Identification of mature peptides from pban and capa genes of the moths Heliothis peltigera and Spodoptera littoralis.

By transcriptome analysis, we identified PBAN and CAPA precursors in the moths Spodoptera littoralis and Heliothis peltigera which are among the most damaging pests of agriculture in tropical and subtropical Africa as well as in Mediterranean countries. A combination of mass spectrometry and immunocytochemistry was used to identify mature peptides processed from these precursors and to reveal their spatial distribution in the CNS. We found that the sites of expression of pban genes, the structure of PBAN precursors and the processed neuropeptides are very similar in noctuid moths.

Tomato facultative parthenocarpy results from SlAGAMOUS-LIKE 6 loss of function.

The extreme sensitivity of the microsporogenesis process to moderately high or low temperatures is a major hindrance for tomato (Solanum lycopersicum) sexual reproduction and hence year-round cropping. Consequently, breeding for parthenocarpy, namely, fertilization-independent fruit set, is considered a valuable goal especially for maintaining sustainable agriculture in the face of global warming. A mutant capable of setting high-quality seedless (parthenocarpic) fruit was found following a screen of EMS-mutagenized tomato population for yielding under heat stress.

Interplay of MYB factors in differential cell expansion, and consequences for tomato fruit development.

We previously identified SlFSM1 as an early fruit-specific gene encoding a short protein harboring a non-canonical SANT/MYB-like domain. Here, we investigated the role of FSM1 during fruit development in tomato and its mode of action. By analyzing tomato plants ectopically expressing FSM1, we established that it negatively affects cell expansion, particularly of those cells with the highest potential to expand, such as those residing inner to the vascular bundles in the fruit pericarp.

Improved yielding and reduced puffiness under extreme temperatures induced by fruit-specific expression of rolB in processing tomatoes.

Tomato fruit production is severely hampered by both extremely high and low temperatures, mainly due to impaired microsporogenesis and pollination under these conditions. Even mild temperature stress, leading to partial damage to pollen viability can result in the production of under-fertilized puffy fruits of poor quality, while severe stress can abolish fruit set completely. Genetic or transgenic parthenocarpy that enables fertilization-independent fruit development offers a solution for tomato yielding under conditions unfavorable for pollen production and/or fertilization.

Modulated fatty acid desaturation via overexpression of two distinct omega-3 desaturases differentially alters tolerance to various abiotic stresses in transgenic tobacco cells and plants.

Changes in the degree of fatty acid (FA) desaturation are implicated in plant responses to various abiotic stresses, including heat, salt and drought. However, it is still not known whether decreased levels of linolenic acid, found in many plants subjected to salt and drought stress, reflect a mechanism of defence or damage. We addressed this question by generating tobacco cells and plants ectopically overexpressing two FA desaturases: the cytosolic FAD3 or the plastidic FAD8.

The tomato early fruit specific gene Lefsm1 defines a novel class of plant-specific SANT/MYB domain proteins.

We describe here a novel plant-specific gene, Lefsm1 (fruit SANT/MYB-like 1) harboring a single SANT/MYB domain. The expression of Lefsm1 is specific to the very early stages of tomato (Lycopersicon esculentum) fruit development. Ectopic expression of Lefsm1 results in severe developmental alterations manifested in retarded growth, and reduced apical dominance during tomato and Arabidopsis seedling development.

Induction of parthenocarpy in tomato via specific expression of the rolB gene in the ovary.

The molecular signals for the development of the ovary into fruit following ovule fertilization are not clear. However, in many species, including tomato ( Lycopersicon esculentum Mill.), auxins and auxin transport inhibitors can substitute for fertilization as activators of fruit set, suggesting that this plant hormone plays a key role in this process.

Physical mapping of plastid DNA variation among eleven Nicotiana species.

Plastid DNA of seven American and four Australian species of the genus Nicotiana was examined by restriction endonuclease analysis using the enzymes Sal I, Bgl I, Pst I, Kpn I, Xho I, Pvu II and Eco RI. These endonucleases collectively distinguish more than 120 sites on N. tabacum plastid DNA.

Isolation of folded chromosomes from the yeast Saccharomyces cerevisiae.

Two fast-sedimenting chromatin complexes with sedimentation velocities of approximately 4600 and 3000 S can be isolated from logarithmically growing diploid Saccaromyces cerevisiae cells. The DNA in both structures appears to be folded into at least 60 domains and characterized by a negative superhelical density. Sensitivity to proteases and insensitivity to RNases suggest that proteins and not RNA are important in maintaining the organization of the chromosomes in both structures.

DNA Degradation and reduced recombination following UV irradiation during meiosis in yeast (Saccharomyces cerevisiae).

Irradiation of meiotic yeast cells with moderate doses of ultraviolet irradiation (1,600 erg/mm2) leads to the arrest of premeiotic DNA synthesis, massive (5-40%) DNA degradation, and a 40-50% loss of cell viability. In contrast, such doses of UV irradiation had a minor effect on viability (15-20% loss) of logarithmically growing cells, and no comparable DNA degradation was observed in irradiated synchronized vegetative cells. Meiotic recombination is also affected by UV irradiation.

Sensitivity of meiotic yeast cells to ultraviolet light.

Sporulating cells of Saccharomyces cerevisiae show an increasing sensitivity to ultraviolet irradiation. Maximum sensitivity is reached at a time comparable to meiotic prophase. Sensitivity is expressed as reduced sporulation after the irradiation.