Autumnal leaf senescence inMiscanthus×giganteusand leaf [N] differ by stand age

Nicholas N. Boersma; Frank G. Dohleman; Fernando E. Miguez; Emily A. Heaton

doi:10.1093/jxb/erv129

Ethephon Activates the Transcription of Senescence-Associated Genes and Nitrogen Mobilization in Grapevine Leaves (Vitis vinifera cv. Riesling)

Plants ◽

10.3390/plants10020333 ◽

2021 ◽

Vol 10 (2) ◽

pp. 333

Author(s):

Maximilian Hendgen ◽

Stefan Günther ◽

Sven Schubert ◽

Otmar Löhnertz

Keyword(s):

Vitis Vinifera ◽

Leaf Senescence ◽

Methodological Approach ◽

Leaf Transcriptome ◽

Berry Ripening ◽

Model Plant Arabidopsis Thaliana ◽

N Remobilization ◽

Grapevine Leaves ◽

Nitrogen Mobilization ◽

Leaf N

Nitrogen (N) remobilization in the context of leaf senescence is of considerable importance for the viability of perennial plants. In late-ripening crops, such as Vitis vinifera, it may also affect berry ripening and fruit quality. Numerous studies on the model plant Arabidopsis thaliana have confirmed an involvement of the plant hormone ethylene in the regulation of senescence. However, ethylene research on grapevine was mostly focused on its involvement in berry ripening and stress tolerance until now. To investigate the effect of ethylene on the initiation, regulation, and progress of senescence-dependent N mobilization in grapevine leaves, we treated field-grown Vitis vinifera cv. Riesling vines with 25 mM ethephon at the end of berry ripening. Ethephon induced premature chlorophyll degradation and caused a shift of the leaf transcriptome equivalent to developmental leaf senescence. The upregulated metabolic processes covered the entire N remobilization process chain, altered the amino acid composition in the leaves, and resulted in an average 60% decrease in leaf N. Our findings increase the fundamental knowledge about the initiation and manipulation of leaf N remobilization in perennial woody plants by ethephon. This offers a methodological approach to the targeted induction of senescence and thus to an improvement in the N supply of grapes.

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Nitrogen resorption and protein degradation during leaf senescence in Chenopodium album grown in different light and nitrogen conditions

Functional Plant Biology ◽

10.1071/fp06307 ◽

2007 ◽

Vol 34 (5) ◽

pp. 409 ◽

Cited By ~ 24

Author(s):

Yuko Yasumura ◽

Kouki Hikosaka ◽

Tadaki Hirose

Keyword(s):

Protein Degradation ◽

Leaf Senescence ◽

Chenopodium Album ◽

Growth Conditions ◽

Sink Strength ◽

Physiological Factors ◽

Nitrogen Resorption ◽

Protein Pool ◽

N Resorption ◽

Leaf N

The extent of nitrogen (N) resorption and the degradability of different protein pools were examined in senescing leaves of an annual herb, Chenopodium album L., grown in two light and N conditions. Both N resorption efficiency (REFF; the proportion of green-leaf N resorbed) and proficiency (RPROF; the level to which leaf N content is reduced by resorption) varied among different growth conditions. During leaf senescence, the majority of soluble and membrane proteins was degraded in all growth conditions. Structural proteins were also highly degradable, implying that no particular protein pool constitutes a non-retranslocatable N pool in the leaf. Leaf carbon/N ratio affected the timing and duration of senescing processes, but it did not regulate the extent of protein degradation or N resorption. Sink–source relationships for N in the plant exerted a more direct influence, depressing N resorption when N sink strength was weakened in the low-light and high-N condition. N resorption was, however, not enhanced in high-light and low-N plants with the strongest N sinks, possibly because it reached an upper limit at some point. We conclude that a combination of several physiological factors determines the extent of N resorption in different growth conditions.

