Relationships between biomass allocation, axis organogenesis and organ expansion under shading and water deficit conditions in grapevine

2015 ◽  
Vol 42 (12) ◽  
pp. 1116 ◽  
Author(s):  
Benoît Pallas ◽  
Angélique Christophe
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Leaf Area ◽  
Water Deficit ◽  
Biomass Allocation ◽  
Abiotic Stresses ◽  
Sink Strength ◽  
Secondary Axis ◽  
Whole Plant ◽  
Abiotic Constraints

The relationships between whole-plant growth and morphogenetic processes under abiotic stresses are still partly unknown. Whole-plant biomass growth can be decreased by many abiotic stresses, including water deficit and shading. Two experiments were performed on potted plants of one grapevine cultivar (Vitis vinifera L. cv. Syrah) subjected to watering and shading treatments. Under water stress, plants reduced their primary and secondary axis leaf production rate, whereas secondary axis budburst was relatively unaffected. Individual leaf area was reduced and a strong decrease in leaf expansion rate was observed. Under shading, primary axis organogenesis was maintained, both secondary axis budburst rate and phytomer appearance rate were decreased, and individual leaf area slightly increased. Specific leaf area did not change under soil water deficit, whereas it increased under shading. These results confirm the existence of dynamic changes in organ sink strength and biomass allocation patterns to favour plant leaf area growth under shading, and to reduce plant leaf area and water losses by transpiration under water stress. From a modelling point of view, this study shows that functional structural models based on a C balance are not fully relevant for simulating plant growth under abiotic constraints if they do not include non-trophic relationships (hormonal signalling or plant hydraulic properties) that modify organ sink strength according to abiotic constraints.

Sink strength of citrus rootstocks under water deficit

2021 ◽  
Author(s):  
Simone F da Silva ◽  
Marcela T Miranda ◽  
Vladimir E Costa ◽  
Eduardo C Machado ◽  
Rafael V Ribeiro
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Water Deficit ◽  
Carbon Allocation ◽  
Sink Strength ◽  
Rangpur Lime ◽  
Carbon Supply ◽  
Valencia Orange ◽  
Source Sink ◽  
Orange Trees

Abstract Carbon allocation between source and sink organs determines plant growth and is influenced by environmental conditions. Under water deficit, plant growth is inhibited before photosynthesis and shoot growth tends to be more sensitive than root growth. However, the modulation of source-sink relationship by rootstocks remain unsolved in citrus trees under water deficit. Citrus plants grafted on Rangpur lime are drought tolerant, which may be related to a fine coordination of the source-sink relationship for maintaining root growth. Here, we followed 13C allocation and evaluated physiological responses and growth of Valencia orange trees grafted on three citrus rootstocks (Rangpur lime, Swingle citrumelo and Sunki mandarin) under water deficit. As compared to plants on Swingle and Sunki rootstocks, ones grafted on Rangpur lime showed higher stomatal sensitivity to the initial variation of water availability and less accumulation of non-structural carbohydrates in roots under water deficit. High 13C allocation found in Rangpur lime roots indicates this rootstock has high sink demand associated with high root growth under water deficit. Our data suggest that Rangpur lime rootstock used photoassimilates as sources of energy and carbon skeletons for growing under drought, which is likely related to increases in root respiration. Taken together, our data revealed that carbon supply by leaves and delivery to roots are critical for maintaining root growth and improving drought tolerance, with citrus rootstocks showing differential sink strength under water deficit.

scholarly journals Growth of sweet pepper plants submitted to water tensions in soil and potassium silicate doses

2019 ◽  
Vol 37 (1) ◽  
pp. 82-88
Author(s):  
Alexandre Igor A Pereira ◽  
João de Jesus Guimarães ◽  
João Victor Costa ◽  
Fernando S de Cantuário ◽  
Leandro C Salomão ◽  
...  
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Soil Water ◽  
Leaf Area ◽  
Capsicum Annuum ◽  
Sweet Pepper ◽  
Potassium Silicate ◽  
Growth Responses ◽  
Resistance Inducers ◽  
Pepper Plants

