scholarly journals Leachates from plants recently infected by root-feeding nematodes cause increased biomass allocation to roots in neighbouring plants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Peihua Zhang ◽  
Dries Bonte ◽  
Gerlinde B. De Deyn ◽  
Martijn L. Vandegehuchte

AbstractPlants can adjust defence strategies in response to signals from neighbouring plants attacked by aboveground herbivores. Whether similar responses exist to belowground herbivory remains less studied, particularly regarding the spatiotemporal dynamics of such belowground signalling. We grew the grass Agrostis stolonifera with or without root-feeding nematodes (Meloidogyne minor). Leachates were extracted at different distances from these plants and at different times after inoculation. The leachates were applied to receiver A. stolonifera plants, of which root, shoot, and total biomass, root/shoot ratio, shoot height, shoot branch number, maximum rooting depth and root number were measured 3 weeks after leachate application. Receiver plants allocated significantly more biomass to roots when treated with leachates from nematode-inoculated plants at early infection stages. However, receiver plants’ root/shoot ratio was similar when receiving leachates collected at later stages from nematode-infected or control plants. Overall, early-collected leachates reduced growth of receiver plants significantly. Plants recently infected by root-feeding nematodes can thus induce increased root proliferation of neighbouring plants through root-derived compounds. Possible explanations for this response include a better tolerance of anticipated root damage by nematodes or the ability to grow roots away from the nematode-infected soil. Further investigations are still needed to identify the exact mechanisms.

2006 ◽  
Vol 86 (3) ◽  
pp. 809-815 ◽  
Author(s):  
Youbin Zheng ◽  
Mike Dixon ◽  
Praveen Saxena

Current field cultivation and wild-harvest methods for the medicinal plant Echinacea are struggling to meet the requirements for a high-quality, uniformly produced crop for human consumption. To help meet this challenge, the potential of using a greenhouse production system for Echinacea production was explored. Echinacea purpurea (L.) Moench and angustifolia DC. var. angustifolia plants were grown in three types of greenhouse production systems: (1) deep flow solution culture (D), (2) pots with either Pro-Mix (P) or (3) sand (S). Plants were irrigated with one of three nutrient solutions containing NO3−/NH4+ ratios of 7:1, 5:1 or 3:1, respectively. The plants grown in the Pro-Mix and the sand systems were either well-watered or subjected to periodical water stress. The results obtained after 12 wk of growth showed that Echinacea root production in the greenhouse systems was comparable with or better than that in the field. Based on root and total biomass production, the Pro-Mix system was the best production system for both E. angustifolia and E. purpurea. In most cases, the NO3−/NH4+ ratio did not have significant effects on the growth of either species. When effects were seen, however, higher NO3−/NH4+ levels generally resulted in greater leaf area, root and total biomass, and a higher root/shoot ratio. Mild periodic water stress did not affect the root/shoot ratio or the root biomass in either species. The application of a periodic water stress reduced leaf area of both species, but a reduction in total biomass was only observed in E. purpurea. Key words: Echinacea, greenhouse production, hydroponic production, medicinal plant, NO3−/NH4+ ratio, water stress


2020 ◽  
Author(s):  
Peihua Zhang ◽  
Dries Bonte ◽  
Gerlinde B. De Deyn ◽  
Martijn L. Vandegehuchte

AbstractCommunication between plants mediated by herbivore-induced volatile organic compounds has been extensively studied aboveground. However, the role of root herbivory in belowground plant-plant communication is much less understood. We here investigated whether root herbivores can trigger plant roots to emit warning signals to neighbouring plants that are not yet in direct contact with them.We used a split-root system and infected half of the roots of Agrostis stolonifera plants with root-knot nematodes (Meloidogyne minor) and left the other half uninfected. As a control, we grew plants without nematodes in separate pots. Leachates from each split-root soil compartment and from soils with control plants were applied to separate pots with A. stolonifera plants, of which biomass allocation and morphological traits were measured one month after leachate addition.Plants receiving leachates from the soil with the nematode-free roots of the nematode-infected plants showed a significantly larger total biomass, more root branches, and deeper rooting than plants receiving leachates from the soil with the nematode-infected roots or from soil with control plants. Plants were taller and the root/shoot ratio was higher in plants receiving leachates from soil with the nematode-free roots than in plants receiving leachates from soil with nematode-infected roots. Shoot tiller number was higher in plants receiving leachates from either soil of the nematode-infected plants than in plants receiving control leachates.Our results suggest that an overcompensation response was triggered by systemically induced root-derived compounds from nematode-free roots of a plant locally infected with root-feeding nematodes. Signals from directly attacked roots of the same nematode-infected plant only caused receiver plants to develop more shoot tillers, possibly for future stolon development to grow away from the infected area. This may indicate an anticipatory tolerance response to root feeders that are still distant and an additional generalized escape response to root feeding.


