scholarly journals Reduced mesophyll conductance by cell wall thickening and chloroplasts decreasing driven the decline of photosynthesis under sole NH4+ supply

2022 ◽  
Author(s):  
yiwen cao ◽  
Yonghui Pan ◽  
Tianheng Liu ◽  
Min Wang ◽  
Shiwei Guo
Keyword(s):  
Cell Wall ◽  
Wall Thickening ◽  
Mesophyll Conductance ◽  
N Sources ◽  
Unit Leaf ◽  
Use Efficiency ◽  
The Difference ◽  
The Relationship ◽  
Exposed Surface Area ◽  
N Use

The relationship between nitrogen (N) sources and photosynthetic capacity of leaf differs between species. However, the leaf anatomical variabilities related to photosynthesis (A) of shrubs under different forms of N remain imperfectly known. Here, Lonicera Japonica (a shrub) was grown hydroponically in the presence of three forms of N (sole NH4+, 50%/50% NH4+/NO3– and sole NO3–). A and photosynthetic N use efficiency significantly decreased under sole NH4+ supply, in parallel with down-regulated stomatal conductance (gs), mesophyll conductance (gm), and electron transfer rate (J). Up to the total A decline of 41.28% in sole NH4+ supply (compare with sole NO3–), the gm attributed to 60.3% of the total limitations. Besides, the decreased internal air space explained the increase of gas-phase resistance, and the increased liquid-phase resistance in sole NH4+ supply was ascribed to the thicker cell wall thickness (Tcw) and decreased chloroplasts exposed surface area per unit leaf area (Sc/S). The discrepancy of Sc/S could be interpreted by the altered chloroplasts numbers and the distance between adjacent chloroplasts (Dchl-chl). These results indicate the alteration of Tcw and chloroplast numbers were the main causes of the difference in gm in coping with varied N sources.

scholarly journals Differences in xylem development between Dutch and Japanese tomato (Solanum lycopersicum) correlate with cytokinin levels in hypocotyls

2020 ◽  
Vol 126 (2) ◽  
pp. 315-322 ◽  
Author(s):  
Xiaohua Qi ◽  
Hirokazu Takahashi ◽  
Yasushi Kawasaki ◽  
Yuya Ohta ◽  
Masahide Isozaki ◽  
...  
Keyword(s):  
High Yield ◽  
Growth Stages ◽  
Cytokinin Biosynthesis ◽  
Xylem Development ◽  
Isopentenyl Adenine ◽  
Use Efficiency ◽  
The Difference ◽  
Leaf Photosynthetic Rate ◽  
The Relationship ◽  
Different Growth Stages

Abstract Background and Aims Dutch tomato cultivars tend to have a greater yield than Japanese cultivars even if they are grown under the same conditions. Factors contributing to the increased yield of the Dutch cultivars were a greater light use efficiency and greater leaf photosynthetic rate. On the other hand, the relationship between tomato yields and anatomical traits is still unclear. The aim of this study is to identify the anatomical traits related to the difference in yield between Dutch and Japanese cultivars. Methods Anatomical properties were compared during different growth stages of Dutch and Japanese tomatoes. Hormone profiles and related gene expression in hypocotyls of Dutch and Japanese cultivars were compared in the hypocotyls of 3- and 4-week-old plants. Key results Dutch cultivars have a more developed secondary xylem than Japanese cultivars, which would allow for greater transport of water, mineral nutrients and phytohormones to the shoots. The areas and ratios of the xylem in the hypocotyls of 3- to 6-week-old plants were larger in the Dutch cultivars. In reciprocal grafts of the Japanese and Dutch cultivars, xylem development at the scion and rootstock depended on the scion cultivar, suggesting that some factors in the scion are responsible for the difference in xylem development. The cytokinin content, especially the level of N6-(Δ 2-isopentenyl) adenine (iP)-type cytokinin, was higher in the Dutch cultivars. This result was supported by the greater expression of Sl-IPT3 (a cytokinin biosynthesis gene) and Sl-RR16/17 (a cytokinin-responsive gene) in the Dutch cultivars. Conclusions These results suggest that iP-type cytokinins, which are locally synthesized in the hypocotyl, contribute to xylem development. The greater xylem development in Dutch cultivars might contribute to the high yield of the tomato.

scholarly journals A Decrease in Mesophyll Conductance by Cell-Wall Thickening Contributes to Photosynthetic Downregulation

