Drought strongly influences root activities in crop plants and weeds. This paper is focused on the performance of the heavy metal accumulator Solanum nigrum, a plant which might be helpful for phytoremediation. The water potential in a split root system was decreased by the addition of polyethylene glycol (PEG 6000). Rubidium, strontium and radionuclides of heavy metals were used as markers to ...

1. The composition of the sterol ester fraction of the shoot, root, scutellum and endosperm of 10-day-old maize seedlings was investigated. 2. The scutellum and endosperm together contain 80% of the sterol ester of the seedling. 3. beta-Sitosteryl linoleate is the major sterol ester of the scutellum and endosperm. 4. beta-Sitosteryl and stigmasteryl palmitate, palmitoleate, oleate and linoleate...

A recent publication by Schellmann et al. (2002) in The EMBO Journal has provided important insights into the control of cell fate and pattern formation in plants. To study the underlying molecular mechanisms, the authors made use of the development of root hairs and trichomes in Arabidopsis thaliana. A. thaliana trichomes are large, unicellular structures that project out from the shoot epider...

The substrate supply system for respiration of the shoot and root of perennial ryegrass (Lolium perenne) was characterized in terms of component pools and the pools’ functional properties: size, half-life, and contribution to respiration of the root and shoot. These investigations were performed with perennial ryegrass growing in constant conditions with continuous light. Plants were labeled wi...

Mineral nutrients taken up by the roots are, as a rule, transported in the xylem to the shoot, and photoassimilates transported in the phloem to the roots. According to the Thornley model of photosynthate partitioning, nutrient deficiencies should favour photosynthate partitioning to the roots. Examples are cited to show that this preferential partitioning is dependent on phloem mobility and he...

Plants continuously extend their root and shoot systems through the action of meristems at their growing tips. By regulating which meristems are active, plants adjust their body plans to suit local environmental conditions. The transport network of the phytohormone auxin has been proposed to mediate this systemic growth coordination, due to its self-organising, environmentally sensitive propert...

Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly incre...

The uptake of arsenite (As(III)i) at the Casparian band via Lsi1 and Lsi2 Si transporters is responsible for ~75% of shoot As(III)i uptake in rice and, therefore, ~25% of shoot As(III)i is taken up by other transport pathways. We hypothesized that areas devoid of Casparian bands—lateral root junctions and root apices—can transport As(III)i into roots. We analyzed the elemental distribution and ...

Whole vine (K(plant)) and individual root (K(root)) hydraulic conductances were measured in kiwifruit (Actinidia chinensis Planch. var. chinensis 'Hort16A') vines to observe hydraulic responses following partial root system excision. Heat dissipation and compensation heat pulse techniques were used to measure sap flow in trunks and individual roots, respectively. Sap flux and measurements of xy...

abstract growth retardants are new chemical organic compounds that increase period of flowering, leave chlorophyll, lateral shoot number, flower number and decrease vegetative growth. they also increase dry, cold and heat tolerance. paclobutrazol and cycocel are examples of these compounds. this study was conducted to evaluate the effect of paclobutrazol and cycocel on some quantitative and qua...