2013 ◽  
Vol 864-867 ◽  
pp. 2478-2484
Author(s):  
Long Hua Ye ◽  
Hai Yong Bao ◽  
Zhi Yun Wang ◽  
Gan Wen Lie ◽  
Hong Yue Chen ◽  
...  

Seedlings ofMichelia macclurei,Cinnamomum camphora,RhodoleiachampioniiandMytilaria laosensiswere placed in open-top chambers (OTC) with three ozonic treatments including E20 (20 ppb), E40 (nature air, 40 ppb) and E160 (160 ppb) and two water treatments. Root biomass, stem biomass and leaf biomass total biomass and root/shoot ratio of four seedling types were evaluated. The results showed that there were no significant differences in impacts of ozone stress and drought stress on root, stem, leaf, and total biomass ofM. macclureiamong different treatments. The biomass ofM. laosensisdecreased with increasing ozone concentration, whereas biomass ofC. camphoraandR. championiichanged irregularly. Most of the biomass of four kind seedlings under ozone and drought intercross stresses was lower than those under ozone stress. The root/shoot ratios of four seedling species were all low. The ratios under high concentration ozone (160 ppb) were lower than the control treatment. And the ratios of different treatments under drought were lower than those were not under drought when they were under the same concentration of ozone.


2017 ◽  
Vol 9 (1) ◽  
pp. 502-507 ◽  
Author(s):  
Parvaze A. Sofi ◽  
Iram Saba ◽  
Zakir Amin

The present study was aimed at assessing the root traits and rhizobial inoculation in relation to drought in common bean, Phaseolus vulgaris. Drought caused the largest decrease in shoot biomass followed by plant height, while an increase was recorded inroot/shoot ratio. Rhizobial inoculation caused largest increase in shoot biomass followed by root volume and root biomass and smallest increase in rooting depth. WB-216 and WB-185 had better rooting depth in all treatments. However, WB-83 (92.67) had highest rooting depth under irrigated conditions and SR-1 had highest rooting depth under irrigated conditions treated with rhizobium (108.50). Similarly, WB-216 had highest root/shoot ratio under drought (2.693) followed by WB-185 (1.285) while lowest value was recorded for Arka Anoop (0.373). In rhizobium treated drought condition, WB-216 recorded highest root/shoot ratio (5.540) followed by SFB-1 (1.967). Under irrigated conditions (both with and without rhizobium), WB-185 recorded highest root/shoot ratio while lowest was recorded for SR-1 (0.166). The mean squares due to root depth, root biomass and root volume were significant whereas the mean squares due to water and rhizobium were non-significant. Among interactions the genotype x water regime was significant for rooting depth (5 % level), genotype x rhizobia was significant for rooting depth and root volume (1 % level) and the interaction of genotype x water regime x rhizobium was significant for rooting depth, root biomass and root volume (1 % level). The results reinforce the need to further analyse the potential of other soil microbes in common bean rhizosphere in amelioration of the effects of water stress.


Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 49 ◽  
Author(s):  
Elizabeth Rogers ◽  
Ronald Zalesny ◽  
Richard Hallett ◽  
William Headlee ◽  
Adam Wiese

Root–shoot allocation of biomass is an underrepresented criterion that could be used for tree selection in phytoremediation. We evaluated how root–shoot allocations relate to biomass production and overall health of poplar and willow clones grown in landfill soil treatments. Fifteen poplar clones and nine willows were grown in a greenhouse for 65 days in soils from five Wisconsin landfills and one greenhouse control. We tested for treatment, clone, and interaction differences in root–shoot ratio (RSR), health, and growth index, along with relationships between RSR with diameter, health, height, total biomass, and growth index. Treatments, clones, and their interactions were not significantly different for poplar RSR, but willow clones differed (p = 0.0049). Health significantly varied among willow clones (p < 0.0001) and among the clone × treatment interaction for poplars (p = 0.0196). Analysis of means showed that willow clones ‘Allegany’ and ‘S365’ exhibited 28% and 21% significantly greater health scores than the overall mean, respectively. Root–shoot ratio was not significantly correlated with health in either genus but was positively correlated with growth index for poplars, which was corroborated via regression analyses. Selecting clones based on a combination of biomass allocation, health, and growth indices may be useful for using phyto-recurrent selection to satisfy site-specific ecosystem services objectives.


2010 ◽  
Vol 28 (2) ◽  
pp. 63-68 ◽  
Author(s):  
Olena P. Zhivotovsky ◽  
Yulia A. Kuzovkina

Abstract Physiological responses and growth of two Salix species — S. miyabeana and S. cinerea — were compared during one and two drought cycles. Photosynthetic rate (Asat), stomatal conductance (gs), and transpiration (E) were determined for each species. The highest total biomass and root: shoot ratio were recorded for S. cinerea. After two drought cycles, S. cinerea had significantly higher Asat at wilting and recovery stages compared to S. miyabeana. In addition, after two drought cycles, the stem water potential and water use efficiency were higher in S. cinerea than in S. miyabeana. Based on the results obtained in this study, S. cinerea is more drought tolerant than S. miyabeana.