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Macronutrient Allocation to Leaves and Fruit of Mature, Alternate-bearing Pistachio Trees: Magnitude and Seasonal Patterns at the Whole-canopy Level

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.122.2.267 ◽

1997 ◽

Vol 122 (2) ◽

pp. 267-274 ◽

Cited By ~ 31

Author(s):

G.A. Picchioni ◽

P.H. Brown ◽

S.A. Weinbaum ◽

T.T. Muraoka

Keyword(s):

Leaf Senescence ◽

Nutrient Content ◽

Leaf Biomass ◽

Potential Contribution ◽

Alternate Bearing ◽

Crop Load ◽

Seed Fill ◽

N Resorption ◽

Leaf N ◽

Pistachio Trees

Estimates of leaflet and fruit macronutrient (N, P, K, Ca, and Mg) accumulation and resorption were developed in six (three heavily cropping, on-year and three noncropping, off-year) mature pistachio (Pistacia vera L. `Kerman') trees over three growing seasons during three stages of phenology [the spring growth flush (April to June); seed fill (late June to September); and leaf senescence (September to November)]. Crop load influenced total nutrient content per tree in annual organs (leaves and fruit), the relative allocation of nutrients between leaves and fruit, temporal patterns of nutrient accumulation in annual organs, and the magnitude of net leaf nutrient resorption per tree prior to leaf fall. In off-year trees, macronutrient accumulation in annual organs (leaves) was concentrated during the spring flush of growth. In contrast, significant macronutrient accumulation in annual organs of on-year trees (leaves plus fruit) occurred not only during the spring flush of growth but also during seed fill. Duration and magnitude of macronutrient accumulation were greater in on-year vs. off-year trees. Fruit N and P demand during seed fill was partially met by a net decrease in the N and P contents of the pericarp. These decreases in pericarp nutrient content during seed fill were equivalent to 32% and 26% of embryo accumulation of N and P, respectively. Fruit demand for N, P, and K during the spring flush of “on” years was accompanied by reduced leaf N, P, and K contents per tree. Net leaf N, Ca, and Mg resorption per tree during leaf senescence differed with crop load. Net leaf N resorption was significantly greater in off-year trees than on-year trees. Leaf N resorption presumably represents an important component of the N pool stored in perennial tree parts during dormancy. The greater leaf N resorption following “off” years was a function of greater leaf N concentration and greater leaf biomass per tree. In contrast, net leaf resorption of Ca and Mg was greater in on-year vs. off-year trees. Experimental validation of the magnitude and periodicity of nutrient uptake by mature pistachio trees is needed during the alternate-bearing cycle, especially in light of the potential contribution of current fertilization practices to groundwater contamination.

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Leaf Nitrogen and Phosphorus Stoichiometry of Chinese fir Plantations across China: A Meta-Analysis

Forests ◽

10.3390/f10110945 ◽

2019 ◽

Vol 10 (11) ◽

pp. 945 ◽

Cited By ~ 1

Author(s):

Ran Tong ◽

Benzhi Zhou ◽

Lina Jiang ◽

Xiaogai Ge ◽

Yonghui Cao ◽

...

Keyword(s):

Age Groups ◽

N:P Ratio ◽

Leaf Nitrogen ◽

Chinese Fir ◽

Stand Age ◽

Mean Annual Temperature ◽

P Concentration ◽

N Concentration ◽

Leaf P ◽

Leaf N

Leaf nitrogen (N) and phosphorus (P) stoichiometry at a large geographical scale is the result of long-term adaptation to the environment. Therefore, the patterns of leaf N and P spatial distributions and their controlling factors represent an important issue in current ecological research. To explore the leaf stoichiometry of Chinese fir at a national level, we conducted a meta-analysis based on the dataset of the leaf nitrogen (N) and phosphorus (P) concentrations and the N:P ratio from 28 study sites across China. For all of the age groups considered, the average concentrations of the leaf N and P concentrations and the N:P ratio were 11.94 mg g−1, 1.04 mg g−1, and 12.93, respectively. Significant differences were found in the leaf P concentration and N:P ratio between the five age groups, while the differences in the leaf N concentration between the groups were not significant. Linear fitting results indicated that the leaf P concentration decreased, and the leaf N:P ratio increased with the increase of the MAT (mean annual temperature) and soil N concentration. Redundancy analysis (RDA) revealed that the first axis, with an explanatory quantity of 0.350, indicated that the MAT (mean annual temperature), soil nitrogen concentration and stand age had a good relationship with the leaf P concentration and N:P ratio, while the second axis, with an explanatory quantity of 0.058, indicated that the leaf N concentration was less affected by the environmental factors. These results demonstrate that the leaf P concentration and N:P ratio are affected by the stand age, an uneven distribution of the heat and soil nutrient concentration status, and N, as the limiting element, remaining relatively stable. Overall, our findings revealed the response of leaf stoichiometric traits to environment change, which benefits the management of Chinese fir plantations.

