Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants.

Since the publication of this paper it has become apparent that an error was made in the scale of the vertical axis in Fig. 6I. This has no impact at all on any of the conclusions in the paper since the differences between the treatments remain as published.

Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants.

Background And Aims: Volatile organic compounds (VOCs) play various roles in plant-plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar 'Alva' cause changes in biomass allocation in plants of the cultivar 'Kara'. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant-plant signalling remains unknown.

Ethylene modulates the role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 in cross talk between salicylate and jasmonate signaling.

The plant hormones salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) play crucial roles in the signaling network that regulates induced defense responses against biotic stresses. Antagonism between SA and JA operates as a mechanism to fine-tune defenses that are activated in response to multiple attackers. In Arabidopsis (Arabidopsis thaliana), NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) was demonstrated to be required for SA-mediated suppression of JA-dependent defenses.

Ethylene-induced differential growth of petioles in Arabidopsis. Analyzing natural variation, response kinetics, and regulation.

Plants can reorient their organs in response to changes in environmental conditions. In some species, ethylene can induce resource-directed growth by stimulating a more vertical orientation of the petioles (hyponasty) and enhanced elongation. In this study on Arabidopsis (Arabidopsis thaliana), we show significant natural variation in ethylene-induced petiole elongation and hyponastic growth.

Midday depression of net photosynthesis in the tropical rainforest tree Eperua grandiflora: contributions of stomatal and internal conductances, respiration and Rubisco functioning.

High midday temperatures can depress net photosynthesis. We investigated possible mechanisms underlying this phenomenon in leaves of Eperua grandiflora (Aubl.) Benth.

Regulation of alternative oxidase activity in six wild monocotyledonous species. An in vivo study at the whole root level.

The activity of the alternative pathway is affected by a number of factors, including the level and reduction state of the alternative oxidase (AOX) protein, and the reduction state of the ubiquinone pool. To investigate the significance of these factors for the rate of alternative respiration in vivo, we studied root respiration of six wild monocotyledonous grass species that were grown under identical controlled conditions. The activity of the alternative pathway was determined using the oxygen isotope fractionation technique.

The effect of nitrate-nitrogen supply on bacteria and bacterial-feeding fauna in the rhizosphere of different grass species.

Microbial growth in the rhizosphere is affected by the release of organic material from roots, so differences in carbon budgets between plants may affect their rhizosphere biology. This was tested by sampling populations of bacteria and bacteriophagous fauna from the rhizosphere of Lolium perenne, Festuca arundinacea, Poa annua, and Poa pratensis, under conditions of high and low nitrate availability. Concentrations of soluble phenolics and lignin varied considerably between the species but were not related to differences in rhizosphere biology.

Possible involvement of inhibin in the interrelationship between numbers of antral follicles and peripheral FSH concentrations in female rats.

The possible dependence of peripheral concentrations of FSH on a non-steroidal, ovarian factor, was studied in adult female rats. Increases in FSH levels during the periovulatory period were not correlated with decreases of steroid concentrations, and administration of steroids did not result in a reduction of FSH levels to basal values. However, a negative correlation between FSH levels and numbers of large follicles (volume greater than or equal to 200 x 10(5) micron 3) was demonstrated, and injection of steroid-free bovine follicular fluid, which contains inhibin-like activity, suppressed FSH levels to basal values.

Effects of factors from ovarian follicular fluid and Sertoli cell culture medium on in-vivo and in-vitro release of pituitary gonadotrophins in the rat: an evaluation of systems for the assay of inhibin.

Inhibin-like activity is present both in testicular and ovarian fluids. Various methods can be used for the detection of this activity. Indirect methods, using organ weights as an endpoint, lack the specificity required for reliable estimation of inhibin-like activity.

Follicle growth in the immature rat ovary.

In ovaries of immature rats the following parameters were estimated from autoradiographs prepared after pulse labelling with tritiated thymidine: 1) The time it takes follicles to grow from one stage of development to another. This could be derived from the total number of granulosa cells in these stages and from their doubling times. The doubling time of granulosa cells was determined from their labelling index and the duration of their DNA-synthesis phase.

Administration of antiserum against ovine follicle-stimulating hormone or ovine luteinizing hormone at pro-poestrus in the rat: effects on follicular development during the oncoming cycle.

Cyclic rats received at 13.00 h on the day of pro-oestrus a single i.v.

Levels of follicle-stimulating hormone, luteinizing hormone, oestradiol-17 beta and progesterone, and follicular growth in the pseudopregnant rat.

Throughout a period of pseudopregnancy the peripheral blood levels of progesterone, oestradiol-17 beta, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), as well as the size-distribution of ovarian antral follicles were estimated in the rat. The progesterone concentrations, as measured by a competitive protein-binding technique, exceeded metoestrous values (25 ng/ml plasma) from day 3 of pseudopregnancy onwards. The highest levels were found on days 6 and 8 (91 ng/ml).