Transcriptomic and physiological shade avoidance responses in potato (Solanum tuberosum) plants.

Plants detect competitors in shaded environments by perceiving a reduction in photosynthetically active radiation (PAR) and the reduction between the red and far-red light (R:FR) ratio and blue photons. These light signals are detected by phytochromes and cryptochromes, which trigger shade avoidance responses such as shoot and petiole elongation and lead to increased susceptibility to pathogen attack. We studied morphological, anatomical, and photosynthesis differences in potato plants (Solanum tuberosum var.

Phytochrome B enhances plant growth, biomass and grain yield in field-grown maize.

Background And Aims: Phytochrome B (phyB) is a photosensory receptor important for the control of plant plasticity and resource partitioning. Whether phyB is required to optimize plant biomass accumulation in agricultural crops exposed to full sunlight is unknown. Here we investigated the impact of mutations in the genes that encode either phyB1 or phyB2 on plant growth and grain yield in field crops of Zea mays sown at contrasting population densities.

Glucuronoarabinoxylans as major cell walls polymers from young shoots of the woody bamboo Phyllostachys aurea.

Young shoots of Phyllostachys aurea showed glucuronoarabinoxylans (GAX) as the major hemicellulosic components, being extracted in major amounts with 1M KOH (ratio Xyl:Ara:GlcA, 100:67:8), but also with water, showing a broad structural variability. Mixed linkage glucans were also present, but in minor amounts, mostly concentrated in the 4M KOH extracts, while pectin polymers were very scarce. Arabinogalactan proteins were an important part of water extracts, determined by the presence of the typical arabinogalactan structures (3- and 6-linked Gal p; terminal and 5-linked Ara f), in addition to small amounts of hydroxyproline (2-3% of total protein) and positive reaction to Yariv's reagent.

Soybean fruit development and set at the node level under combined photoperiod and radiation conditions.

In soybean, long days during post-flowering increase seed number. This positive photoperiodic effect on seed number has been previously associated with increments in the amount of radiation accumulated during the crop cycle because long days extend the duration of the crop cycle. However, evidence of intra-nodal processes independent of the availability of assimilates suggests that photoperiodic effects at the node level might also contribute to pod set.

Achene structure, development and lipid accumulation in sunflower cultivars differing in oil content at maturity.

Background And Aims: Sunflower cultivars exhibit a wide range of oil content in the mature achene, but the relationship between this and the dynamics of oil deposition in the achene during grain filling is not known. Information on the progress, during the whole achene growth period, of the formation of oil bodies in the components of the achene and its relationship with variations in final oil content is also lacking.

Methods: The biomass dynamics of achene components (pericarp, embryo, oil) in three cultivars of very different final oil concentration (30-56 % oil) were studied.