Benzenesulfonamide compounds for somatic embryogenesis in plants

Benzenesulfonamide compounds potentiate 2,4-D induced embryogenesis in plants. In particular, 4-chloro-N-methyl-N-(2-methylphenyl) benzenesulfonamide and analogs induce somatic embryogenesis in plants. Methods of inducing somatic embryogenesis comprise exposing selected plant tissues, e.g. seed embryos, to auxins, e.g. 2.4-D and the benzenesulfonamide compounds. Compounds can be prepared by reacting sulfonyl chloride, an amine and pyridine in CH2CI2. Crude product is suspended in ethyl acetate and washed in sodium and potassium hydrogen sulphates and brine, then dried and filtered

Substituted dihydropyrtoines for somatic embryogenesis in plants

Cyclopentyl 2,7,7-trimethyl-5-oxo-4-(4-pyridinyl)-1,4,5,6,7,8-hexahydro-3- quinolinecarboxylate and similar compounds are potentiators of auxin-induced somatic embryogenesis in plants. In particular, the inventors have discovered certain of these compounds induce somatic embryogenesis in Arabidopsis in the presence of 2,4-D. Also tested is BAY K 8644. Methods of inducing somatic embryogenesis comprise exposing selected plant tissues, e.g. seed embryos, to auxins, e.g. 2.4-D and the compounds

Gas exchange and heart rate in the harbour porpoise, Phocoena phocoena

The respiratory physiology, heart rates and metabolic rates of two captive juvenile male harbour porpoises (both 28 kg) were measured using a rapid-response respiratory gas analysis system in the laboratory. Breath-hold durations in the laboratory (12 +/- 0.3 s, mean +/- SEM) were shorter than field observations. although a few breath-holds of over 40 s were recorded. The mean percentage time spent submerged was 89 +/- 0.4%. Relative to similarly-sized terrestrial mammals, the respiratory frequency was low (4.9 +/- 0.19 breaths min(-1)) but with high tidal volumes (1.1 +/- 0.01 l), enabling a comparatively high minute rate of gas exchange. Oxygen consumption under these experimental conditions (247 +/- 13.8 ml O-2. min(-1)) was 1.9-fold higher than predicted by standard scaling relations. These data together with an estimate of the total oxygen stores predicted an aerobic dive limit of 5.4 min. The peak end-tidal O-2 values were related to the length of the previous breath-hold, demonstrating the increased oxygen uptake from the lung for the longer dives. Blood oxygen capacity was 23.5 +/- 1.0 ml.100 ml(-1), and the oxygen affinity was high, enabling rapid oxygen loading during ventilation.</p

Mis-expression of the CLV3/ESR-like gene CLE19 in Arabidopsis leads to a consumption of root meristem

Mild heat shock treatment (32 °C) of isolated Brassica napus microspores triggers a developmental switch from pollen maturation to embryo formation. This in vitro system was used to identify genes expressed in globular to heart-shape transition embryos. One of the genes isolated encodes a putative extra-cellular protein that exhibits high sequence similarity with the in silico identified CLV3/ESR-related 19 polypeptide from Arabidopsis (AtCLE19) and was therefore named BnCLE19. BnCLE19 is expressed in the primordia of cotyledons, sepals and cauline leaves, and in some pericycle cells in the root maturation zone. Mis-expression of BnCLE19 or AtCLE19 in Arabidopsis under the control of the CaMV 35S promoter resulted in a dramatic consumption of the root meristem, the formations of pin-shaped pistils and vascular islands. These results imply a role of CLE19 in promoting cell differentiation or inhibiting cell divisio

Cross-talk between sporophyte and gametophyte generations is promoted by CHD3 chromatin remodelers in Arabidopsis thaliana

Angiosperm reproduction requires the integrated development of multiple tissues with different genotypes. To achieve successful fertilization, the haploid female gametophytes and diploid ovary must coordinate their development, after which the male gametes must navigate through the maternal sporophytic tissues to reach the female gametes. After fertilization, seed development requires coordinated development of the maternal diploid integuments, the triploid endosperm, and the diploid zygote. Transcription and signaling factors contribute to communication between these tissues, and roles for epigenetic regulation have been described for some of these processes. Here we identify a broad role for CHD3 chromatin remodelers in Arabidopsis thaliana reproductive development. Plants lacking the CHD3 remodeler, PICKLE, exhibit various reproductive defects including abnormal development of the integuments, female gametophyte, and pollen tube, as well as delayed progression of ovule and embryo development. Genetic analyses demonstrate that these phenotypes result from loss of PICKLE in the maternal sporophyte. The paralogous gene PICKLE RELATED 2 is preferentially expressed in the endosperm and acts antagonistically with respect to PICKLE in the seed: loss of PICKLE RELATED 2 suppresses the large seed phenotype of pickle seeds. Surprisingly, the alteration of seed size in pickle plants is sufficient to determine the expression of embryonic traits in the seedling primary root. These findings establish an important role for CHD3 remodelers in plant reproduction and highlight how the epigenetic status of one tissue can impact the development of genetically distinct tissues