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Combining diverse data for the quantification of terrestrial carbon and nitrogen allocations

10.5194/egusphere-egu21-8252 ◽

2021 ◽

Author(s):

Yunke Peng ◽

Colin Prentice ◽

Keith Bloomfield ◽

Matteo Campioli ◽

Zhiwen Guo ◽

...

Keyword(s):

Primary Production ◽

Biomass Production ◽

Net Primary Production ◽

Leaf Nitrogen ◽

Global Distribution ◽

Stand Age ◽

Soil Conditions ◽

N Fixation ◽

N Flux ◽

Leaf N

Plants not only acquire carbon to sustain biomass production, autotrophic respiration, and the production of non-structural compounds, but also require nitrogen to support carboxylation and growth. However, available observations have not fully been integrated and used for modelling growth, carbon allocation to different compartments, and how different compartments&#8217; nitrogen-to-carbon ratio vary across large climatic and soil gradients. This leaves substantial uncertainty in estimates of the global distribution of growth and nitrogen uptake by plants.&#160;Here, we used the P-model, a first principles-derived and remote sensing-driven model for terrestrial gross primary production (GPP) to simulate the global distribution of GPP. Using comprehensive datasets with locally measured covariates for climatic and edaphic conditions and vegetation structure, we modelled the fractional allocation of GPP to biomass production (BP), aboveground net primary production (ANPP), and leaf NPP based on linear mixed-effects regression models. We defined BP as the sum of NPP in leaves, wood and roots. It thus does not include additional components such as exudates and labile carbon to mycorrhizae. Leaf nitrogen-to-carbon was modelled based on the maximum rate of carboxylation at 25 degrees Celsius (Vcmax25) and leaf mass per area (LMA). We then used global gridded data for the covariates that entered as predictors in site-level empirical models to simulate global C and N allocated to each component. We finally validated our global simulation results with an extended set of globally distributed GPP, BP and nitrogen-to-carbon ratio observations.&#160;GPP was well predicted (R2 = 0.61). In forests, ratios of BP/GPP and ANPP/GPP decreased with soil C/N and stand-age but increased with humidity and with the fraction of absorbed photosynthetically active radiation (fAPAR). The ratio of leaf NPP to ANPP, increased with light availability and growth temperature, but decreased with vapor pressure deficit. Leaf nitrogen-to-carbon ratio was positively related to the ratio of Vcmax25 to LMA. Leaf nitrogen resorption efficiency (NRE) was increased in drier and colder environments. Through our data validation at the end, we have shown a prediction for NPP (R2 = 0.26), ANPP (R2 = 0.28), leaf NPP (R2 = 0.39), NRE (R2 = 0.30), leaf N/C (R2 = 0.26) and leaf N flux (R2 = 0.35).&#160;Simulated global total GPP is 125 Pg C yr-1. Based on these statistical models, global mean carbon-use-efficiency (BP/GPP) was estimated to be 40%. The ratio of ANPP/BP was 72%, and ANPP was further split with 46% to leaf NPP and 54% to wood NPP. Simulated global total nitrogen acquisition (total of uptake from the soil and symbiotic N fixation) was 860 Tg N yr-1. Growth in the leaf, wood and root compartment accounted for 39%, 23% and 38% of global N acquisition, respectively. We suggest that plant adaptations result in higher ANPP, leaf NPP and finally leaf N flux under warmer, wetter, more abundant light and N-rich soil conditions, which aims to support higher rate of photosynthesis with greater nitrogen investment in the leaf.