2020 ◽  
Vol 183 (4) ◽  
pp. 1600-1611 ◽  
Author(s):  
Daisuke Sugiura ◽  
Ichiro Terashima ◽  
John R. Evans
Keyword(s):  
Cell Wall ◽  
Wall Thickening ◽  
Mesophyll Conductance ◽  
Photosynthetic Downregulation

Seasonally varying relationship between stem respiration, increment and carbon allocation of Norway spruce trees

2020 ◽  
Vol 40 (7) ◽  
pp. 943-955
Author(s):  
Eva Darenova ◽  
Petr Horáček ◽  
Jan Krejza ◽  
Radek Pokorný ◽  
Marian Pavelka
Keyword(s):  
Cell Wall ◽  
Norway Spruce ◽  
Carbon Allocation ◽  
Stem Growth ◽  
Wall Thickening ◽  
Radial Increment ◽  
Stem Respiration ◽  
Energy Demands ◽  
The Relationship ◽  
Stem Radial Increment

Abstract Stem respiration is an important component of an ecosystem’s carbon budget. Beside environmental factors, it depends highly on tree energy demands for stem growth. Determination of the relationship between stem growth and stem respiration would help to reveal the response of stem respiration to changing climate, which is expected to substantially affect tree growth. Common measurement of stem radial increment does not record all aspects of stem growth processes, especially those connected with cell wall thickening; therefore, the relationship between stem respiration and stem radial increment may vary depending on the wood cell growth differentiation phase. This study presents results from measurements of stem respiration and increment carried out for seven growing seasons in a young Norway spruce forest. Moreover, rates of carbon allocation to stems were modeled for these years. Stem respiration was divided into maintenance (Rm) and growth respiration (Rg) based upon the mature tissue method. There was a close relationship between Rg and daily stem radial increment (dSRI), and this relationship differed before and after dSRI seasonal maximum, which was around 19 June. Before this date, Rg increased exponentially with dSRI, while after this date logarithmically. This is a result of later maxima of Rg and its slower decrease when compared with dSRI, which is connected with energy demands for cell wall thickening. Rg reached a maxima at the end of June or in July. The maximum of carbon allocation to stem peaked in late summer, when Rg mostly tended to decrease. The overall contribution of Rg to stem CO2 efflux amounted to 46.9% for the growing period from May to September and 38.2% for the year as a whole. This study shows that further deeper analysis of in situ stem growth and stem respiration dynamics is greatly needed, especially with a focus on wood formation on a cell level.

N uptake, N partitioning, and photosynthetic N-use efficiency of an old and a new maize hybrid

1994 ◽  
Vol 74 (3) ◽  
pp. 479-484 ◽  
Author(s):  
D. E. McCullough ◽  
A. Aguilera ◽  
M. Tollenaar
Keyword(s):  
Dry Matter ◽  
N Uptake ◽  
N Use Efficiency ◽  
Maize Hybrid ◽  
Unit Leaf ◽  
N Supply ◽  
N Partitioning ◽  
Use Efficiency ◽  
N Use ◽  
Leaf N

An old maize (Zea mays L.) hybrid (Pride 5) has been shown to be less tolerant to N stress than a new maize hybrid (Pioneer 3902) during early phases of development. The objective of this study was to quantify the response of the two hybids to N supply in terms of N uptake, N partitioning, and photosynthetic N–use efficiency. Plants were grown under controlled-environment conditions until the 12-leaf stage at three levels of N supply (i.e., 15 mM N, 2.5 mM N, and 0.5 mM N) and were sampled at the 4-, 8-, and 12-leaf stages. Rates of N uptake per unit ground area were higher for Pioneer 3902 than for Pride 5 under maximum N stress during the 8- to 12-leaf phase, but rates were higher for Pride 5 at high N. Rates of N uptake per unit root weight were higher for Pioneer 3902 than for Pride 5 under both medium and low N supply. The old hybrid (Pride 5) partitioned more dry matter and N to leaves than the new hybrid under low N supply, but leaf N per unit leaf area was higher for the new hybrid. The new hybrid (Pioneer 3902) maintained greater rates of leaf photosynthesis per unit leaf N regardless of N supply. Consequently, results indicate that the higher N-use efficiency of Pioneer 3902 under low N supply is associated with higher N uptake and a higher leaf N per unit leaf area. Key words:Zea mays L., dry matter accumulation, photosynthesis, leaf N

scholarly journals The difference between breeding for nutrient use efficiency and for nutrient stress tolerance