ABSTRACT Water stress compromises plant growth. Resistance inducers, such as potassium silicate (K2SiO3), can reduce negative effects of this stress on Solanaceae, Capsicum annuum. Plant height, stem diameter and leaf area may indicate the efficiency of potassium silicate foliarsprayagainst water stress. The aim of this study was to evaluate the growth of sweet pepper plants under water stress and K2SiO3 doses. The experiment was conducted in randomized blocks in a split-plot scheme in space. The treatments consisted of four soil water stresses: 15 kPa (field capacity), 25 (intermediate value), 35 and 45 kPa (water stress) and three doses of potassium silicate (0, 0.4 and 0.8 L 100 L-1 water), acting as resistance inducers to water stress. The resistance inducer maintained greater heights of the sweet pepper plants, under water stress (35 and 45 kPa) at the initial stage [(20 days after transplanting (DAT)]. Smaller plant diameters were observed at 80 and 100 DAT at 35 and 45 kPa. Sprays using K2SiO3 maintained sweet pepper leaf area with higher values, even under stress condition. The soil water tension from 35 kPa limited, in general, the plant growth. Growth responses in Capsicum annuum to K2SiO3, via foliar spraying, varied according to plant age, as well as the growth parameter considered in this experiment.

Effect of endophytic fungus Piriformospora indica on yield and some physiological traits of millet (Panicum miliaceum) under water stress

2018 ◽  
Vol 69 (6) ◽  
pp. 594 ◽  
Author(s):  
Goudarz Ahmadvand ◽  
Somayeh Hajinia
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Leaf Area ◽  
Water Deficit ◽  
Flag Leaf ◽  
Piriformospora Indica ◽  
Physiological Traits ◽  
Water Deficit Stress ◽  
Panicum Miliaceum ◽  
Severe Water Stress

Piriformospora indica is one of the cultivable root-colonising endophytic fungi of the order Sebacinales, which efficiently promote plant growth, uptake of nutrients, and resistance to biotic and abiotic stresses. The aim of this study was to evaluate the effect of P. indica on millet (Panicum miliaceum L.) under water-stress conditions. Two field experiments were carried out in a factorial arrangement at Bu-Ali Sina University of Hamedan, Iran, during 2014 and 2015. The first factor was three levels of water-deficit stress, with irrigation after 60 mm (well-watered), 90 mm (mild stress) and 120 mm (severe stress) evaporation from pan class A. The second factor was two levels of fungus P. indica: inoculated and uninoculated. Results showed that water-deficit stress significantly decreased grain yield and yield components. Colonisation by P. indica significantly increased number of panicles per plant, number of grains per panicle and 1000-grain weight, regardless of water supply. Inoculation with P. indica increased grain yield by 11.4% (year 1) and 19.72% (year 2) in well-watered conditions and by 35.34% (year 1) and 32.59% (year 2) under drought stress, compared with uninoculated plants. Maximum flag-leaf area (21.71 cm2) was achieved with well-watered conditions. Severe water stress decreased flag-leaf area by 53.36%. Flag-leaf area was increased by 18.64% by fungus inoculation compared with the uninoculated control. Under drought conditions, inoculation with P. indica increased plant height by 27.07% and panicle length by 9.61%. Severe water stress caused a significant decrease in grain phosphorus concentration, by 42.42%, compared with the well-watered treatment. By contrast, grain nitrogen and protein contents were increased about 30.23% and 30.18%, respectively, with severe water stress. Inoculation with P. indica increased grain phosphorus by 24.22%, nitrogen by 7.47% and protein content by 7.54% compared with control. Water stress reduced leaf chlorophyll and carotenoid concentrations, whereas P. indica inoculation enhanced chlorophyll concentrations by 27.18% under severe water stress. The results indicated the positive effect of P. indica on yield and physiological traits of millet in both well-watered and water-stressed conditions.