2012 ◽  
Vol 48 (3) ◽  
pp. 378-387 ◽  
Author(s):  
NEERAJ KUMAR ◽  
A. S. NANDWAL ◽  
R. S. WALDIA ◽  
S. SINGH ◽  
S. DEVI ◽  
...  

SUMMARYRoot traits, such as depth and root biomass, have been identified as the most promising plant traits in chickpea for terminal drought tolerance. With this objective, five contrasting genotypes of chickpea, viz. ICCV-4958, H-208, HC-5, RSG-931 and CSJ-379, having wide adaptability to drought prone areas at national level were assessed for various root characteristics under two environments, i.e. irrigated and rain-fed. The sampling was done at full bloom stage and there were significant differences in the rooting depth among the genotypes both under irrigated and rain-fed conditions. The chickpea roots penetrated to a minimum depth of 92 cm in CSJ-379 and maximum of 122 cm in ICCV-4958 under rain-fed conditions. The rooting depth remained higher under rain-fed than irrigated environment. Under irrigated conditions, the chickpea roots were able to grow to a maximum depth of 99 and 97 cm in HC-5 and ICCV-4958, respectively. Among the genotypes, biomass per plant of the root was higher in ICCV-4958 (6.7 g) and HC-5 (5.6 g) under rain-fed conditions. Similar observations were recorded for root/shoot ratio, dry weights of stem, leaf, nodules and total dry weight per plant. The moisture stress increased the biomass partitioning towards the roots. The water potential (ψw), osmotic potential (ψs) and relative water content (RWC %) of leaf were –0.98 MPa, –1.82 MPa and 60%, respectively, in the genotype HC-5, and –1.02 MPa, –1.72 MPa and 64%, respectively, in ICCV-4958 under rain-fed conditions. The rates of photosynthesis, and transpiration, values of the stomatal conductance and photochemical efficiency/quantum yield as indicated by Fv/Fm ratio were in the range of 6.7 to 10.6 (μmol m−2 s−1), 1.27 to 2.38 (mmol m−2 s−1), 0.23 to 0.48 (mol m−2 s−1) and 0.457 to 0.584, respectively, under rain-fed conditions. Genotypes HC-5 and ICCV-4958 also maintained higher photosynthetic and transpiration rates and Fv/Fm ratio than others. The maximum Fv/Fm values in these genotypes were correlated with the higher photosynthetic rate and dry matter yield per plant. Relative stress injury (RSI %) values in HC-5 and ICCV-4958 noticed were 25.3% and 23.7%, respectively. The results of this study indicate that under rain-fed conditions, genotypes ICCV-4958 and HC-5 had higher dry weight of stem, leaves, roots, nodules and total dry weight per plant, rooting depth, root/shoot ratio, photosynthetic and transpiration rates, photochemical efficiency and better plant water status but lower stomatal conductance than other genotypes. These traits are directly associated with maximum seed yield per plant, i.e. 15.6 g and 14.7 g per plant, respectively, in these genotypes. Therefore, both the genotypes in future can be used in crop improvement programme of chickpea breeding for drought tolerance.


2013 ◽  
Vol 39 (12) ◽  
pp. 2228 ◽  
Author(s):  
Ye FENG ◽  
Feng GUO ◽  
Bao-Long LI ◽  
Jing-Jing MENG ◽  
Xin-Guo LI ◽  
...  

1965 ◽  
Vol 7 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Miroslav Penka
Keyword(s):  

2021 ◽  
Author(s):  
Xuhui Zhou ◽  
Lingyan Zhou ◽  
Yanghui He ◽  
Yuling Fu ◽  
Zhenggang Du ◽  
...  

Abstract Biomass allocation in plants is fundamental for understanding and predicting terrestrial carbon storage. Recent studies suggest that climate warming can differentially affect root and shoot biomass, and subsequently alter root: shoot ratio. However, warming effects on root: shoot ratio and their underlying drivers at a global scale remain unclear. Using a global synthesis of >300 studies, we here show that warming significantly increases biomass allocation to roots (by 13.1%), and two factors drive this response: mean annual precipitation of the site, and the type of mycorrhizal fungi associated with a plant. Warming-induced allocation to roots is greater in relatively drier habitats compared to shoots (by 15.1%), but lower in wetter sites (by 4.9%), especially for plants associated with arbuscular mycorrhizal fungi compared to ectomycorrhizal fungi. Root-biomass responses to warming predominantly determine the biomass allocation in terrestrial plants suggesting that warming can reinforce the importance of belowground resource uptake. Our study highlights that the wetness or dryness of a site and plants’ mycorrhizal associations strongly regulate terrestrial carbon cycle by altering biomass allocation strategies in a warmer world.


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