2011 ◽  
Vol 11 (3) ◽  
pp. 270-275 ◽  
Author(s):  
Ciro Maia ◽  
Júlio César DoVale ◽  
Roberto Fritsche-Neto ◽  
Paulo Cezar Cavatte ◽  
Glauco Vieira Miranda
Keyword(s):  
Nutrient Use Efficiency ◽  
Nutritional Stress ◽  
Inbred Lines ◽  
Tropical Maize ◽  
Nutrient Use ◽  
Use Efficiency ◽  
Low Levels ◽  
Selection For ◽  
The Difference ◽  
The Relationship

This study aimed to verify the relationship between breeding for tolerance to low levels of soil nutrients and for nutrient use efficiency in tropical maize. Fifteen inbred lines were evaluated in two greenhouse experiments under contrasting levels of N and P. The relationship between nutritional efficiency and tolerance to nutritional stress was estimated by the Spearman ranking correlation between the genotypes for the traits related to N and P use efficiency and phenotypic plasticity indices. The lack of relationship between the traits, in magnitude as well as significance, indicates that these characters are controlled by different gene groups. Consequently, simultaneous selection for both nutrient use efficiency and tolerance to nutritional stress is possible, if the mechanisms that confer efficiency and tolerance are not competitive.

The growth of hill lambs on herbage diets

1977 ◽  
Vol 88 (3) ◽  
pp. 683-692 ◽  
Author(s):  
Richard H. Armstrong ◽  
J. Eadie
Keyword(s):  
Cell Wall ◽  
Organic Matter ◽  
Weight Gain ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Growth Rates ◽  
Live Weight ◽  
Grazing Experiment ◽  
The Difference ◽  
The Relationship

SUMMARYEarly-weaned lambs were penned indoors for 6 weeks and individually fed to appetite on cold-stored ryegrass (Lolium perenne) or indigenous Agrostis-Festuca herbage of differing maturity. In another experiment similar lambs grazed for 12 weeks on swards of perennial ryegrass or Agrostis-Festuca. Live-weight gain (LWG), herbage organic-matter intake (OMI) and digestibility (OMD) were measured. In the indoor experiment ryegrass was 4–6 percentage units higher in OMD than was Agrostis-Festuca;first harvests were superior to later harvests by the same amount. The intake of ryegrass was 22% greater than that of Agrostis-Festuca. The correlation between OMI/W'73 and herbage cell-wall constituents was —0·80, and that between OMI/W'3 and OMD was 0·78. OMI/W0·73 increased progressively up to about 13 weeks of age.LWG was higher on ryegrass than on Agrostis-Festuca; and LWG on the early harvests of each herbage type exceeded those on the later harvests. LWG was significantly correlated with the intake of digested organic matter (DOMI) (r = 0·85).In the grazing experiment, OMD, OMI and LWG were all lower than in the indoor experiment. LWG on ryegrass was again superior to that on Agrostis-Festuca, and the difference was partly explained by the relationship between DOMI and LWG which had been established indoors.These results suggest that the increase in the growth rates of hill lambs consequent on the improvement of indigenous Agrostis-Festucaswards would be less than that due to the provision of sown pastures of perennial ryegrass.

scholarly journals Lignification and cell wall thickening of ray parenchyma cells in Scots pine sapwood

IAWA Journal ◽  
2021 ◽  
pp. 1-9
Author(s):  
Katrin Zimmer ◽  
Andreas Treu
Keyword(s):  
Cell Wall ◽  
Scots Pine ◽  
Microscopic Analysis ◽  
Tree Level ◽  
Wall Thickening ◽  
Heartwood Formation ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
The Difference ◽  
Ray Parenchyma Cells

Abstract Scots pine exhibits variations in ray anatomy, which are poorly understood. Some ray parenchyma cells develop thick and lignified cell walls before heartwood formation. We hypothesized that some stands and trees show high numbers of lignified and thick-walled parenchyma cells early in the sapwood. Therefore, a microscopic analysis of Scots pine sapwood from four different stands in Northern Europe was performed on Safranin — Astra blue-stained tangential micro sections from outer and inner sapwood areas. Significant differences in lignification and cell wall thickening of ray parenchyma cells were observed in the outer sapwood between all of the stands for the trees analyzed. On a single tree level, the relative lignification and cell wall thickening of ray parenchyma cells ranged from 4.3% to 74.3% in the outer sapwood. In the inner sapwood, lignification and cell wall thickening of ray parenchyma cells were more frequent. In some trees, however, the difference in lignification and cell wall thickening between inner and outer sapwood was small since early lignification, and cell wall thickening was already more common in the outer sapwood. Ray composition and number of rays per area were not significantly different within the studied material. However, only one Scottish tree had a significantly higher number of ray parenchyma cells per ray. The differences discovered in lignification and cell wall thickening in ray parenchyma cells early in the sapwood of Scots pine are relevant for wood utilization in general and impregnation treatments with protection agents in particular.

