Allelopathy studies the interactions among plants, fungi, algae and bacteria with the organisms living in a certain ecosystem, interactions that are mediated by the secondary metabolites produced and exuded into the environment. Consequently, allelopathy is a multidisciplinary science where ecologists, chemists, soil scientists, agronomists, biologists, plant physiologists and molecular biologists offer their skills to give an overall view of the complex interactions occurring in a certain ecosystem. As a result of these studies, applications in weed and pest management are expected in such different fields as development of new agrochemicals, cultural methods, developing of allelopathic crops with increased weed resistance, etc. The present paper will focus on the chemical aspects of allelopathy, pointing out the most recent advances in the chemicals disclosed, their mode of action and their fate in the ecosystem. Also, attention will be paid to achievements in genomics and proteomics, two emerging fields in allelopathy. Rather than being exhaustive, this paper is intended to reflect a critical vision of the current state of allelopathy and to point to future lines of research where in the authors' opinion the main advances and applications could and should be expected.

Allelopathy--a natural alternative for weed control.

Allelopathy can be defined as an important mechanism of plant interference mediated by the addition of plant-produced secondary products to the soil rhizosphere. Allelochemicals are present in all types of plants and tissues and are released into the soil rhizosphere by a variety of mechanisms, including decomposition of residues, volatilization, and root exudation. Allelochemical structures and modes of action are diverse and may offer potential for the development of future herbicides. We have focused our review on a variety of weed and crop species that establish some form of potent allelopathic interference, either with other crops or weeds, in agricultural settings, in the managed landscape, or in naturalized settings. Recent research suggests that allelopathic properties can render one species more invasive to native species and thus potentially detrimental to both agricultural and naturalized settings. In contrast, allelopathic crops offer strong potential for the development of cultivars that are ...

Weed and Crop Allelopathy

In the twelve years since the first review article dealing with chemical constituents of the Hepaticae appeared in this series as Volume 42 (19), several short reviews concerned with chemical constituents of bryophytes have been published (22, 96, 144, 265, 271, 647, 649, 650) In 1988, a Symposium on Chemistry and Chemical Taxonomy of Bryophytes was organised on the behalf of the Phytochemical Society of Europe; the proceedings of this meeting appeared as a book entitled Bryophytes: Their Chemistry and Chemical Taxonomy (651) The symposium concerned itself with phytochemical, biochemical, botanical, chemotaxonomical, pharmaceutical, biotechnological and environmental aspects of bryophytes as well as with the synthesis of the terpenoids and aromatic compounds bryophytes elaborate The physiological and biochemical aspects of bryophytes have also been described in a recent book Bryophytes Development: Physiology and Biochemistry (139)

Chemical Constituents of the Bryophytes

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1125&context=bbmb_ag_pubs

Two rings in them all: The labdane-related diterpenoids

Plant--fungal interactions: the search for phytoalexins and other antifungal compounds from higher plants.

Momilactones, Growth inhibitors from rice, Oryza sativa L

Growth and germination inhibitors in rice husks

1-Acyl-2-alkyl-6-hydroxyfulvenes have been found to rearrange to 1-acyl-3-alkyl-6-hydroxyfulvenes on heating. Kinetics and other mechanistic studies including 13C-labeling experiment indicate that the acyl group migrates intramolecularly. The acyl migration may proceed by two consecutive [1,5] acyl shifts via a 5,5-diacylcyclopentadiene toward the less crowded 3-alkyl isomer.

Kenichi Fujita

Papers

Momilactones, Growth inhibitors from rice, Oryza sativa L

Growth and germination inhibitors in rice husks

Thermal rearrangement of 1-acyl-2-alkyl-6-hydroxyfulvenes to 1-acyl-3-alkyl-6-hydroxyfulvenes