Plant-Plant Communications: Rhizosphere Signaling between Parasitic Angiosperms and Their Hosts

International Allelopathy Society has redefined Allelopathy as any process involving secondary metabolities produced by plants, algae, bacteria, fungi and viruses that influences the growth and development of agricultural and biological system; a study of the functions of secondary metabolities, their significance in biological organization, their evolutionary origin and elucidation of the mechanisms involving plant-plant, plant-microorganisms, plant-virus, plant-insect, plant-soil-plant interactions.

Download Full-text

Plant–plant communication and community of herbivores on tall goldenrod

Ecology and Evolution ◽

10.1002/ece3.7575 ◽

2021 ◽

Author(s):

Kaori Shiojiri ◽

Satomi Ishizaki ◽

Yoshino Ando

Keyword(s):

Plant Communication ◽

Tall Goldenrod ◽

Plant Plant

Download Full-text

Competition-free gaps are essential for the germination and recruitment of alpine species along an elevation gradient in the European Alps

Alpine Botany ◽

10.1007/s00035-021-00264-9 ◽

2021 ◽

Author(s):

Vera Margreiter ◽

Janette Walde ◽

Brigitta Erschbamer

Keyword(s):

Vegetation Cover ◽

Seedling Recruitment ◽

Environmental Control ◽

Elevation Gradient ◽

European Alps ◽

Plant Interactions ◽

Experimental Conditions ◽

Positive Effects ◽

Seed Sowing ◽

Plant Plant

AbstractSeed germination and seedling recruitment are key processes in the life cycle of plants. They enable populations to grow, migrate, or persist. Both processes are under environmental control and influenced by site conditions and plant–plant interactions. Here, we present the results of a seed-sowing experiment performed along an elevation gradient (2000–2900 m a.s.l.) in the European eastern Alps. We monitored the germination of seeds and seedling recruitment for 2 years. Three effects were investigated: effects of sites and home sites (seed origin), effects of gaps, and plant–plant interactions. Seeds of eight species originating from two home sites were transplanted to four sites (home site and ± in elevation). Seed sowing was performed in experimentally created gaps. These gap types (‘gap + roots’, ‘neighbor + roots’, and ‘no-comp’) provided different plant–plant interactions and competition intensities. We observed decreasing germination with increasing elevation, independent of the species home sites. Competition-released gaps favored recruitment, pointing out the important role of belowground competition and soil components in recruitment. In gaps with one neighboring species, neutral plant–plant interactions occurred (with one exception). However, considering the relative vegetation cover of each experimental site, high vegetation cover resulted in positive effects on recruitment at higher sites and neutral effects at lower sites. All tested species showed intraspecific variability when responding to the experimental conditions. We discuss our findings considering novel site and climatic conditions.

Download Full-text

Trichoderma Strains and Metabolites Selectively Increase the Production of Volatile Organic Compounds (VOCs) in Olive Trees

Metabolites ◽

10.3390/metabo11040213 ◽

2021 ◽

Vol 11 (4) ◽

pp. 213

Author(s):

Irene Dini ◽

Roberta Marra ◽

Pierpaolo Cavallo ◽

Angela Pironti ◽

Immacolata Sepe ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Gas Chromatography Mass Spectrometry ◽

Lipid Signaling ◽

Plant Interactions ◽

Growth Promoters ◽

Volatile Organic ◽

Trichoderma Fungi ◽

Olive Trees ◽

Plant Plant

Plants emit volatile organic compounds (VOCs) that induce metabolomic, transcriptomic, and behavioral reactions in receiver organisms, including insect pollinators and herbivores. VOCs’ composition and concentration may influence plant-insect or plant-plant interactions and affect soil microbes that may interfere in plant-plant communication. Many Trichoderma fungi act as biocontrol agents of phytopathogens and plant growth promoters. Moreover, they can stimulate plant defense mechanisms against insect pests. This study evaluated VOCs’ emission by olive trees (Olea europaea L.) when selected Trichoderma fungi or metabolites were used as soil treatments. Trichoderma harzianum strains M10, T22, and TH1, T. asperellum strain KV906, T. virens strain GV41, and their secondary metabolites harzianic acid (HA), and 6-pentyl-α-pyrone (6PP) were applied to olive trees. Charcoal cartridges were employed to adsorb olive VOCs, and gas chromatography mass spectrometry (GC-MS) analysis allowed their identification and quantification. A total of 45 volatile compounds were detected, and among these, twenty-five represented environmental pollutants and nineteen compounds were related to olive plant emission. Trichoderma strains and metabolites differentially enhanced VOCs production, affecting three biosynthetic pathways: methylerythritol 1-phosphate (MEP), lipid-signaling, and shikimate pathways. Multivariate analysis models showed a characteristic fingerprint of each plant-fungus/metabolite relationship, reflecting a different emission of VOCs by the treated plants. Specifically, strain M10 and the metabolites 6PP and HA enhanced the monoterpene syntheses by controlling the MEP pathway. Strains GV41, KV906, and the metabolite HA stimulated the hydrocarbon aldehyde formation (nonanal) by regulating the lipid-signaling pathway. Finally, Trichoderma strains GV41, M10, T22, TH1, and the metabolites HA and 6PP improve aromatic syntheses at different steps of the shikimate pathway.

Download Full-text