Effect of sink size on growth response to elevated atmospheric CO2 within the genus Brassica

1998 ◽  
Vol 76 (5) ◽  
pp. 829-835 ◽  
Author(s):  
Edward G Reekie ◽  
Glenn MacDougall ◽  
Ivan Wong ◽  
Peter R Hicklenton
Keyword(s):  
Leaf Area ◽  
Carbon Storage ◽  
Biomass Allocation ◽  
Growth Response ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Sink Strength ◽  
Carbon Sinks ◽  
Source To Sink ◽  
Storage Structures

Many plants grown at elevated CO2 concentrations exhibit enhanced photosynthetic rates. However, this increase in photosynthesis is often reduced after prolonged exposure to elevated CO2. This reduction may be related to the capacity of plants to utilize the extra photosynthate produced at elevated CO2. This study examined the effect of source to sink ratio on the capacity of plants to respond to elevated CO2. Seven species or cultivars within the genus Brassica were germinated and grown at either 350 or 1000 ppm CO2. Broccoli (Brassica oleracea L.) and cauliflower (B. oleracea L.) have large carbon sinks in the reproductive structures; Chinese broccoli (Brassica campestris L.) and marrow stem kale (B. oleracea) have carbon sinks in the stem; turnip (B. campestris) stores carbon in the root; rape (Brassica napus L.) and white mustard (Brassica alba (L.) Rabenh.) have no obvious carbon storage structures and were assumed to have a lower sink strength relative to the above cultivars. Plants were harvested at three stages of development and total plant weight, leaf area ratio, and allocation to leaf, root, and stem determined. As young seedlings, all cultivars responded positively to elevated CO2. The long-term growth response of different cultivars to CO2 was independent of sink location, but was dependent on sink size. Cultivars with no obvious carbon storage structures showed no significant growth enhancement by elevated CO2 by the end of the experiment. However, neither leaf area ratio nor biomass allocation pattern were reliable predictors of response to CO2 suggesting that assessing differences in source to sink ratio is not necessarily straightforward.Key words: biomass allocation, sink strength, functional groups, elevated carbon dioxide, leaf area ratio.

scholarly journals Biomass Allocation and Root Characteristics of Early-Stage Poplars (Populus spp.) for Assessing Their Water-Deficit Response During SRC Establishment

2021 ◽  
Author(s):  
Matthias Meyer ◽  
Kristin Morgenstern ◽  
Dávid Heilig ◽  
Bálint Heil ◽  
Gábor Kovács ◽  
...  
Keyword(s):  
Leaf Area ◽  
Water Deficit ◽  
Biomass Allocation ◽  
Root Length ◽  
Root Biomass ◽  
Fine Root ◽  
Drought Risk ◽  
Total Leaf Area ◽  
Total Leaf ◽  
Fine Root Length

AbstractEarly above- and belowground biomass fractionation, root diameter composition and allocation of cumulated fine root length per total leaf area of Populus clones have been measured for a pre-assessment of the risk for plantation establishment during spring drought conditions. Four clones of Populus × euramericana, and one P. nigra × P. maximowiczii clone (cv. Max 3), were planted in sandy mix substrate and were exposed to one normal and one deficit watering regime over 65-day greenhouse experiments conducted during early summer. The P. × euramericana hybrids showed plasticity of their root biomass fractions. Although clone Max 3 was among the productive clones, even under deficit watering, it was not able to respond plastically to deficit watering. It showed no increase in the root biomass fraction and no increase in the ratio of cumulated fine root length per total leaf area. Therefore, the clone Max 3 should not be planted under high risk for spring drought. Planting the investigated P. × euramericana clones under water deficit likely involves a lower risk, but clone differences within this group must be considered. It can be concluded that the water deficit response of biomass allocation to roots and of the ratio of fine root length per unit leaf area is suitable traits to improve drought risk assessments that are based on yield response of poplar clones to drought. Percent plant loss data and the yield at the end of the first SRC rotation will be suitable to verify the present greenhouse assessment.

scholarly journals Rethinking root-shoot growth dynamics

2020 ◽  
Author(s):  
David Robinson
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Biomass Allocation ◽  
Plant Biomass ◽  
Wide Spectrum ◽  
Growth Dynamics ◽  
Adaptive Allocation ◽  
Physiological Properties ◽  
Whole Plant ◽  
Rates Of Growth

