Biotic Interactions in the Rhizosphere: Effects on Plant Growth and Herbivore Development

Analysis of hydrocyanic acid contents of the roots of six sorghum strains revealed the concentration to be high in the seedling, and that it reduced with age. Hydrocyanic acid was also present in the roots of ratoon plants but in lower concentrations than in seed plants of the same strain. Rhizosphere effects on the microbial populations at different stages of plant growth were observed and the effect varied with the strain and age of plant. The rhizosphere:soil (R:S) ratio for bacteria ranged from 1 to 25, for fungi 1 to 17, and for actinomycetes 1 to 6. The rhizosphere effect continued in the ratoon plants in all strains, though to a lesser extent than in seed plants. Statistical analysis of the data for correlation between hydrocyanic acid concentration in roots and the population of rhizosphere microorganisms did not indicate any uniform effect in all the sorghum strains.

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Climate change alters beneficial crop-microbe-invertebrate interactions

10.1101/709089 ◽

2019 ◽

Cited By ~ 1

Author(s):

Sharon E. Zytynska ◽

Moritz Eicher ◽

Michael Rothballer ◽

Wolfgang W. Weisser

Keyword(s):

Climate Change ◽

Plant Growth ◽

Cropping Systems ◽

High Stress ◽

Biotic Interactions ◽

Plant Health ◽

Climate Change Scenarios ◽

Negative Effects ◽

Insect Growth ◽

Rhizosphere Bacterium

Increasing levels of CO2 and tropospheric ozone (O3) due to climate change are contributing to reduced plant health and unstable crop yield production1. The inoculation of plant roots with beneficial fungi or bacteria can increase plant health2. However, this is often studied under very controlled conditions and it is unknown how climate change or interactions with other species can alter the resulting benefits. Here we show that the rhizosphere bacterium Acidovorax radicis N35 can increase plant growth and reduce insect growth – with increased impact in a high-stress elevated O3 environment, but reduced impact under elevated CO2. In a fully-factorial climate chamber experiment we disentangled the impacts of climate factors (elevated CO2 and elevated O3) and biotic interactions (plant cultivar, sap-feeding insects and earthworms) on cereal growth and insect suppression mediated by A. radicis N35. Earthworms promoted plant aboveground growth, whereas A. radicis N35 promoted root growth, and overall plant growth was higher when both species were present. However, earthworms also promoted insect growth and therefore increased plant damage through herbivory. While A. radicis N35 inoculation was able to mitigate these negative effects to some extent under an ambient environment this was lost under climate change conditions. Our results show that knowledge-based solutions for sustainable agriculture should include biotic interactions and must be tested across variable climate change scenarios in order to build resilient cropping systems.

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The Impact of Phosphorus on Plant Immunity

Plant and Cell Physiology ◽

10.1093/pcp/pcaa168 ◽

2021 ◽

Author(s):

Ching Chan ◽

Ya-Yun Liao ◽

Tzyy-Jen Chiou

Keyword(s):

Plant Growth ◽

Immune Responses ◽

Plant Immunity ◽

Biotic Interactions ◽

P Availability ◽

Phosphate Transporters ◽

Soil P ◽

Soil P Availability ◽

The Impact ◽

Significant Attention

Abstract Phosphorus (P) is the second most essential macronutrient in terms of limiting plant growth. The genes involved in P acquisition, transport, storage, utilization and respective regulation have been extensively studied. In addition, significant attention has been given to the crosstalk between P and other environmental stresses. In this review, we summarize recent discoveries pertaining to the emerging function of P in plant immunity. The roles of external soil P availability, internal cellular P in plants, P starvation signaling machinery and phosphate transporters in biotic interactions are discussed. We also highlight the impact of several phytohormones on the signaling convergence between cellular P and immune responses. This information may serve as a foundation for dissecting the molecular interaction between nutrient responses and plant immunity.

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Stability and dynamics of enzyme activity patterns in the rice rhizosphere: Effects of plant growth and temperature

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2017.06.005 ◽

2017 ◽

Vol 113 ◽

pp. 108-115 ◽

Cited By ~ 41

Author(s):

Tida Ge ◽

Xiaomeng Wei ◽

Bahar S. Razavi ◽

Zhenke Zhu ◽

Yajun Hu ◽

...

Keyword(s):

Enzyme Activity ◽

Plant Growth ◽

Activity Patterns ◽

Rice Rhizosphere ◽

Rhizosphere Effects

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Cytokinin Regulation of Source-Sink Relationships in Plant-Pathogen Interactions

Frontiers in Plant Science ◽

10.3389/fpls.2021.677585 ◽

2021 ◽

Vol 12 ◽

Author(s):

Kathryn E. McIntyre ◽

Daniel R. Bush ◽

Cristiana T. Argueso

Keyword(s):

Amino Acids ◽

Cell Division ◽

Plant Growth ◽

Plant Hormones ◽

Plant Pathogen ◽

Growth And Development ◽

Biotic Interactions ◽

Plant Growth And Development ◽

Source Sink ◽

Plant Pathogen Interactions

Cytokinins are plant hormones known for their role in mediating plant growth. First discovered for their ability to promote cell division, this class of hormones is now associated with many other cellular and physiological functions. One of these functions is the regulation of source-sink relationships, a tightly controlled process that is essential for proper plant growth and development. As discovered more recently, cytokinins are also important for the interaction of plants with pathogens, beneficial microbes and insects. Here, we review the importance of cytokinins in source-sink relationships in plants, with relation to both carbohydrates and amino acids, and highlight a possible function for this regulation in the context of plant biotic interactions.

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Mechanisms of ethylene biosynthesis and response in plants

Essays in Biochemistry ◽

10.1042/bse0580061 ◽

2015 ◽

Vol 58 ◽

pp. 61-70 ◽

Cited By ~ 11

Author(s):

Paul B. Larsen

Keyword(s):

Plant Growth ◽

Growth And Development ◽

Ethylene Biosynthesis ◽

Unsaturated Hydrocarbon ◽

Flower Senescence ◽

Detailed Knowledge ◽

Plant Growth And Development ◽

Step Process ◽

Ethylene Response ◽

Ethylene Signalling

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.

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Episodic whole plant growth patterns in Ligustrum

Physiologia Plantarum ◽

10.1034/j.1399-3054.1993.890106.x ◽

1993 ◽

Vol 89 (1) ◽

pp. 33-39 ◽

Cited By ~ 1

Author(s):

Jeff S. Kuehny ◽

Mary C. Halbrooks

Keyword(s):

Plant Growth ◽

Growth Patterns ◽

Whole Plant

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