reproductive effort in plants 1. Carbon allocation to reproduction. American Naturalist 129: 876–896.[CrossRef][Web of Science]
Shitaka Y, Hirose T. 1993. Timing of seed germination and the reproductive effort in Xanthium canadense. Oecologia 95: 334–339.[CrossRef]
Shitaka Y, Hirose T. 1998. Effects of shift in flowering time on the reproductive output of Xanthium canadense in a seasonal environment. Oecologia 114: 361–367.[CrossRef][Web of Science]
Steingrobe B, Schmid H, Claassen N. 2001. Root production and root mortality of winter barley and its implication with regard to phosphate acquisition. Plant and Soil 237: 239–248.[CrossRef]
Swinnen J, Van Veen JA, Merckx R. 1995. Root decay and turnover of rhizodeposits in field-grown winter wheat and spring barley estimated by 14C pulse-labelling. Soil Biology and Biochemistry 27: 211–217.[CrossRef]
Szaniawski RK, Kielkiewicz M. 1982. Maintenance and growth respiration in shoots and roots of sunflower plants grown at different root temperatures. Physiologia Plantarum 54: 500–504.[CrossRef]
Thornley JHM. 1970. Respiration, growth and maintenance in plants. Nature 227: 304–305.[Medline]
Thornley JHM, Cannell MGR. 2000. Modelling the components of plant respiration: respiration and realism. Annals of Botany 85: 55–67.
Van Noordwijk M, Brouwer G, Koning H, Meijboom FW, Grzebisz W. 1994. Production and decay of structural root material of winter wheat and sugar beet in conventional and integrated cropping systems. Agriculture Ecosystems and Environment 51: 99–113.[CrossRef]
Veen BW. 1980. Energy costs of ion transport. In: Rains DW, Valentine RC, Hollaender A, eds. Genetic engineering of osmoregulation: impact on plant productivity for food, chemicals, and energy. New York: Plenum Press, 187–195.
Veen BW. 1981. Relation between root respiration and root activity. Plant and Soil 63: 73–76.[CrossRef]
Villar R, Held AA, Merino J. 1995. Dark leaf respiration in light and darkness of an evergreen and a deciduous plant species. Plant Physiology 107: 421–427.[Abstract]
Wagner AM, Krab K. 1995. The alternative respiration pathway in plants – role and regulation. Physiologia Plantarum 95: 318–325.[CrossRef]
Wang XZ, Lewis JD, Tissue DT, Seemann JR, Griffin KL. 2001. Effects of elevated atmospheric CO2 concentration on leaf dark respiration of Xanthium strumarium in light and in darkness. Proceedings of the National Academy of Sciences of the USA 98: 2479–2484.
Williams K, Percival F, Merino J, Mooney HA. 1987. Estimation of tissue construction cost from heat of combustion and organic nitrogen content. Plant, Cell and Environment 10: 725–734.
Willson MF. 1983. Plant reproductive ecology. New York: Wiley.
Winkler E. 1971. Kartoffelbau in Tirol II. Photosynthesevermögen und respiration von verschiedenen Kartoffelsorten. Potato Research 14: 1–18.
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