AbstractUsing a simple plant growth model based on the logistic equation I re-evaluate how biomass allocation between roots and shoots articulates dynamically with the rate of whole-plant biomass production. Defined by parameters reflecting lumped physiological properties, the model constrains roots and shoots to grow sigmoidally over time. From those temporal patterns detailed trajectories of allocation and growth rate are reconstructed. Sigmoid growth trajectories of roots and shoots are incompatible with the dominant ‘functional equilibrium’ model of adaptive allocation and growth often used to explain plants’ responses to nutrient shortage and defoliation. Anything that changes the differential rates of growth between roots and shoots will automatically change allocation and, unavoidably, change whole-plant growth rate. Biomass allocation and whole-plant growth rate are not independent traits. Allocation and growth rate have no unique relationship to one another but can vary across a wide spectrum of possible relationships. When root-shoot allocation seems to respond to the environment it is likely to be a secondary illusory consequence of other primary responses such as localised root proliferation in soil or leaf expansion within canopy gaps. Changes in root-shoot allocation cannot themselves compensate directly for an impairment of growth rate caused by an external factor such as nutrient shortage or defoliation; therefore, such changes cannot be ‘adaptive’.‘The reasons are so simple they often escape notice.’ (James 2012, p. 6).

scholarly journals Nutrient Solution Concentration Affects Whole-plant CO2 Exchange and Growth of Subirrigated Pansy

2002 ◽  
Vol 127 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Marc W. van Iersel ◽  
Jong-Goo Kang
Keyword(s):  
Plant Growth ◽  
Exchange Rates ◽  
Leaf Area ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Gross Photosynthesis ◽  
Whole Plant ◽  
Wide Range ◽  
Shoot To Root Ratio ◽  
Fertilizer Solution

To determine the effect of fertilizer concentration on plant growth and physiology, whole-plant C exchange rates of pansies (Viola ×wittrockiana Gams.) subirrigated with one of four fertilizer concentrations were measured over 30 days. Plants were watered with fertilizer solutions with an electrical conductivity (EC) of 0.15, 1.0, 2.0, or 3.0 dS·m-1 (N at 0, 135, 290, or 440 mg·L-1, respectively). Plants watered with a fertilizer solution with an EC of 2 dS·m-1 had the highest shoot dry weight (DW), shoot to root ratio, leaf area, leaf area ratio (LAR), and cumulative C gain at the end of the experiment compared to those watered with a solution with a higher or lower EC. Shoot tissue concentrations of N, P, K, S, Ca, Fe, Na, and Zn increased linearly with increasing fertilizer concentration. A close correlation between final DW of the plants and the measured cumulative C gain (CCG) (r2 = 0.98) indicated that the C exchange rates were good indicators of plant growth. There were quadratic relationships between fertilizer EC and gross photosynthesis, net photosynthesis, and dark respiration, starting at 13, 12, and 6 days after transplanting, respectively. Although plants fertilized with a fertilizer solution with an EC of 2 dS·m-1 had the highest C exchange rates, the final differences in shoot DW and CCG among ECs of 1.0, 2.0, and 3.0 dS·m-1 were small and it appears that pansies can be grown successfully with a wide range of fertilizer concentrations. Plants with a high LAR also had higher DW, suggesting that increased growth was caused largely by increased light interception. A detrimental effect of high fertilizer concentrations was that it resulted in a decrease in root DW and a large increase in shoot to root ratio.

Whole-Plant Carbon Balance During Osmotic Adjustment to Drought and Salinity Stress

1986 ◽  
Vol 13 (1) ◽  
pp. 33 ◽  
Author(s):  
KJ Mccree
Keyword(s):  
Water Stress ◽  
Leaf Area ◽  
Osmotic Adjustment ◽  
Carbon Balance ◽  
Crop Production ◽  
Metabolic Cost ◽  
Co2 Exchange ◽  
Unit Leaf ◽  
Whole Plant ◽  
The Cost

The whole-plant daily carbon balance (the 24-h sum of photosynthetic input of substrate carbon per plant and loss of carbon through respiration) is the CO2 exchange measure that relates most closely to crop production rates. Water stress reduces the photosynthetic input, reducing both leaf area and photosynthetic rate per unit leaf area. Respiratory losses are reduced more or less proportionately. A less-than-proportional loss was observed during osmotic adjustment in sorghum (Sorghum bicolor (L) Moench): the metabolic cost of storing photosynthate and using it for osmotic adjustment was less than the cost of converting it to new biomass. A slightly increased metabolic cost is often found under salt stress but, in sorghum plants that were salinized and then water stressed, the adverse effects of salt were mitigated by decreased water loss rates and enhanced osmotic adjustment during water stress. More tests involving combined salt and water stress are needed.

