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Lateral Shoots (lateral + shoot)

Distribution by Scientific Domains

Life Sciences	75%

Selected Abstracts

Modelling polar auxin transport in developmental patterning

PLANT BIOLOGY, Issue 2010
F. Santos
Abstract Auxin interacts with its own polar transport to influence cell polarity and tissue patterning. Research over the past decade has started to deliver new insights into the molecular mechanisms that drive and regulate polar auxin transport. The most prominent auxin efflux protein, PIN1, has subsequently become a crucial component of auxin transport models because it is now known to direct auxin flow and maintain local auxin gradients. Recent molecular and genetic experiments have allowed the formulation of conceptual models that are able to interpret the role of (i) auxin, (ii) its transport, and (iii) the dynamics of PIN1 in generating temporal and spatial patterns. Here we review the current mathematical models of patterning in two specific developmental contexts: lateral shoot and vein formation, focusing on how these models can help to untangle the details of auxin transport-mediated patterning. [source]

Host plant variation in plant-mediated indirect effects: moth boring-induced susceptibility of willows to a specialist leaf beetle

ECOLOGICAL ENTOMOLOGY, Issue 2 2008
SHUNSUKE UTSUMI
Abstract 1.,We examined the plant-mediated indirect effects of the stem-boring moth Endoclita excrescens (Lepidoptera: Hepialidae) on the leaf beetle Plagiodera versicolora (Coleoptera: Chrysomelidae) in three willow species, Salix gilgiana, S. eriocarpa, and S. serissaefolia. 2.,When the stem-boring moth larvae damaged stems in the previous year, willows were stimulated to produce vigorously growing lateral shoots on these stems. These new lateral shoots were significantly longer and the upper leaves had significantly higher nitrogen and water content than current-year shoots on unbored stems, although the carbon content and leaf dry mass were not different between lateral and current-year shoots. 3.,In the field, leaf beetle larvae and adults had significantly greater densities on lateral shoots of bored stems than on current-year shoots of unbored stems. A laboratory experiment showed that female beetles had significantly greater mass and fecundity when fed on leaves of newly-emerged lateral shoots. Thus, the stem-boring moth had a positive effect on the temporally and spatially separated leaf beetle by increasing resource availability by inducing compensatory regrowth. 4.,The strength of the indirect effects on the density and performance of the leaf beetle differed among willow species, because there was interspecific variation in host quality and herbivore-induced changes in plant traits. In particular, we suggest that the differences in magnitude of the changes among willow species in shoot length and leaf nitrogen content greatly affected the strength of the plant-regrowth mediated indirect effect, coupled with host-plant preference of the leaf beetle. [source]

Sensitivity of Crops to Increased Ultraviolet Radiation in Northern Growing Conditions

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2002
K. Hakala
Crops growing at high latitudes are adapted to low intensities of solar ultraviolet B radiation (UV-B). As a result of destruction of stratospheric ozone layer especially at the Polar Regions of the globe, the intensity of UV-B is projected to increase at high latitudes. In order to find out the consequences of increased UV-B on crops, the sensitivity of different varieties of barley, wheat, oats, clover, timothy, meadow fescue, tall fescue and potato was tested in Jokioinen, Finland. The experiment was conducted in the field, under natural light, with a continuous 30 % increase in UV-B. Both increased UV-B and the control with slightly increased UV-A radiation affected the number of lateral shoots in cereals, and the specific leaf area and the content of phenolic substances in grasses. The effects varied according to plant variety and time of growing season. However, no visible damage, nor changes in biomass and yield production were found in any of the crops. Long-term effects on, e.g. genetic stability and germination of crop seed remain to be studied. Empfindlichkeit von Kulturpflanzenbeständen gegenüber einer Erhöhung der ultravioletten Einstrahlung unter nördlichen Wachstumsbedingungen Kulturpflanzenbestände, die unter hohen Breitengraden wachsen, sind an geringe Intensitäten der solaren ultravioletten B Einstrahlung (UV-B) angepasst. Aufgrund der Destruktion der Stratosphäre, insbesondere der Ozonschicht, im Bereich der polaren Gebiete der Erde, ist eine zunehmende Intensität der UV-B Strahlung in hohen Breitengraden festzustellen. Um die Konsequenzen einer Erhöhung von UV-B auf Kulturpflanzenbestände zu bestimmen, wurde die Empfindlichkeit unterschiedlicher Arten wie Gerste, Weizen, Hafer, Klee, Wiesenlieschgras, Wiesenschwingel, Rohrschwingel und Kartoffel in Jokioinen, Finnland, untersucht. Das Experiment wurde im Felde durchgeführt unter natürlichen Lichtbedingungen mit einer kontinuierlichen Zunahme von 30 % für UV-B. Sowohl eine Erhöhung der UV-B als auch die Kontrolle mit leicht erhöhten UV-B Strahlungen beeinflussten die Anzahl der Nebenwurzeln bei den Getreidepflanzen und die spezifische Blattfläche sowie den Gehalt an phenolischen Substanzen bei den Gräsern. Die Wirkungen variierten entsprechend der Pflanzenvarietät und der Anbauzeit. Allerdings wurden keine erkennbare Schädigungen noch Änderungen in der Biomasse und in der Ertragsproduktion bei einer der untersuchten Pflanzenbestände gefunden. Langzeitwirkungen auf die genetische bedingte Stabilität und Keimung der Kulturpflanzen sollte weiterhin untersucht werden. [source]