The study was undertaken to assess whether seedling age played any role in governing the vulnerability of tomato to the bacterial wilt pathogen, Ralstonia solanacearum, based on the preliminary observations that the extent of mortality during seedling-stage screening was relatively less in older seedlings. Employing the virulent strain ‘NH-Av01’ isolated from tomato, 2-, 3-, 4or 5-weekold seedl...

Changes in plants following insect attack are referred to as induced responses. These responses are widely viewed as a form of defence against further insect attack. In the current study we explore whether it is possible to make generalizations about induced plant responses given the unpredictability and variability observed in insect-plant interactions. Experiments were conducted to test for c...

PHYTOCHROME-INTERACTING FACTOR5 (PIF5), a basic helix-loop-helix transcription factor, interacts specifically with the photoactivated form of phytochrome B (phyB). Here, we report that dark-grown Arabidopsis thaliana seedlings overexpressing PIF5 (PIF5-OX) exhibit exaggerated apical hooks and short hypocotyls, reminiscent of the triple response induced by elevated ethylene levels, whereas pif5 ...

Seasonal dynamics of net photosynthesis (Anet) in 2-year-old seedlings of Pinus brutia Ten., Pinus pinea L. and Pinus pinaster Ait. were investigated. Seedlings were grown in the field in two light regimes: sun (ambient light) and shade (25% of photosynthetically active radiation (PAR)). Repeated measures analyses over a 12-month period showed that Anet varied significantly among species and fr...

The main objective of this thesis was to examine the effects of climate change and simulated herbivory (artificial foliage damage) on growth responses and leaf characteristics (chemical and morphological structure and consequent palatability) of silver birch (Betula pendula) seedlings. In order to achieve this target, seedlings were grown in climate controlled closed-top chambers under ambient ...

hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (vi) or chromium nitrate chromium (iii). although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (iii) than those in chromium (vi), majority being in...

The flu mutant of Arabidopsis thaliana overaccumulates in the dark the immediate precursor of chlorophyllide, protochlorophyllide (Pchlide), a potent photosensitizer, that upon illumination generates singlet oxygen ((1)O2). Once (1)O2 has been released in plastids of the flu mutant, mature plants stop growing, while seedlings die. Several suppressor mutations, dubbed singlet oxygen-linked death...

Root and hypocotyl elongation, water status and solute accumulation were studied in osmotically stressed seedlings of the tropical tree, Colophospermum mopane (Kirk ex Benth.) Kirk ex J. Léonard, which grows in hot arid areas of southern and central Africa. Seeds were imbibed for 24 h and then subjected to a polyethylene-glycol-generated osmotic stress of -0.03 (control), -0.2, -0.8, -1.6 or -2...

This study evaluates how preference by a generalist slug herbivore Arion subfuscus changes inversely with seedling size across three levels of fertilization for three full-sib families of willow seedlings. We analyzed seedlings for condensed tannin and protein concentration, and related these data to changes in palatability. In preference tests over time, leaf discs from more fertilized seedlin...

Seed of onion (Allium cepa L.) cv. Ailsa Craig were exposed to various doses of gamma radiation, i.e. 10,20.40.80. and 100 krad. Irradiation doses have no significant effect on seed viability, except the highest dose (100 krad) which resulted in reduced viabi lity. However, electrical conductivities of the leachates of seeds exposed to gamma radiation were higher than that of un irradiated seed...