Tangential Youngs Modulus of Coniferous Early Wood Investigated Using Cell Models

Holzforschung ◽  
1999 ◽  
Vol 53 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Ugai Watanabe ◽  
Misato Norimoto ◽  
Toshimasa Ohgama ◽  
Minoru Fujita
Keyword(s):  
Cell Wall ◽  
Young’S Modulus ◽  
Cell Model ◽  
Young's Modulus ◽  
Cell Models ◽  
Young’S Moduli ◽  
The Difference ◽  
Radial Cell Wall ◽  
Experimental Values ◽  
The Relationship

Summary The relationship between the tangential Young's modulus and the transverse cell shape in coniferous early wood was investigated by using cell models constructed by power spectrum analysis. The calculated Young's moduli of the cell models explained qualitatively the change of the experimental Young's moduli with density as well as the difference in the experimental values among species. The calculated Young's moduli differed significantly among species depending on the cell model shapes when compared at the same density. With increasing element angle in the model, the Young's modulus greatly increased without a significant change in the density, especially at the larger ratios of the axial length of the tangential cell wall to that of the radial cell wall.

scholarly journals Variation for Nitrogen Use Efficiency Traits in Wheat Under Contrasting Nitrogen Treatments in South-Eastern Europe

2021 ◽  
Vol 12 ◽  
Author(s):  
Marko Ivić ◽  
Sonja Grljušić ◽  
Ivana Plavšin ◽  
Krešimir Dvojković ◽  
Ana Lovrić ◽  
...  
Keyword(s):  
Yield Potential ◽  
Wheat Cultivars ◽  
Selection Strategies ◽  
Environment Effects ◽  
South Eastern Europe ◽  
N Remobilization ◽  
Use Efficiency ◽  
Nitrogen Treatments ◽  
The Relationship ◽  
N Use

Wheat cultivars differ in their response to nitrogen (N) fertilizer, both in terms of its uptake and utilization. Characterizing this variation is an important step in improving the N use efficiency (NUE) of future cultivars while maximizing production (yield) potential. In this study, we compared the agronomic performance of 48 diverse wheat cultivars released between 1936 and 2016 at low and high N input levels in field conditions to assess the relationship between NUE and its components. Agronomic trait values were significantly lower in the low N treatment, and the cultivars tested showed a significant variation for all traits (apart from the N remobilization efficiency), indicating that response is genotype-dependent, although significant genotype × environment effects were also observed. Overall, we show a varietal improvement in NUE over time of 0.33 and 0.30% year–1 at low and high N, respectively, and propose that this is driven predominantly by varietal selection for increased yield. More complete understanding of the components of these improvements will inform future targeted breeding and selection strategies to support a reduction in fertilizer use while maintaining productivity.

Relationship between nitrogen resorption and leaf size in the aroid vine Rhodospatha oblongata (Araceae)

2017 ◽  
Vol 65 (5) ◽  
pp. 431 ◽  
Author(s):  
André Mantovani ◽  
Dulce Mantuano ◽  
Eduardo Arcoverde de Mattos
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Primary Sources ◽  
Nitrogen Resorption ◽  
Unit Leaf ◽  
Use Efficiency ◽  
Nutrient Conservation ◽  
N Resorption ◽  
N Acquisition ◽  
N Use

Nitrogen resorption (NR) from senescing leaves enhances nutrient conservation in plants. Leaf area in lianescent aroid vines increases dramatically as the plant ascends vertically on its host. In Rhodospatha oblongata Schott, the largest leaves have up to 35 times the area and 50 times the N content of the smallest. We hypothesised that despite the costs of reallocating nitrogen within the plant, the huge increase in nitrogen cost to produce larger new leaves in R. oblongata should lead to increased NR from large leaves, mitigating the high demands on N acquisition from primary sources. The amount of veins available per unit leaf area may however constrain the ability to reutilise nitrogen within the plant. It was found that N concentration was 2–3% in green and 1–2% in senescent leaves, independent of leaf area, whereas vein density increased with leaf area. N use efficiency, resorption efficiency, and proficiency were not affected by leaf area; however, results indicate that R. oblongata does not have a conservative use of N despite occurring in oligotrophic soils. The absence of increased N resorption indicates that R. oblongata may have the capacity to acquire large amounts of soil and aerial N to produce new larger leaves, which after leaf fall may positively affect litter decomposition.

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