scholarly journals Influence of Water Stress on Grapevines Growing in the Field: From Leaf to Whole-Plant Response

1993 ◽  
Vol 20 (2) ◽  
pp. 143 ◽  
Author(s):  
T Winkel ◽  
S Rambal
Keyword(s):  
Water Stress ◽  
Leaf Area ◽  
Water Status ◽  
Stomatal Closure ◽  
Indirect Evidence ◽  
Hydraulic Conductance ◽  
Water Vapour Pressure ◽  
Vitis Vinifera L ◽  
Plant Water ◽  
Whole Plant

A comparative study of soil-plant water relations was conducted on three grapevine cultivars (Vitis vinifera L. cvv. carignane, merlot, shiraz) to investigate their adjustment to short-term and long-term water stress under field conditions. Adjustment was a function of the relative stability of the internal plant water status on diurnal and seasonal scales. On a diurnal scale, stomatal closure in response to water vapour pressure directly contributed to this stability. Indirect evidence suggested an influence of the soil water status on the diurnal stomatal activity. On a seasonal scale, sufficient leaf hydration required high whole-plant hydraulic conductance. This was achieved by either daily stomatal regulation or limitation of leaf area. Physiological adjustment to water stress through stomatal control was well developed in cv. carignane, which originated in a Mediterranean environment. However, cv. shiraz, which was of mesic origin, apparently adjusted to water stress by reducing leaf area. Our study demonstrates the utility of integrating data on stomatal conductance, leaf water potential and whole-plant hydraulic conductance to interpret whole plant adaptation to water stress, and elucidates two mechanisms by which genotypes differentially acclimate to water stress.

scholarly journals Limitations on Growth and Net Gas Exchange of Diploid and Tetraploid Citrus Rootstock Cultivars Grown at Elevated CO2

2000 ◽  
Vol 125 (2) ◽  
pp. 228-234 ◽  
Author(s):  
J.P. Syvertsen ◽  
L.S. Lee ◽  
J.W Grosser
Keyword(s):  
Gas Exchange ◽  
Plant Growth ◽  
Leaf Area ◽  
Dry Weight ◽  
Poncirus Trifoliata ◽  
Plant Transpiration ◽  
Whole Plant ◽  
Volkamer Lemon ◽  
Citrus Rootstock ◽  
Fibrous Roots

Diploid (2x) and autotetraploid (4x) Citrus L. rootstock cultivars were grown at elevated CO2 to obtain insights into limitations on growth and net gas exchange that have been associated with tetraploidy. Well-nourished 2x and 4x seedlings of `Volkamer' lemon (Volk, C. volkameriana Ten & Pasq.), `Troyer' citrange [Troy, C. sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.] and `Cleopatra' mandarin (Cleo, C. reticulata Blanco.), were grown in greenhouses at either ambient or twice ambient CO2 for 4 months. Plant growth, water relations, mineral nutrition, and net gas exchange characteristics of leaves were measured. Most 4x plants were smaller and had lower rates of whole plant transpiration but shorter fibrous roots than 2x plants. Fibrous roots of 4x were thicker than 2x roots as indicated by a lower specific root length (SRL) in 4x than in 2x roots. Root hydraulic conductivity was correlated to total plant growth but there were no effects of CO2 or ploidy on root conductivity. Tetraploid leaves had lower N concentrations than 2x leaves when expressed on a dry weight basis but these differences disappeared when N concentration was expressed on an leaf area basis because 4x leaves had more leaf dry weight per area (LDW/a) than 2x leaves. Plant growth was greater and SRL was lower at elevated CO2 than at ambient CO2. LDW concentrations of N, P, and K were lower at elevated CO2 than at ambient apparently due to a growth dilution effect. LDW/a, net CO2 assimilation (ACO2), and leaf water use efficiency were greater at elevated CO2 than at ambient. Overall, there was no effect of ploidy on ACO2 but 4x Volk and Troy had lower rates of ACO2 than their 2x at elevated CO2. Net gas exchange of tetraploid leaves was less responsive to elevated CO2 than 2x leaves. The low SRL of tetraploids was correlated with low whole plant transpiration rates and low leaf area-based N concentrations, which may be operative in determining the growth characteristics associated with tetraploidy.

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