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Timing of Nitrogen Resorption-Related Processes during Fall Senescence in Southern Oak Species

Forest Science ◽

10.1093/forsci/fxy062 ◽

2018 ◽

Vol 65 (3) ◽

pp. 245-249 ◽

Cited By ~ 1

Author(s):

Richard Sample ◽

Benjamin A Babst

Keyword(s):

Leaf Senescence ◽

Limited Resource ◽

Leaf Protein ◽

Future Studies ◽

Nitrogen Resorption ◽

Southern Us ◽

Quercus Species ◽

Chlorophyll Protein ◽

N Resorption ◽

Leaf N

Abstract Oak (Quercus) species are prominent in southern US forests. The ability to recycle nitrogen (N) during dormancy is an important adaptation to conserve a limited resource, but N resorption in southern oaks is not well understood. Leaf protein and chlorophyll are both degraded during senescence to release N that can be stored in stems and roots. We hypothesized that leaf N would decrease soon after degradation of leaf protein and/or chlorophyll. Chlorophyll, protein, and N content were measured in leaves of Q. texana, Q. phellos, and Q. nigra during fall 2016 and 2017, in Arkansas. Degradation of protein, which holds the majority of leaf N, started early, in September, whereas chlorophyll degradation and N export from leaves occurred in late November. The delay between protein degradation and N export indicates that N resorption is drawn out over months in southern oaks, because of an unknown mechanism. Protracted leaf senescence could be due to a physiological or biochemical constraint, or it could be an adaptive trait where fall is typically warm and water-limited, but occasionally wet. Our results lay a foundation for future studies to examine how environmental stress may affect nutrient resorption during leaf senescence in southern oak species.

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Effects of strobilurin fungicide programmes and fertilizer nitrogen rates on winter wheat: severity ofSeptoria tritici, leaf senescence and yield

The Journal of Agricultural Science ◽

10.1017/s0021859611000670 ◽

2011 ◽

Vol 150 (4) ◽

pp. 411-426 ◽

Cited By ~ 5

Author(s):

S. ISHIKAWA ◽

M. C. HARE ◽

P. S. KETTLEWELL

Keyword(s):

Winter Wheat ◽

Plant Height ◽

Leaf Senescence ◽

Field Experiments ◽

Fertilizer Nitrogen ◽

N Concentration ◽

Progress Curve ◽

Strobilurin Fungicide ◽

Leaf N Concentration ◽

Leaf N

SUMMARYFour field experiments were conducted over 3 years to study whether adding a strobilurin fungicide to a triazole fungicide programme for disease control in winter wheat had any influence, in combination with different rates of fertilizer nitrogen (N), on the severity of foliar diseases, the degree of leaf senescence and consequently on yield.Septoria triticiwas the dominant foliar disease observed in all experiments. The area under the disease progress curve (AUDPC) tended to be greater for untreated plots than those treated with fungicides; however, the performance of the programme containing a strobilurin fungicide did not always exceed that of the triazole-only programme. Fitting a quadratic equation to relationships between leaf N concentration and the proportion of leaf area covered withS. triticion a relative scale across the four experiments indicated a possibility that there could be an optimum N concentration in host plants forS. triticito develop, rather than a simple increase or decrease with a rise in plant N concentration. Plant height tended to be reduced following an application of a mixture of epoxiconazole and trifloxystrobin; however, it was not clear whether there was any association between plant height and the severity ofS. tritici. S. triticicaused a reduction in mean grain weight (MGW) in most of the experiments. It was concluded that an optimum leaf N concentration may exist forS. triticiin winter wheat.

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Autumn Foliage Applications of ZnSO4 Reduced Leaf Nitrogen Remobilization in Peach and Nectarine

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.115.1.79 ◽

1990 ◽

Vol 115 (1) ◽

pp. 79-83 ◽

Cited By ~ 7

Author(s):

S.P. Castagnoli ◽

T.M. DeJong ◽

S.A. Weinbaum ◽

R.S. Johnson

Keyword(s):

Leaf Senescence ◽

Prunus Persica ◽

Unit Area ◽

Dry Weight ◽

Leaf Nitrogen ◽

Nitrogen Remobilization ◽

Application Timing ◽

Area Basis ◽

N Remobilization ◽

Leaf N

Premature defoliation of peach and nectarine (Prunus persica L. Batsch) trees resulting from foliar applications of ZnSO4 reduced N remobilization that typically occurs during leaf senescence. Leaf N remobilization in unsprayed control trees ranged from 45% to 50%, irrespective of tree N status. Leaf N remobilization in trees receiving foliar applications of ZnSO4 ranged from a positive influx of N into the leaf to ≈30% of the N remobilized, depending on ZnSO4 application timing and method of expressing leaf N levels. Early ZnSO4 applications resulted in less N remobilization. Measuring leaf N on an area basis was a more precise indicator of N remobilization than N per unit dry weight, because leaf weight per unit area changes during leaf senescence.

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