The aim of this study was to determine the relationship between shoot nitrate concentration, mediated by nitrate supply to roots, and root exudation from Hordeum vulgare. Plants were grown for 14 d in C-free sand microcosms, supplied with nutrient solution containing 2 mM nitrate. After this period, three treatments were applied for a further 14 d: (A) continued supply with 2 mM nitrate (zero b...

Root systems of 6-month-old, cold-hardened, container-grown black spruce seedlings (Picea mariana (Mill.) B.S.P.) were exposed to 0, -5, -10, -15, -20, or -22.5 degrees C. Freezing-induced damage to fine roots, coarse roots and the whole root system was assessed by various viability tests including leakage of electrolytes, leakage of phenolic compounds, water loss, root and shoot water potentia...

Salinity is a major environmental factor that influences rapeseed production in arid and semi-arid regions of central and southern Iran. In this study, effect of applied NaCl on shoot and root growth and distribution and accumulation of Na, Cl, K, Ca and Mg in the canola plant (Brassica napus L. cv: Hayola 308 and cv: PP 401) was investigated. The experiment was arranged in a completely randomi...

In order to investigate the identification index of drought resistance in the forage triticale seedlings, 30 triticales with different genotypes were identified by 20%–PEG6000. Results showed that responses of each gene to water stress were relatively obvious, water content decreased, the root-shoot ratio enhanced, and leaf curvature and root hyperplasied; There was significant difference among...

Roots are the primary organs that first sense the soil environment. Plant growth and development are largely dependent on the plant root system, due to its crucial role in water and mineral uptake. Symbiotic microorganisms affect and improve the root response to stresses. Root endophytes and bacteria synthesize a wide array of plant-protecting chemicals, hormones, and compounds acting on hormon...

Most plants form root symbioses with arbuscular mycorrhizal (AM) fungi, which provide them with phosphate and other nutrients. High soil phosphate levels are known to affect AM symbiosis negatively, but the underlying mechanisms are not understood. This report describes experimental conditions which triggered a novel mycorrhizal phenotype under high phosphate supply: the interaction between pea...

Calcium ions (Ca) and Ca-related proteins mediate a wide array of downstream processes involved in plant responses to abiotic stresses. In Arabidopsis (Arabidopsis thaliana), disruption of the vacuolar Ca/H transporters CAX1 and CAX3 causes notable alterations in the shoot ionome, including phosphate (Pi) content. In this study, we showed that the cax1/cax3 double mutant displays an elevated Pi...

The shoot and root apical meristems (SAMs and RAMs, respectively) of higher plants are mechanistically and structurally similar. This has led previously to the suggestion that the SAM and RAM represent modifications of a fundamentally homologous plan of organization. Despite recent interest in plant development, especially in the areas of meristem regulation, genes specifically required for the...

Shoot tips excised from shoot culture of Salvia officinalis were encapsulated in 2% or 3% (w/v) sodium alginate and exposed to 50 mM calcium chloride for complexation. Immediately or after 6, 12 or 24 weeks of storage at 4°C, the synthetic seeds were cultured for 6 weeks on half-strength MS medium supplemented with indole-3acetic acid (IAA) (0.1 mg/l) and solidified with 0.7% agar. The frequenc...

Salinity limits crop productivity, in part by decreasing shoot concentrations of the growth-promoting and senescence-delaying hormones cytokinins. Since constitutive cytokinin overproduction may have pleiotropic effects on plant development, two approaches assessed whether specific root-localized transgenic IPT (a key enzyme for cytokinin biosynthesis) gene expression could substantially improv...